JP2010533742A - Gas reforming system including means for optimizing the efficiency of gas conversion - Google Patents

Abstract

The present invention provides a system and method for efficiently reforming an initial gas having relevant characteristics into a product gas having desired characteristic parameters in a substantially sealed, encased, controlled environment. . The gas reforming system uses a gas activation region to later recombine the molecules of the initial gas and the appropriate type and amount of process additive molecules to be injected to produce the output gas having the desired parameters. Dissociate into their constituent atoms to form The gas reforming system further includes a control system that regulates the process and thereby allows optimization of the process. The gas activation region may be provided at least in part by a hydrogen burner or a plasma torch.

Description

The present invention relates to the field of gas reforming. Specifically, the present invention relates to a gas reforming system that includes means for optimizing the efficiency of gas conversion.

Off-gas (syngas) is generated from various material conversion processes such as gasification, plasma gasification and / or plasma melting. These gases can be utilized for appropriate downstream applications (eg, power generation, industrial synthesis of chemicals and liquid fuels), stored for later use, or combusted. Occasionally, there is interest in modifying the gas produced to improve the chemical composition for effective use in downstream applications.
In a gasification process, a carbonaceous feed is supplied to a gasifier along with a controlled and / or limited amount of oxygen, and sometimes steam, to produce a feed gas. Off-gas from the gasification process depends on the raw material composition, H ₂ O, H ₂ , N ₂ , O ₂ , CO ₂ , CO, CH ₄ , H ₂ S, NH ₃ , C ₂ H ₆ , and acetylene, olefin , Aromatics, phenols, and other hydrocarbons such as tar. Raw materials useful for gasification include municipal waste, industrial waste and biomedical waste, sewage, sludge, coal, heavy oil, petroleum coke, heavy oil refinery residue, refined waste, hydrocarbon contamination Includes soil, biomass, agricultural waste, tires, and other hazardous waste.
Factors affecting the quality of the gas produced in the gasification process include: feedstock characteristics such as particle size; gasifier heating rate; residence time; drying or slurry feed system, feed-reactant flow profile, ash Or plant configuration including whether to utilize the design of a slag mineral removal system; whether to use direct or indirect heat generation and transportation methods; and a syngas purification system.
Some gasification facilities utilize a gas processing system to convert the gas to a more acceptable gas composition prior to cooling and purification via a gas quality control system. The treated gas can undergo further processing steps to remove undesirable compounds such as metals, sulfur compounds, and particulates. For example, particulate matter and acid gas can be removed using a dry filtration system or a wet scrubber.
Plasma has been used in the industry for two major energy sources. The first is an energy source as a powerful heat source, and the second is used to initiate and facilitate many chemical processes that require dissociating molecules into (reactive) dissociated fragments. It is an energy source as a possible free electron source. Electron collisions can excite molecules in any dissociated state and refine them into fragments, an important mechanism by which radicals and molecular fragments are generated in many environments.
Plasma is a luminescent gas that is at least partially ionized and is composed of an excited gaseous material containing electrons and ions. The plasma can be generated with many gases, so the working gas is neutral (eg, argon, helium, neon), reducible (eg, hydrogen, methane, ammonia, carbon monoxide), or oxidative (eg, , Oxygen, carbon dioxide), so that excellent control over the chemical reaction in the plasma is performed.
Different plasmas are classified according to their temperature and density. The term “plasma density” usually means itself the density of electrons, ie the number of free electrons per unit volume. The degree of ionization of the plasma is the fraction of atoms that have lost (or gained) electrons and are often controlled by temperature.
Plasma temperature is usually measured in Kelvin or eV and is an informal measure of average thermodynamic energy per particle. Due to the large difference in mass, electrons are in a thermodynamic equilibrium between electrons much more quickly than they are in equilibrium with ions or neutral atoms. For this reason, the “ion temperature” can be very different from the “electron temperature” (usually lower). Based on the relative temperature of electrons, ions, and neutral atoms, plasmas are classified as “thermal plasmas” or “non-thermal plasmas”. A thermal plasma has electrons and heavy particles at the same temperature, ie they are in thermodynamic equilibrium with each other. On the other hand, non-thermal plasma has ions and neutral atoms at a very low temperature, whereas electrons have a much "hot" temperature.
Non-thermal, low-temperature plasma destroys relatively low concentrations of volatile organic compounds at atmospheric pressure, making it possible to handle compounds that are resistant to low-level waste concentration processing and processing by standard chemical means. It is known in the art to be particularly attractive. These low temperature plasma processing techniques generally involve either high energy electron beam irradiation or a discharge scheme such as pulse corona, dielectric barrier, capillary, hollow cathode, surface, and packed bed corona discharge. All these techniques rely on the fact that electrical energy can generate electrons with much higher kinetic energy than surrounding gas phase ions and molecules. These energetic electrons interact with the background gas to produce highly reactive species (ie radicals, anions, cations, and secondary electrons) that selectively destroy pollutants. Can do.
In the field of waste management, hazardous waste is gasified, melted, and converted into off-gas (ie, synthesis gas) and the residue containing mainly inorganic substances is melted into slag. Plasma torches have been used as a heat source to promote destruction. Some plasma gasification systems not only facilitate the gasification process, but also convert long-chain volatiles into smaller molecules with or without the addition of other inputs or reactants. Some also use plasma torches to treat the raw off-gas in the gasification chamber by reconfiguring or improving.
Plasma sources have also been used as a source of active species. These active species have been used to initiate and facilitate the conversion of harmful gas molecules to less toxic species. One example is provided by US Pat. No. 6,810,821, which describes a cyclonic oxidizer designed to reduce the carbon black / soot of carbon present in the off-gas from a graphite electrode plasma arc furnace. . The cyclonic oxidizer uses a plasma torch to ionize a working gas that does not contain nitrogen and contains a mixture of carbon dioxide and oxygen. When the gaseous mixture is ionized in the plasma arc zone, carbon dioxide is converted to carbon monoxide and very reactive atomic oxygen. Since the chamber of the cyclonic oxidizer receives off-gas in the tangential direction at a very high speed near the upstream end thereof, a cyclone state is formed in the cyclonic oxidizer. Combines the presence of reactive atomic oxygen with the enhanced turbulent environment in the cyclonic oxidizer to effectively convert and destroy transient toxic substances in carbon black / soot and by-product gases Can do.
US Pat. No. 6,810,821 also teaches that additional oxidant is provided by injection of sprayed oxygen and steam sprayed by a high temperature resistant spray nozzle and injected into the chamber as oxidant. Oxidation reaction efficiency is increased by vigorous internal mixing of by-product gases and injected atomized oxygen and steam caused by the intense cyclone action forces within the cyclonic oxidizer. For waste with low calorific value, the cyclonic oxidizer completely converts by-product gas into water and carbon dioxide. For waste with high calorific value, the final by-product gas can be a high quality combustible synthesis gas for power generation. Although this cyclonic oxidizer can treat (i.e. purify) off-gas by oxidizing pollutants, it is not designed to reform the gas to a product gas of a designed chemical composition. The apparatus does not use a plasma torch to form a gas reforming zone that can be used to reform off-gas to a defined composition gas.
Another example is provided by US Pat. No. 6,030,506, which describes a method and apparatus for delivering an exogenous non-thermal plasma activated species to a liquid of interest, comprising: (a) activation Creating a species activated by the means, and (b) introducing the activated species into the liquid of interest using a fast injection means. The present invention refers to air pollution regulations and the provision of apparatus and methods for performing large scale chemistry for bleaching, chemical reaction enhancement, and decontamination.
US patent application Ser. No. 11 / 745,414 provides the first example of a gas reforming system where a plasma torch is placed in the system to provide a reaction zone in front of each torch so that off-gas can be reformed. Is provided. These plasma torch and air jet arrangements are designed to optimize the gas flow pattern and residence time in the chamber.
The system described above does not optimize the energy mechanism and overall efficiency of reforming most of the raw synthesis gas to a designed chemical composition gas. For commercial facilities that want to convert carbonaceous feedstock into energy, such as electricity, in the most cost-effective manner overall, to effectively convert synthesis gas into a gas designed for downstream applications. System is required. Accordingly, it is a significant advancement in the art to provide a gas reforming system that optimizes the overall efficiency of the process and / or a step that includes the overall process of converting an initial gas to a gas of a defined composition. It is.

The present invention provides a system incorporating one or more energy sources that initiate a gas reforming process by initiating dissociation of molecules into reactive dissociation fragments (intermediates). The energy source (s) transfer energy throughout the gas reforming process in addition to optimizing the amount of gas reformed (gas reforming rate) relative to the amount of gas input into the system Is combined with a gas manipulator designed to optimize the efficiency of the gas reforming process.
It is an object of the present invention to provide a gas reforming system that includes means for optimizing the efficiency of gas conversion. According to one aspect of the invention, a system for reforming an initial gas into a reformed gas having designed characteristics, the means for detecting at least one characteristic of the initial gas, and the initial gas A means for modifying the process input for reforming based on at least one feature of the reforming gas and the designed feature of the reforming gas, and substantially reforming the gas molecules of the initial gas Means for applying one or more energy sources, means for promoting the reforming, means for stabilizing the reformed gas, and a control system, which are sufficient to reform A system is provided.
According to another aspect of the invention, a process for reforming an initial gas into a reformed gas having a desired characteristic, the method comprising detecting at least one characteristic of the initial gas, and detecting the initial gas. Sufficient to modify the majority of the gas molecules to their constituent atoms and to modify the process input for modification based on the developed characteristics and the desired characteristics of the output gas Applying a gas activation region, facilitating efficient process acceleration to reform constituent atoms into a reformed gas with designed characteristics, and de-excitation and stability of newly formed molecules A process is provided that includes one or more of the following steps to promote design and maintain designed characteristics and to manage efficient conversion of initial gas to output gas.
In accordance with another aspect of the present invention, a system for gas reforming comprising one or more energy sources for initiating a gas reforming process and energy throughout the gas reforming process. One or more gas manipulators for optimizing movement, the one or more energy sources and one or more gas manipulators are integrated to optimize the gas reforming rate, A system is provided.
In accordance with another aspect of the present invention, a gas reforming system comprising one or more gas reforming zones, one or more gas stabilization zones, and a control system that coordinates the overall process; Optionally, one or more gas additive zones, and / or optionally one or more gas purification zones, the zone of the system being designed with the majority of the initial gas A gas reforming system is provided that is arranged and controlled to be reformed into a gas of composition.
According to another aspect of the present invention, a method for reforming an initial gas into a reformed gas, the method comprising delivering the initial gas to a gas reforming chamber, the input gas with at least one process additive. Mixing to produce a pre-compounded gas; exposing the pre-compounded gas to a gas activation region to dissociate molecules in the gas into their constituent atoms; and the constituent atoms to a designed chemical composition A method is provided that includes generating a reformed gas and removing the reformed gas from the chamber.
In accordance with another aspect of the present invention, a system for reforming an initial gas to a reformed gas, the chamber lined with one or more refractories, for receiving the initial gas One or more inlets, one or more outlets for releasing the reformed gas, one or more process additive inlets in fluid communication with the chamber, and disposed in the one or more chambers. A system is provided that includes a chamber having one or more gas manipulators and means for forming a gas activation region in the one or more chambers.
Specifically, the system converts from one or more sources to a gas of an initial chemical composition (pre-blended gas) so that the gas is modified in an effective manner to a gas of the designed chemical composition. And designed to optimize energy transfer throughout the reforming process. The system is designed to minimize the overall amount of energy required to reform a gas and to maximize the rate of gas reforming to a gas of a designed chemical composition. It includes a design strategy embodied in a gas manipulator that functions to facilitate the speed, efficiency, and thoroughness of the reforming reaction as the gas passes through the gas reforming chamber.
Thus, the gas reforming system includes one or more “gas reforming zones” and one or more “gas stabilization zones”. The system typically has one or more “gas additive zones” located upstream of the gas reforming zone (with or without means for achieving gas and additive mixing, usually mixing May be realized by increasing turbulence in the gas) and / or optionally further comprising one or more “gas purification zones” usually located downstream of the gas stabilization zone . The gas stabilization zone optionally includes heat exchange means for capturing heat from the gas as it cools. The zones of the system are arranged and controlled so that after passing through the system of the present invention, the majority of the initial gas is reformed to a designed gas composition. The gas reforming system further includes a control system that coordinates the overall process.

1-77 are diagrams illustrating various embodiments of the present invention and / or its components.
FIG. 2 shows various zones of a gas reforming system. Dashed lines indicate optional zones. The gas can be processed in a series of continuous zones, or in a parallel arrangement, as shown in FIGS. 2BA and 2BB. FIG. 2 shows various zones of a gas reforming system. Dashed lines indicate optional zones. The gas can be processed in a series of continuous zones, or in a parallel arrangement, as shown in FIGS. 2BA and 2BB. FIG. 2 shows various zones of a gas reforming system. Dashed lines indicate optional zones. The gas can be processed in a series of continuous zones, or in a parallel arrangement, as shown in FIGS. 2BA and 2BB. 1 is a schematic diagram of a gas reforming system according to an embodiment of the present invention. 1 is a schematic diagram of one embodiment of a gas reforming system of the present invention coupled to a gasifier. 1 is a schematic diagram of one embodiment of a gas reforming system of the present invention coupled to two gasifiers. 1 is a schematic illustration of one embodiment of a gas reforming chamber of the present invention coupled to two gasifiers via a common initial gas inlet. FIG. 2 shows the following types of gas activation sources: hydrogen burner, radio frequency (RF) and microwave plasma, laser plasma, corona plasma. FIG. 2 shows the following types of gas activation sources: hydrogen burner, radio frequency (RF) and microwave plasma, laser plasma, corona plasma. FIG. 1 shows the following types of plasma sources: non-transfer arc torch, transfer arc torch, inductively coupled plasma torch, microwave plasma torch. FIG. 2 illustrates the use of an inductively coupled plasma torch, a microwave plasma torch, and a hydrogen burner in a gas reforming system, according to various embodiments of the present invention. FIG. 2 illustrates the use of an inductively coupled plasma torch, a microwave plasma torch, and a hydrogen burner in a gas reforming system, according to various embodiments of the present invention. It is a figure which shows a hydrogen burner. FIG. 2 shows the following types of gas activation sources: hydrogen burner, radio frequency (RF) and microwave plasma, laser plasma, corona plasma. FIG. 2 shows the following types of gas activation sources: hydrogen burner, radio frequency (RF) and microwave plasma, laser plasma, corona plasma. FIG. 3 illustrates various embodiments of gas reforming channels. FIG. 3 illustrates various embodiments of gas reforming channels. FIG. 3 illustrates various embodiments of gas reforming channels. FIG. 3 illustrates various embodiments of gas reforming channels. It is a figure which shows the gas reforming channel using a mixing device. FIG. 4 illustrates the use of a constriction in a gas reforming chamber to facilitate gas mixing, according to two embodiments of the present invention. FIG. 4 illustrates the use of a constriction in a gas reforming chamber to facilitate gas mixing, according to two embodiments of the present invention. FIG. 6 shows various gas reforming chamber designs. FIG. 6 shows various gas reforming chamber designs. FIG. 6 shows various gas reforming chamber designs. FIG. 6 shows various gas reforming chamber designs. FIG. 6 illustrates various embodiments of a gas reforming system in which the gas stream is divided into smaller gas streams and undergoes reforming in parallel. It is a figure which shows various arrangement | positioning of the gas activation source with respect to an initial stage gas flow. FIG. 3 shows different shapes of a flow restrictor inserted into a gas reforming chamber, according to various embodiments of the present invention. FIG. 3 shows different shapes of a flow restrictor inserted into a gas reforming chamber, according to various embodiments of the present invention. FIG. 3 shows different shapes of a flow restrictor inserted into a gas reforming chamber, according to various embodiments of the present invention. FIG. 5 shows a flow restrictor extending substantially the entire length of the gas reforming chamber, according to three embodiments of the present invention. FIG. 5 shows a flow restrictor extending substantially the entire length of the gas reforming chamber, according to three embodiments of the present invention. FIG. 3 is a three-dimensional view of a gas reforming chamber equipped with a flow restrictor that extends substantially the entire length of the chamber, in accordance with two embodiments of the present invention. FIG. 3 is a three-dimensional view of a gas reforming chamber equipped with a flow restrictor that extends substantially the entire length of the chamber, in accordance with two embodiments of the present invention. It is a figure which shows different embodiment of a flow restrictor. FIG. 4 is a diagram illustrating a rotating shaft having a plurality of disks according to an embodiment of the present invention. FIG. 4 shows different disk structures that can be used with a rotating shaft to enhance the interaction between gas and activation region. FIG. 6 illustrates different ways of rotating the shaft and disk according to various embodiments of the present invention. FIG. 3 shows the use of a deflector for directing a gas activation region and a deflector based on the Coanda effect, respectively, according to two embodiments of the invention. FIG. 3 shows the use of a deflector for directing a gas activation region and a deflector based on the Coanda effect, respectively, according to two embodiments of the invention. FIG. 3 illustrates the use of one or more air nozzles to actively control the spatial distribution of a plasma plume, according to two embodiments of the present invention. FIG. 3 illustrates the use of one or more air nozzles to actively control the spatial distribution of a plasma plume, according to two embodiments of the present invention. FIG. 5 shows the use of different deflectors to redirect the plasma plume in the gas reforming chamber. FIG. 6 illustrates the use of an asymmetric rotational axis type object deflector according to various embodiments of the present invention. 1 is a schematic diagram of a portion of a gas reforming system according to an embodiment of the present invention showing details of a torch mounted system. FIG. 3 is a diagram illustrating a gas activation source arranged to direct a gas activation region that runs counter to a gas flow according to an embodiment of the present invention. FIG. 38B shows the embodiment of FIG. 38A where gas flows near the top and flows out toward the bottom. 1 is a schematic diagram showing the orientation of the inlet and plasma torch of one embodiment. FIG. 5 shows various arrangements of gas activation sources for the gas reforming chamber and injection gas flow. FIG. 5 shows various arrangements of gas activation sources for the gas reforming chamber and injection gas flow. It is a figure which shows arrangement | positioning of the baffle in a gas reforming chamber. FIG. 41A shows the air flow in a gas reforming chamber with a partition baffle. FIG. 41B is a diagram showing air flow in a gas reforming chamber with a turbulator or choke ring baffle. It is a figure which shows arrangement | positioning of the baffle in a gas reforming chamber. FIG. 41A shows the air flow in a gas reforming chamber with a partition baffle. FIG. 41B is a diagram showing air flow in a gas reforming chamber with a turbulator or choke ring baffle. FIG. 5 shows a flow restrictor extending substantially the entire length of the gas reforming chamber, according to three embodiments of the present invention. FIG. 4 shows the inclusion of a turbulent zone for enhanced reforming. FIG. 4 shows the inclusion of a turbulent zone for enhanced reforming. An example of a turbulent flow generator is shown. FIG. 2 shows a gas to be reformed that is processed by a plasma torch and a gas manipulator and that enters the modified reactor tangentially while forming a vortex. FIG. 3 shows an exemplary means for generating turbulence. FIG. 3 shows an exemplary means for generating turbulence. It is a figure which shows the airflow which flows out out of an A type nozzle. It is a figure which shows the airflow which flows out out of a B type nozzle. It is a figure which shows the fixed bed of the char used as a catalyst within a reforming chamber. It is a figure which shows the fixed bed of the char used as a catalyst within a reforming chamber. FIG. 2 shows a gasifier combined with a gas reforming chamber, and the char formed in the gasifier causes catalyst cracking. It is a figure which shows the various structures for combining a catalyst bed and an activation area | region for the modification | reformation of the gas generated within the gasifier. It is a figure which shows the various structures for combining a catalyst bed and an activation area | region for the modification | reformation of the gas generated within the gasifier. It is a figure which shows the various structures for combining a catalyst bed and an activation area | region for the modification | reformation of the gas generated within the gasifier. Fig. 4 illustrates various positions where a catalyst bed can be installed in a gas reforming chamber, according to one embodiment of the present invention. Fig. 4 illustrates various positions where a catalyst bed can be installed in a gas reforming chamber, according to one embodiment of the present invention. Fig. 4 illustrates various positions where a catalyst bed can be installed in a gas reforming chamber, according to one embodiment of the present invention. FIG. 2 is a diagram related to a heat exchange system used in a stabilization zone of a gas reforming system, according to one embodiment of the present invention. FIG. 2 is a diagram related to a heat exchange system used in a stabilization zone of a gas reforming system, according to one embodiment of the present invention. 1 is a schematic diagram of one embodiment of a gas reforming chamber. FIG. 60B is a cross-sectional view of the gas reforming chamber of FIG. 60A showing the refractory support in detail. It is a figure which shows various structures of a gas reforming chamber, a gasifier, and a carbon converter. It is a figure which shows various structures of a gas reforming chamber, a gasifier, and a carbon converter. It is a figure which shows various structures of a gas reforming chamber, a gasifier, and a carbon converter. It is a figure which shows various structures of a gas reforming chamber, a gasifier, and a carbon converter. 1 is a diagram illustrating a gasifier that can be coupled to the gas reforming system of the present invention. FIG. FIG. 2 is various views of an exemplary gas manipulator designed to be incorporated into a cylindrical gas reforming chamber. FIG. 2 is various views of an exemplary gas manipulator designed to be incorporated into a cylindrical gas reforming chamber. FIG. 2 is various views of an exemplary gas manipulator designed to be incorporated into a cylindrical gas reforming chamber. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 67 is a top view of a gas reforming chamber without the exemplary gas manipulator of FIG. 66. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 2 is various views of an exemplary gas manipulator designed to be incorporated into a cylindrical gas reforming chamber. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 67 is various views of the exemplary gas manipulator of FIG. 66 attached to a cylindrical gas reforming chamber. FIG. 2 is various views of an exemplary gas manipulator designed to be incorporated into a cylindrical gas reforming chamber. It is a figure which shows various expressions of the gas activation source used in FIGS. All expressions are equivalent and can be used to indicate any of the gas activation sources specifically set forth herein or will be known to those skilled in the art.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
As used herein, the term “about” means ± 10% variation from the reference value. It is understood that such variations are always included in any given value provided herein, whether or not specifically mentioned.
The term “reactive species” refers to energy species that are formed throughout the reforming process. Non-limiting examples include free electrons generated by an energy source such as plasma, or radicals or dissociated intermediates that are formed in off-gas (eg, synthesis gas) that transfers energy to other molecules. Intermediates) and / or other molecularly dissociated intermediates / fragments (“pre-formulated molecules”) of the pre-compounding gas and modifying them to the designed standard chemical composition it can. One skilled in the art will recognize that some pre-compounded molecules will in turn become reactive species and transfer their acquired energy to other molecules in the gas reforming zone as the energy transfer process continues. I understand that.
The term “raw off-gas” refers to the gas that results from the raw material throughout the process of converting to slag. This type and quality of gas is often referred to in the art as “syngas”.
The term “partially treated feed off-gas” refers to the powerful heat or reaction produced in gasification systems such as plasma melting systems designed for waste destruction and conversion to gas and slag. It refers to a raw material off gas (raw material synthesis gas) that has been treated in some form depending on the conditions such as the species. Such processing may include exposing the source offgas to a plasma or other energy source.
The term “initial gas” refers to a gas that is to be modified to a chemical composition designed for one or more downstream applications. It includes a raw material off gas (raw material synthesis gas) and / or a partially processed raw material off gas.
The term “pre-blended gas” is used to describe a gas that enters the gas reforming zone. This gas includes an initial gas, in addition to any optional process additives that are added to adjust the chemical composition of the gas prior to modification to the designed chemical composition. For example, if the gas requires increased hydrogen levels, the gas being reformed contains an amount of hydrogen species that is sufficient to provide the proper chemical composition of the final reformed gas product. As such, steam may be added as a process additive upstream of the gas reforming zone. If the optional process additive is not added, the “pre-formulated gas” has the same composition as the “initial gas”.
The term “reformed gas” refers to the gas exiting the gas reforming system.
The term “gas reforming rate” is used to describe the amount of reformed gas relative to the amount of gas input to the system. It can be represented by the following formula:
As an alternative and in particular when no process additive gas is used, it can be represented by the following equation:
The gas reforming rate can be evaluated indirectly or directly. The indirect evaluation of the gas reforming rate can be performed by comparing the energy generation downstream of the reformed gas with the pre-blended gas. Downstream energy production reflects the proportion of reformed gas. An increase in downstream energy production suggests that the proportion of reformed gas has increased.
The term “gas manipulator” means a feature incorporated into the system of the present invention that functions to facilitate the process of gas reforming.
The terms “carbonaceous feedstock” and “feedstock” are used interchangeably herein and are defined to refer to a carbonaceous material that can be used in a gasification process. Examples of suitable raw materials include hazardous and non-hazardous waste materials including municipal waste, waste produced by industrial activities, biomedical waste, carbonaceous materials that are inappropriate for reuse, including non-reusable plastics Materials, including sewage sludge, coal, heavy oil, petroleum coke, bitumen, heavy oil refinery residue, refined waste, hydrocarbon contaminated soil, biomass, agricultural waste, municipal solid waste, hazardous waste and industrial waste It is not limited to. Examples of biomass useful for gasification include, but are not limited to, waste wood, raw wood, residue from processing of fruits, vegetables and grains, paper mill litter, firewood, grass, and manure.
The term “gas activation source” is any energy source known to those skilled in the art that can be used to impart energy to a pre-blended gas to allow it to be reformed to a gas of a defined composition. Point to. Examples thereof include, but are not limited to, a plasma generation source, an irradiation source, a hydrogen burner, and an electron beam gun.
The term “gas activation region” refers to the electric field effect produced by one or more gas activation sources used in the system to provide the gas with the energy necessary for the reforming process to occur. Used for. For example, the gas activation region formed by the plasma torch represents a three-dimensional space that varies depending on the output of the torch, the composition of the working gas, the position of the torch, the orientation of the torch and the like.
As used herein, the term “sensing element” is used to sense, detect, read, monitor, etc. one or more characteristics, parameters, and / or information of a system, input and / or output. Are used in a broad sense to describe aspects of any element associated with a gas reforming system.
As used herein, the term “responsive element” is used to describe aspects of any element associated with a gas reforming system that can respond to a signal.
Gas reforming system
The present invention includes a system for effective reforming of gas derived from the gasification of a carbonaceous feedstock. The initial gas to be input to the system typically includes a complex mixture of hydrocarbon molecules of various lengths. The chemical composition of the gas and the quality of the pollutants depend on the raw material composition, the process used to produce the gas, and the conditions in the gasification system. Some gasifiers are designed for single-stage processes where various forms of heat are used to generate gas in a single chamber. Other gasifiers produce gas in a multi-stage process in different parts of one chamber or different chambers, or some combination thereof. Either system may involve some degree of raw material off-gas pre-treatment, usually by a heat source in the gasification chamber.
One of the main objectives of these design strategies is to optimize the amount of effective exposure of the raw syngas and / or pre-blended gas to the reactive species in the gas activation zone. The greater the degree of effective exposure, the greater the efficiency of energy transfer, and the higher the rate at which pre-blended gas is converted to the designed chemical composition gas in the most cost effective manner.
Examples of design strategies include overall system design. For example, important design strategies include the premixed gas flow pattern (turbulence) for the gas activation region, in particular, the amount of gas that passes through that region within a particular time. An example of these strategies is a system design in which a pre-blended gas passes through a plasma that generates an electric arc (s). Another example is a system design in which the plasma torch is arranged so that the plasma plume flows backward and flows directly into the pre-blended gas. In another embodiment, the pre-blended gas passes through a continuous or parallel gas activation region.
The reforming system of the present invention is designed to optimize the amount of pre-blended gas that is reformed to product gas. In one embodiment, the efficiency of the system is expressed by the term gas reforming rate, which is the percentage of the amount of product gas reformed divided by the amount of pre-blended gas or initial gas multiplied by 100. Is done. In one embodiment, the modification rate is 95% or more. In one embodiment, the modification rate is 90% or more. In one embodiment, the modification rate is 85% or more. In one embodiment, the modification rate is 80% or more. In one embodiment, the modification rate is 75% or more. In one embodiment, the modification rate is 70% or more. In one embodiment, the modification rate is 65% or more. In one embodiment, the modification rate is 60% or more. In one embodiment, this concept is expressed as a ratio of the value of the reformed gas compared to the initial gas. In one embodiment, the value is an energy value related to power generation.
In order to effectively reform the initial gas to a gas of the designed composition, the present invention includes one or more “gas reforming zones” and one or more “gas stabilization zones”. The gas stabilization zone optionally includes heat exchange means for capturing heat from the gas as it cools. The system optionally includes one or more “gas additive zones” that are usually mixed upstream or non-mixed upstream of the gas reforming zone. The system also optionally includes one or more “gas purification zones” typically located downstream of the gas stabilization zone.
For purposes of clarity, these zones are described separately. However, although these zones are usually interrelated in the system and remain as an alternative option, the system is limited to including separate, physically separated zones. Please understand that it is not. Depending on the design of the particular embodiment, they are separated, with minor differences. Also, for ease of reference only, these zones are named primarily according to the process steps that take place within the zone. However, those skilled in the art will appreciate that depending on the nature of the reforming process, other process steps may occur within the zone to a lesser extent.
A system that effectively reforms the gas needs to be able to raise their energy so that the initial gas molecules begin to reform. Specifically, the reaction intermediate is initiated. The energy process of the reaction is represented by a curve as shown below.
As will be appreciated by those skilled in the art, the arrows point to the energy required to induce gas molecules of the initial chemical composition to begin reforming to molecules of the designed chemical composition. The dashed line represents the energy required when the catalyst is used to reduce the amount of energy required to cause molecular modification. Those of ordinary skill in the art will need sufficient energy to be imparted to the initial gas at a general level to facilitate breakage of bonds and modification to modified molecules and atoms. To understand the. Under appropriate conditions, when the modified molecules and / or atoms are allowed to mix thoroughly, the atoms recombine according to the relative concentrations of the species present. Furthermore, when a considerable amount of pre-blended gas passes through the activation region, a substantial amount of gas is reformed.
In order to achieve the goal of effectively reforming the gas, one skilled in the art can understand that the following four chemical processes occur throughout the gas reforming: 1) the initiation of the intermediate, 2) Growth of at least a portion of the intermediate, 3) Stopping of the intermediate, and 4) Stabilization of the product gas.
The gas reforming process can be assumed to involve four general processes. In the first process, reactants such as initial gas molecules and an energy source (including but not limited to free electrons and other activated or activated species such as ions or free radicals) are mixed. To reach species-to-species contact. As a result of such contact and mixing at a sufficient energy level, reactant interactions result in the formation of chemical intermediates. Some intermediates react and stop together, but at least some of the intermediates go to another stage, with or without the involvement of reactants to produce other intermediates. The intermediates react to cause a chain chemical reaction. In another process, the intermediate is stopped by chemical and / or physical means to yield a specific product. In the fourth and final step, the product formed is stabilized if specific chemical and / or physical conditions are maintained.
Therefore, the initiation of the intermediate is considered to be the main process that takes place early in the gas reforming zone where an intermediate guiding means (energy source) is provided and brought into contact with the gas entering the gas reforming zone Can do. Mixing, energy transfer, and / or irradiation that allows the reactants to turn into an initial intermediate. It can be said that the reactant is excited.
The intermediate growth stage can be thought of as another important process that takes place within the gas reforming zone where the initial intermediates react to form other intermediates. These intermediates can form a series of reactions with a group of intermediates derived from previous intermediates.
In general, the intermediate termination process can be considered to occur at the end of the gas reforming zone, and in some embodiments, chemical and / or physical so as to prevent further chain reaction. It may even be thought of as defining the outer edge of the zone where the dynamic conditions are changed. However, it should be understood that depending on the nature of the process, the reactants / intermediates, and the stability of the final product, the shutdown process can occur in other parts of the gas reforming zone. A specific product is formed when the chain reaction is terminated, either by controlled stop or proceeding uninterrupted.
The gas stabilization zone can be thought of as being where product stabilization is the main process, and in order to stabilize the product formed when the recombination of intermediates ceases, It can be defined as a zone where conditions are maintained. These products are usually desired for specific applications. Since different points in the chain reaction process correspond to different intermediates that produce different products when stopped and stabilized, efforts to adjust the intermediate stop points when different products are required It may be necessary to do.
There are many intermediate induction means. These include heating, plasma plumes, hydrogen burners, electron beams, lasers, irradiation, and the like. Seeing that the reactant molecules have sufficient energy to reorganize in the presence of a catalyst, and in a situation where they are contacted with such a catalyst, the catalyst serves as an intermediate inducing means. Can do. A common feature of an energy source that provides an intermediate inducing means is to cause a chemical change in the reactants to follow the path to the final product. Thus, the intermediate formed is different in different intermediate induction means and has different levels of activation.
There are several ways to raise the energy of the initial gas to a level that modifies the molecules to molecules of the designed chemical composition. Heat can be applied to the initial gas. In order to transfer the energy required to modify the molecules in the “pre-compounded gas” that is the initial gas and process additive into modified molecules and atoms, it is found in the plasma or from a hydrogen source. Activated species such as electrons and cations generated can be used.
As noted above, there are a variety of catalysts known to those skilled in the art that can be used to reduce the amount of energy required to modify the molecule. Catalysts such as dolomite, olivine, zinc oxide, and char are some examples of commonly used catalysts.
The present invention provides an efficient, intentional approach to the production of an initial gas with associated characteristic features (eg, chemical composition), with characteristic features designed for a particular downstream purpose. Provide a high performance, integrated gas reforming system for planned reforms. Optimization involves achieving reformation in an overall cost-effective manner, including upfront costs such as electricity and downstream costs such as processing of contaminated catalysts.
Process of gas reforming system
(1) Identify the appropriateness of the initial gas characteristic parameters, including but not limited to chemical composition, humidity, flow rate, etc., directly or indirectly. Optionally, the system can sense characteristics and / or parameters of the upstream and / or downstream system, or its inputs or outputs.
(2) Modify various input parameters for the reforming process based on the detected initial gas characteristic parameters and the desired output gas parameters (e.g., optionally, the appropriate amount of process additive). Increase or decrease, change the amount of power, etc.).
(3) Sufficient to interact with off-gas molecules (initial gas or pre-blended gas) to transfer energy to gas molecules so that most gas molecules are modified into modified molecules and atoms One or more gas reforming zones are created that contain various energy species.
(4) In the reforming zone, the initiated gas molecular components (initiated) are combined so that the chemical composition determined by the relative concentration of species present in the reformed gas is combined. Promote efficient mixing of intermediates).
(5) Stabilized, newly formed molecules are deactivated (eg, cooled or made unaffected by the catalyst or gas activation source) and thus stabilized to maintain the desired characteristics Provide a zone.
(6) Provide a control system for overall control of the gas reforming process.
The gas reforming system and method includes a substantial amount of off-gas, such as produced from gasification of a carbonaceous feedstock, a reformed gas containing optimal levels of molecules such as carbon monoxide and hydrogen and a minimum level of undesirable molecules It can be used to modify.
In the following description, the following parts of the gas reforming system will be considered in more detail. The basic process is taught starting from the description of “gas reforming zone” and “gas stabilization zone”. Strategies and strategies for optimizing the extent and efficiency of gas reforming are illustrated by considering gas manipulators including catalysts and other gas manipulators. Optional features included in the system include a “gas additive zone” and a “gas purification zone”. Finally, this description considers the design of a gas reforming chamber and control system to manage all the above processes.
Gas reforming zone
A modification zone is a zone in the system where pre-formulated molecules are generated that are sufficiently activated to modify into molecular species of a designed chemical composition. Generally, this zone is designed to incorporate means for causing turbulence and mixing during the reforming process.
Gas activation source
The gas activation source modifies these molecules by providing the initial energy required to overcome the molecular binding energy between the initial gas and the process additive (pre-formulated gas) in the gas reforming system. And finally CO and H₂It plays the role of modifying the molecule to the designed chemical composition. These activation sources serve to provide energy for the initiation of the reactive intermediate and, if necessary, provide energy to support the growth of the intermediate.
Various elements are contemplated within the present invention to provide a gas activation zone. The energy level required to meet gas reforming energy requirements depends on a variety of factors including, but not limited to, initial gas characteristics (eg, composition), process additives, and the presence of catalysts. It is envisioned that temperature, residence time and / or turbulence, and means for increasing mixing are also included in the design and fabrication of this zone.
The energy required for gas activation to induce and react intermediates can be provided by various sources called activation sources, such as heating, plasma, hydrogen burner, electron beam, laser, irradiation, and the like. These general features are to bring chemical changes to the reactants and follow the path to the final product.
Plasma source
The plasma primarily provides an energy source in the form of electrons and positively charged ions that can interact with the pre-formulated gas to provide gas reforming energy to the molecules.
In one embodiment of the present invention, one or more plasma-based sources (eg, plasma torches) operated in combination with or without other gas activation sources are sufficient for gas reforming. Since it is used to raise the energy of the initial gas to a high level, it will provide a gas activation zone. Appropriate energy levels depend on various factors including, but not limited to, the characteristics of the initial gas and process additive, and can be readily determined by one skilled in the art.
Although heat contributes to the process, most of the substantial amount of energy is supplied by the reactive species in the plasma. In one embodiment of the invention, the temperature is between about 800 ° C and about 1200 ° C. The amount of energy required for the source can be reduced by the use of a catalyst.
From various types including, but not limited to, non-transitional and transitional arcs, alternating current (AC) and direct current (DC), plasma torches, high frequency induction plasma devices, and inductively coupled plasma torches (ICP), etc. One or more plasma sources may be selected. In all arc generation systems, the arc is initiated between the cathode and the anode. The selection of an appropriate plasma source is within the skill of one skilled in the art.
Transfer arcs and non-transfer arcs (both AC and DC) torches can use appropriately selected electrode materials. Suitable materials for electrodes known in the art include copper, tungsten alloys, hafnium, and the like. The life of the electrode depends on various factors such as the arc working area on the electrode, which in turn depends on the design of the plasma torch and the spatial arrangement of the electrodes. In small arc operating regions, the electrode typically wears out in a short period of time unless the electrode is designed to be cooled by thermionic emission. As the electrodes are consumed during the lifetime, the electrode spacing varies, but any variation can be reduced by spatially adjusting the electrodes.
Carrier gas for plasma torch: air, argon, helium, neon, hydrogen, methane, ammonia, carbon monoxide, oxygen, nitrogen, carbon dioxide, C₂H₂And C₃H₆Various gases including, but not limited to, can be used. The carrier gas may be neutral, reducing or oxidizing and is selected based on the requirements of the reforming process and the ionization potential of the gas. It is within the ordinary skill of one of ordinary skill in the art to understand the selection of an appropriate carrier gas and the means for introducing a carrier gas that may affect its efficiency into the plasma torch. In particular, the introduction of poorly designed carrier gases may result in a non-uniform plasma plume with hot and cold zones.
In one embodiment, the gas reforming system includes one or more non-migrating reverse polarity DC plasma torches. In one embodiment, the gas reforming system includes one or more water-cooled, copper electrodes, NTAT DC plasma torches. In one embodiment of the invention, the gas reforming system includes one or more AC plasma torches.
AC plasma torches can be either single phase or multiphase (eg, three phases) with associated arc stability variations. The three-phase AC plasma torch can be powered directly from a conventional utility network or generator system. Higher phase AC systems (eg, 6 phase) and hybrid AC / DC torches, or other hybrid devices using hydrogen burners, lasers, electron beam guns, or other ionized gas sources may be used. It is not limited.
Multiphase AC plasma torches generally have less loss of power supply. In addition, the rapid movement of the arc along the electrodes due to the railgun effect results in improved redistribution of the thermal load between the electrodes. Due to the redistribution of the thermal load along this arbitrary electrode cooling mechanism, a material such as a copper alloy having a relatively low melting point but a high thermal conductivity can be used for the electrode.
The plasma source can include a variety of commercially available plasma torches that provide a suitably high flame temperature over time when applied. Generally, such plasma torches are available in sizes from about 100 kW to over 6 MW. In one embodiment, the plasma torches are two 300 kW plasma torches, each operating at the required (partial) capacity.
Hydrogen burner
In one embodiment of the invention, the gas activation region is provided at least in part by a hydrogen burner, where oxygen and hydrogen react to form ultra high temperature steam (> 1200 ° C.). At such high temperatures, steam can be present in an ionized form that enhances the gas reforming process. The hydrogen burner can be operated in combination with or without other gas activation sources such as a plasma torch. Activated hydrogen species have the advantage of rapid dispersion of reactive species and extensive vapor cracking, both of which result in high initial gas conversion at lower temperatures than can be achieved using plasmas.
In one embodiment of the present invention, the hydrogen burner plays a significant part of the energy activation and therefore serves as the element of the main activation area.
Hydrogen for the hydrogen burner can be obtained by electrolysis. The oxygen source can be pure oxygen or air. Other sources of hydrogen and oxygen can be used as is known to those skilled in the art. For the burner design, standard modeling tools such as tools based on computational fluid dynamics (CFD) can be used. The burner can be configured and sized to meet the requirements of the gas reforming system, taking into account various factors including but not limited to the amount of gas for reforming, the shape of the chamber, and the like.
In one embodiment of the present invention, the hydrogen burner includes a cylindrical nozzle body, and an upper cover and a lower cover are connected to the upper and lower ends, respectively, to define a predetermined annular space S in the body. The gas supply pipe is connected to the side wall of the main body so that the pipe is inclined downward from the side wall. The top cover can be integrated with the main body into a single structure and includes a heat transfer portion having a thickness sufficient to dissipate heat easily. The plurality of nozzle orifices that release hydrogen into the atmosphere are formed through a heat exchanging section that has an exposed recess formed on the upper surface thereof so as to communicate with each nozzle orifice. The airflow chamber is also defined so that air passes through the chamber. The guide protrusion is formed on the inner surface of the space and guides the flow of hydrogen gas in a desired direction in the space. Further, the upper end portion of the annular space S communicating with the lower end portion of the nozzle orifice is formed in a dome shape, and defines an arch type guide for guiding hydrogen gas to the orifice.
Hydrogen burners operate at lower temperatures and typically mix hydrogen with air. They can also use oxygen-hydrogen mixtures that operate at significantly higher temperatures. This higher temperature is capable of producing more radicals and ions and makes the gas very reactive with hydrocarbon vapors and methane.
In one embodiment of the invention, the hydrogen burner serves as a source of high temperature chemical radicals that can accelerate the reforming of gaseous hydrocarbons to synthesis gas. Hydrogen burners are operated with oxidants, where air and oxygen are two common options. One skilled in the art will understand the relative ratio of hydrogen to the required oxidant. In addition to generating hot radicals, the hydrogen burner also generates a controllable amount of steam. Typically, the hydrogen burner can be powered with similar efficiency as a plasma torch.
Electron beam gun
Electron beam guns can be made practical by either emission mechanisms such as thermionic emission, photocathode emission, and field emission, focusing using pure electrostatic fields or magnetic fields, and the use of several electrodes. An electron beam having a precise dynamic energy is generated.
An electron beam gun can be used to ionize particles by adding electrons to or removing electrons from atoms. Those skilled in the art will readily appreciate that such electron ionization processes have been used to ionize gas particles in mass spectrometry.
The design of electron beam guns is readily known in the art. For example, DC and electrostatic thermoelectric guns are heated cathodes that generate an electron flow by ion emission when heated, electrodes such as Wehnelt cylinders that form an electric field to focus the beam, and accelerate and further focus the electrons. It is formed from several sites including one or more anode electrodes. Due to the large voltage difference between the cathode and anode, the electrons accelerate faster. A repelling ring located between the cathode and anode focuses the electrons to a small point on the anode. The small spot may be designed to be a hole, in which case the electron beam is collimated before reaching the second anode, called the collector.
radiation
Ionizing radiation refers to high energy particles or waves that can ionize atoms or molecules. Ionizing power is a function of the energy of individual packets of radiation (photons for electromagnetic radiation). Examples of ionizing radiation are energetic beta particles, neutrons, and alpha particles.
The ability of electromagnetic radiation to ionize atoms or molecules varies across the electromagnetic spectrum. X-rays and gamma rays ionize almost every molecule or atom, far ultraviolet rays ionize many atoms and molecules, and near ultraviolet and visible light hardly ionize molecules. Suitable sources of ionizing radiation are known in the art.
Energy reuse
The external energy required to maintain the gas reforming process can also be reduced by utilizing any heat generated by the process. The amount of heat generated by the gas reforming process depends on the characteristics of the initial gas and the reformed gas. In one embodiment, carbon or multi-carbon molecules are predominantly CO and H₂The heat released during reforming to the amount of process additive is the amount and type of process additive injected into the gas reforming system (eg, air, O₂) Is optimized.
Detectable heat present in the gas leaving the reforming zone can be captured using a heat exchanger in the gas stabilization zone and reused to improve the external efficiency of the reforming process Is done.
As will be apparent to those skilled in the art, other activation sources based on thermal energy or lasers can be used.
Gas manipulator
A gas manipulator represents an embodiment of a design strategy that seeks to optimize the process of gas reforming. They include the design of the chamber that optimizes the pre-blended gas flow pattern for the gas activation region, in particular the amount of gas that passes through this region within a specific time. Another example of a gas manipulator is a system design in which an energy source (such as a plasma torch) is oriented with respect to an incoming reforming gas that maximizes mixing of the incoming gas with the energy species in the energy source. is there. Another example is the location and placement of process additive nozzles that are designed to increase turbulence and mixing. Another example may include the arrangement of consecutive gas reforming zones versus parallel gas reforming zones.
The gas manipulator includes a structural device designed and incorporated into the system to increase the efficiency of the gas reforming process. Examples include, but are not limited to, structural devices such as baffles and deflectors that direct the pre-blended gas more effectively toward and through the gas activation region. Other examples include structural devices that increase turbulence throughout the process, increasing the mixing of the activation source and the gas being reformed.
The gas manipulator also includes an aspect of the system that determines the physical orientation of the activation source to change the size of the activation region, such as a plasma plume orientation determination device, and / or provides energy to the plasma source. Changes to the working gas flow rate, etc. are examples of non-limiting aspects of the system of the present invention that can be modified to result in changes in the dimensions of the pre-blended gas activation region.
The catalytic gas manipulator increases the efficiency of energy transfer and includes a catalyst. An example of a gas manipulator is a system design where a pre-blended gas passes through an electric arc (s) that generates a plasma. The inclusion of a gas manipulator balances the amount of energy consumed in the process of supplying energy to a production pre-blended gas that is sufficient for the system to reform the synthesis gas to a gas of the designed chemical composition. Is intended to optimize.
There are various categories of gas manipulators.
One category of gas manipulators is referred to as Source Energy Exposure Manipulators. The main design strategy of this aspect of the invention is to optimize the exposure of the required amount of pre-blended gas to the initial energy source to support the reforming reaction.
Another category of gas manipulators is referred to as mixing manipulators. The main design strategy of this aspect of the present invention is to optimize the mixing of reactive species to facilitate energy transfer throughout the reforming process.
Another category of gas manipulators is referred to as catalyst manipulators. The main design strategy of this aspect of the invention is to optimize the catalyst activity within the system in order to increase the overall efficiency of the reforming process.
Overall efficiency also means thorough reformation process (represented by gas reforming rate) in addition to the overall cost of achieving reformation. For example, for overall efficiency, consider the cost of using a catalyst that can become “toxic” during the process and its replacement cost. Also consider the cost of energy sources.
The gas reforming system of the present invention is designed to increase the efficiency of the reforming process. Various means to achieve this are referred to as “gas manipulators”, which promote efficiency, effectiveness, and thorough reformation processes. Since the reforming process occurs as the pre-blended gas passes through the system chamber, residence time is an important aspect that determines the efficiency of the process and the thoroughness of conversion. Factors that accelerate the rate and extent of energy transfer throughout the molecules of the pre-blended gas and the mixing of the reforming species optimize the thorough conversion before the gas exits the system.
The proximity of a gas molecule to a source of active species provided in the plasma and / or providing energy such as heat depends on the length of time that the gas molecule is exposed to the source. Means provided within the system to facilitate the process of energy transfer across the pre-blended gas molecules and thereby initiate reforming maximizes the number of molecules being reformed. There is also a means of increasing the active species / reaction intermediate mix so that they are reorganized to new species (the composition of which depends largely on the relative concentrations of species present in the reformed gas). Maximize the amount of engineered molecules produced.
The gas manipulator is designed, arranged and operated to increase the efficiency of the reforming process. In some embodiments, the gas manipulator is designed to increase high turbulence in the system. The increase in turbulence affects the gas by thoroughly mixing the gas molecules to be activated and the gas molecules in the process of reforming into new molecules, whose chemical composition depends on the individual chemistry within the gas reforming zone. It is largely determined by the relative concentration of the species.
Gas manipulators bring about changes in their relative spatial distribution and their mechanical evolution through targeted reorientation of at least one of the gas activation zone, initial gas, process additive, and its components, It can be designed to change the fluid dynamics in the gas reforming system. The gas manipulator can be designed to ensure that a highly turbulent environment is created at the targeted location to assist in the activation and modification process.
By improving exposure of the gas activation region (eg, plasma plume) to the initial gas and process additives, an improvement of the reaction process for activation and modification is achieved at the lowest possible temperature.
Those skilled in the art will readily understand that the gas manipulator must be designed and arranged based on the location of the gas activation source and process additive inlet, and the overall design of the chamber.
Exposure manipulator
In some embodiments, the gas manipulator is designed and configured to substantially facilitate exposure of the pre-blended gas to the improved zone. As described above, these gas manipulators can be separate structural devices attached to the gas reforming chamber (s) or can be integrated within the gas reforming chamber.
Chamber design for exposure operations
In one embodiment, the gas manipulator includes a chamber design that optimizes the premixed gas flow pattern for the gas activation region, particularly the amount of gas that passes through the region within a particular time. This is achieved by a suitable design of the internal walls of the chamber, which makes a difference in the gas reforming channel, ie the gas flow path within the chamber. The gas reforming channel may be of various types including but not limited to the following types: linear, curved, bifurcated-concentrated, and labyrinth type.
Various embodiments of gas reforming channels are shown in FIGS. Those skilled in the art will readily appreciate that several design changes are possible for the embodiments of FIGS. 25-28 based on the design of additional features of the chamber, such as, for example, an air injection pole. Design considerations for gas reforming channels include, but are not limited to, exposure to energy sources, cross-sectional areas, temperature profiles, velocity profiles, velocity profiles, gas residence times, mixing, and pressure drops.
Referring to FIG. 15A, and according to one embodiment of the present invention, the chamber is straight and includes a constricted throat where the plasma torch is located. The gas that passes through the constricted throat is mixed with a reactive ionized plasma carrier gas (gas activation zone), thereby promoting reforming. The throat portion is as large as the visible portion of the plasma plume and involves a temperature in excess of 2000 ° C. The carrier gas is much more active because it flows out in an ionized phase at such temperatures. Design criteria such as channel size (eg, its cross-sectional area), velocity profile, and temperature profile are determined by the chemical processes required to promote gas reforming. Because of the higher speed at the throat, any particulate material present in the reformed gas can be drawn and deposited at the second portion of the chamber.
The chamber can be further designed to facilitate the separation of particulate material. Referring to FIG. 15B, and in accordance with one embodiment of the present invention, the second portion of the chamber is positioned downward so that the particulate material can be carried separately at the bottom. Alternatively, the second portion of the chamber can be designed such that gas is introduced tangentially from the main portion of the chamber so that the resulting swirling flow can facilitate the separation of particulate matter from the gas flow.
The advantages of the designs of FIGS. 15A and 15B can also be achieved using a simplified mechanical design by properly installing the structural device therein. Referring to FIG. 15C, and according to one embodiment of the present invention, the shape of the chamber has not changed throughout its length, and the channel is located substantially in the center of the chamber for passing offgas. ing. Because the chamber diameter is fixed, refractory installation and chamber manufacture and installation are simplified. Internal structural devices can be sufficiently insulated and cooled for optimal performance using methods known in the art such as additional cooling piping, fans, and controllers.
The plasma plume generated using a single plasma torch is of a certain finite length in a few milliseconds, after which the temperature drops below about 2000 ° C. and the ionized gas returns to the non-plasma state. Those skilled in the art will appreciate that the time after which the ionized gas returns to the non-plasma state includes various parameters of the plasma torch including, but not limited to, enthalpy of torch, gas flow, ambient gas temperature, and amperage. Understand that depends on. In a gas reforming chamber with curved types of channels, to provide a continuous flow of reactive ionized gas for interaction with the incoming off-gas, thus increasing the efficiency of the tar cracking process Two or more plasma torches can be properly positioned.
Various designs are possible for the curved channel, not limited to the embodiment of FIGS. According to one embodiment of the present invention, the second part of the chamber allows gas to be introduced tangentially from the main part of the chamber, so that the resulting swirl flow is granular from the gas stream. Promotes material separation. Those skilled in the art will readily appreciate that numerous curved channel designs are possible, for example, based on the difference in the angle of the curves.
Referring to FIG. 17, and according to one embodiment of the present invention, the channel is tapered and the shape of the channel allows for variations in local conditions such as speed, pressure, etc., as needed.
Referring to FIG. 18, and according to one embodiment of the present invention, the channel is labyrinth type. Those skilled in the art will readily understand that this channel design can accommodate longer residence times if desired.
In one embodiment of the present invention, the chamber is a linear, substantially horizontal, cylindrical, operatively coupled to a source of gas (eg, a gasifier) via a vertically oriented connector. Structure. The chamber and / or connector walls serve as a gas manipulator, i.e., precisely redirect the pre-blended gas flow to interact with the gas activation region and optionally with process additives. Can be designed to facilitate.
In one embodiment of the invention, the chamber is constricted at a suitable location to facilitate the interaction of the pre-blended gas with the gas activation region (eg, plasma plume) and / or process additive. Referring to FIG. 20A, and according to one embodiment of the present invention, the constriction 3999 in the chamber 3202 is located slightly above the two plasma torches 3208. Referring to FIG. 20B, and according to one embodiment of the present invention, the constriction 3999 is more gradual and the plasma torch 3208 is positioned within the constricted portion of the chamber 3202. Those skilled in the art will readily understand the effect of different arrangements of the constriction on the plasma torch.
In one embodiment of the invention, an injector plasma torch that uses its own injector flow as a carrier gas is used to create an ionized region in a chamber containing electrodes driven by a multilayer AC current, Filled with pre-blended gas to be reformed. When the pre-blended gas passes directly through the chamber, the activation and reforming process is facilitated. Various embodiments of the gas manipulator described below may be further utilized to ensure that the injector plasma torch plume is accurately oriented within the primary electrode gap.
Referring to FIGS. 21A and 21B, various embodiments of the gas reforming system may be considered based on the activation source, additive flow, and gas input and output configurations.
The gas reforming system can also be designed so that the gas stream is divided into smaller streams and undergoes reforming in parallel. With reference to FIGS. 24A and 24B, each smaller gas stream passes through a dedicated reforming zone formed by an independent activation source. FIG. 24B shows the use of the moved arc torch. FIG. 24C shows that a dedicated reforming zone for each separate gas stream can be formed by multiple gas activation sources. FIG. 24D shows the embodiment of FIGS. 24A and 24B where mixing elements are introduced into the respective paths of the smaller gas flow.
FIGS. 25A-C show three gas reforming systems in which the gas activation source is placed in the reforming chamber at an angle. The source can direct its activation region either towards or against the gas flow, or any combination thereof.
The chamber may further include one or more ports for a secondary torch heat source to assist in preheating or heating the chamber with the torch.
Pre-blending gas direction determination device
Gas manipulators can be used in advance by manipulating the spatial distribution of pre-blended gas and its mechanical evolution within the chamber (s), either directly or indirectly, using active or passive means or both. Exposure of the gas mixture to the gas activation region can be facilitated. Such a gas manipulator can be a separate structural device. Examples include, but are not limited to, structural devices such as baffles and deflectors that more effectively direct the pre-blended gas toward and through the gas activation region. Other examples include the design of a chamber to create a particular desired hydrodynamic flow path.
In one embodiment of the present invention, a gas manipulator is provided at the initial gas inlet or to ensure that the initial gas has a more uniform composition and / or temperature and is properly mixed with the process additive. It is positioned near it.
Referring to FIGS. 26A-C and according to one embodiment of the present invention, the gas manipulator includes a flow restrictor 3999 that alters the flow of gas entering the chamber 3202. Those skilled in the art will readily appreciate that the differences to the gas flow pattern depend on a variety of factors including, but not limited to, the size and shape of the flow restrictor 3999 and their arrangement.
The flow restrictor can be attached to the chamber using various locking means. In one embodiment of the invention, the flow restrictor is suspended from the top (downstream end) of the chamber. In one embodiment of the invention, the flow restrictor is attached to the chamber wall using a bracket.
Referring to FIGS. 27A and 27B, and according to one embodiment of the present invention, the flow restrictor 3999 extends substantially the entire length of the chamber 3202, resulting in an annular space in which gas reforming occurs. Yes. As shown in FIG. 42, the flow restrictor 3999 can be rotated using a motor 7001, which is an example of the use of dynamic means for direct manipulation of off-gas flow. The rotation of the flow restrictor can optionally be controlled dynamically, along with a control system designed to tune and optimize the overall gas reforming process.
FIGS. 28A and 28B show a three-dimensional view of a chamber that includes a flow restrictor and is directly connected to a laterally oriented gasifier. The flow restrictor must be designed to withstand the high temperatures typically present in the chamber.
Figures 29A-G show different flow restrictors according to various embodiments of the present invention. In these figures, the plasma torches are shown to be at the same altitude. Alternatively, the flow restrictor can be installed above or below the plasma torch. Also shown below the torch is an additive port for injection of process additives such as air and steam.
In one embodiment of the present invention, as shown in FIG. 29A, the flow restrictor is designed with two spirals designed to induce more circulating flow mixing of the incoming off-gas and the plasma plume. Has wings. FIG. 29B shows a flow restrictor with two helical vanes but different shapes according to one embodiment of the present invention. In one embodiment of the present invention, as shown in FIG. 29D, one helical vane of the flow restrictor is larger than the other, further inducing a circulating flow and mixing of off-gas and plasma plume. In one embodiment of the present invention, as shown in FIG. 29G, before starting as two new vanes, the vane spiral covers only half of the restrictor.
In one embodiment of the present invention, as shown in FIGS. 29C-F, the flow restrictor is attached to a cooling pipe and a cooling medium (eg, air, water, hot oil) controls the temperature of the flow restrictor. . In one embodiment of the invention shown in FIG. 29E, the additive (eg, air, steam, etc.) flows from the top of the support bar to the bottom of the flow restrictor before entering the off-gas stream. This design allows the flow restrictor to cool while preheating the additive prior to injecting the additive.
Referring to FIG. 30A, and according to one embodiment of the present invention, the chamber includes a gas manipulator in the form of one or more rotating shafts attached to a motor, each shaft being carefully selected for stable rotation. Includes one or more discs with adjustable weight. In embodiments having multiple disks on the shaft, the disks can be arranged in an offset fashion. Those skilled in the art will readily appreciate that the disk can incorporate cooling. The flow restrictor as described above can be attached to the end of the rotating shaft.
FIG. 30B shows different types of disks that can be attached to the rotating shaft. Referring to FIG. 30BA, the disk has a section that allows gas to flow from one side of the disk to the other. Referring to FIG. 30BB, it has a spiral section designed to pull up the gas and enter the center of the chamber. Alternatively, the spiral section can be designed to push the gas up and out to the periphery of the chamber. Referring to FIGS. 30BC and 30BD, the rotating disk is a plurality of winged spokes. One skilled in the art will readily understand that for stable rotation, the wing orientation and weight distribution should be balanced.
FIGS. 31A-C show different embodiments of the rotating shaft shown in FIG. 42, the upper disk being able to rotate on the ball bearing and held in place by the support. Optionally, a coolant or additive can be piped through the center of the shaft. In one embodiment of the invention, as shown in FIG. 31A, the motor is on one or more supports having a drive shaft attached to a rotating wheel (sprocket). The shaft projects into the chamber as the mechanical energy rotates the disk.
Referring to FIG. 31B, an electromagnet is used between or as part of the supports to cause rotation. Referring to FIG. 31C and according to one embodiment of the present invention, an electromagnet is used to stabilize the shaft in the chamber. Electromagnets can be used as a primary or secondary means for creating a rotational moment in the shaft and disk. In one embodiment of the present invention, the disc rotates independently of the shaft, for example, the shaft may be stationary, rotated at another speed, or even rotated in another direction. Also good. In one embodiment of the present invention, the disk has a permanent magnet and the cooling is done on the disk plane because it is almost hollow with a ball bearing cooled with a hot fluid connected to the shaft.
Activation source direction determination device
The activation source direction determining device is a gas manipulator that directs the physical orientation of the activation source and / or supplied to the plasma source, for example, to change the dimensions of the gas activation region, such as a plasma plume direction determination device. Changes to energy, working gas flow rates, etc. are non-limiting examples of aspects of the system of the present invention that can be modified to affect changes in the dimensions of the gas activation region.
In addition, the gas manipulator can directly or indirectly use the active or passive means or both to spatially distribute the gas activation region (eg, plasma plume) within the chamber (s) and its mechanical evolution. To promote exposure of the pre-blended gas to the gas activation area. In one embodiment of the invention, this can be achieved by the placement and orientation of the activation source (eg, plasma torch).
In one embodiment of the invention, the gas manipulator is a deflector 3998 that redirects the plasma plume 3997 from the plasma torch 3208, as shown in FIG. 33A. Appropriate turning of the plasma plume includes deflector 3998, including but not limited to the distance from the plasma torch 3208, the angle of orientation relative to the direction of the plasma plume, the size compared to the width of the plasma plume, and its constituent materials. Depends on various design factors. The refractory material ensures that the deflector can withstand the high temperatures that occur proximal to the plasma torch 3208. Those skilled in the art will readily understand the different materials that can be used to withstand high plasma temperatures.
Referring to FIG. 33B, and in accordance with one embodiment of the present invention, the gas manipulator is a Coanda effect based deflector 3996 used to manipulate the plasma plume 3997.
Referring to FIGS. 34A and 34B, and in accordance with one embodiment of the present invention, one or more fluid jets 3208 (eg, air nozzles) redirect a plasma plume 3997 generated by a plasma torch (s) 3208. Used to make. A fluid jet is an example of a dynamic means used for direct manipulation of the plasma plume. In one embodiment of the invention, the fluid jet is dynamically controlled, optionally with a control system designed to tune and optimize the overall gas reforming process.
FIGS. 35A-D show an embodiment of a deflector that can be used to redirect a plasma plume in a gas reforming chamber. In one embodiment of the invention, the deflector is attached to the casing of the plasma torch, as shown in FIGS. By adjusting the shape of the deflector, the spread of the dispersion of the plasma plume can be controlled. For example, the deflector of FIG. 35B provides a wider plume dispersion than the deflector of FIG. 35A.
FIGS. 35C-D show an embodiment of the present invention in which the deflector is not attached to the casing of the plasma torch. In one embodiment of the present invention, the deflector is attached to a rotating shaft, as shown in FIG. 35D. One skilled in the art understands that the finish of the deflector surface (eg, smooth, rough, or sloped) affects the distribution of the plume.
Figures 36A-D show different embodiments of the present invention in which the object of rotation axis has a non-planar surface. The number of edges, torch, and torch angle can be used to optimize the plasma plume and / or to spread the plasma plume evenly, thereby reducing the contact between the plume and off-gas. maximize. In one embodiment of the invention, the plasma torch is pointing straight to the center of the chamber.
In one embodiment of the invention shown in FIG. 36A, because the plasma torch has a gradient, at least a portion of the plasma plume hits the central object. Alternatively, the plasma plume can be directed away from the central object. In one embodiment of the invention shown in FIG. 36B, the axis object is rotated to the opposite angle to the torch, thus pushing the plasma plume out of the chamber.
In one embodiment of the invention shown in FIGS. 36C-D, the plasma plume is bounced from the deflector toward the central axis. The deflector can be attached to the casing of the plasma torch as shown in FIG. 36C, or it can be attached to the chamber wall as shown in FIG. 36D. The axes in FIGS. 36C-D can be rotated in either direction.
Optionally, a port for attaching the plasma torch facilitates insertion and removal of the plasma torch (s) into the chamber and seals the port after withdrawing the plasma torch (s) Can be fitted with a sliding mechanism, which may include an automatic gate valve to do. In one embodiment of the present invention, a port for a tangentially mounted plasma torch is located above the air inlet so as to provide maximum exposure to the plasma torch. Such an attachment mechanism can be modified so that the arrangement of the gas activation source can be adjusted.
Referring to FIG. 38A, and in accordance with one embodiment of the present invention, the plasma torch 3208 is arranged such that the gas injected into the chamber 3202 flows back against the plasma plume generated therein. Those skilled in the art should readily understand variations in the spatial distribution of the plasma plume when the orientation and arrangement of the plasma torch is different.
In one embodiment of the invention, the gas activation source (eg, plasma torch) is installed such that the resulting zone (eg, plasma plume) is oriented perpendicular to the direction of initial gas flow. In one embodiment of the invention, the chamber is substantially cylindrical and the plasma plume is oriented perpendicular to the axial direction with respect to a flow that is substantially axial of the initial gas flow. Alternatively, the initial gas flow can be directed axially, while the plasma plume can be directed axially along a gas purification chamber that is substantially cylindrical. In one embodiment of the invention, the chamber is substantially cylindrical and the plasma plume is oriented perpendicular to the tangential direction with respect to a flow that is substantially axial of the initial gas flow.
FIG. 39 shows cross-sectional views of cylindrical gas reforming chambers with various arrangements of gas activation sources that result in changes related to the shape and dimensions of the resulting gas activation region. In one embodiment of the invention, the gas activation source used may be either an AC or DC plasma torch. FIG. 39A shows two gas activation sources oriented tangentially into the chamber. Referring to FIG. 39B, the chamber includes three electrodes where an arc passes between the electrodes. Gas passes through this arc, plasma is formed, and the gas is reformed. FIG. 39C shows an embodiment similar to FIG. 39B except that there is a central ground electrode where the arc from the wall electrode forms an arc. One skilled in the art understands that the ground electrode is electrically shielded except at the point of contact. FIG. 39D shows a plurality of gas activation sources where the chamber is sufficient to ensure that substantially all of the gas passing through the chamber is activated (either straight to the center as shown or in a vortex pattern). ) Includes one example embodiment. 39E and 39F are similar to the embodiment of FIGS. 39B and 39C, respectively, but include 6 torches (3 or 6 phases). A larger number of torches can also be considered in the embodiments of FIGS. 39B, 39C, 39E, and 39F.
FIG. 40 illustrates two exemplary embodiments of the present invention where the initial gas and / or pre-blended gas flow is introduced directly into the reforming chamber via a gas activation region formed by a gas activation source. The
The gas manipulator at least partially manipulates the spatial distribution of the pre-blended gas and the gas activation region relative to each other and their mechanical evolution.
Mixing manipulator
In some embodiments, the gas manipulator is designed and configured to substantially facilitate mixing of gas and energy species during reforming in the gas activation region. Gas manipulators can also promote turbulence throughout the process, resulting in improved mixing.
In one embodiment of the present invention, the location and placement of process additive nozzles designed to increase turbulence and mixing.
In one embodiment, the gas manipulator is one or more baffles located within the chamber to induce turbulence and thus mixing of the gas being reformed. Different baffle arrangements are known in the art, including cross bar baffles, partition wall baffles, choke ring baffle arrangements and the like. However, it is not limited to these. The baffle may also be located at or near the initial gas inlet to ensure that the initial gas is of a more uniform composition and / or temperature and is properly mixed with the process additive. .
Referring to FIGS. 43A-B, turbulence can be formed before or after the gas activation source. FIG. 43C shows three exemplary embodiments of the means for creating turbulent flow: (i) a passive grid, (ii) an active grid utilizing a rotational axis, and (iii) a shear generator. Figures 45 and 46 show additional exemplary embodiments of means for generating turbulence.
In one embodiment, the gas manipulator includes a design that places an activation source that can contribute to the mixing of the gas and energy species being reformed in the gas activation region. Thus, the activation source may be arranged to optimize the gas reforming process, which arrangement depends on various factors including, but not limited to, the gas reforming chamber (chamber) design. In one embodiment of the invention, two plasma torches are arranged tangentially to form a vortex direction similar to the air and / or oxygen inlet. In one embodiment of the present invention, the two plasma torches are arranged at opposing positions along the periphery of the chamber.
Inlet placement for process additives (chemical composition contributions discussed below) is based on a variety of factors including, but not limited to, chamber design, desired flow, jet velocity, permeation, and mixing. . Various arrangements of process additive ports and ports for gas activation sources are contemplated by the present invention.
For example, the oxygen inlet or port, the steam inlet or port, and the gas activation source port may be arranged in layers around the periphery of the chamber, and the tangential direction of the gas activation zone, oxygen, and vapor and Allows layered injection. In one embodiment, nine oxygen source ports are provided that are arranged in three layers around the periphery of the chamber. In one embodiment, two opposing vapor inlet ports are provided that are arranged in two layers around the periphery of the chamber. In embodiments where the air and / or oxygen inlet ports are arranged in layers, they can be arranged to maximize the mixing effect.
In one embodiment of the invention, the air and / or oxygen inlet port is tangentially arranged so that the lower level inlet port premixes the gas and the torch heats it to swirl into the gas It becomes possible to start exercise. The upper level air inlet port can accelerate the swirl movement and thereby be recirculated so that the vortex pattern is deployed and sustained.
Referring to FIG. 44, and according to one embodiment of the present invention, the gas to be reformed enters the reforming chamber in a tangential direction, thus forming a vortex. The present embodiment also illustrates an exemplary gas manipulator that is shaped and arranged to facilitate exposure of a gas stream to a gas activation source.
In one embodiment, the lowest level air inlet port consists of four jets that premix the gas produced from the lower gasifier and the torch heats it. The other two levels of air nozzles provide the main momentum and oxygen to mix the gas and heat the torch to the required temperature. The arrangement of the steam inlets or ports is free in their number, level, orientation, and angle as long as they are placed in positions that provide optimized temperature control capabilities.
The oxygen and / or steam inlet ports can also be arranged such that they inject oxygen and steam into the chamber at an angle to the inner wall of the chamber, facilitating gas turbulence or swirling. The angle is selected to achieve sufficient jet penetration based on the chamber diameter and the designed air inlet port flow and velocity. The angle can vary between about 50 ° and 70 °.
The air inlet ports can be arranged to be in the same plane or can be arranged to be in a continuous plane. In one embodiment, the air inlet ports are disposed at a lower level and an upper level. In one embodiment, there are four air inlet ports at the lower level, and six more air inlet ports, of which three inlet ports are more than the other three to form a cross-jet mixing effect. Slightly higher.
Optionally, air may be blown into the chamber at an angle so that the air forms a rotational or cyclonic motion of the gas through the chamber. A gas activation source (eg, a plasma torch) may be angled to provide further flow rotation.
In one embodiment of the present invention, the air and / or oxygen and / or steam inlet includes a high temperature resistant spray nozzle or jet. Suitable air nozzles are known in the art and may include commercially available types such as the A and B nozzles shown in FIGS. The nozzle can be a single type or different types. The type of nozzle can be selected based on functional requirements, for example, type A nozzles change the direction of air flow to form the desired vortex, type B nozzles form a high speed air flow, Selected to achieve specific penetration and maximum mixing.
The nozzle can be designed to direct the air at a desired angle. In one embodiment, the air jet is arranged tangentially. In one embodiment, an angled blast is achieved by having a deflector at the tip of the inlet nozzle, thereby allowing the inlet pipe and flange to be perpendicular to the chamber.
In one embodiment of the present invention, one or more air jets (eg, air swirl jets) are positioned at or near the initial gas inlet and injected with a small amount of air into the initial gas. By utilizing the velocity of air, a swirl motion is formed in the initial gas flow. The number of air swirling jets can be designed to provide a substantially maximum vortex based on the designed air flow and outflow velocity so that the jet can penetrate to the center of the chamber.
Catalyst manipulator
The catalyst manipulator includes a catalyst and increases the efficiency of energy transfer. The catalyst increases the rate of chemical reaction by reducing the time required to reach equilibrium. Catalysts work by using various mechanisms to provide an alternative easier path from reactant to product, in each case by reducing the activation energy of the reaction. . A homogeneous catalyst exists in the same phase as the reactants and functions by combining with the molecules or ions in the reaction to form unstable intermediates. These intermediates combine with other reactants to produce the desired product and regenerate the catalyst. The heterogeneous catalyst is present in a different phase than the reactant and product phases. They are usually solids in the presence of gaseous or liquid reactants. The reaction takes place on the surface of the heterogeneous catalyst. For this reason, the catalyst is a finely divided solid or has a particle shape that provides a high surface area to volume ratio. Petroleum cracking and hydrocarbon improvement are common industrial applications of the use of heterogeneous catalysts. One of the difficulties in using heterogeneous catalysts is that most of them are easily “contaminated” and the impurities in the reactants coat the catalyst with non-reactive materials or modify its surface. The activity is lost. Although not necessarily, contaminated catalysts are often purified and can be used again.
By providing an alternative reaction path, the use of a suitable catalyst in the gas reforming system can reduce the energy level required for the gas reforming process. The exact pathway provided by the catalyst depends on the catalyst used. The feasibility of using catalysts in gas reforming systems generally depends on their lifetime. The lifetime of the catalyst can be shortened by "contamination", i.e. degradation of the catalyst capacity due to impurities in the gas.
The gas reforming system can be designed to facilitate catalyst replacement. In one embodiment of the present invention, the catalyst is incorporated into the gas reforming chamber in the form of a catalyst bed mounted on a sliding mechanism. The sliding mechanism allows easy removal and replacement of the catalyst bed. The catalyst bed can be inserted at various locations within the gas reforming system.
In one embodiment of the present invention, the hot offgas from the gasification chamber contacts a catalyst that effectively lowers the energy threshold required for gas reforming, before the offgas stream is exposed to the gas activation region. To be modified. In one embodiment of the invention, therefore, the gas reforming system includes a catalyst at a location upstream of the gas activation source (s). In one embodiment, as disclosed in FIG. 57, the catalyst bed is inserted before and / or after the gas activation source (eg, plasma torch).
The catalytic capacity also depends on the temperature of operation. The appropriate operating temperature depends on the various catalysts known in the art. The gas reforming system can incorporate a suitable cooling mechanism to ensure that the catalyst is maintained within an optimal operating temperature range. Additives such as steam, air, oxygen, or recirculated reformed gas can be added to help raise or lower the temperature near the catalyst bed. One skilled in the art understands that the particular additive selected to control the temperature depends on the location of the catalyst bed and the gas temperature therein.
The irregularity of the catalyst surface and good contact between the large organic molecules and the surface₂And the opportunity to modify to smaller molecules such as CO.
Catalysts that can be used include, but are not limited to, olivine, calcined olivine, dolomite, nickel oxide, zinc oxide, and char. The presence of iron and magnesium oxides in olivine imparts the ability to modify longer hydrocarbon molecules. One skilled in the art understands that in the gas environment of the system, one selects a catalyst that does not degrade rapidly.
Both non-metallic and metal catalysts can be used to facilitate the reforming process. The calcined form of dolomite is the most widely used non-metallic catalyst for the reforming of gases from biomass gasification processes. They are relatively inexpensive and are considered disposable. When the dolomite is operated using steam, the efficiency of the catalyst is high. The optimum temperature range is between about 800 ° C and about 900 ° C. The activity of the catalyst and the physical properties of the dolomite degrade at higher temperatures.
Dolomite has the general chemical formula CaMg (CO₃)₂Calcium magnesium ore with about 20% MgO, about 30% CaO, and about 45% CO on a weight basis₂In addition to other trace mineral impurities. For dolomite firing, CO₂Accompanied by decomposition of carbonate minerals to form MgO-CaO. Complete dolomite calcination occurs at very high temperatures, usually at 800 ° C to 900 ° C. Thus, depending on the dolomite calcination temperature, the effective use of this catalyst is limited to these relatively high temperatures.
Another naturally occurring mineral, olivine, also showed catalytic activity similar to calcined dolomite. Olivine is typically more powerful than calcined dolomite.
Other catalyst materials that can be used include, but are not limited to, carbonate rock, lime dolomite, and silicon carbide (SiC).
Char can act as a catalyst at low temperatures. In one embodiment of the present invention, the gas reforming system is operably coupled to the gasifier and at least a portion of the char formed in the gasifier is transferred to the gas reforming system and used as a catalyst. Is done. In embodiments using char as the catalyst, the catalyst bed is placed in front of the activation zone, such as typically provided by a plasma torch.
FIG. 49 shows a fixed bed of char used as a catalyst in the reforming chamber. The char used as the catalyst can be obtained from a gasifier as shown in FIG. This can be particularly applied when the gas reforming chamber is operably connected to the gasifier and used to reform the gas produced therefrom. When the char loses its catalytic properties, it can be moved to a residue conditioning chamber or carbon converter.
FIG. 51 shows an exemplary configuration of a gasifier operably coupled to a plasma torch-based gas reforming chamber, wherein the char formed in the gasifier is an off-gas catalyst formed by gasification. Assist with cracking. The catalyst cracking achieved in the latter stage of the gasifier is followed by further gas reforming by exposing the gas to the gas activation region formed by the plasma torch. Various types of gasifiers that can be readily understood by those skilled in the art, such as fluidized bed gasifiers and entrained flow gasifiers, can also be utilized.
In one embodiment of the present invention, the initial gas is heated to a temperature of 900-950 ° C. and passed over a nickel-based catalyst whereby light hydrocarbons including tar composition and methane are converted to CO and H.₂Is converted to Nickel-based catalysts can be particularly useful when the initial gas contains a minimal amount of sulfur species (such as hydrogen sulfide) such as, for example, gas produced by biomass gasification. The life of the nickel-based catalyst can be extended by using a promoter such as a rare metal.
In one embodiment of the present invention shown in FIG. 52, a catalyst bed is attached immediately after the gasifier to convert most of the volatile materials. The temperature of the catalyst bed inlet can be raised to 600-950 ° C. by burning a small amount of volatile material. The temperature at the catalyst bed outlet is expected to drop to 850 ° C. and the exhaust gas is fed to the gas activation zone for further reforming. The gas activation zone can be operated at 1000 ° C. for this purpose, and the resulting synthesis gas is sent to a recuperator to initiate the subsequent gas purification process.
In one embodiment of the invention shown in FIG. 53, volatile material from the gasifier passes through a gas activation zone that is at a temperature between about 900 ° C. and about 1000 ° C. A catalyst bed is used for further reforming. The temperature of the synthesis gas is expected to drop to 850 ° C. at the catalyst bed outlet. The gas is then sent to a recuperator that forms part of a heat exchanger or gas stabilization zone.
In one embodiment of the invention shown in FIG. 54, heat recovery is achieved before the catalyst bed. Most of the volatile material from the gasifier is reformed at a temperature of about 1000 ° C. in the gas activation zone. The hot output gas passes through a heat exchanger (ie, a recuperator) to preheat the process air, at which point the temperature drops to about 700 ° C. Thereafter, the cooled synthesis gas is heated to 900 ° C. by burning a minute amount thereof and supplied to the catalyst bed. The synthesis gas obtained at 850 ° C. is optionally sent for further gas purification.
In embodiments where the catalyst bed is installed before the activation zone, the temperature of the gas is typically suitable for high catalyst activity. However, in embodiments where the catalyst bed is after the activation zone (such as generated by a plasma torch), the gas temperature may be too high for olivine, dolomite, and many other typical catalysts. . As shown in FIG. 55, the circulation of the coolant can reduce the gas temperature to an appropriate level (to avoid deterioration of the catalyst bed). Suitable coolants may include, but are not limited to, recycled reformed gas (shown in the embodiment of FIG. 56), water, and steam.
In embodiments where the catalyst bed is after the recuperator (heat exchanger), the recirculated steam of the reformed gas can be inserted either before or after the recuperator.
In one embodiment of the invention, the improvement zone includes a catalyst bed and the catalyst manipulator is designed to facilitate exposure of the pre-blended gas and / or gas during reforming to the catalyst bed.
Gas stabilization zone
The system provides one or more stabilization zones, whereby newly formed molecules are deactivated (eg, to ensure that desired characteristics such as the designed chemical composition are maintained). , Cooled, or unaffected by the catalyst or activation source).
The temperature of the gas entering the stabilization zone varies from about 400 ° C. to over 1000 ° C. The temperature can optionally be lowered by a heat exchange system in the stabilization zone of the gas reforming system that recovers heat from the reformed gas and thus cools the reformed gas. Such a decrease in gas temperature may be required for downstream applications and components.
Referring to FIG. 22B, the gas reforming chamber 3002 in the stabilization zone can be specifically shaped to facilitate inactivation and stabilization of newly formed molecules. The gas reforming chamber 3002 is generally a cylindrical chamber having a bulbous extension downstream of the plasma or optionally proximal to one or more reformed gas outlets 3006. The bulbous extension stabilizes newly formed molecules by allowing gas inactivation.
Optional heat recycling means
Heat can be recovered in the stabilization zone or downstream of the stabilization zone. The recovered heat can be used for a variety of purposes including, but not limited to: heating of process additives (eg, air, steam) for gas reforming processes; Power generation in a complex circulation system. The recovered electricity can be used to drive the gas reforming process, thus reducing the cost of local power consumption. The amount of heat that is captured depends on various factors including, but not limited to, characteristics of the initial gas and reformed gas (eg, chemical composition, flow rate).
In one embodiment of the present invention, heat recovered from the stabilization zone of the gas reforming system is supplied to a gasification system that operates with the gas reforming system. The heat exchanger can be operated with a control system that is optionally configured to minimize energy consumption and maximize energy production / recovery for increased efficiency.
In one embodiment of the invention, a gas-liquid heat exchanger is used in the stabilization zone to transfer heat from the reformed gas to the liquid, producing a heated liquid and a cooled gas. The heat exchanger includes means (eg, a conduit system) for moving the reformed gas and liquid to and from the heat exchanger. Suitable liquids include, but are not limited to air, water, oil, or another gas such as nitrogen or carbon dioxide.
The conduit system can optionally use one or more regulators (e.g., blowers) located appropriately to manage the reformate gas and liquid flow rates. These conduit systems can be designed to minimize heat loss in order to increase the amount of sensible heat that can be recovered from the reformed gas. Heat loss can be minimized, for example, by using a thermal barrier including a thermal insulation material known in the art around the conduit and / or by reducing the surface area of the conduit. is there.
In one embodiment of the present invention, the gas-liquid heat exchanger is a gas-air heat exchanger and heat is transferred from the reformed gas to air to produce heated exchange air. In one embodiment of the present invention, the gas-liquid heat exchanger is a heat recovery steam generator, where heat is transferred to water to produce heated water or steam.
Various classes of heat exchangers can be used, including shell and tube heat exchangers (both straight single path designs and U-shaped multiple path designs), and plate heat exchangers. The selection of a suitable heat exchanger is within the knowledge of those skilled in the art.
Because particulate matter can be present in the gas, gas-air heat exchangers are typically designed for high particle loading. The particle size can typically vary from about 0.5 to about 100 microns. In one embodiment shown in FIG. 58, the heat exchanger is a single path vertical heat exchanger 5104B, with reformed gas 5020 flowing to the tube side and air 5010 flowing to the shell side. The reformed gas 5020 flows vertically through the “through-flow” design, minimizing areas where deposition and erosion can occur from particulate matter. The rate of the reformed gas should be maintained at a rate that minimizes erosion while being sufficient for self-cleaning and can vary from about 3000 to about 5000 mm / sec.
Due to the large temperature difference between the air inlet temperature and the hot product gas, each tube of the gas-air heat exchanger preferably has an individual expansion bellows to avoid tube rupture. Tube rupture can occur when a single tube is clogged and cannot be further expanded / stretched with the remaining tube bundle. In these embodiments where the air pressure is higher than the pressure of the reformed gas, tube rupture represents a greater risk due to problems caused by air entering the gas mixture.
After heat is recovered in the gas-liquid heat exchanger, the cooled reformed gas may still contain too much heat for further downstream systems. The selection of a suitable system for further cooling the product gas prior to conditioning is within the knowledge of those skilled in the art.
In one embodiment, as shown in FIG. 59, hot reformed gas 5020 passes through gas-air heat exchanger 5103 to produce partially cooled reformed gas 5023 and heated exchange air 5015. To do. The input of air to the heat exchanger can be supplied by a process air blower. The partially cooled reformed gas 5023 undergoes a dry fire extinguishing step 6103 and the addition of a controlled amount of spray water 6030 results in a further cooled product gas 5025.
Cooling of the reformed gas can also be achieved using wet, dry, or hybrid cooling systems. The wet and dry cooling systems can be direct or indirect. Appropriate cooling systems are known in the art, and those skilled in the art will be able to select an appropriate system in view of system requirements.
In one embodiment, the cooling system is a wet cooling system. The wet cooling system can be direct or indirect. A cooling system using indirect wet cooling provides a circulating cooling water system that absorbs heat from the reformed gas. Heat is released into the atmosphere by evaporation through one or more cooling towers. Alternatively, water vapor is condensed and returned to the system in a closed loop to promote water saving.
In one embodiment, the cooling system is a dry cooling system. The dry cooling system can be direct or indirect. In one embodiment, the dry cooling system is a ventilated dry cooling system. Dry cooling costs some equipment but may be preferable in areas where water supply is limited.
In one embodiment, the syngas cooler is a radiant gas cooler. Various radiant gas coolers are known in the art, including those described in US Patent Application No. 20070119577 and US Patent No. 5,233,943.
The reformed gas may be cooled by direct water evaporation in evaporated XXXX, such as a quenching agent.
The reformed gas outlet temperature recirculates the cooled reformed gas to the stabilization zone of the gas reforming system via an appropriately located inlet for mixing with the newly generated reformed gas. Depending on the situation, it can also be cooled.
Optional gas additive zone
The chamber optionally has one or more process additive ports for injecting process additives such as oxygen sources, carbon dioxide, other hydrocarbons, or additional gases into the chamber. May be. Sources of oxygen known in the art include, but are not limited to, oxygen, oxygen-enriched air, air, oxidizing media, steam, and other oxygen sources that can be readily understood by those skilled in the art. In one embodiment, the chamber has one or more ports for air and / or oxygen input, and optionally one or more ports for steam input.
Optional addition of process additives such as air, steam, and other gases can also be achieved without an inlet dedicated to their injection. In one embodiment of the present invention, it is possible to add process additives into the gas source or conduit from which the gas reforming system obtains its initial gas flow. Process additives can also be added to the chamber via a gas activation source such as a plasma torch.
Optionally, a port or inlet can be provided so that reformed gas that does not meet quality standards is recirculated into the chamber to be further processed. Such ports or inlets may be located at various angles and / or locations to facilitate turbulent mixing of materials within the chamber.
One or more ports may be included to allow measurement of process temperature, pressure, gas composition, and other relevant conditions.
Optionally, plugs, covers, valves and / or gates are provided to seal one or more of the ports or inlets of chamber 3002. Suitable plugs, covers, valves and / or gates are known in the art and can include manual or automatic. The port may further include a suitable seal such as a sealing gland.
Optional gas purification zone
The system optionally includes one or more gas purification zones located downstream of the gas stabilization zone. Embodiments of the present invention that include one or more gas stabilization zones incorporate means for injecting a substance into the chamber that purifies the gas prior to exiting the system. For example, oxygen and / or steam may be atomized by a high temperature resistant spray nozzle and injected into the chamber to purify the stabilized reformed gas.
Optional additional processing
The stabilized reformed gas stream can be further processed before being utilized, stored or burned in downstream applications. For example, the reformed gas can be passed through a gas conditioning system where particulate matter, acid gases (HCl, H, H₂S) and / or heavy metals can be removed and the temperature and / or humidity of the gas can be adjusted. For example, if dust is present, it can be removed from the gas using an innovative cleaning dust collector including an electrical filter or a cloth baghouse filter.
The reformed gas can also be passed through a homogenization chamber, and its residence time and shape are designed to facilitate mixing of the reformed gas and reduce variations in the characteristics of the gas.
Gas reforming chamber
3, and according to one embodiment of the present invention, the chamber 3002 of the gas reforming system 3000 includes one or more initial gas inlets 3004, one or more reformed gas outlets 3006, 1 One or more gas activation sources (eg, plasma sources) 3008, and optionally one or more process additive (eg, oxygen) inlets 3010, a gas manipulator (not shown), and a control system.
In the embodiment shown in FIG. 4, the gas reforming system 3000 is designed such that the chamber 3002 is directly connected to a gas source (eg, a gasifier, gas storage tank) and is in gas communication. To facilitate maintenance or repair, the gas reforming system 3000 may optionally be reversibly coupled to the gasifier so that the gas reforming system 3000 can be removed as needed. .
In one embodiment, illustrated by FIG. 5, gas reforming system 3000 is a self-supporting unit that receives initial gas from two gas sources via separate piping or conduits. In the embodiment shown in FIG. 6, the independent gas streams are integrated before being injected into the gas reforming system 3000. In a self-supporting unit, the gas reforming system can further include a suitable support structure.
An induction blower may be provided in gas communication downstream of the chamber to maintain the chamber pressure at a desired pressure, for example, a pressure of about 0-5 mbar.
The efficiency of the gas reforming process that occurs in the chamber depends on the internal volume and shape of the chamber, the gas flow rate, the distance that the gas travels through the chamber, and / or the path of the gas (ie, a straight path or swirl). Whether it is a cyclonic, spiral, or other non-linear path). Thus, the chamber must be shaped and sized to obtain the desired gas hydrodynamics therein. For example, an air jet can be used to facilitate the swirling flow of gas through the chamber so that the gas path is non-linear. An overall gas reforming system flow model to ensure that the specific chamber design facilitates the conditions required for the desired gas reforming (eg, proper interaction of process inputs). Can be used.
The one or more chambers of the gas reforming system can be designed in a variety of shapes and placed in a variety of locations, as will be readily appreciated by those skilled in the art. The chamber may be oriented substantially vertically, substantially horizontally or tilted.
In one embodiment of the invention, the chamber includes a first (upstream) end and a second (downstream) end and is oriented in a substantially vertical position or a substantially horizontal position. A straight tubular or venturi-type structure. In one embodiment of the present invention, the chamber is a linear cylinder having a length to diameter ratio in the range of about 2: 6, with a related effect on the achievable gas velocity. In one embodiment, the chamber length to diameter ratio is 3: 1.
In one embodiment shown in FIG. 60A, the chamber 3202 is configured to be directly coupled to the gasifier and is a straight, substantially vertical, refractory lined, lidded, cylindrical shape. The structure has an open bottom (upstream) end 3204 and one reformed gas outlet 3206 proximal or at the top (downstream) end of the chamber. The upper (downstream) end of the chamber may be covered with a refractory lined lid 3203 that may be removably sealed to the chamber to facilitate maintenance or repair.
The chamber walls may be lined with a refractory material or manufactured to withstand high temperatures. The chamber may be covered with a water jacket for cooling and / or generation of steam, or recovery of usable torch heat. The chamber can have multiple walls, along with a cooling mechanism for heat recovery, and the gas reforming system can be a heat exchanger for high pressure / high temperature steam generation, or other heat recovery function. Can be included.
Conventional refractory materials that are suitable for use in high temperature unpressurized chambers are known to those skilled in the art and include high temperature fired ceramics, ie, aluminum oxide, aluminum nitride, aluminum silicate, boron nitride, zirconium phosphate, glass ceramic, High alumina bricks, mainly including silica, alumina, chromia and titania, include but are not limited to ceramic blankets and refractory insulating bricks. Materials such as Didier Didoflo 89CR and Radex Compacflo V253 can be used when a tougher refractory material is required.
In one embodiment, the refractory design has multiple layers with dense layers inside to withstand high temperatures, erosion, and corrosion present in the chamber, to reduce variations in gas properties Provide heat sink. The outside of the high density material is a low density material that has a low coefficient of erosion but has a high thermal insulation coefficient. Optionally, the outside of this layer is an outer ultra-low density foam material with a very high thermal insulation coefficient that can be used because it is not exposed to the corrosive environment that may be present in the chamber. is there. The multilayer design provides an outer layer between the foam plate and the container shell, which is the material of the ceramic blanket, to provide a flexible layer to allow different expansion between the solid refractory and the container shell. Optionally include. Suitable materials for use in multilayer refractories are well known in the art.
In one embodiment, the multi-layer refractory may further include a compressible refractory segment that separates sections of the incompressible refractory to allow expansion of the refractory. The compressible layer can optionally be protected from erosion by overlapping expandable high density refractories. In one embodiment, the multilayer refractory may include an inwardly oriented chromia layer, a central alumina layer, and an outer INSULBoard layer.
In some embodiments of the invention, the chamber is spanned throughout the chamber to ensure that process heat is kept maximal while being unaffected by chemical reactions of reaction intermediates formed during processing. Includes layers of up to about 17 inches or more of a specially selected refractory lining.
The refractory lining at the bottom of the chamber may tend to wear and deteriorate because it must withstand higher temperatures from the operating plasma torch heat source. Thus, in one embodiment, the lower refractory is designed to include a “working surface” refractory that is more durable than the chamber walls and upper refractory. For example, the refractories for the walls and the top can be made of DIDIER RK30 brick, and the refractories for the different “working surfaces” for the bottom can be made with RADEX COMPAC-FLO V253.
In embodiments where the chamber is lined with refractory, the walls of the chamber optionally incorporate a support for the refractory lining or refractory anchor.
The chamber can have a collector for solid particulate material. In embodiments where the chamber is operated with a gasifier, any collected material may be supplied to the gasifier for further processing or supplied to a solid residue conditioning chamber for further processing. Also good. Collectors for solid particulate material known in the art include, but are not limited to, centrifuges, internal impingement baffles, and filters. In embodiments in which the gas reforming system is directly connected to the gasifier, additional solid particulate collectors may not be necessary because the particles that are formed can partly return directly to the gasifier.
Chamber ports, inlets, and outlets
The chamber includes one or more initial gas inlets for supplying initial gas into the chamber for reforming, and one or more reformed gas outlets for passing the reformed gas further downstream. including. The inlet can include an opening, or alternatively can include a device for controlling the flow of initial gas into the chamber and / or a device for injecting the initial gas into the chamber. it can. The device can include a gas manipulator to properly inject the initial gas to promote reforming and / or can include sensing elements to measure various characteristics of the initial gas. .
The initial gas inlet can be incorporated to facilitate co-current, reverse flow, radial, tangential, or other feed flow directions. In one embodiment, the single initial gas inlet is gradually conical.
The initial gas inlet may be located at or near the first or upstream end of the chamber. In one embodiment, the inlet includes an open first end of the chamber in direct gas communication with a gas source (eg, a gasifier). In one embodiment, the inlet includes an opening located at the closed first (upstream) end of the chamber. In one embodiment, the inlet includes one or more openings in the wall of the chamber proximal to the first (upstream) end.
In embodiments where the gasifier and the gas reforming system are directly connected, the mounting location on the gasifier side for connecting the gas reforming system is such that the gas flow is optimized before entering the chamber. And / or strategically so as to maximize mixing of the initial gas. In one embodiment, the chamber is located in the center of the gasifier.
In embodiments where the chamber is connected to one or more gasifiers, the one or more initial gas inlets of the chambers are in direct communication with the one or more gasifiers via a common opening. Or it can be connected to the gasifier via piping 3009 as shown in FIG. 5 or via a suitable conduit.
The reformed gas produced in the reforming reaction exits the chamber through one or more reformed gas outlets located at or near the second or downstream end. The outlet can include an opening or, alternatively, can include a device for controlling the flow of reformed gas exiting the chamber. The device can include a sensing element for measuring various characteristics of the reformed gas.
In one embodiment, the outlet includes an open second (downstream) end of the chamber. In one embodiment, the outlet includes one or more openings located at the closed second (downstream) end of the chamber. In one embodiment, the outlet includes one or more openings in the chamber wall near the second (downstream) end.
The chamber optionally includes one or more process additive ports, one or more ports for a gas activation source, optionally one or more access ports, an observation port and / or a meter. Various ports are included, including device ports. Gas activation sources include, but are not limited to, plasma-based sources (eg, plasma torches), hydrogen burners, and optional secondary sources. Ports, inlets, and outlets can be incorporated at various angles and / or locations to facilitate reaction stream interactions within the chamber.
Control system
A control system controls and / or controls one or more processes implemented and / or performed by various systems and / or subsystems disclosed herein. May be provided to provide control of one or more process devices contemplated herein to affect In general, the control system is associated with a given system, subsystem, or component thereof, and / or a gasification in which various embodiments of the invention may be operated in or in conjunction with. It is possible to operatively control various local and / or regional processes associated with one or more global processes that are performed within a larger system, such as a system. Adjust its various control parameters, adapted to influence the process and to have a defined result. Accordingly, various sensing and response elements can be distributed throughout the control system (s) or in conjunction with one or more components thereof, and various processes, reactants, and / or Or obtain product features and compare these features to a suitable range of such features to help achieve the desired result and proceed through one or more controllable process devices It can be used to respond by implementing changes in one or more of the processes within.
The control system typically includes, for example, one or more features associated with the system (s), the process (s) performed therein, the input (s) provided thereto, And / or one or more sensing elements for sensing the product (s) produced thereby. One or more computing platforms are communicatively coupled to these sensing elements to access feature values that are representative of the detected feature (s), and the feature value (s) are Comparing these features to a predetermined range of such values defined to be suitable for the selected action and / or downstream outcome, and maintaining the feature values in this predetermined range It is configured to calculate one or more process control parameters useful for: The plurality of response elements may be operatively coupled to one or more process devices that operate to affect the system, process, input and / or output, thereby detecting the detected feature. May be communicatively coupled to the computing platform (s) for adjusting and accessing the calculated process control parameter (s) and operating the process device (s) accordingly
In one embodiment, the control system provides predictive control of various systems, processes, inputs and / or outputs related to feedback, feedforward, and / or conversion of carbonaceous feedstock to gas, Increase the efficiency of one or more processes performed in conjunction. For example, various process characteristics can be evaluated and controllably adjusted to affect these processes, including heat and / or feed composition, product gas characteristics (e.g., heat Temperature, pressure, flow, composition, carbon content, etc.), the degree of variation allowed for such characteristics, and input cost versus output values. Heat source output, additive feed (eg, oxygen, oxidant, steam, etc.), feed feed (eg, one or more separate and / or mixed feeds), gas and / or system pressure / Continuous and / or real-time adjustments to various control parameters may include, but are not limited to, flow regulators (eg, blowers, relief and / or control valves, flares, etc.) Process-related features can be implemented in a manner that is evaluated and / or optimized according to design and / or downstream standards.
In systems using pure feedforward control, changes in the system environment in the form of measured disturbances are pre-defined responses to maintain the system in the desired state, as opposed to systems using feedback control. Bring. Therefore, feedforward control may not have the problem of stability of feedback control.
Feedforward control can be very effective if the following requirements are met. The disturbance must be measurable, the effect of the disturbance on the system output must be known, and the time it takes for the disturbance to affect the output is longer than the time that the feedforward control affects the output. There must be.
While feedforward control can respond more quickly to known and measurable disturbances, it is not very useful for new disturbances. Conversely, feedback control accommodates any deviation from the desired system behavior, but requires a measured system variable (output) to react to disturbances in order to notice the deviation.
Feedforward and feedback control are not mutually exclusive and feedforward control provides a quick response, while the feedback system allows them to handle any errors in a given adjustment made by the feedforward system. Can be combined.
In one embodiment of the invention, model predictive control techniques can be used.
In corrective or feedback control, the value of a control parameter or control variable monitored via an appropriate sensing element is compared to a specified value or range. A control signal is determined based on the deviation between the two values and provided to the control element to reduce the deviation. A conventional feedback or response control system may be further configured to include adaptive and / or predictable components, the response to a given condition providing a response that is responsive to the sensed feature It is understood that while being able to be adjusted according to the modeled and / or previously monitored response, it limits potential overshoots in the compensation action. For example, acquired and / or historical data provided for a given system configuration is within a given range from the optimal value whose previous response has been monitored and adjusted to provide the desired result. It can be used cooperatively to adjust the response to the system and / or process characteristics to be detected as much as possible. Such adaptive and / or predictable control schemes are well known in the art and as such are not considered to depart from the general scope and spirit of the present disclosure.
Alternatively and in addition, the control system may ensure that proper operation is performed and, optionally, if regulatory standards are applied, the process (s) performed thereby will thereby regulate the regulation. To ensure that it is within the criteria, it can be configured to monitor the operation of various components of a given system.
According to one embodiment, the control system can be further used in monitoring and controlling the overall energy impact of a given system. For example, a given system may increase the recovery (eg, waste heat) of energy generated by, for example, or by optimizing one or more of the processes performed thereby. Can be manipulated so that its energy impact is reduced or minimized again. Alternatively, and in addition, the control system may determine the composition and / or other characteristics (eg, temperature, pressure, flow, etc.) of the product gas produced through the controlled process Not only is it suitable for downstream use, but can be configured to adjust to be substantially optimized for efficient and / or optimal use. For example, in embodiments where the product gas is used to drive a given type of gas engine for the generation of electricity, these features are best suited for optimal input features for such engines. As such, the characteristics of the product gas can be adjusted.
In one embodiment, the limits or performance guidelines relating to the residence times of the reactants and / or products in the various components or to the various processes of the overall process are met and / or optimized. The control system can be configured to regulate a given process. For example, the speed of the upstream process can be controlled to substantially match one or more subsequent downstream processes.
Further, in various embodiments, the control system can be adapted for sequential and / or simultaneous control of various aspects of a given process in a continuous and / or real-time format.
In general, the control system can include any type of control system architecture that is suitable for the application at hand. For example, the control system can include a substantially centralized control system, a distributed control system, or a combination thereof. A centralized control system is usually controlled by separately detecting a centralized controller configured to communicate with various local and / or remote sensing devices and various features associated with the controlled process. A response element configured to respond to it via one or more controllable process devices configured to directly or indirectly affect the process. Most of the hardware and / or software required to implement process control is achieved because most calculations are performed centrally through a centralized processor (s) using a centralized architecture. Located in the same place.
Distributed control systems typically can communicate with separate sensing and response elements to monitor local and / or regional features, so as to affect local processes or sub-processes It includes two or more distributed controllers responsive to it via configured local and / or regional process devices. Communication can occur between the distributed controllers via various network configurations, and features detected via the first controller can communicate with the second controller for a response therein And such a distal response can affect the feature sensed at the first location. For example, the characteristics of the downstream product gas can be detected by a downstream monitoring device and can be adjusted by adjusting control parameters associated with the converter controlled by the upstream controller. In a distributed architecture, control hardware and / or software is also distributed among the controllers, and the same but modular control scheme can be implemented on each controller, or various collaborative modular control schemes can be implemented. It can be implemented in each controller.
Alternatively, the control system can be subdivided into separate but communicatively coupled local, regional, and / or global control subsystems. Such an architecture allows a given process or series of interrelated processes to occur and can be controlled locally with minimal interaction with other local subsystems. To do. In doing so, each global master control system communicates with a separate local control subsystem to support the adjustments necessary for local processes for global results.
The control system of the present invention can use any of the above architectures or any other architecture generally known in the art that is considered to be within the general scope and spirit of the present disclosure. It may be used. For example, the processes controlled and implemented in the context of the present invention are optional external to any centralized and / or remote control system used for the associated upstream or downstream process, if applicable. It can be controlled in a dedicated local environment with communication. Alternatively, the control system can include regional and / or global control system sub-components designed to coordinately control regional and / or global processes. For example, a modular control system provides interactive communication between modules as needed for regional and / or global control while the control module interactively controls various subcomponents of the system. Can be designed to
The control system is typically a centralized networked and / or distributed one or more processors, one or more inputs for receiving the latest features detected from various sensing elements. , And one or more outputs for communicating new or updated control parameters to various response elements. One or more computing platforms of the control system may include various predetermined and / or readjusted control parameters, characteristic operating ranges of set or preferred systems and processes, system monitoring and control software, operating data One or more local and / or remote computer readable media (eg, ROM, RAM, removable media, local and / or network access media, etc.) Can also be included. Optionally, the computing platform can also have access to process simulation data and / or system parameter optimization and modeling means, either directly or via various data storage devices. The computing platform also includes one or more optional graphical user interfaces and inputs to provide management access to the control system (system upgrades, maintenance, modifications, adaptation to new system modules and / or equipment, etc.) Various optional output peripherals for communicating data and information with peripherals and external sources (eg, modems, network connections, printers, etc.) may also be provided.
Any one of the processing system and the sub-processing system can exclusively include hardware or any combination of hardware and software. Any of the sub-processing systems may be one or more proportional (P), integral (I), or differential (D) controllers, such as, for example, a P-controller, I-controller, Pi-controller, PD controller, PID controller, etc. Any combination of the above may be included. For those skilled in the art, the ideal combination of P, I, and D controllers is the dynamics and delay times of some of the reaction processes of the gasification system, the range of operating conditions and combinations that the combination is intended to control It will be understood that it depends on the dynamics of the controller and the delay time. Those skilled in the art will recognize that these combinations continuously monitor the value of the feature via the sensing element and control each to make sufficient adjustments to reduce the difference between the observed value and the specified value. It will be apparent that it can be implemented in the form of an analog wiring connection that can be compared to a specified value via the response element so as to influence the element. It will be further apparent to those skilled in the art that the above combinations can be implemented in a mixed digital hardware software environment. The additional optional sampling, data acquisition, and related effects of digital processing are well known to those skilled in the art. Combination control of P, I, and D can be implemented in feedforward and feedback control schemes.
Control element
As defined and explained above, sensing elements contemplated within this context include gas chemical composition, product gas flow rate and temperature monitoring elements, temperature monitoring elements, pressure monitoring elements, gas Can include, but is not limited to, elements that monitor various parameters associated with opacity and gas activation sources (eg, power and position).
H obtained in reformed gas₂: CO ratio depends on operating conditions (pyrolysis or sufficient O₂/ With air), processing temperature, moisture content, and initial gas H₂: Depends on various factors not limited to C0 ratio. Gasification techniques typically vary from a maximum of about 6: 1 to a minimum of about 1: 1 H.₂: Generates CO ratio gas and is ideal for downstream applications₂: Determines the CO ratio. In one embodiment, the resulting H₂The ratio of: CO varies from about 1.1 to about 1.2. In one embodiment, the resulting H₂The ratio of: CO is 1.1: 1.
Taking into account one or more of the above factors, the control system of the present invention can apply an applied gas activation region (eg, plasma torch heat) and a process additive (eg, air, oxygen, carbon, steam). By adjusting the balance of the reformed gas, the reformed gas composition can be optimized for a particular downstream application, allowing the reformed gas composition to be H₂: Adjust within the range of CO ratio.
Several operating parameters are monitored periodically or continuously to determine whether the gas reforming system is operating at an optimal set point range. The monitored parameters vary according to chemical composition, reformate gas flow rate and temperature, temperature at various points in the system, system pressure, and gas activation source (eg, plasma torch power and position). The parameters can include, but are not limited to, the data is used to determine whether the system parameters require adjustment.
Reformed gas composition and opacity
The product gas can be extracted and analyzed as a sample using methods well known to those skilled in the art. One method that can be used to determine the chemical composition of the product gas is gas chromatography (GC) analysis. Extraction points for these analyzes can be located throughout the system. In one embodiment, the composition of the gas is measured using a Fourier Transform Infrared (FTIR) analyzer that measures the infrared spectrum of the gas.
Part of the present invention is to determine whether there is too much or too little oxygen present in the reformed gas stream and adjust the process accordingly. In one embodiment, an analyzer or sensor in the carbon monoxide stream detects the presence and concentration of carbon dioxide or other suitable reference oxygen-enriched material. In one embodiment, oxygen is measured directly.
In one embodiment of the present invention, a thermogravimetric analyzer (TGA) can be used.
In one embodiment, the sensor analyzes the reformed gas composition for carbon monoxide, hydrogen, hydrocarbons, and carbon dioxide. Based on the analyzed data, the controller sends a signal to the oxygen and / or steam inlet and / or gas activation source (s) to control the amount of oxygen and / or steam injected into the chamber. Signal).
In one embodiment, one or more optional opacity monitors are mounted within the system to provide real-time feedback of opacity, thereby reducing the particulate matter below the maximum allowable concentration. In order to maintain the level, an optional mechanism for automation of process additive (primarily steam) input is provided.
Temperature at various locations in the system
In one embodiment, means are provided for monitoring the temperature of the reformed gas and temperatures throughout the system, and such data is continuously acquired. The means for monitoring the temperature in the chamber can be located, for example, on the outer wall of the chamber, or inside the upper refractory, in the middle and lower part of the chamber. A sensor for monitoring the outlet temperature of the reformed gas is also provided.
In one embodiment, the means for monitoring the temperature uses thermocouples installed in several places in the system as required.
System pressure
In one embodiment, means are provided for monitoring the pressure in the chamber, and such data is continuously acquired on a real-time basis. In further embodiments, these pressure monitoring means include pressure sensors, such as pressure transducers or pressure taps, which may be located anywhere on the reaction vessel (eg, the vertical wall of the reaction vessel).
Gas flow rate
In certain embodiments, means are provided for monitoring reformate flow rates throughout the system, such data being acquired continuously.
Variations in gas flow may be the result of non-uniform conditions (eg, torch failure, malfunction due to electrode changes, or other support equipment failure). As a first aid, gas flow fluctuations can be corrected by feedback control of blower speed, material feed flow, secondary feed, air, steam, and torch output. If gas flow fluctuations persist, the system may be shut down until the problem is resolved.
Addition of process additives
In certain embodiments, the control system includes a response element for adjusting the reactants, including any process additives, to manage chemical reforming of the initial gas to the reformed gas. For example, process additives can be supplied to the chamber to facilitate efficient reforming of an initial gas of a particular chemical composition into a reformed gas of a different desired chemical composition.
In one embodiment, steam and / or oxygen injection is reduced when the sensor detects excess carbon dioxide in the reformed gas.
As defined and explained above, response elements contemplated in this context are process-related that are configured to affect a given process by adjusting a given control parameter associated with the given process. The device can include, but is not limited to, various control elements operably coupled. For example, an operable process device via one or more response elements in the present context may include elements that regulate the oxygen source (s) input and the gas activation source (s). However, it is not limited to these.
Adjustment of gas activation area (eg power supply to torch)
The gas activation area can be changed. In one embodiment, the heat of the plasma torch is controlled to promote the reaction. The addition of air into the chamber also bears a portion of the torch's thermal load by burning the reformed gas and releasing the torch's thermal energy. The process air flow rate is adjusted to keep the torch power in a suitable operating range.
In one embodiment, the output of the plasma torch is adjusted to stabilize the reformed gas outlet temperature at a design set point. In one embodiment, the design set point is above 1000 ° C. to promote complete decomposition of tar and soot in the gas.
Pressure adjustment in the system
In one embodiment, the control system includes a response element for controlling the internal pressure of the chamber. In one embodiment, the internal pressure is maintained at a negative pressure, i.e., slightly below atmospheric pressure. For example, the chamber pressure can be maintained under a vacuum of about 1-3 mbar. In one embodiment, the system pressure is maintained at a positive pressure.
An exemplary embodiment of such means for controlling internal pressure is provided by an induction blower in gas communication with a gas reforming system. In this way, the induction fan used maintains the system at positive pressure. In systems where positive pressure is maintained, a command may be given to operate at a lower RPM than in the case of negative pressure, or a compressor may be used.
Depending on data acquired by pressure sensors located throughout the system, depending on whether the pressure in the system is increasing (fan is accelerating) or decreasing (fan is decelerating) The speed of the induction fan is adjusted.
Furthermore, the process of the present invention allows the system to be maintained at a slightly negative pressure rather than atmospheric pressure to prevent gas being released into the environment.
The pressure can be stabilized by adjusting the speed of the reformed gas blower. Optionally, at a speed below the blower's minimum operating frequency, secondary control takes precedence and adjusts the recirculation valve instead. Once the recirculation valve is fully closed, primary control is again involved.
Example 1
This example shows an example of a gas manipulator designed to be incorporated into an existing gas reforming chamber design. FIG. 60A shows a gas reforming system (GRS) 3200 designed to be directly coupled to a gasifier that is horizontally oriented and lined with refractory.
The gas passes through the gas outlet of the gasifier and is hermetically coupled to the gasifier via a mounting flange 3214 that connects the gas outlet of the gasifier directly to the GRS single cylinder input gas inlet. Into the GRS3200. Air is injected into the input gas stream through the swivel port 3212, creating a swirling motion or turbulence in the input gas stream, thereby mixing the input gas and forming a vortex that recirculates in the GRS. The residence time of the gas in the GRS is about 1.2 seconds.
Referring to FIG. 60A, the GRS has a length-to-diameter ratio of about 3: 1 and has a substantially cylindrical input gas inlet with a gasifier connected through a mounting flange 3214. And has a cylindrical chamber lined with refractory and attached to the. The chamber is covered with a refractory lined lid 3203, thereby forming a sealed gas reforming chamber 3202.
The gas reforming chamber includes one or more ports for heater 3216, one or more ports for one or more oxygen sources 3210, and optionally one or more access or observation ports. It has various ports, including 3326 and / or instrumentation port 3226. The gas reforming chamber also includes a lifting point 3230.
The refractory used on the walls of the chamber is an inner high density layer that is resistant to the high temperatures, erosion, and corrosion present in the chamber, an intermediate low density material layer that is less resistant but has a higher thermal insulation coefficient, And a multilayer design with an outer ultra-low density foam plate layer with a very high thermal insulation coefficient. The outer layer between the foam plate and the container steel shell is a ceramic blanket material that provides a flexible layer to allow different expansion between the solid refractory and the container shell. The up and down expansion of the refractory is provided by a layer of compressible refractory that separates portions of the incompressible refractory. The compressible layer is protected from erosion by a high density refractory that is overlapping but expandable.
Referring to FIG. 60B, the gas reforming chamber further includes a refractory support system that includes a series of circumferential expansion shelves 3220. Each shelf is divided and includes a gap to allow for expansion. Each shelf segment 3222 is supported by a series of support brackets 3224.
In this GRS embodiment, the one or more inputs for the one or more oxygen sources include air and steam inputs.
The GRS further comprises a three-stage air nozzle arranged tangentially, two plasma torches located tangentially, six thermocouple ports, two burner ports, two pressure transmitter ports, and several spare ports.
The air is in the upper level, with the three jets slightly higher than the other three so as to form a cross jet mixing effect to achieve better mixing with the lower level four jets 3212. It is injected into the gas stream by a three stage air nozzle containing another six jets 3211.
The GRS further includes a 300 kW, water-cooled, copper electrode, two NTAT DC plasma torches mounted tangentially on the sliding mechanism. Two plasma torches are located above the air nozzle to provide maximum exposure to the heat of the plasma torch.
The plasma power source converts the three-phase AC power of each plasma torch into DC power. As an intermediate step, the unit first converts the three-phase AC input to a single high frequency phase. This allows better linearization of the final DC power in the chopper section. The unit allows the output DC voltage to be varied in order to maintain a stable DC current.
Referring to FIG. 37, each plasma torch 3208 is mounted on a sliding mechanism that can move the torch 3208 in and out of the gas reforming chamber. The torch 3208 is sealed in the gas reforming chamber 3202 by a sealing gland. This gland is sealed with respect to the gate valve and thus is mounted on and sealed to the container. In order to remove the torch 3208, the torch 3208 is pulled out of the reforming chamber 3202 by a sliding mechanism. The first movement of the slide turns off the high voltage torch power for safety purposes. When the torch 3208 is withdrawn and past the valve, the gate valve automatically closes and the coolant circulation is stopped. The hose and cable are disconnected from the torch 3208, the gland is released from the gate valve, and the torch 3208 is lifted by the hoist.
The replacement of the torch 3208 may be performed using the reverse of the above procedure, and the sliding mechanism may be adjusted to change the insertion depth of the torch 3208. The gate valve is mechanically operated so that the operation is automatic. A pneumatic actuator 3233 is used to automatically retrieve the torch if the cooling system fails. Compressed air for operating the actuator is supplied from a dedicated air reservoir so that power is always available even in the event of a power failure. The same reservoir provides air for the gate valve 3234. By preventing the high voltage torch from approaching the connection, an electrically interlocked cover is used as an additional safety feature.
Thermocouples are placed at various positions in the gas reforming chamber so that the temperature of the reformed gas in the GRS is maintained at about 1000 ° C., and below this temperature, power or air to the plasma torch Injection is increased.
In this example, the airflow entering the GRS may be dynamically changed to adjust the temperature and process generated at each stage of the gasifier and / or GRS.
Molecules in the gaseous mixture in the gas reforming chamber dissociate into their constituent elements in the plasma arc zone and are subsequently improved to the reformed gas. Hot reformed gas flows out of the GRS through the reformed gas outlet 3206.
Gas manipulators are also designed to enhance gas reforming processes by enhancing exposure to reactive species formed by plasma torches and mixing of reaction intermediates produced by such exposure, as well as large hydrocarbons. Designed to achieve the highest molecular degradation rate.
69 and 70, the gas manipulator is located substantially above the center of the gas reforming chamber, the air nozzle and the two plasma torches. Thus, the initial gas received from the gasifier is mixed with the air introduced through the air nozzle at a high injection rate.
The shape of the gas manipulator is shown in FIGS. The pre-blended gas obtained by mixing the initial gas from the gasifier and the injected air, and the ionized gas of the plasma torch are forced to pass through the two channels by the design of the gas manipulator. . Since the plasma torch is located substantially at the inlet of the channel, the pre-blended gas is exposed to the maximum in the gas activation region formed by the plasma torch.
The temperature of the gas in the channel of the gas manipulator is about 1100 ° C. The gas passing through these channels changes the direction of the flow when hitting the deflector shown in FIG. 66, resulting in continuous mixing. The deflector also helps maintain the heat in the channel of the gas manipulator, thus allowing for enhanced gas reforming reaction rates.
Referring to FIG. 67, the beveled surface of the gas manipulator inlet facilitates the separation of particulate matter from the gas stream.
As shown in FIG. 68, the gas manipulator has a steel structure lined with a refractory. The steel structure is cooled by air. Cooling air is introduced through three support pipes. Cooling air passes through an empty chamber inside to cool the steel structure. The heated cooling air returns to the basic process via a nozzle at the bottom of the gas manipulator chamber.
The cooling air flow rate is controlled to keep the steel surface as hot as possible (close to the chimney) but still maintain the strength of the steel below a fairly good temperature of 550 ° C.
Having described the invention in this way, it will be apparent that the invention may be varied in many ways. Such modifications are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications that would be apparent to a person skilled in the art are included within the scope of the following claims. Is intended.
Embodiments of the invention that claim exclusive ownership or privilege are defined below.

Claims (15)

A system for reforming an initial gas into a reformed gas having designed characteristics,
a) means for detecting at least one characteristic of the initial gas;
b) means for modifying a process input for reforming based on the at least one characteristic of the initial gas and the designed characteristic of the reformed gas;
c) means for applying one or more energy sources sufficient to reform substantially the majority of gas molecules of the initial gas to the reformed gas;
d) means for promoting the reforming;
e) means for stabilizing the reformed gas;
f) a control system;
Including the system. The system of claim 1, wherein the means for modifying a process input comprises means for adding an appropriate amount of a process additive. A process for reforming an initial gas into a reformed gas having desired characteristics, comprising the following steps:
a) detecting at least one characteristic of the initial gas;
b) modifying a process input for reforming based on the detected characteristics of the initial gas and the desired characteristics of the output gas;
c) applying a gas activation region that is sufficient to modify the majority of the gas molecules to their constituent atoms;
d) facilitating efficient process acceleration to reform the constituent atoms into a reformed gas having designed characteristics;
e) promoting de-excitation and stabilization of newly formed molecules to maintain the designed features;
f) A process comprising one or more of the steps of managing the efficient conversion of the initial gas to the output gas. 4. The process of claim 3, wherein modifying the process input for reforming comprises adding an appropriate amount of process additive. A system for gas reforming, comprising:
a) one or more energy sources for initiation of the gas reforming process;
b) one or more gas manipulators for optimization of energy transfer throughout the gas reforming process;
Including
The system wherein the one or more energy sources and the one or more gas manipulators are integrated to optimize the gas reforming rate. A gas reforming system,
a) one or more gas reforming zones;
b) one or more gas stabilization zones;
c) a control system that coordinates the overall process;
d) optionally one or more gas additive zones, and / or e) optionally one or more gas purification zones;
Including
A gas reforming system in which the zones of the system are arranged and controlled such that a majority of the initial gas is reformed to a designed composition gas. A method for reforming an initial gas comprising the following steps:
(A) delivering the initial gas to a gas reforming chamber;
(B) mixing the input gas with at least one process additive to produce a pre-blended gas;
(C) dissociating molecules in the gas into their constituent atoms by exposing the pre-blended gas to a gas activation region;
(D) generating the reformed gas by modifying the constituent atoms to molecular species of a designed chemical composition;
(E) removing the reformed gas from the chamber;
Including steps. The method of claim 7, wherein the gas activation region is formed by one or more plasma torches. The method of claim 7, further comprising exposing the reformed gas to a gas stabilization zone prior to removing the reformed gas from the chamber. The method of claim 7, wherein the modification is enhanced by a gas manipulator. A system for reforming an initial gas to a reformed gas,
A chamber lined with one or more refractories,
One or more inlets for receiving said initial gas;
One or more outlets for releasing the reformed gas;
One or more process additive inlets in fluid communication with the chamber;
One or more gas manipulators disposed within the one or more chambers;
Means for forming a gas activation region in the one or more chambers;
Including the system. The system of claim 11, wherein the means for forming the gas activation region is one or more plasma torches. 13. A system according to claim 11 or 12, wherein the one or more gas manipulators increase turbulence in the chamber. 13. A system according to claim 11 or 12, wherein the one or more gas manipulators alter fluid dynamics in the chamber. 13. A system according to claim 11 or 12, wherein the one or more gas manipulators improve the exposure of the pre-blended gas to the gas activation area.