JP2009536259A - Heat recycling system for use with gasifier - Google Patents

Abstract

The present invention provides a system for reusing heat recovered from the hot product of a carbonaceous feedstock gasification process back to the gasification process. The hot gaseous product is used to heat working fluids such as air and water to produce hot air, hot water or steam. The heated fluid is used to return heat to the gasification process. The system also includes a control system that optimizes the efficiency of the gasification process by maximizing energy production while minimizing the energy consumption of the process.

Description

The present invention relates to a gasification of carbonaceous feedstock, and more particularly to a system that recovers heat generated by the gasification process and reuses heat for use in the system and optionally for external devices.

Gasification is a process that allows the conversion of carbonaceous feedstock, such as municipal solid waste (MSW) or coal, into combustible gases. The gas can be used to generate electricity, steam, or as a basic raw material for producing chemicals and liquid fuels. Possible uses of the gas include the production of steam for internal processing and / or other external purposes, or combustion in a boiler for the generation of electricity by a steam turbine; for the generation of electricity Direct combustion in gas turbines or gas engines; fuel cells; production of methanol and other liquid fuels; as further raw materials for the production of chemicals such as plastics and fertilizers; hydrogen as a separate industrial fuel gas And extraction of both carbon monoxide; and other industrial applications.

In general, the gasification process consists of delivering a carbonaceous feedstock into a heating chamber (gasifier) with a controlled and / or limited amount of oxygen and optionally steam. In contrast to incineration or combustion, which operates with excess oxygen to produce CO ₂ , H ₂ O, SO _x , and NO _x , the gasification process produces CO, H ₂ , H ₂ S, and NH ₃ . A raw gas composition containing is produced. After cleaning, interesting primary gasification products are H ₂ and CO.

Useful raw materials include all municipal waste, industrial waste, and biomedical waste, sewage, sludge, coal, heavy oil, petroleum coke, heavy oil refinery residue, refinery waste, hydrocarbon pollution It may include soil, biomass, and agricultural waste, tires, and other hazardous waste. Depending on the origin of the raw materials, the volatiles can be H ₂ O, H ₂ , N ₂ , O ₂ , CO ₂ , CO, CH ₄ , H ₂ S, NH ₃ , C ₂ H ₆ , acetylenes, olefins , Aromatics, tars, hydrocarbon liquids (oils), and carbides (carbon black and ash). When the raw material is heated, the first component generated is water. Thermal decomposition occurs when the temperature of the dry raw material increases. During pyrolysis, the feedstock is decomposed with heat to release tars, phenols, and photovolatile hydrocarbon gases, while the feedstock is converted to carbides.

Carbides include residual solids composed of organic and inorganic materials. After pyrolysis, the carbide has a higher concentration of carbon than the dry feed and can serve as a source of activated carbon. In a gasifier operating at high temperatures (> 1,200 ° C.) or in a system having a high temperature zone, inorganic minerals are dissolved or vitrified to form a molten glassy material called slag.

Because the slag is in a molten and vitrified state, it is usually considered harmless and can be disposed of in a landfill as a harmless material or sold as ore, roadbed, or other construction material. Dispose of waste material by incineration because it is extremely wasteful of fuel in the heating process, and it is even more wasteful to dispose of useful syngas and materials that can be converted into solid materials as residual waste Is becoming less desirable.

The means for realizing the gasification process vary widely, but there are four options: the atmosphere in the gasifier (oxygen concentration or air or steam content), the design of the gasifier, the internal and external heating means, and the operating temperature of the process. Depends on major engineering factors. Factors affecting the quality of the product gas include: feed composition, preparation, and particle size; gasifier heating rate; residence time; using dry or slurry delivery system, feed reactant flow shape, dry ash or Plant configurations that include the design of slag mineral removal systems; whether direct or indirect heat generation and transfer methods are used; and syngas cleaning systems. Gasification is typically carried out at a temperature in the range of about 650 ° C. to 1200 ° C., either under vacuum, atmospheric pressure, or pressures up to about 100 atmospheres.

A number of systems have been proposed for capturing heat generated by a gasification process and using such heat to generate electricity, commonly known as combined cycle systems.

The energy in the product gas, coupled with the substantial amount of recoverable sensible heat produced by the process throughout the gasification system, generally produces enough electricity to drive the process, thereby local power consumption Can reduce the cost. The amount of electric power required to gasify a large amount of carbonaceous raw material depends directly on the chemical composition of the raw material.

If the gas produced in the gasification process contains a wide variety of volatiles, such as the types of gases that tend to be produced in low temperature gasifiers by “low quality” carbonaceous feedstock, the gas is generally off-gas. It is called. When a gas in which CO and H ₂ are dominant chemical species is generated depending on the characteristics of the raw material and the conditions in the gasifier, the gas is referred to as synthesis gas. Some gasification facilities use techniques to convert raw off-gas or raw syngas into a more purified gas composition before cooling and cleaning the gas quality conditioning system.

Utilizing plasma heating techniques to gasify materials is a technique that has been used commercially for many years. Plasma is a high temperature luminescent gas that is at least partially ionized and is composed of gas atoms, gas ions, and electrons. The plasma can thus be produced by any gas. Because the gas can be neutral (eg, argon, helium, neon), reductive (eg, hydrogen, methane, ammonia, carbon monoxide), or oxidative (eg, oxygen, carbon dioxide) This gives excellent control of the chemical reaction in the plasma. In the bulk phase, the plasma is electrically neutral.

In some gasification systems, plasma heat is used to drive the gasification process at high temperatures and / or with the addition of other inputs or reactants when gaseous molecules come into contact with the plasma heat. Regardless, the offgas / syngas is purified by converting, reconstituting, or reforming long chain volatiles and tars into smaller molecules that will dissociate into their constituent atoms. Many of these atoms will react with other charged molecules to form new molecules, while others may recombine with similar atoms. When the temperature of the molecule in contact with the plasma heat decreases, all atoms recombine completely. Since the input gas can be stoichiometrically controlled, the output gas can be controlled, for example, to produce a substantial level of carbon monoxide and a slight level of carbon dioxide.

The ultra-high temperatures (3,000-7,000 ° C.) achievable by plasma heating are the same for virtually any input material, including as-received waste, including liquids, gases, and solids in any form or combination. Enables a hot gasification process that can be adapted. The plasma technology may be positioned in the primary gasification chamber to cause all reactions to occur simultaneously (high temperature gasification), or may be positioned in the system to generate them sequentially (high temperature). Low temperature gasification with refining), or some combination thereof.

The gas produced during the gasification of the carbonaceous feedstock is usually extremely hot, but may contain small amounts of unwanted compounds and requires further treatment to convert it to a usable product . When the carbonaceous material is converted to a gaseous state, undesirable substances such as metals, sulfur compounds, and ash can be removed from the gas. For example, dry filtration systems and wet scrubbers are often used to remove particulate matter and acid gases from gas produced during gasification. A number of gasification systems have been developed, including systems for treating the gas produced during the gasification process.

These factors include, for example, US Pat. Nos. 6,686,556, 6,630,113, 6,380,507, 6,215,678, 5,666,891, Considered in the design of the various different systems described in US Pat. Nos. 5,798,497, 5,756,957, and US Patent Application Nos. 2004/0251241, 2002/0144981. U.S. Pat. Nos. 4,141,694, 4,181,504, 4,208,191, 4,410,336, 4,472,172, 4,606,799. Gasify coal for the production of synthesis gas for use in various applications, including No. 5,331,906, 5,486,269, and 6,200,430 There are numerous patents on different technologies for.

Prior art systems and processes have not fully addressed the challenges that must be dealt with continuously in response to changes. Some of these types of gasification systems describe means for coordinating the process of producing useful gases from gasification reactions. Accordingly, providing a system that can sufficiently gasify the carbonaceous feedstock in a manner that maximizes the overall efficiency of the process, and / or steps that involve the entire process, represents a significant advance in the art. I will.

This background is intended to provide known information believed by the applicant to have the potential to be relevant to the present invention. It is not necessarily intended to be approved and none of the foregoing information should be construed as constituting any prior art to the present invention.

The present invention is a system for optimizing the efficiency of gasifying a carbonaceous feedstock by recovering sensible heat from a gasification process and reusing it for use in the system and optionally for external equipment. I will provide a.

The present invention provides a system that reuses the heat recovered from the hot gas and returns the recovered heat to the gasifier. Specifically, the system includes means for transferring the hot gas to a gas-to-fluid heat exchanger, wherein heat from the hot gas is transferred to the fluid to produce a heated fluid and a cooled gas; Means for moving the heated fluid to the gasifier. The heated fluid is passed to the gasifier to provide the heat necessary to cause the gasification reaction. The heated fluid can optionally be used to preheat or pretreat the raw material to be gasified, either directly or indirectly.

In accordance with one embodiment of the present invention, the system also includes a sensing element for monitoring system operating parameters and a response element for adjusting operating conditions within the system to optimize the gasifier. The efficiency of the gasification process by minimizing process energy consumption while maximizing energy production by adjusting the operating conditions in the system according to the data obtained from the sensing element To optimize.

In accordance with an aspect of the present invention, a carbonaceous feed gas is obtained by using a gas to fluid heat exchanger to recycle sensible heat from the hot gas produced by the gasification process back to the gasification process. A process for improving the efficiency of a gasification process, passing a hot product gas through a gas-to-fluid heat exchanger, and passing a cooling fluid through a gas-to-fluid heat exchanger; A gas to produce a cooled production gas exhausted from the heat exchanger via the cooled production gas outlet and a heated fluid exhausted from the heat exchanger via the heated fluid outlet A process for transferring heat from a hot product gas to a cooling fluid via a heat to fluid heat exchanger, and using a heated fluid to provide heat for the carbonaceous feed gasification process; , Process provided is provided.

These and other features of the invention will become more apparent in the following detailed description with reference to the accompanying drawings.

1 is a schematic diagram of a system for reusing heat recovered from a hot gas product of a gasification process back to a gasifier in accordance with one embodiment of the present invention. FIG. FIG. 3 is a block flow diagram of heat recovery from a syngas product of a gasification process using a heat exchanger and a heat recovery steam generator, according to one embodiment of the invention. 1 is a schematic diagram of a system for cooling a hot gas product, in accordance with an embodiment of the present invention, a heat exchanger for recovering heat from the gas product of the gasification process, and a quench for further cooling the product gas Includes steps. FIG. 4 is a schematic diagram illustrating functional requirements of a gas to air heat exchanger according to one embodiment of the present invention. 1 is a schematic diagram depicting a gas to air heat exchanger according to an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a gas to air heat exchanger according to one embodiment of the present invention. FIG. FIG. 6 is a schematic diagram of a converter and its various inputs, according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating possible end uses of exchange / steam produced by heat recovery from the product gas of a heat recovery steam generator, in accordance with various embodiments of the present invention. 1 is a schematic diagram illustrating a piping system for transferring replacement air to a converter according to an embodiment of the present invention. FIG. 3 is a schematic diagram depicting various temperature controls of a high level concept in a system, according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a high level view of a gas flow / pressure control subsystem, in accordance with one embodiment of the present invention. FIG. 3 is a block flow diagram depicting an overview of various embodiments of the present invention. FIG. 3 is a cross-sectional view of one embodiment of a gasifier according to one embodiment of the present invention, showing details of the location of the raw material input, gas outlet, solid residue outlet, and exchange air inlet. 1 is a cross-sectional view in the center longitudinal direction of one embodiment of a gasifier showing in detail the location of the raw material inlet, gas outlet and air box. It is a figure showing in detail the air box assembly of the gasifier shown by FIG.

Details of the invention

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” refers to a +/− 10% variation from the nominal value. It should be understood that such variations are always included in any given value provided in this application, whether or not specifically mentioned.

For the purposes of the present invention, the term synthesis gas refers to the product of the gasification process and can include carbon monoxide, hydrogen, and carbon dioxide in addition to methane, nitrogen and water vapor.

As used herein, the term “exchanged air” is used in accordance with the present invention after being heated using sensible heat from product gas using a gas-to-air heat exchanger. Refers to air. It is within the scope of the present invention to use the system described herein to heat a gas other than air, including but not limited to oxygen or enriched air.

As used herein, the term “converter” refers to an apparatus for converting a carbonaceous feedstock into a raw syngas product, also referred to as product gas. The converter includes a gasifier and a plasma gas reformer.

As used herein, the term “(carbonaceous) feedstock” can be any carbonaceous material suitable for gasification in the gasification process, such as any waste material, coal May include, but is not limited to, petroleum coke, heavy oil, biomass, sewage sludge, sludge from pulp and paper mills and agricultural waste (not suitable for coal power generation, including lower high sulfur coal) . The most suitable waste materials for gasification are hazardous waste such as municipal waste, waste produced by industrial activities (painted sludge, poorly painted products, used adsorbents), used tires punctured by automobiles, and biomedical waste Unsuitable for recycling both non-hazardous and harmless plastics, non-reusable plastics, sewage sludge, coal, heavy oil, petroleum coke, heavy oil refining residue, refined waste, unit price hydrogen-contaminated solid waste and biomass Includes carbonaceous materials, agricultural waste, tires, hazardous waste, industrial waste and biomass. Examples of biomass useful for gasification include, but are not limited to, waste or unused wood, fruits, vegetables and grain processing debris, paper mill residues, straw, grass and organic fertilizers.

As used herein, the term “product gas” generally refers to the gas produced by a gasification facility prior to cooling and cleaning by a process designated to remove contaminants. Depending on the design of the gasification facility, it may be used, for example, to refer to raw offgas, raw syngas, reformed offgas, or reformed syngas.

As used herein, the terms “gas to air heat exchanger” and “gas heat exchanger” can be used interchangeably to transfer sensible heat from a hot gas product to air. Refers to the heat exchanger used in

A “sensing element” is defined to describe any element of a system that is configured to sense a process, process input, or process output characteristic, wherein the characteristic is one or more local, area, or It can be expressed by characteristic values useful in overall process monitoring, adjustment and / or control. The sensing element is a process, fluid and / or material temperature, pressure, in addition to the composition and / or nature of the material at any specified time in the system and any operational characteristics of any process equipment used in the system. Including, but not limited to, sensors, detectors, monitoring devices, analytical devices, or any combination thereof, for sensing flow, composition and / or other properties.

A “response element” is a system configured to respond to sensed characteristics to operate an operatively associated process device in response to one or more predefined or computed control parameters And one or more control parameters are defined to provide the desired process results. Responsive elements include drivers, static and dynamically variable power sources, inducers, and any other elements that can be configured to cause the device to perform physical actions based on one or more control parameters. Can be, but is not limited to. The response element can be operatively coupled to a variety of process devices. Process equipment includes material input mechanism, plasma heat source, additive input means, gas blower, additive input blower, gas flow adjustment device, additive input flow adjustment device, solid residue conditioner additive input conditioner and plasma heat source adjustment device And process equipment operable to affect any local, regional and / or overall process may include, but is not limited to.

The present invention provides a system for optimizing the efficiency of a process for gasifying a carbonaceous feedstock into a gaseous product by minimizing process energy consumption while maximizing energy production. Specifically, the present invention provides a gas in which sensible heat from a gasification process is efficiently recovered, and the recovered heat is transferred to one or more processes in the system, and optionally to processes outside the system. A heat recycling system for use with a combustor is provided.

The system includes a heat exchanger for recovering heat from the hot product gas, which transfers the sensible heat from the product gas to the appropriate fluid. Optimal fluids for the heat exchange process include, but are not limited to, air, water, oil or other gases such as nitrogen or carbon dioxide. Specifically, the system comprises a conduit system for transferring the hot product gas of the gasification process to a gas-to-fluid heat exchanger, wherein the heat from the hot product gas is cooled with the heated fluid. Move to fluid to produce product gas. The system further comprises another conduit system for transferring the heated fluid to the gasification process.

In one embodiment, the gas-to-fluid heat exchanger is a gas-to-air heat exchanger where heat is transferred from the product gas to the air so as to produce heated exchange air. In one embodiment, the gas-to-fluid heat exchanger is a heat recovery steam generator where heat is transferred to the water to produce hot water or steam.

In accordance with one embodiment of the present invention, a heat recycling system 5000 for returning the heat produced during the gasification process back to the converter 1000 to cause a gasification reaction, as schematically represented in FIG. Is provided. In this embodiment, this is done in the converter 1000 of the gas-to-air heat exchanger 5100 to produce a heated air product (hereinafter referred to as exchange air 5015) and a cooled product gas 5025. This is realized by heating the air 5010 with the heat from the high-temperature production gas 5020 to be produced and returning the heated exchange air 5015 to the converter 1000.

Therefore, the recovered sensible heat is recycled back into the gasification process, reducing the amount of energy input required from external energy sources for the raw material drying, volatilization and gasification steps. The system optimizes energy efficiency. The recovered sensible heat also has the effect of minimizing the amount of plasma heat required to achieve the specified product gas quality. As described above, the present invention enables efficient gasification of a carbonaceous raw material, and heat necessary for gasification is provided by high-temperature exchange air, and the exchange air is sensible heat recovered from the high-temperature production gas. Is heated using.

The sensible heat transferred from the product gas to the heated exchange air can be used not only for the heating device of the gasification process but also for an external heating device.

For example, heated exchange air can be used directly or indirectly to preheat or pretreat the gasified feed. In the case of a direct heating / pretreatment step, the exchange air passes directly through the raw material to remove heat and / or moisture. In the case of an indirect heating / pretreatment step, heat is transferred from the heated exchange air to oil (or water to generate steam), and the heated oil (or steam product) is fed into the feed dryer. / Used to heat the preheater wall. In any case, the reuse of sensible heat minimizes the amount of energy input required for these heating devices.

Therefore, it is within the scope of the present invention to transfer heat from the heated exchange air to any working fluid of interest. The working fluid of interest includes, but is not limited to, oil, water or another gas such as nitrogen or carbon dioxide. If heat is transferred to a working fluid other than air, a suitable heat exchange system is used.

After heat is recovered in a gas-to-air heat exchanger, as is known in the art, the product gas may be cooled but still contain excessive heat to undergo a filtering or conditioning step There is. Thus, the present invention also optionally provides a step of further cooling the product gas prior to subsequent filtering and conditioning steps.

In the embodiment shown in FIG. 2, the heat recycling system 5001 heats gas to air to produce a heated air product (hereinafter referred to as exchange air 5015) and a partially cooled product gas 5023. Heat from the hot product gas 5020 in the exchanger 5102 heats the air 5010 and returns the heated exchange air to the converter 1000.

The heat recycling system 5001 also includes a subsystem for recovering additional heat from the product gas after the partially cooled product gas 5023 passes through the gas-to-air heat exchanger 5102. Thus, the system 5001 further comprises a heat recovery steam generator 5302 so that additional heat recovered from the product gas is used to convert water 5030 into steam (referred to as exchange steam 5035) and is completely cooled. The produced product gas product 5025 is also produced.

Exchange steam produced in a heat recovery steam generator can be used to drive a downstream energy generator such as a steam turbine and / or used in a direct drive turbine and / or added to a gasification process Is possible. The exchange steam can also be used in other systems such as, for example, petroleum extraction from tar sands or local heating applications. Or it can be provided to local industrial clients according to their respective purposes. In one embodiment, the steam produced using heat from the product gas is saturated steam. In another embodiment, the steam produced using heat from the product gas is superheated steam, produced directly by heat exchange either between water and product gas or between saturated steam and product gas. Is possible.

The system of the present invention is a system for use with a converter where the feed is converted (via an off-gas intermediate) to a hot raw gaseous product. A typical converter for use with the present invention comprises a feed inlet for introducing feed to be gasified and one or more exchange air for providing heated exchange air to facilitate the gasification process. An inlet, a hot product gas outlet, and optionally one or more process additive inlets. The converter also includes one or more plasma heat sources to convert off-gas intermediates of the gasification process into raw product gas.

If the system does not include a system for recovering additional heat from the partially cooled product gas after passing through the gas-to-air heat exchanger, another system for further cooling the product gas before conditioning A system may be provided. In one embodiment, as shown in FIG. 3, system 5003 produces high temperature production in a gas-to-air heat exchanger 5013 that produces partially cooled production gas 5023 and heated exchange air 5015. In addition to cooling gas 5020, a dry quench step 6103 is also provided to further cool the product gas prior to conditioning. The dry quench step is extra from the product gas by adding a controlled amount of atomized water 6030 to provide a cooled product gas 5025 as may be required for subsequent filtering and conditioning steps. Provided to remove heat. It is within the knowledge of those skilled in the art to select an appropriate system to further cool the product gas prior to conditioning.

In accordance with one embodiment of the present invention, the system comprises a sensing element for monitoring system operating parameters and a response element for adjusting operating conditions within the system to optimize the gasifier. It also includes a control subsystem, and the response element adjusts the operating conditions in the system according to the data obtained from the sensing element, thereby maximizing energy production while minimizing process energy consumption Optimize the efficiency of the gasification process.

The control subsystem also optimizes the composition of the produced product gas (ie heating value) and, optionally, ensures that the system is maintained within safe operating parameters. Can also be used.

Heat exchanger

The present invention provides a system for returning heat generated during the gasification process back to the gasifier to facilitate the gasification reaction. It uses a heat exchange system (eg, a gas-to-fluid heat exchanger) to recover sensible heat from the hot product gas and transfer the heat from the product gas to the appropriate working fluid and be heated. Can be achieved by producing a fresh fluid and a cooled product gas. In one embodiment, the heated fluid produced in the gas-to-fluid heat exchanger is sent back to the gasifier.

In one embodiment, the gas to fluid heat exchanger comprises one or more gas to air heat exchangers.

The functional requirements of a gas-to-air heat exchanger are shown in FIG. 4A, but the hot product gas 5020 and air 5010 pass through the gas-to-air heat exchanger 5104A, respectively, so sensible heat is Moving from hot product gas 5020 to air 5010 (sent by process air blower 5012), heated exchange air 5015 and cooled product gas 5025 are provided.

The system can use a variety of heat exchangers, including shell and tube heat exchangers, both straight single pass designs and U-tubes, multiple pass designs, and plate heat exchangers. The selection of a suitable heat exchanger is within the knowledge of those skilled in the art.

Since some particulate matter is present in the product gas, the gas-to-air heat exchanger 5104A is designed specifically for high level particle loading. The particle size is typically 0.5 to 100 microns. In one embodiment shown in FIG. 4B, the heat exchanger is a single pass vertical flow heat exchanger 5104B, with product gas 5020 flowing into the tube side and air 5010 flowing in the shell side. In a single pass vertical flow embodiment, the product gas 5020 flows vertically in a “one-through” design, minimizing the area where particulate material buildup or erosion can occur.

The rate of product gas needs to be kept high enough for self-cleaning while minimizing erosion. In one embodiment, the gas velocity is between 3000 and 5000 m / min. Under normal flow conditions, the gas velocity is from about 3800 m / min to about 4700 m / min.

Because of the significant difference between the air input temperature and the hot product gas, each tube of the gas-to-air heat exchanger preferably has a separate expansion bellows that avoids tube rupture. If a single tube becomes clogged and the rest of the tube bundle does not expand / contract, tube rupture may occur. In embodiments where the process air pressure exceeds the product gas pressure, tube rupture is very dangerous due to problems caused by air entering the gas mixture.

In an embodiment of the present invention, the system operates intermittently, that is, in response to multiple starts and ends as desired. Therefore, it is important that the instrument be designed to withstand repeated temperature expansion and contraction.

To minimize the risk from tube leaks, the system of the present invention further comprises one or more individual temperature transmitters, as shown in FIG. For example, the temperature transmitter 5581 is located at the product gas inlet 5521, the temperature transmitter 5582 is located at the product gas outlet 5526 of the gas to air heat exchanger, and the temperature transmitter 5583 is located at the exchange air outlet 5517. Is done. If a temperature transmitter is associated with the product gas outlet 5526 of the gas-to-air heat exchanger 5105, the temperature transmitter will detect a temperature rise due to combustion if the exchange air is leaking into the product gas derivation. Placed in. When such a temperature rise is detected, the process air blower 5012 automatically stops so as to eliminate the oxygen source.

If a temperature transmitter is associated with the exchange air outlet 5517 of the gas-to-air heat exchanger 5105, the temperature transmitter does not necessarily exceed the temperature setting range required for the gasification process. As used. In order to avoid providing excessive (or too hot exchange air) heated exchange air to the gasification process as the feedstock can overheat, so as to release excess exchange air to the atmosphere, Control valve 5590 opens.

In addition, a heat exchanger is provided with ports for metering, sensing and maintenance, as well as conduit repair and / or cleaning, if desired.

In one embodiment, the gas-to-fluid heat exchanger is a heat recovery steam generator that uses the recovered heat to generate exchange steam. In one embodiment, the water is provided to the heat exchanger in the form of cold steam. In another embodiment, the exchange steam produced is saturated or superheated steam.

Thus, the produced exchange steam can be used as a process steam additive for a gasification process, or used to drive a power generation turbine or to drive a rotating process facility such as a gas blower. Is possible.

Steam that is not used in the conversion process that drives the power generation or rotating process equipment can be used for other commercial purposes such as local heating applications or to improve the extraction of petroleum from tar sands. The exchange steam can also be used to indirectly heat the raw material of the raw material conditioner and dry the raw material before gasifying the converter.

The heat recovery steam generator employed in one embodiment of the system of the present invention is a shell and tube heat exchanger where the product gas flows vertically through the tube and the water boils on the shell side.

The heat exchange system for the heat recovery steam generator was designed with the understanding that some particulate matter would be present in the product gas. Again, the product gas velocity is maintained at a high enough rate to self-clean the tube while minimizing erosion.

Converter used in this system

The system includes a converter for converting the feedstock into a gaseous product. This conversion occurs through the gasification of the raw material and the modification of the intermediate gaseous product. The raw material gasification stage consists of i) drying the raw material to eliminate residual moisture, ii) volatilizing the volatile constituents of the dry raw material to produce carbonized intermediates, and iii) converting the carbides to off-gas and ash. ,including. Thus, the gaseous products of the gasification process include volatile antibiotics and off-gas, which are optionally subjected to a reforming step that provides the gaseous products. In one embodiment, the modification step is a plasma assisted modification step.

The converter thus comprises a refractory chamber having at least one feed inlet, one or more exchange air inlets, a gas outlet and a solid residue outlet. The converter also optionally includes one or more process additive inlets and one or more plasma heat sources.

In one embodiment, the converter is a gasifier arranged in a horizontal direction, and the raw material is fed into the gasifier through a raw material inlet located at one end of the gasifier. The raw material is subjected to gasification so as to move toward a solid residue outlet disposed at one end on the opposite side of the gasifier.

The gasification process can also be performed in one of several standard gasifiers, as is known to those skilled in the art. Examples of gasifiers known to those skilled in the art include, but are not limited to, entrained flow reactors, fluidized bed reactors, and rotary furnace reactors. Each of these is adapted to receive a raw material in the form of a solid, particle, slurry, liquid, gas, or a combination thereof. The gasifier can have a wide range of length to diameter ratios and can be oriented in either the longitudinal or horizontal direction.

In accordance with the present invention, in each of these embodiments, the gasification process is facilitated by introducing a heated fluid through a suitably adapted heated fluid inlet. In one embodiment, the gasification process is facilitated by introducing heated exchange air through the exchange air inlet.

In accordance with the present invention, heated fluid is provided as needed in different areas of the gasifier via independent heated fluid delivery and distribution systems.

In one embodiment, the heated fluid delivery and distribution system includes an exchange air inlet that allows heated exchange air to be introduced into the gasification region.

These inlets are arranged in the converter so as to distribute heated exchange air through the converter so as to start and advance the gasification of the feedstock. In one embodiment, the replacement air inlet comprises perforations disposed on the bottom surface of the gasifier. In one embodiment, the replacement air inlet comprises perforations disposed on the wall of the gasifier.

In one embodiment, the replacement air inlet comprises a separate air box in each region through which hot replacement air can pass from perforations in the converter floor of that region. In one embodiment, the replacement air inlet is a separately controlled sparger for each region.

Optionally, the inlet hole size is selected to constrain the entire hole and thus create a pressure drop so that the replacement air inlet is not clogged during the process. This pressure drop is sufficient to prevent waste particles from entering the inlet hole. The inlet hole can optionally be tapered outward toward the top surface so that particles do not clog the hole.

The converter can be designed such that the process (ie, gasification and reforming steps) for converting the feedstock to product gas occurs both in a single region or chamber within the system.

The converter also allows the conversion process from raw material to product gas to occur in more than one region, that is, the gasification and reforming steps are separated to some extent and occur in separate regions within the system. It can also be designed as follows. In these types of converters, the process occurs in either two or more regions within a chamber, individual chambers, or some combination thereof, but the regions are in fluid communication with each other.

In a multi-region converter, the first or main region or chamber (also referred to as a gasifier) is used to heat the raw material to dry the raw material (if there is residual moisture) and to volatile composition of the raw material The off-gas product is produced by extracting the product and converting the resulting carbide to gaseous product and ash, but a second zone or chamber (also referred to as a reformer) is used to generate plasma heat and Other process additives (eg, air and / or steam) are applied to completely convert off-gas and volatiles to product gas. When two or more separate regions or chambers are used for feed gasification and off-gas to product gas conversion, the gas present in the final region of the converter is the product gas.

In one embodiment, different stages of the gasification process can occur in different areas of the gasifier. Those skilled in the art can conceptually optimize gasifier conditions at any location in response to the characteristics of the raw material at a particular location by separating the gasifier into a myriad of regions. Understand that there is. However, a practical embodiment of this concept is to separate the gasifier into a myriad of regions that are optimized according to the characteristics of a larger or general feedstock. Those skilled in the art will therefore appreciate that the gasifier may be separated into two, three, four or more regions depending on the properties of the feedstock.

In accordance with one embodiment of the invention, each stage of the gasifier is facilitated by introducing an appropriate amount of heated exchange air through an appropriately adapted exchange air inlet.

The feedstock is arranged to provide maximum exposure of the feedstock to heated exchange air or other heated fluid in order for the feedstock to be completely and efficiently converted to a gaseous product. It introduces through the above raw material inlet.

In one embodiment, the system enables the supply of high carbon feedstock (HCF), such as crushed plastic, in combination with feedstock before introduction into the converter or via a dedicated HCF outlet, which is necessary. It will be possible to respond quickly to process acceptance for higher or lower carbon input to meet gas quality.

An optional process additive inlet provides additional gas to the converter, such as oxygen, air, oxygen enriched air, steam or other gases useful for the gasification process. The process additive inlet can include an air input port, a steam input port, an exchange air input port, and an exchange steam input port. These ports are located in the converter to optimally distribute the process additives throughout. The steam additive can be provided by a heat recovery steam generator.

The oxygen of the exchange air is used for chemical equilibration to produce the necessary product gas and eliminate the maximum amount of carbon. Oxygen also initiates or accelerates the exothermic reaction that produces carbon monoxide, carbon dioxide, hydrogen and other large hydrocarbon particles. The heat from the exothermic reaction, along with the heat provided by the heated exchange air and / or other heated fluid, increases the converter process temperature.

FIG. 6 is a schematic diagram summarizing the various inputs and outputs associated with one embodiment of a converter for use with the system of the present invention. This embodiment is a converter 1006 comprising a horizontally oriented gasifier 2006 having a feed inlet 2604, the feed comprising municipal solid waste MSW and a high carbon feed HCF (such as plastic). Converter 1006 has a plurality of exchange air inlets 2619A, 2619B and 2619C arranged to provide the exchange air 5015 required for the gasification reaction. The converter also has an exchange air inlet 3616 and a steam inlet 3630 in the vicinity of the plasma torch so as to provide the air and steam additives necessary for the plasma reforming reaction. Converter 1006 has a solid residue outlet 2608 in communication with solid residue conditioning chamber 4620.

The material moves laterally from the gasifier to facilitate certain stages of the gasification process (drying, volatilization, carbon to ash conversion). The lateral movement of material through the gasifier is achieved through the use of one or more lateral transfer units. The transfer unit can include, but is not limited to, movable shelves, movable platforms, pusher rams, pluses, screw elements or belts.

One or more lateral transfer units can operate in an emphasized manner. Alternatively, the individual lateral transfer units can operate independently. In order to optimize the control of the material flow rate and the height of the deposits, the individual lateral transfer units can be moved individually at different speeds, at different distances of movement and with different movement frequencies. The lateral transfer unit needs to be able to operate efficiently in the difficult situation of the gasifier, in particular to be able to operate at high temperatures.

The converter can be one or a combination of conventional refractory materials that have been found to be optimal for use in vessels for reactions that do not apply high pressure (eg, temperatures of about 1100 ° C. to 1400 ° C.) Covered with refractory material. Examples of such refractory materials are high temperature fired ceramics (aluminum oxide, aluminum nitride, aluminum silicate, boron nitride, zirconium phosphate, chromium oxide), glass ceramics and high alumina containing essentially silica, alumina, and titania. Including but not limited to quality bricks.

The solid residue outlet is arranged so that the solid byproduct of the gasification reaction can be eliminated from the converter. Gasifier solid by-products, also referred to as solid residues, can be in the form of carbides, ash, slag or some combination thereof, continuously from the converter through a suitably adapted outlet. Or intermittent. The carbide can be eliminated before it is completely converted to a gaseous product. Alternatively, it can be left in the gasifier for further modification to ash. The ash product is then removed via the solid residue outlet, for example, to an ash collection chamber or optionally to a solid residue conditioning chamber for further processing. The appropriate solid residue removal outlet design and arrangement of the converter is selected using the knowledge of those skilled in the relevant art, depending on the requirements of the system and the types of by-products to be excluded.

The solid residue outlet is typically located at or near the bottom of the chamber so that the residue can be passively eliminated using gravity flow. Some systems optionally employ a solid residue removal system to actively carry residue from the bottom of the converter. Such active solid residue removal can be provided by one of a variety of devices known in the art. Examples include, but are not limited to, screws, pusher rams, horizontal rotating paddles, horizontal rotating arms and horizontal rotating wheels.

In embodiments where the solid residue (eg, ash byproduct) of the gasification process is further converted to slag, the ash to slag conversion is performed in a solid residue conditioning chamber. A plasma heat source can be employed in the solid residue conditioning chamber to melt the ash into slag. The molten slag can be periodically or continuously discharged from the solid residue conditioning chamber, for example, at a temperature of about 1100 ° C. to about 1600 ° C., so that it is cooled to form a solid slag material. Such slag material can be landfill waste. The solid product can be further crushed into sand for conventional use. Alternatively, the molten slag can flow into the container to form a bar, brick, tile or similar building material.

If the solid residue of the gasification process contains some unrecovered carbon, the plasma heat of the slag conditioning step ensures that the unrecovered carbon is completely converted into a hot gaseous product with fuel value. This gaseous product is called residue gas. In one embodiment, heat is recovered from the hot residue gas using a dedicated residue gas to air heat exchanger to produce a heated air product and a cooled residue gas. The cooled residue gas is optionally further conditioned in a dedicated gas conditioner subsystem to produce a gas product that can be mixed with the gaseous product of the main gasification process.

System for further cooling of the product gas before the conditioning step

In addition to a gas-to-fluid heat exchanger, the present invention optionally includes a system for further cooling the produced gas prior to the conditioning step. In one embodiment, a system for further cooling the product gas prior to cleaning and conditioning is also provided for recovering additional heat. If the goal is to further recover sensible heat from the product gas, heat is transferred from the gas to another working fluid such as water, oil or air. The products of such embodiments can each include hot water (or steam), heated oil, or additional hot air.

In one embodiment, the system of the present invention uses a heat exchanger to recover more sensible heat from the product gas to transfer heat from the partially cooled product gas to the water, so hot water or steam Any of these and further cooled gas. In one embodiment, the heat exchanger employed in this step is a heat recovery steam generator and uses the recovered heat to generate exchange steam. In one embodiment, the water is provided to the heat exchanger in the form of cold steam. In another embodiment, the exchange steam produced is saturated or superheated steam.

FIG. 7 illustrates the relationship between a gas to air heat exchanger 5107 and a heat recovery steam generator 5307 in accordance with one embodiment of the present invention. The exchange steam 5035 produced in the heat recovery steam generator 5307 can be used in a variety of downstream applications. FIG. 7 depicts different possible end users (A to G) of exchange steam produced using a heat recovery steam generator, in accordance with various embodiments of the present invention.

For example, as represented as Option D, the produced exchange steam 5035 can flow through the converter 1007 as a process steam additive in one embodiment of the present invention. Exchange steam 5035 can be used as a process steam additive during the gasification process to ensure maximum conversion of raw material to product gas with sufficient free oxygen and hydrogen. The use of steam as the oxygen containing process additive is preferred because of its low cost and simple processing. Steam also contains hydrogen, which may be a desirable product of the gasification process.

The produced exchange steam can also pass through a turbine 5715 to drive a rotating process facility, such as an exchange air blower 5712 (Option B) or a production gas blower 5722 (Option C).

Steam that is not used in the conversion process or to drive the rotating process equipment can be used for other commercial purposes, such as a steam turbine 5705 (Option A) or a localized heating application 5710 (Option E). Alternatively, it can be provided to local industrial clients for their respective purposes. Alternatively, it can be used to improve petroleum extraction from tar sand 5780 (Option F). The exchange steam can also be used to indirectly heat the raw material of the raw material conditioner 5765 to dry the raw material before gasifying the converter (Option G).

In one embodiment where the system for further cooling the product gas prior to conditioning does not include additional heat recovery, the cooling step comprises a dry quench step and the product gas temperature directly controls the mist water. It is lowered by injecting (adiabatic saturation).

In one embodiment, excess heat can be removed (and recovered) by a water cooling step when cooling of different systems or processes is required. The resulting hot water can then be used to heat the working fluid for use elsewhere in the gasification process. Hot water can be obtained from a variety of sources, such as but not limited to a gas cooling process in a gas conditioning system or a plasma heat source cooling system. Hot water can also be used to preheat oil for a variety of uses.

Conduit system

A conduit system is employed to move gas from one component of the system to another. Thus, the system comprises a product gas conduit system that moves the hot product gas product to a heat exchanger for recovering sensible heat. The system also includes an exchange air conduit system that moves the heated exchange air to the converter, where the heated exchange air is introduced into the converter from the exchange air inlet. A conduit system typically employs one or more pipes or lines through which gas is carried.

Where the system includes a heat recovery steam generator, the system also includes an exchange steam conduit system for moving heated exchange steam for use in one or more of the facilities listed above. The exchange steam conduit system can comprise a number of pipe or branch conduit systems running in parallel, with the designated branch dedicated to a particular application.

Conduit system gas line material and size specifications are selected as needed to provide safe and efficient transport of gas. If the gas being transported is a hot product gas, the thickness and type of the refractory design used should be approximately 200 ° C to keep the shell wall temperature above the acid gas dew point to prevent corrosion. Selected to be. In one embodiment, the hot production gas line is coated with refractory in carbon steel. In one embodiment, the heated exchange air line comprises a stainless steel pipe.

In order to maximize the amount of sensible heat that can be recovered from the hot product gas or to minimize the cooling of heated exchange air or exchange steam, the conduit system optionally includes heat to the ambient environment. Means are provided for minimizing losses. Heat loss can be minimized, for example, by designing a factory to minimize the length of the conduit, using a thermal insulation layer with insulation as is known in the art around the conduit. it can. This is particularly important for high temperature conduits.

In one embodiment, the heated exchange air is exhausted from a single pipe gas-to-air heat exchanger and then provided to different areas of the converter as needed. , Some diameters are divided into smaller pipes. Each branch of the pipe system includes an air flow control valve that controls the flow of air heated to different areas of the converter as needed.

The production gas conduit system optionally employs one or more flow regulators and / or blowers disposed throughout the system to provide a means for managing the gaseous product flow rate.

The replacement air conduit system optionally employs one or more flow regulators, flow meters and / or blowers located throughout the system as needed to control the flow rate of the replacement air. In one embodiment, as represented in FIG. 8, replacement air flow control valves 5890A, 5890B and 5890C are provided to control the flow of replacement air 5015 to each level in the gasification region. The control valve limits the flow of exchange air to the air inlets 2812, 2814 and 2816 of the gasifier 2008. In one embodiment, control valves 5890A, 5890B and 5890C are independently controllable to adjust the amount of replacement air 5015 introduced into each region of the gasifier.

In one embodiment, there is one replacement air flow control valve 5892 to control the flow of replacement air to the reformer 3008. In this embodiment, exchange air is provided as a process additive.

The exchange air conduit also optionally comprises means for sending exchange air to, for example, a discharge outlet or an optional additional heat exchange system.

The flow regulator and / or the blower and / or the bypass means are optionally controlled by a control subsystem, as will be described in detail below.

The conduit system also optionally includes a service port that provides access to the system for performing regular maintenance as well as conduit repair and / or cleaning.

Plasma heat source

The system of the present invention employs one or more plasma heat sources that convert off-gas produced by the gasification process into product gas. A plasma heat source is also provided for a solid residue conditioner that melts and conditions the solid residue.

A variety of commercially available plasma heat sources can be utilized in the system that can produce a suitable high temperature flame for a sustained period at the point of action. Generally, such a plasma heat source has a size of about 100 kW to 6 MW or more. The plasma heat source can be employed in one or a combination of suitable working gases. Examples of suitable working gases include, but are not limited to, air, argon, helium, neon, hydrogen, methane, ammonia, carbon monoxide, oxygen, nitrogen and carbon dioxide. In one embodiment of the present invention, the plasma heat source uses air as the plasma medium so that the gasifier produces a temperature from about 900 ° C. to about 1300 ° C. or higher as needed to convert off-gas to product gas. Operate continuously.

In this regard, several alternative plasma technologies are suitable for use in the present system. For example, it can be seen that a transfer arc or a non-transfer arc torch (both AD and DC) using an appropriately selected electrode material can be employed. It can also be seen that an inductively coupled plasma torch (ICP) can also be employed. The selection of a suitable plasma heat source is within the knowledge of those skilled in the art.

In one embodiment of the invention, one or more plasma heat sources are arranged to optimize the conversion of off-gas to product gas. The location of the one or more plasma heat sources is selected depending on the design of the gasification system, for example, whether the system employs a one-stage or two-stage gasification process. For example, in embodiments employing a two-stage gasification process, the plasma heat source can be positioned at and directed toward the inlet where off-gas enters the reforming chamber or reforming zone. In embodiments employing a one-stage gasification process, one or more plasma heat sources extend toward the center of the gasifier. In all cases, the location of the plasma heat source is selected according to system requirements and to optimize the conversion of off-gas to product gas.

In one embodiment, the plasma heat source used in the plasma reformer is provided by a DC non-transferred arc.

In one embodiment, the plasma heat source is positioned next to one or more air and / or steam input ports such that air and / or steam additives are injected into the plasma discharge path of the plasma heat source.

In further embodiments, the plasma heat source can be movable, fixed or a combination thereof.

In one embodiment, the plasma heat used in the solid residue conditioner is provided by a DC non-transfer arc torch. In another embodiment, the plasma heat used in the solid residue conditioner is provided by a DC transfer arc torch.

Control system

In order to optimize the efficiency of the present invention, a system is optionally provided for controlling the conditions under which the process is performed as well as the operating conditions of the system according to the present invention. If the end use of the gas product is power generation, the control subsystem also provides optimal energy production by ensuring that the gas composition and pressure are within the acceptable range of the gas engine / generator used for power generation To do.

In one embodiment of the present invention, by a control system, within the various systems and / or subsystems disclosed herein, and / or by the various systems and / or subsystems disclosed herein. Can provide control of one or more implemented processes, and / or provide control of one or more process equipment discussed herein to affect such processes. . In general, a control system is implemented in a system, such as a gasification system, associated with a specified system, subsystem, or component thereof, and / or in various embodiments or in cooperation with which the invention can operate. Since various local and / or regional processes associated with one or more overall processes can be operatively controlled, they are adapted to influence these processes for defined results These various control parameters can be adjusted. Various sensing and response elements can therefore be distributed throughout the control system or in conjunction with one or more of those components to obtain various process, reaction and / or production characteristics. Compare these characteristics to the appropriate range of these characteristics to achieve the desired result, and respond by implementing changes in one or more running processes from one or more controllable process devices can do.

A control system is typically one for detecting one or more characteristics in relation to, for example, the system, processes implemented in the system, inputs provided, and / or outputs generated thereby. The above detection elements are provided. One or more computing platforms are communicatively coupled to these sensing elements to access the characteristic value representation of the detected characteristic, and the characteristic value is appropriate for the selected action and / or downstream result. One or more process control parameters are computed that are compared to a defined range of these values defined to characterize these properties and that lead to the maintenance of the property values within this defined range. In this way, multiple response elements can be operatively coupled to one or more process devices operable to affect the system, process, inputs and / or outputs, thus adjusting sensed characteristics. And can be communicatively coupled to a computing platform to access the computed control parameters and operate the process equipment in response thereto.

In one embodiment, the control system may provide a variety of systems, processes, inputs and / or outputs related to the conversion of carbonaceous feedstock to gas to facilitate the efficiency of one or more processes implemented in association. Feedback, feedforward, and / or predictive control. For example, various process characteristics can be evaluated and adjusted in a controlled manner to affect these processes.
These include heating value and / or feed composition, product gas characteristics (eg, heating value, temperature, pressure, flow rate, composition, carbon content, etc.), the degree of variation possible for such characteristics, and the cost of input. Including but not limited to the value of the output. Continuous and / or real-time adjustments to various control parameters include heat source output, additive feed rate (oxygen, oxide, steam, etc.), feed rate (one or more individual and / or mixed feeds) Including, but not limited to, gas and / or system pressure / flow regulators (blowers, safety / control valves, flares, etc.), etc., depending on design and / or downstream specifications This is done in a way that the properties are evaluated and optimized.

Alternatively or additionally, the control system can ensure proper operation, and optionally, if the criteria apply, to ensure that the implemented process is within standard criteria, It can be configured to monitor the operation of various components of a specified system.

Depending on one embodiment, the control system can further use the overall energy impact of the specified system in monitoring and control. For example, a specified system can be energetic, for example, by optimizing one or more implemented processes, or again by increasing the recovery of energy generated by these processes (such as waste heat). It is possible to operate in such a way that the influence is reduced or here again. Alternatively, or in addition, the control system can not only ensure that the composition and / or other characteristics (temperature, pressure, flow rate, etc.) of the product gas generated from the control process are suitable for downstream applications, but also efficient and optimal It can be configured to adjust so that it is substantially optimized for the application. For example, in embodiments where the product gas is used to drive a gas engine for certain types of power generation, the characteristics of the product gas are such that these characteristics best match the optimal input characteristics of such an engine. Can be adjusted.

In one embodiment, the control system is configured with a specified process to meet and / or optimize limits or performance guidelines related to various component reactions and / or product residence times, or various processes throughout the process. Can be configured to adjust. For example, the upstream process volume can be controlled to substantially match one or more subsequent downstream processes.

Further, the control system can be adapted for sequential and / or simultaneous control of various aspects of a specified process cell in various embodiments, in a continuous and / or real-time manner.

In general, the control system can comprise any type of control system design suitable for the following applications. For example, the control system can comprise a substantially central control system, a distributed control system, or a combination thereof. A centralized control system generally has a central controller configured to communicate with various local and / or remote sensing devices and a response configured to detect various features associated with the process being controlled, respectively. And respond to it via one or more controllable process devices adapted to directly or indirectly affect the controlled process. Since most computation is centrally implemented by the central processing unit using a centralized architecture, most of the hardware and / or software required to implement the control of the process is located in the same place.

Distributed control systems generally include two or more distributed controllers that can communicate with each sensing and response element, respectively, to monitor local and / or regional features and affect local processes or sub-processes. Will respond via a local and / or regional process device configured to exert Communication between distributed controllers can also occur via various network configurations, and features detected by the first controller can be communicated to a second controller for responding there, such as The distal response may affect the features detected at the first location. For example, downstream product gas characteristics may be adjusted by adjusting control parameters associated with a converter that is detected by a downstream monitoring device and controlled by an upstream controller. In a distributed architecture, control hardware and / or software is also distributed among the controllers, in which case the same but modular control scheme can be implemented in each controller, or various cooperative modular control schemes can be implemented. It can be implemented in each controller.

Alternatively, the control system may be subdivided into separate but communicatively linked local, regional, and / or global control subsystems. Such an architecture may allow a given process or series of correlated processes to be controlled locally with minimal interaction with other local control subsystems. The global master control system can then communicate with each respective local control subsystem to direct the necessary adjustments to the local process for global results.

The control system of the present invention may use any of the architectures described above, or any other architecture generally known in the art, within the general scope and nature of the present disclosure. It is considered to be. For example, a process controlled and implemented within the intent of the present invention, if applied, by optional external communication to any central and / or remote control system used for the associated upstream or downstream process. Can be controlled in a dedicated local environment. Alternatively, the control system can comprise subcomponents of the regional and / or global control system designed to coordinately control the regional and / or overall process. For example, a modular control system can be designed such that the control module interactively controls various subcomponents of the system while providing communication between modules as needed for regional and / or overall control. .

The control system typically includes one or more central, networked and / or distributed processors, one or more inputs for receiving currently sensed characteristics from various sensing elements, and various response elements. And one or more outputs for communicating new or updated control parameters. In addition, one or more computing platforms of the control system store various defined and / or re-adjusted control parameters, settings or priority systems and process characteristics operating ranges, system audits and controls and wear, operating data, etc. One or more local and / or remote machine readable media (ROM, RAM, removable media, local and / or network access media, etc.) may also be provided. Optionally, the computing platform can also have access to process and mutation 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 to provide administrative access to the control system (system updates, maintenance, changes, adaptation to new system modules and / or equipment, etc.) It can be equipped with a variety of optional output devices for data and information communication with input peripherals, as well as external information sources (modems, network connections, printers, etc.).

Any one of the processing system and sub-processing system may comprise exclusively hardware or some combination of hardware and software. Any of the sub-processing systems may include any combination of one or more proportional (P), integral (I), or differential (D) controllers, eg, P controller, I controller, A PI controller, PD controller, PID controller, or the like may be provided. The ideal choice of P, I, and D controller combinations is the dynamics and delay times of the reaction process portion of the gasification system, the range of operating conditions that are intended to be controlled by the combination, and the combination controller's It will be apparent to those skilled in the art that it depends on kinetics and delay time. These combinations continuously monitor the feature value with the sensing element, compare it with the specified value, affect each control element, make sufficient adjustments with the response element, and adjust the observed value to the specified value. It will be apparent to those skilled in the art that an analog wiring topology can be implemented that can reduce the difference between them. Furthermore, it will be apparent to those skilled in the art that these combinations can be implemented in a mixed digital hardware and software environment. The effects associated with any further sampling, data acquisition, and digital processing are known to those skilled in the art. P, I, D combined control may be implemented with feedforward and feedback control schemes.

In correction or feedback control, the value of the control parameter or control variable monitored by the appropriate sensing element is compared with a defined value or a predetermined range. A control signal is determined based on the deviation between the two values and provided to the control element to reduce the deviation. The conventional feedback or response control system may be further adapted to include an adaptation and / or prediction component, and the response to a given condition was detected while limiting potential excess in compensation action. It will be appreciated that it can be organized according to modeled and / or previously monitored responses to provide a response response to the feature. For example, using the acquired and / or historical data provided for a given system configuration in a coordinated manner, a previous response is monitored and a given range from an optimal value adjusted to provide the desired result. Responses to systems and / or process features that are detected to be within can be adjusted. Such adaptive and / or predictive control schemes are known to those skilled in the art and are therefore not considered to depart from the general scope and nature of the present disclosure.

Control element

The sensing elements discussed herein were defined and described as above, but the temperature, gas flow rate, gas pressure, gasifier raw material deposition height, gas composition at specific points throughout the system. And one or more parameters are provided for monitoring, such as but not limited to heating values.

The response elements discussed herein are operational to process-related devices configured to affect a specified process by adjusting the associated specified control parameters as defined and described above. May include, but is not limited to, various control elements coupled to the. For example, a process device operable within the present specification from one or more response elements may include an air or product gas blower, a feed input, a pressure or temperature regulator, a lateral transfer unit, and a plasma heat source. Although it can, it is not limited to these. Thus, examples of operating conditions that can be adjusted by response elements of the control subsystem include one or more replacement air flow rates (ie, process air blower speed), feed rate, feed rate ratio (MSW vs. high carbon feed). System pressure, lateral transfer unit movement, input of process additives such as steam, and power source for plasma heat source.

In one embodiment of the invention, the control subsystem comprises a temperature sensing element that monitors the temperature at a point throughout the system. The temperature sensing element for monitoring the temperature can be a temperature transmitter, such as a thermocouple or optical thermometer attached to a location in the system as needed.

FIG. 9 outlines various means for monitoring and controlling the temperature in the system, and shows the mounting position of the temperature transmitter and the flow regulator in the entire system. For example, the temperature transmitter 5982 is arranged to monitor the temperature of the product gas at the product gas outlet 5926 of the gas to air heat exchanger. The temperature transmitter 5981 is arranged to monitor the temperature of the exchange air 5015 heated at the exchange air outlet 5917 of the gas-to-air heat exchanger 5109.

A temperature transmitter can be placed in the converter to monitor the process temperature during the gasification and reforming process. For example, by monitoring the temperature in the converter area where the gasification process takes place, the raw material is kept as high as possible for as long as possible without reaching the temperature at which the raw material is melted or agglomerated so that optimum conversion efficiency is achieved. Guaranteed. The temperature control within the deposition is heated to the designated area of the gasifier 2009 via control valves 5994A, 5994B and 5994C to stabilize the temperature following the needs of different stages of the gasification process. This is realized by adjusting the flow rate of the replacement air. The different stages of temperature are measured by temperature transmitters 5984A, 5984B and 5984C, respectively. Temperature control at different stages of the gasification process can also be achieved by controlling the movement of the raw material throughout the gasifier by means of a lateral transfer unit.

The temperature of the converter reforming region 3009 is monitored by a temperature transmitter 5983. The power supply to the plasma torch 2980 stabilizes the temperature of the reforming zone 3009 in order to maintain the optimum temperature for fully reforming off-gas, volatiles, tar and soot to the defined gas product. Can be adjusted as needed.

The heat recycling process under conditions that ensure that the air is heated to a temperature suitable for use in the gasification process by a temperature transmitter 5981 attached to the exchange air outlet 5917 that measures the temperature of the heated exchange air. Is guaranteed to be executed. For example, if the optimal temperature of the replacement air for use in the gasifier is about 600 ° C, a temperature transmitter attached to the air outlet side will ensure that the temperature of the replacement air does not exceed, for example, 625 ° C. Can be used to If excessive heating exchange air (or exchange air that is too hot) is provided to the gasification process, it can cause the raw material to overheat. To prevent this, the control valve 5990 is opened to remove excess exchange air. Exhaust into the atmosphere.

Accordingly, a means for controlling the control valve 5990 for exhausting the exchanged air to the atmosphere is also optionally provided. For example, equipment considerations (eg, at the beginning of a shutdown procedure) may require heating more air than is necessary for the process. In such a case, the replacement air can be discharged as necessary.
In accordance with one embodiment of the present invention, the control scheme sets a fixed set point for optimal heated exchange air output temperature, for example, about 600 ° C. In such an embodiment, even if the exchange air flow rate through the gas to air heat exchanger is reduced, the exhaust gas temperature of the gas to air heat exchanger remains the same. When the amount of air passing through the gas-to-air heat exchanger is reduced, therefore, the next stage of the process of exhausting from the gas-to-air heat exchanger, e.g., of the product gas entering the heat recovery steam generator The temperature rises. However, as the flow rate through the system is reduced, the product gas flow rate is correspondingly reduced, so the rise in the product gas inlet temperature of the heat recovery steam generator is only temporarily increased. For example, when the flow rate is reduced to 50%, the temporary maximum product gas inlet temperature of the steam generator is about 800 ° C., which is within the design temperature limits.

By monitoring the temperature of the product gas at the gas-to-air heat exchanger inlet, it is also possible to ensure that the temperature of the product gas entering each heat exchanger does not exceed the ideal operating temperature of the device It is. For example, if the design temperature of the gas-to-air heat exchanger is 1050 ° C., the temperature data obtained from the temperature transmitter on the inlet gas vapor to the heat exchanger is used to maintain the optimal product gas temperature It can be used to control both the exchange air flow rate of the entire system and the plasma heat source. Furthermore, measuring the product gas temperature at the product gas outlet of the gas-to-air heat exchanger may be useful to ensure that the optimum amount of sensible heat is recovered from the product gas during the heat recovery stage.

If the temperature of the gas exhausted from the converter exceeds the specified limit temperature, it may indicate the start of tube blockage, in which case it is necessary to shut down the system for maintenance. Therefore, the heat exchanger is provided with a port as needed for convenient inspection and maintenance.

In one embodiment of the invention, the control subsystem comprises a sensing element that monitors pressure and gas flow rate throughout the gasification system. These pressure sensing elements may be, for example, pressure transducers, pressure transmitters or pressure taps installed in the system in relation to the vertical walls of the gasifier or downstream elements of the gasification system, such as gas storage tanks. A pressure sensor can be included.

Data related to pressure and gas flow in the system is used by the control subsystem to determine whether adjustments to parameters such as torch power or additional amount of solid residue material are required.

In one embodiment of the present invention, the control subsystem includes a response element for regulating the pressure in the system so that the desired pressure of the system is maintained within a certain prescribed culture range. For example, any pressure fluctuations that occur when the product gas blower speed or exchange air input is adjusted are corrected by making adjustments to certain operating parameters determined by the control subsystem.

FIG. 10 represents an overview of various means for monitoring and controlling the product gas pressure and flow rate of the entire system. The pressure transmitter 7095 of the downstream gas storage tank 7010 sends a signal to the replacement air flow control valve of the converter 1010. For example, when the gas storage tank pressure decreases, a signal for increasing the exchange air flow rate to the gasifier 2010 is transmitted and vice versa. The flow rate of replacement air to the gasifier 2010 is controlled using control valves 5994A, 5994B and 5994C. As the amount of exchange air 5015 sent to the gasifier 2010 increases, the amount of feed gas 5020 increases (and the system pressure increases) because the amount of feed gasified increases.

Any change in demand for the replacement air 5015 of the gasifier 2010 will affect the process air blower discharge pressure measured by the pressure transmitter 5095 so that the speed of the variable frequency drive (VFD) of the process air blower 5012 is adjusted. The The process air blower speed 5012 increases when a low pressure is detected in the storage tank 7010 and the speed decreases when a high pressure is detected in the storage tank. As the amount of gas produced increases, the control subsystem can automatically adjust the speed of the gas blower VFD to increase this pressure, so the amount of gas sent to the storage tank increases and the storage tank The pressure increases.

In response to data acquired by pressure sensors located throughout the system, the speed of the downstream induction blower increases or decreases (fan speed decreases) or decreases (fan speed decreases) in the system. It is adjusted according to whether it is. In one embodiment, data related to pressure at a point throughout the system is continuously acquired, so the control subsystem frequently adjusts the fan speed to maintain the system pressure within a specified setting. can do.

In one embodiment, the system is maintained at a slightly negative pressure from atmospheric pressure to prevent gas from leaking into the surrounding environment.

In one embodiment, the internal pressure is adjusted using an induction blower located downstream of the operating gas device by venting the product gas outside the gas device. Thus, the employed induction blower maintains the system at atmospheric or negative pressure. In one embodiment, a control valve is provided in the gas outlet line to increase or limit the flow rate of gas being discharged by the downstream gas blower.

In systems where positive pressure is maintained, the blower is operated so that when the production gas emissions are reduced or stopped, the gas is “pushed” into the system to a high (positive) pressure.

Variations in the gas volume may occur as a result of a non-uniform state of the gasification process (torch malfunction, gas line blockage, or feed stop). If the gas flow continues to change, the system can be shut down until the problem is solved.

The addition of high carbon feedstock and / or steam process additives during the gasification process affects chemical conversion, so it is desirable to monitor the product gas composition. In one embodiment of the invention, the control subsystem comprises a sensing element that monitors the composition of the gas product. Monitoring the composition of the product gas can be realized, for example, by means of a gas analyzer. The gas analyzer can determine, for example, the content of hydrogen, carbon monoxide and / or carbon dioxide in the product gas. One method that can be used to determine the chemical composition of the product gas is gas chromatography (GC) analysis. The collection points for these analyzes can be located throughout the system. In one embodiment, the gas composition is measured using a Fourier Transform Infrared (FTIR) Analyzer that measures the infrared spectrum of the gas.

Although hot gas analyzers exist, the composition is generally measured after the product gas is cooled and after undergoing a conditioning step that eliminates particulate matter and other contaminants.

The product gas composition is controlled by controlling the composition of the gasified feedstock (MSW to HCF ratio) in addition to the amount of air and / or steam process additives added to the gasification and reforming reactions. It is possible to control. Thus, the control subsystem provides a means to control the ratio of MSW to HCF, feed rate addition rate, and the amount of air and / or steam process additives being added to the converter.

In one embodiment of the invention, the control subsystem comprises means for adjusting the air input rate and / or amount to the gasifier and / or reformer. In one embodiment of the present invention, the control subsystem comprises means for adjusting the rate and / or amount of steam input to the reformer.

In one embodiment of the present invention, the control subsystem adds a high carbon feedstock (HCF) input to the gasifier in response to the need for a process that increases or decreases the carbon input to provide the desired gas composition. Means for adjusting the rate;

In one embodiment of the invention, the control system comprises means for adjusting the amount of MSW added to the gasifier. MSW and optionally HCF inputs are added to the gasifier using several possible input means that are selected and adapted according to the needs of the shape of the material being added. The material can be added in a continuous manner, for example using a rotating screw or Auger mechanism. Alternatively, the material can be added in a discontinuous manner, for example, using a pusher arm that adds a portion of the material as needed.

In one embodiment, the feed rate is controlled by adjusting the feed screw conveyor speed from the drive motor variable frequency drive (VDF). The input amount is adjusted as necessary in accordance with the heating capacity of the heated exchange air input.

The system further comprises means for monitoring and controlling the deposition height (or level) to maintain stable process conditions within the converter. This provides the ability to maintain a stable deposition height within the converter. Controlling the height of the deposit prevents fluidization of the material due to exchange air injection that can occur at low levels, while at the same time impairing the temperature distribution throughout the deposit by limiting the air flow that occurs at high levels Also prevent. By maintaining a stable deposition height, a constant converter residence time is also guaranteed.

A series of level switches in the gasifier measure the depth of deposition. In one embodiment, the level switch is a microwave device with an emitter on one side of the gasifier and a receiver on the other side to detect the presence of solid material at that point in the converter.

In one embodiment of the invention, a lateral transfer unit is provided for moving material being gasified from different areas of the gasifier. The amount and location of the raw material of the gasifier is a function of the feed rate, the movement of the lateral transfer unit, and the heated exchange air charge. Thus, in such an embodiment, the control subsystem comprises means for controlling the movement of material from different areas of the gasifier as needed.

In one embodiment, the lateral transfer unit is an arm and the feed is carried through different areas of the gasifier at a rate determined by the length and frequency of the stroke. For example, the control subsystem may include a limit switch or a control switch, such as a computer controlled variable speed monitoring drive that controls the length, speed and / or frequency of the ram stroke so that the amount of material moving with each stroke can be controlled. Other movement control means can be provided.

In one embodiment, the transverse transfer unit comprises one or more screw conveyors, and the transfer rate of the material in the gasifier is controlled by adjusting the conveyor speed from a drive motor variable frequency drive.

In one embodiment of the present invention, the control subsystem comprises means for adjusting the power and optionally the position of the plasma heat source. For example, if the temperature of the product gas at the gas outlet of the converter is too high, the control subsystem can instruct the power source of the plasma heat source to be reduced.

Use of gasification systems / processes

The system according to the invention gasifies the feedstock using a process for gasification of the feedstock, which generally comprises the step of passing the feedstock to a converter that depends on the heating action of the heated exchange air. When heated by the exchange air, the raw material is dried and the volatile components of the dried raw material are volatilized. In an embodiment of the present invention, the heated exchange air facilitates complete conversion of the resulting carbon to gaseous constituents, leaving an ash byproduct. The product of the combination of drying, volatilization and combustion steps provides off-gas, by heat from the plasma heat source, and further off-gas uses carbon monoxide, carbon dioxide, hydrogen, steam (and air in the gasification process) Is converted into a hot gas product containing nitrogen). Steam and / or air process additives can optionally be added in the gasification and / or off-gas conversion stages.

In an embodiment of the invention, the process further comprises the step of heating the byproduct ash to form a slag product by means of a second plasma heat source.

The process of the present invention includes passing a hot gas product through a heat exchanger, transferring heat from the hot product gas to air to produce heated exchange air and a cooled product gas, carbon, Using heated exchange air for gasification of the raw material.

The process of the present invention involves passing the cooled gas product through a second heat exchanger and further transferring heat from the first cooled gas to water to produce cooled gas and steam. A moving step.

The process of the present invention maximizes net conversion efficiency by creating heat to drive the gasification process, driving a rotating machine, and offsetting the amount of electricity consumed in the power of the plasma heat source. . In applications aimed at power generation, efficiency refers to comparing the energy consumed during the entire gasification process to the amount of energy produced using the product gas (eg, driving a gas turbine or fuel cell technology), And by the recovery of sensible heat to produce the steam that drives the steam turbine.

The gasification process is based on changes in product gas flow / pressure, temperature and / or composition, one or more feed inputs, exchange air flow, product gas flow, steam process additive inputs, and The method may further comprise a feedback control step of adjusting the amount of power provided to the plasma heat source. In this way, the feedback control step allows the synthesis gas flow rate, temperature and / or composition to be kept within acceptable limits.

In one embodiment of the invention, the process further comprises preheating the carbonaceous feedstock before adding it to the converter.

In one embodiment, the gasification process according to the present invention employs the use of exchange air to heat the gasifier to a temperature suitable for raw material gasification. In another embodiment, this is typically used at the start of the system, but air is delivered into the system and uses plasma heat or heat recovered from other stages of the gasification process. To provide a hot starting gas that can be heated and enters a gas-to-air heat exchanger to produce heated exchange air. Exchange air is sent to the exchange air inlet to heat the gasifier so that the entire process can be performed without using fuel.

FIGS. 11A and 11I represent various options for heat reuse in accordance with the present invention.

FIG. 11A is a block flow diagram representing an embodiment of the present invention, in which high-temperature production gas 5020A is produced by gasifying a carbonaceous feedstock with converter 1000A. The hot product gas 5020A passes through the heat exchanger 5100A, and through the heat exchanger, heat is transferred from the hot product gas 5020A to the air 5010A by the air blower 5012A, and heated exchange air. 5015A and the cooled production gas 5025A are produced. The heated exchange air 5015A is then returned to the converter 1000A to facilitate the gasification process. The cooled product gas 5025A is then further cooled by a dry quench step 6111A before passing through the gas conditioning system 6000A. The product gas is combusted by the gas engine 5060A after cooling and cleaning, and high-temperature combustion gas 5061A is discharged to the atmosphere.

FIG. 11B is a block flow diagram representing an embodiment of the present invention, in which high-temperature production gas 5,020B is produced by gasifying a carbonaceous feedstock with converter 1000B. The hot product gas passes through the heat exchanger 5100B, and through the heat exchanger, heat is transferred from the hot product gas 5020B to the air 5010B by the air blower 5012B, and heated exchange air 5015B. And the cooled production gas 5023B is produced. The heated exchange air 5015B is then returned to the converter 1000B to facilitate the gasification process. Additional heat is recovered from the cooled product gas 5023B by passing the product gas through the heat recovery steam generator 5300B prior to passing through the gas conditioning system 6000B. The additional heat is transferred to water 5030B to produce steam 5035B. The product gas is combusted by the gas engine 5060B after cooling and cleaning, and the high-temperature combustion gas 5061B is discharged to the atmosphere.

FIG. 11C is a block flow diagram illustrating the embodiment of FIG. 11B, where the hot combustion gas 5061B from the gas engine passes through the second heat recovery steam generator 5300C and the heat from the hot combustion gas is The water 5030C is moved to generate steam 5030C.

FIG. 11D is a block flow diagram illustrating the embodiment of FIG. 11B, where steam 5035B generated by heat recovery steam generator 5300B is used to drive steam turbine 5065D to generate electricity.

FIG. 11E is a block flow diagram illustrating the embodiment of FIG. 11C, where steam (5035B and 5035C) generated by the heat recovery steam generators (5300B and 5300C) is used to drive a steam turbine 5065E. ,Generate electricity.

FIG. 11F is a block flow diagram illustrating the embodiment of FIG. 11B, where heated exchange air 5015B also passes through the raw conditioner 5067F and is delivered to the converter 1000B for gasification. The raw material 5088F is previously dried.

FIG. 11G is a block flow diagram illustrating the embodiment of FIG. 11B, where steam 5035B generated in heat recovery steam generator 5300B is used to indirectly heat feed conditioner 5067G for gasification. The raw material 5088G is previously dried before being fed to the converter 1000B.

FIG. 11H is a block flow diagram representing an embodiment of the present invention, in which high-temperature production gas 5020H is produced by gasifying a carbonaceous feedstock with converter 1000H. The hot product gas 5020H passes through the heat exchanger 5100H, and heat is transferred from the hot product gas 5020H to the air introduced from the heat exchanger by the air blower 5012H, and heated exchange air 5015H. And the cooled production gas 5025H is produced. The heated exchange air 5015H is then returned to the converter 1000H to facilitate the gasification process. The cooled product gas then passes through a gas conditioning system. The product gas is combusted in the gas engine 5060H after cooling and cleaning, and high-temperature combustion gas 5061H is discharged to the atmosphere. This embodiment includes a solid residue conditioning step, where the hot gas produced in the solid residue conditioning 4020H also passes through the heat exchanger 5105H and heat from the hot gas enters the air 5110H entered from the heat exchanger 5105H. To produce a second heated air product 5115H. The second heated air product 5115H is then used to indirectly heat feed conditioner 5067H, so that feed 5088H is pre-loaded before being fed to converter 1000H for gasification. dry.

FIG. 11I is a block flow diagram representing one embodiment of the present invention, in which hot product gas 5020I is produced by gasifying a carbonaceous feedstock with converter 1000I. The hot product gas 5020I passes through the heat exchanger 5100I, and heat is transferred by the air blower 5012I from the hot product gas 5020I to the air introduced from the heat exchanger, and heated exchange air 5015I. And the cooled production gas 5025I is produced. The heated exchange air 5015I is then returned to the converter 1000I to facilitate the gasification process. The cooled product gas 5025I then passes through the gas conditioning system 6000I and enters the system for storage and homogenization of the gas product 7000I. Part of the product gas 5125I is then combusted in the gas engine 5060I and the hot combustion gas 5061I is exhausted to the atmosphere, while another part of the product gas 5225I is combusted in the bus burner 5067I for another gasification system. Provides heat for preheating the converter 1005I.

The present invention will now be described with reference to specific examples. It will be understood that the following examples are intended to illustrate embodiments of the invention and are not intended to limit the invention in any way.

Example

Generally, the system of the present invention is used by delivering replacement air to a converter where the feed receives sufficient heat to allow gasification to occur.
In the exemplary embodiment shown in FIGS. 12 and 13, gasifiers 2100 and 2200 each have a stepped floor with three floor levels or steps. Optionally, each floor level has a slope between about 5 and about 10 ° C. In a stepped bed gasifier, the individual steps (bed level) provide the right conditions for each drying, volatilization, and carbon to ash conversion stage of the gasification process, enabling optimization of the gasification process Will do.

In each of these typical gasifiers, the feed is fed to the first step and conditions are provided so that drying is a major process and some volatilization and conversion from carbon to ash. . The normal temperature range for this step (measured at the bottom of the material deposition) is between 300 and 900 ° C.

Then, the dried raw material is sent to the second step, and the main process is to volatilize the dried raw material to form carbon, with a small part of the drying operation (remainder) and part of the carbon converted to ash. As such, conditions are provided. The normal temperature range for this step is between 400 and 950 ° C.

Next, the carbon is moved to a third step where conditions are provided such that the conversion of carbon to ash is the main process and a small amount of volatilization (remainder) occurs. The normal temperature range is between 600 and 1000 ° C.

Movement between steps is facilitated by a lateral transfer unit, each step optionally being performed by an independently controlled lateral transfer unit.

In the gasifier embodiment depicted in FIG. 12, the gasifier 2100 is a horizontally oriented gasification chamber covered with a refractory having a raw material input 2104, a gas outlet 2106 and a solid residue outlet 2108. 2102. The gasification chamber 2102 has a stepped floor with a plurality of floor levels 2112, 2114 and 2116. Each floor level has a series of replacement air inlets 2126 located on the side wall near the floor level so that replacement air can be added. The input of exchange air is adjusted to promote gasification of the reaction material.

In the gasifier embodiment depicted in FIG. 13, the gasifier 2200 includes a horizontally oriented gasification chamber covered with a refractory having a raw material input 2204, a gas outlet 2206 and a solid residue outlet 2208. 2202. The gasification chamber 2202 has a stepped floor with a plurality of floor levels 2212, 2214, and 2216.

Each level or step has a perforated floor so that heated air can be introduced. The air delivery for each level or step can be controlled independently. The delivery and distribution of air independently from the perforated floor 2270 is accomplished by separate air boxes 2272, 2274 and 2276 that form the floor at each step.

Although an air box is shown in FIG. 14, the air box perforated top surface 2302 and the connection flange 2280 for connection to the replacement air conduit system are clearly represented.

The off-gas formed in the gasifier is then processed in the reforming chamber by a plasma heat source and optionally steam and additional heat exchange air. These additives are optionally added in the reforming step so that the formation of the product gas necessarily has a defined composition. The temperature during the reforming step is maintained in a sufficiently high range to maintain the reaction at an appropriate level that ensures complete conversion to a defined gas product while minimizing the generation of contaminants. In an exemplary embodiment, the temperature range of the reforming step is from about 900 ° C to about 1300 ° C.

If the temperature of the product gas is too high after the reforming step, steam is optionally added to lower the product gas discharge temperature. The product gas exits the plasma reforming zone at a temperature of about 900 ° C. to about 1100 ° C. In an exemplary embodiment, the product gas discharge temperature is about 1000 ° C. + / − 100 ° C. The flow rate of the hot product gas is about 6000 Nm ³ / hour to about 9500 Nm ³ / hour, typically about 7950 Nm ³ / hour. The hot product gas is then passed to a gas to air heat exchanger.

In the current example, air enters the gas-to-air heat exchanger at ambient temperature, ie, from about −30 ° C. to about 40 ° C. Air circulates system using air blowers, about 1000 Nm ³ / about 5150Nm ³ / time from the time, and typically falls between about 4300Nm ³ / hr for gas heat exchanger to the air.

In this example, the air is heated with a heat exchanger to produce exchange air having a temperature of about 500 ° C. to about 625 ° C. In the exemplary embodiment, the temperature of the exchange air is about 600 ° C. The hot product gas is then cooled to a temperature of about 500 ° C. to about 800 ° C. In an exemplary embodiment, the product gas temperature is about 740 ° C. The heated exchange air is passed from the exchange air inlet to the gasifier and gasifies the raw material as described above.

The gas-to-air heat exchanger of the exemplary embodiment is a shell-tube heat exchanger designed specifically for high levels of specific loads of product gas, with the product gas flowing to the tube side, The air now flows through the counter on the shell side.

In an exemplary embodiment, the cooled product gas is further cooled using a dry quench step to remove excess heat from the product gas, so that the cooled product gas required for subsequent filtering and conditioning steps. Is provided. The cooled product gas then passes through a gas conditioning stage to remove oxidizing gases, heavy metals, particulate matter and other contaminants.

Residual by-products of the gasification process are further conditioned in a residue conditioning chamber by melting with a dedicated plasma heat source. The products of the residue conditioning step are inert slag material and hot gas.

While the invention has been described with reference to certain specific embodiments, various modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims. is there.

The publication of all patents, printed materials such as published patent applications, and referenced database entries are specifically and individually indicated as each individual patent, printed material, and database entry is incorporated by reference. As such, it is specifically incorporated by reference in its entirety.

Claims (10)

A system for reusing heat recovered from high-temperature gas in a carbonaceous raw material gasifier,
Means for transferring the hot gas to a gas-to-fluid heat exchanger, wherein heat from the hot gas is transferred to the fluid to produce a heated fluid and a cooling gas;
Means for moving the heated fluid to the gasifier;
A control system comprising a sensing element for monitoring operating parameters of the system and a response element that adjusts operating conditions in the system to optimize the gasification process;
The response element minimizes the energy consumption of the process while maximizing energy production by adjusting the operating conditions in the system in response to data obtained from the sensing element. A system characterized by optimizing the efficiency of the gasification process.   The system of claim 1, wherein the hot gas is a gas produced during a carbonaceous feed gasification process.   The system of claim 2, wherein the fluid is air, water, oil, nitrogen or carbon dioxide.   4. The system of claim 3, wherein the fluid is air and the gas-to-fluid heat exchanger is a gas-to-air heat exchanger.   The system of claim 3, wherein the fluid is air and the gas-to-fluid heat exchanger is a heat recovery steam generator. A system for reusing heat recovered from high-temperature gas in a carbonaceous raw material gasifier,
Means for transferring the hot gas to a gas-to-air heat exchanger, wherein the heat from the hot gas is transferred to air to produce heated air and cooling gas;
Means for moving the heated air to the gasifier.   The system according to claim 6, wherein the high-temperature gas is a gas produced in a gasifier during a carbonaceous raw material gasification process.   The means for moving the hot gas to the gas to air heat exchanger provides fluid communication between a hot gas outlet on the gasifier and a hot gas inlet of the gas to air heat exchanger. A means for transferring the heated air to the gasifier is provided between an air outlet on the gas-to-air heat exchanger and an air inlet on the gasifier. An air conduit system for providing fluid communication, wherein the hot gas is transferred from the gasifier to the gas-to-air heat exchanger via the hot gas conduit, and the heated air is supplied to the air conduit system. 7. The system of claim 6, wherein the system moves from the gas-to-air heat exchanger to the air inlet of the gasifier. From the hot gas produced by the gasification process using a gas-to-fluid heat exchanger comprising a hot product gas inlet in communication with the cooled product gas outlet and a cooling fluid inlet in communication with the heated fluid outlet A process for improving the efficiency of the gasification process of a carbonaceous raw material by returning sensible heat to the gasification process and reusing it,
Passing the hot product gas to the gas-to-fluid heat exchanger via the hot product gas inlet;
Passing the cooling fluid to the gas-to-fluid heat exchanger via the cooling fluid inlet;
The high temperature production so as to produce a cooled production gas exhausted from the heat exchanger via the cooled production gas outlet and a heated fluid exhausted from the heat exchanger via the heating fluid outlet. Moving gas to the cooling fluid via a gas-to-fluid heat exchanger;
Using the heated fluid to provide heat for the carbonaceous feedstock gasification process.   The process of claim 9, wherein the fluid is air and the gas to fluid heat exchanger is a gas to air heat exchanger.

Images