WO2011029283A1

WO2011029283A1 - Method for composite utilizing coal and system thereof

Info

Publication number: WO2011029283A1
Application number: PCT/CN2010/001407
Authority: WO
Inventors: 毕继诚; 李金来; 甘中学
Original assignee: 新奥科技发展有限公司
Priority date: 2009-09-14
Filing date: 2010-09-14
Publication date: 2011-03-17
Also published as: CN101792680B; CN101792680A

Abstract

A method for composite utilizing coal and a system thereof are provided. Said method comprises: converting coal into clean energy sources such as methane and the like and/or clean electric power by integrating such sub-methods as multi-section coal gasification, coal-based poly-production, hydrogen production by composite energy and/or carbon absorption by algae. In the sub-method of multi-section coal gasification coal powder is added to gasification furnace having a partial pyrolysis region (40), a catalytic gasification region (41) and a residue gasification region (42) to produce a gas stream containing methane in the presence of catalyst and gasification agent. Said system comprises a gasification furnace for producing gas containing methane through coal gasification and a poly-production subsystem. Said furnace has a partial pyrolysis region (40), a catalytic gasification region (41) and a residue gasification region (42).

Description

Comprehensive utilization method and system of coal

The present invention relates to coal chemical industry, and more particularly to a method and system for comprehensive utilization of coal in a multi-zone coal gasification sub-method and sub-system coupled with other sub-methods and subsystems.

Background technique

China is a country rich in coal and oil-poor. With the rapid development of society and economy, China's natural gas demand has risen sharply, and the proportion in the energy structure has increased rapidly. While domestic natural gas is still in the early stage of exploration and development, imports are also in their infancy, and supply capacity is seriously lagging behind, resulting in an increasingly prominent contradiction between natural gas supply and demand. The use of coal with relatively large resource advantages in China can not only promote the efficient and clean utilization of coal; but also utilize existing natural gas pipelines to effectively alleviate the contradiction between supply and demand of natural gas at a lower economic cost. This is a synthesis of inferior coal resources. Powerful measures to take advantage of.

The usual coal gasification technology, that is, the gasification of coal at a high temperature with oxygen (or air) and/or steam (also called steam), produces a synthesis gas containing a small amount of methane (CH ₄ ) ( Mainly hydrogen, carbon monoxide and carbon dioxide), followed by a water gas shift and methanation process, using a two-step process to prepare methane. The coal gasification technology has the disadvantages of high temperature required for gasification reaction, high energy consumption, high requirements on equipment, three reaction devices and complicated processes.

Coal catalytic gasification technology is an important way to clean and use coal. It uses coal catalytic gasification technology. Coal is composed of steam (H ₂ 0 ), hydrogen (H ₂ ) and carbon monoxide (CO) at relatively low temperature. The gasification agent undergoes a gasification reaction under the catalytic action of the catalyst to form a high concentration of decane (CH ₄ ). Compared with other coal gasification technologies, coal catalytic gasification technology has the advantages of high methane content and low temperature required for gasification reaction.

At present, the coal-catalyzed gasification technology mentioned in the relevant patents, the optimum temperature and pressure range required for gasification reaction are 593 ~ 700X and 20 ~ 40atm, using alkali metal carbon The acid salt acts as a catalyst. The cryogenic separation is used to separate the decane in the gas from the carbon monoxide and the hydrogen, and the hydrogen and carbon monoxide in the reaction gas are recycled to the gasification furnace to be converted into decane by a decane reaction in the gasifier. Thereby increasing the production of system methane. The coal catalytic gasification technology has the disadvantages of low gasification reaction rate, long reaction time, low carbon conversion rate and high investment in gas separation system; in order to meet the heat balance of the reactor, it is necessary to heat the superheated steam into the higher temperature. Steam superheating systems and heat exchange systems have high loads and poor economics.

U.S. Patent 4,077,778 proposes a coal catalytic gasification process using a multi-stage fluidized bed reactor to eliminate the deficiencies of the original catalytic gasification process, to make gasification more efficient, to fully utilize feed carbon resources, and to improve carbon conversion. rate. The mainstream bed reactor operates at a higher gas velocity, entraining some of the carbon particles into the secondary fluidized bed reactor, and performing a gasification reaction at a lower gas velocity, increasing the solid phase residence time and maximizing the carbon conversion rate. Multi-stage gasification can increase carbon utilization from 70 - 85% to over 95% compared to single-stage gasification. However, the coal catalytic gasification process uses a plurality of fluidized bed reactors, and the equipment investment is high and the operation is complicated.

In addition, U. The water-soluble catalyst is recovered by multi-stage water washing, and the insoluble catalyst is recovered by lime digestion. U.S. Patent No. 0,277,437, based on U.S. Patent No. 4,094,650, which utilizes a primary treatment to separate the alkali metal material from the reactor solid residue, simplifying the alkali metal. The catalyst recovery process improves the economics and overall efficiency of the catalytic gasification process, but the recovery system is still complicated and the recovery method is expensive.

In addition, in order to make full use of heat and to produce gas, U.S. Patent No. 5,064,444 proposes a method for gasification of pressurized steam, and the fluidized bed gasification furnace is divided into a pyrolysis section, a gasification section, and a cooling section. Separate with a partition. A serpentine coil (snake heat exchanger) is placed in the pyrolysis section and the gasification section of the gasification furnace, and a high temperature gas such as a 900X-950 is introduced into the tube. The burned gas heats the pulverized coal to provide heat for gasification and pyrolysis to produce gas. The fluidized bed gasifier can be vertical or horizontal, with a superheated steam of 700 Π - 800 as a gasifying agent, and a cooling steam is introduced into the cooling section, and the pulverized coal is entrained in the gasification furnace together with the superheated steam. However, the utilization rate of the reaction volume in the gasification furnace is low, which affects the solid phase processing; only the superheated steam is used as the gasifying agent, so that the carbon conversion rate is not high, so the carbon content in the residue is high, and the coal is difficult to be effectively utilized; The heat in the high-temperature gas needs to be transmitted to the coal powder and steam through the wall of the serpentine coil. Compared with the gas-solid contact heat transfer, the indirect heating method has a slow heat transfer rate and low thermal efficiency, and the solid phase in the bed is not heated. At the same time; the equipment is complicated, especially the horizontal furnace.

After the separation of decane from the product of coal catalytic gasification, there is still syngas present, which needs to be further utilized to produce sterol, ethylene glycol, lower alcohol or dimethyl ether. At the same time, the system also produces carbon dioxide, and the impact of carbon dioxide emissions on global climate change has been the focus of the world, so it is necessary to solve the problem of carbon dioxide emissions.

When syngas produces decane, decyl alcohol, ethylene glycol, lower alcohols or dioxins, it is often necessary to adjust the hydrocarbon ratio (such as adding a certain amount of hydrogen to the synthesis gas or supplementing carbon monoxide). At present, about 96% of industrial waste is derived from fossil energy sources such as natural gas, petroleum and media. However, the production technology and process for producing hydrogen from fossil energy cannot solve the problem of carbon dioxide emissions, and thus cannot achieve eco-circulation production. Among other hydrogen production technologies, currently widely used and relatively mature hydrogen production methods include water electrolysis hydrogen production, biological hydrogen production, bioelectrochemical hydrogen production, and photoelectrochemical hydrogen production. The use of renewable energy sources (including solar energy, wind energy, etc.) as a power source for water electrolysis hydrogen production is currently the most promising and most viable technology known as the best way to the hydrogen economy.

In summary, coal-based chemical polygeneration technologies developed in various countries in the world have not systematically considered the problem of carbon dioxide resource utilization. How to control and reduce the carbon dioxide generated by coal in the process of conversion and combustion, and use it to become a new type of coal. The primary problem in the development of chemical technology. Although given the severity of the "greenhouse effect", European and American countries In recent years, the coal-based near-zero emission polygeneration system has been studied. However, due to the stable chemical nature of carbon dioxide, this coal-based near-zero emission polygeneration system cannot achieve carbon dioxide emission reduction in the production process. It can only be used for capture and storage. The method is solved, and this method is costly and cannot really reduce carbon dioxide in quantity. In the long run, it is only a matter of expediency. To completely solve the problem of carbon dioxide, we must break through the limitations of existing fossil energy, introduce renewable energy into the production process of coal-based chemical products, realize the integration of multiple energy sources, convert carbon dioxide into energy chemical products, and realize carbon dioxide in the production process. Near zero emissions.

Summary of the invention

The invention provides a comprehensive utilization method of coal, which comprises:

A multi-zone coal gasification process and a multi-generation sub-process, wherein the multi-zone coal gasification process comprises the following steps:

a. adding pulverized coal to a partial pyrolysis zone of a gasification furnace comprising a partial pyrolysis zone, a catalytic gasification zone and a residue gasification zone, where the pulverized coal is in contact with a gas stream from the catalytic gasification zone for partial heat Solving the pulverized coal to form a methane-containing gas stream and a partially pyrolyzed coal powder,

b. feeding the partially pyrolyzed coal powder to a catalytic gasification zone and contacting the gas stream from the residue gasification zone in the presence of a catalyst, the resulting gas stream entering a partial pyrolysis zone and an insufficiently reacted coal residue entering Residue gasification zone, and

c. contacting the coal residue with the gasifying agent in the residue gasification zone, and the generated gas stream enters the catalytic gasification zone and the generated ash is discharged to the gasification furnace.

In a preferred embodiment, the method of the invention further comprises an algae carbon uptake method.

In a preferred embodiment, the method of the present invention further comprises a composite energy hydrogen generation process.

In a preferred embodiment, the method of the invention further comprises recovering multi-zone coal The catalyst, water or vapor in the gasification process recovers and recycles the solid material in the decane-containing gas stream, and generates or generates steam from waste heat or residual pressure in the process.

The application also provides a comprehensive utilization system for coal, including:

A gasification furnace and a polygeneration subsystem for preparing a methane-containing gas by gasification, wherein the gasification furnace for preparing a gas containing methane by gasification includes, in order from top to bottom:

a part of the pyrolysis zone for contacting the pulverized coal with the gas stream from the catalytic gasification zone, and the generated decane-containing gas stream exits the gasifier and generates a portion of the pyrolyzed pulverized coal to be fed to the catalytic gasification zone ;

b. a catalytic gasification zone for contacting a portion of the pyrolyzed coal powder from the partial pyrolysis zone with a gas stream from the residue gasification zone, the resulting gas stream entering the partial pyrolysis zone and the less fully reacted coal The residue is sent to the residue gasification zone; and

c. a residue gasification zone for contacting the coal residue from the catalytic gasification zone with a gasifying agent, and the generated gas stream enters the catalytic gasification zone, and the generated ash is discharged to the gasification furnace.

In a preferred embodiment, the system of the present invention further comprises an algae carbon uptake subsystem.

In a preferred embodiment, the system of the present invention further includes a composite energy hydrogen production subsystem.

In a preferred embodiment, the system of the present invention further comprises an apparatus for recovering a catalyst, water or steam in a gasification furnace for gasification to produce a gas containing decane, recovering the solid material in the decane-containing gas stream and Circulating equipment, and equipment that uses the residual heat or residual pressure in the system to generate electricity or generate steam.

DRAWINGS

1 is a schematic structural view of a gasification furnace according to an embodiment of the present invention;

2 is a multi-zone coal gasification method and polygeneration method of the present invention, and algae suction A schematic diagram of one embodiment of a combination of a carbon sub-method and a composite energy hydrogen production sub-method. 3 is a schematic view showing another embodiment of the multi-zone coal gasification process of the present invention in combination with a polygeneration process, an algae carbon uptake process, and a composite energy hydrogen generation process.

Figure 4 is a schematic illustration of one embodiment of a multi-zone coal gasification process and a multi-generation sub-method and a sub-method of recovering energy of the present invention.

It is to be understood that the appended drawings are not intended to The scope of the invention should be determined by the content of the claims. Detailed ways

1. Multi-zone coal gasification method and subsystem

To carry out the method of the present application, the multi-zone coal gasification process comprises the steps of: a. adding pulverized coal to a partial pyrolysis zone of a gasification furnace comprising a partial pyrolysis zone, a catalytic gasification zone and a residue gasification zone, Wherein the pulverized coal is contacted with a gas stream from the catalytic gasification zone to partially pyrolyze the pulverized coal to form a decane-containing gas stream and a partially pyrolyzed pulverized coal.

c. contacting the coal residue in the residue gasification zone with the gasifying agent, and the generated gas stream enters the catalytic gasification zone and the generated ash is discharged to the gasification furnace. The core equipment used in the sub-method of the present invention is a multi-zone gasifier. The gasifier is generally placed vertically or tilted, and is inclined at an angle sufficient to cause the solid material in the furnace, such as pulverized coal, to move downward under its own weight. The gasifier can be divided into three zones from bottom to top using a distribution plate. According to the functions of each zone, the residue gasification zone, the catalytic gasification zone and the partial pyrolysis zone are sequentially shown in Fig. 1. The distribution plate is typically a porous distribution plate. Among them, solid materials, such as coal, move from top to bottom, and finally from gas. The slag discharge port at the bottom of the furnace leaves the gasifier, and the gas material moves from the bottom to the bottom, and finally exits the gasifier from the exhaust port at the top of the gasifier. The solid material and the gaseous material are in substantially countercurrent contact form within the gasifier. In the gasification furnace of the present invention, the temperature is substantially closer to the bottom, and the temperature is lower toward the top.

In the sub-method of the present invention, the feed position of the coal, gasification agent and catalyst can be selected or adjusted as needed. For example, at least a portion of the coal may enter the gasifier from any one or more of the partial pyrolysis zone and/or the catalytic gasification zone of the gasifier of the present invention; even when the heat generated by the gasification of the residue alone is insufficient When maintaining the temperature requirements for catalytic gasification, a portion of the coal can also be passed from the residue gasification zone to the gasifier. The catalyst can be fed into two types. For the catalyst which can be gasified at the high temperature of the residue gasification zone of the present invention, for example, an alkali metal carbonate can be obtained from a partial pyrolysis zone of the gasifier and/or Or the catalytic gasification zone and/or the residue gasification zone are passed into the gasification furnace; and for the catalyst which cannot be gasified at the high temperature of the residue gasification zone of the present invention, such as an alkaline earth metal carbonate, from partial pyrolysis The zone and/or catalytic gasification zone is passed to the gasifier; and the gasification agent is passed into the gasifier from the bottom and/or sides of the residue gasification zone. Regardless of the zone from which the coal and catalyst are fed, they eventually contact each other in the catalytic gasification zone of the gasifier and simultaneously with the gas stream containing the syngas. Obviously, the coal and the catalyst may also be mixed, for example, the coal powder is directly mixed with the catalyst itself, or the coal powder is mixed with the aqueous catalyst solution, and the like. When the feed is mixed, the mixture of the two may be fed from one or more of the catalytic gasification zone or the coal pyrolysis zone. There is no limitation on the coal used in the present invention, which may be selected from the group consisting of bituminous coal, anthracite, lignite, etc., and is preferably pulverized into pulverized coal before entering the gasification furnace of the present invention. The particle size of the pulverized coal may generally be 0.1 to 1 mm.

Step a of the first embodiment of the present invention occurs in a partial pyrolysis zone of the gasification furnace, the coal added to the zone is in contact with the gas stream from the catalytic gasification zone, and the coal powder is partially pyrolyzed to form a A gas stream of methane and a partially pyrolyzed coal powder. The All of the gas in the zone leaves the gasifier, while the partially pyrolyzed coal moves down the gasifier. In this step, at least a portion of the coal is passed from the partial pyrolysis zone to a gasifier, preferably a majority of the coal, even more preferably all of the coal, is passed from the partial pyrolysis zone to the gasifier. The advantage of this is that the heat released by the methanation reaction of the synthesis gas in the catalytic gasification zone is fully utilized, and the heat enters the partial pyrolysis zone with the gas after the reaction in the catalytic gasification zone, and the partial pyrolysis zone The coal entering the gasifier contacts, the coal is preheated and rapidly pyrolyzed, and the volatiles in the coal are pyrolyzed. Since the volatile matter of the coal contains decane, the zone not only plays a role in preheating the coal. Further, the decane content in the gaseous product is further increased by partial pyrolysis of the coal. The pyrolysis also produces tar, which leaves the gasifier with the gas product under the conditions of the zone, and the partially pyrolyzed coal powder enters the lower zone of the gasifier to continue the reaction. The temperature in the portion of the pyrolysis zone is primarily regulated by the gas flow rate of the zones below and the amount of coal powder fed to the zone, typically 450-650.

Step b of the first embodiment of the invention occurs in the catalytic gasification zone of the gasifier. In this step, the partially pyrolyzed coal powder is fed into the catalytic gasification zone and contacted with the gas stream from the residue gasification zone by the catalyst to react and form a gas stream and an insufficiently reacted coal residue, wherein The resulting gas stream mainly contains CH ₄ , C0, H ₂ and C0 ₂ , and a small amount of H ₂ S, NH ₃ and the like. The main reactions occurring in this catalytic gasification zone are as follows:

2C + 2H ₂ 0 → 2H ₂ + 2C0 (1)

CO + H ₂ 0 → C0 ₂ + H ₂ (2)

3H ₂ + CO → CH ₄ + H ₂ 0 (3)

C + 2H ₂ → CH ₄ (4)

The reaction temperature of the catalytic gasification zone is 650 ~ 750, and the pressure is 0. 1 ~ 4MPa (absolute pressure, the same below). In the catalytic gasification zone, CO and H ₂ from the gasification zone of the gasifier residue undergo a decaneization reaction under the action of a catalyst, such as reaction formula (3) As shown, the ruthenium yield is increased while the evolved heat of reaction is carried upward by the reaction-generated gas into the partial pyrolysis zone to carry out step a, while the insufficiently reacted coal residue enters the residue gasification zone. In addition, reactions such as carbon gasification reactions (1) and (4), carbon monoxide shift reaction (2), and the like occur. Wherein the catalyst is selected from the group consisting of: (1) an alkali metal or alkaline earth metal oxide, carbonate, hydroxide, acetate, nitrate, halide or a mixture thereof, such as sodium oxide, calcium oxide, sodium carbonate , potassium carbonate, lithium carbonate, calcium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium acetate, calcium nitrate, calcium chloride, etc.; or (2) oxides of transition metals, such as iron, cobalt, nickel, An oxide of molybdenum or the like; or a mixture of the above (1) and (2). When the catalyst is an oxide of a transition metal, the oxide of the transition metal can be formed in situ by adding a decomposable salt or hydroxide of a transition metal to the gasifier, since these decomposable salts or hydroxides are The gasifier is easily decomposed into the corresponding oxide at high temperatures. 5〜 0. 2。 The ratio of the ratio of the catalyst and the pulverized coal is 0. 05 ~ 0. 2.

Step c of the first embodiment of the present invention occurs in the residue gasification zone of the gasifier. After the coal residue of step b enters the zone, it is contacted with a gasifying agent which is introduced into the zone, wherein the gasifying agent contains oxygen and saturated steam or superheated steam, wherein the temperature of the superheated steam may be 200-500. The weight ratio of the oxygen entering the gasifier to the coal powder entering the gasifier is 0.1 to 1. 0. The superheated steam and oxygen may be passed to the zone as a mixture, or may be passed to the zone separately and mixing occurs in the zone. The main reactions that occur in this area are as follows:

C + 0 ₂ → C0 ₂ (5)

C + C0 ₂ → 2C0 (6)

C + H ₂ 0 → CO + H ₂ (7)

CO + H ₂ 0 → C0 ₂ + H ₂ (8) These reactions produce a gas stream including ash and ash, and the total conversion of carbon in the zone can be over 90%. The gas stream including the syngas further includes carbon dioxide and unreacted water vapor and possibly oxygen, the gas stream is directed upward into the catalytic gasification zone to perform step b, and the ash is discharged Gasifier. Since the reaction in this zone is a strong oxidation reaction, a large amount of heat is released, so the temperature in this zone is the highest in the gasifier. The temperature of the zone can be controlled to a temperature suitable for the synthesis gas by adjusting the feed rate and/or composition of the gasifying agent, typically from 800 to 1200, and the heat of reaction evolved to provide the above catalytic gasification zone. Heat. 1 - 1. The weight ratio of the oxygen entering the gas to the gasifier is generally 0. 1 ~ 1. 0. If the catalyst used in the process of the present invention is not vaporizable at the temperature of the zone, the catalyst is withdrawn from the gasifier as the ash is passed to the catalyst recovery unit for recovery; if the catalyst employed in the process of the invention is The gas can be vaporized at the temperature of the zone, and the catalyst is vaporized into a vapor and flows upward into the catalytic gasification zone along with the gas stream including the synthesis gas, and condenses on the coal as the gas temperature decreases. Repeat the catalytic effect.

Alternatively, more broadly, in the multi-zone coal gasification process of the present invention, a partial pyrolysis zone may be omitted, and therefore, the multi-zone coal gasification process of the present invention may include the following steps

1) adding pulverized coal to a catalytic gasification zone of a gasification furnace containing a catalytic gasification zone and a residue gasification zone, where the pulverized coal is contacted with a gas stream from the residue gasification zone in the presence of a catalyst to form a a gas stream of decane and an insufficiently reacted coal residue, and

2) The coal residue of step 1) is sent to the residue gasification zone to be in contact with the gasifying agent, and the generated gas stream enters the catalytic gasification zone and the ash is discharged to the gasification furnace.

At least a portion of the coal enters the gasifier from the catalytic gasification zone. In step 1), the coal in the catalytic gasification zone and the gas stream from the residue gasification zone are in the catalyst Contacting to form a decane-containing gas stream and an insufficiently reacted coal residue, wherein the catalyst, temperature, pressure process conditions, and the like are substantially the same as those described above for step b of the first embodiment, and the resulting The methane gas stream flows upwardly out of the gasifier, while the less fully reacted coal residue moves down to the residue gasification zone.

In step 2), the coal residue from step 1) enters the residue gasification zone and is contacted with a gasifying agent, wherein the reaction occurring in step 2), the type and composition of the gasifying agent, the composition of the generated gas stream, The process conditions of temperature, pressure and the like are also substantially the same as step c of the first embodiment above.

The present invention also relates to a comprehensive utilization system for coal, the system comprising a gasification furnace and a multi-generation subsystem for gasification to produce a gas containing decane, wherein the coal gasification furnace for preparing a gas containing formazan is Top to bottom includes:

a partial pyrolysis zone for contacting the pulverized coal with a gas stream from the catalytic gasification zone, and the generated methane-containing gas stream exits the gasification furnace and the generated partially pyrolyzed coal powder is sent to the catalytic gasification zone;

The zones are separated by a distribution plate having holes for the passage of gaseous material. The gas distribution plate is further provided with an overflow device having a tubular form open at both ends, and the overflow device is for flowing the solid phase raw material from the upper layer to the lower layer space from the upper space through the overflow device.

Alternatively, a part of the pyrolysis zone may be omitted, in which case the gasification furnace for gasification of the decane-containing gas in the system of the present invention is sequentially packed from top to bottom. Includes:

a catalytic gasification zone for contacting a pulverized coal with a gas stream from a residue gasification zone in the presence of a catalyst to form a decane-containing gas stream and an insufficiently reacted coal residue;

2) A residue gasification zone for contacting the coal residue from the catalytic gasification zone with a gasifying agent, and the generated gas stream enters the catalytic gasification zone, and the generated ash is discharged to the gasification furnace.

Feeding equipment for introducing materials such as coal, a catalyst, a mixture of coal and a catalyst, a gasifying agent, etc. into a gasifier may be provided in each zone of the gasifier as needed, and these feeding apparatuses are those skilled in the art. openly known. In addition, discharge means for the gas and ash to leave the gasifier are provided at the bottom and top ends of the gasifier, and such discharge devices are also well known to those skilled in the art.

In a preferred embodiment, the gasifier of the present invention includes equipment for introducing at least a portion of the coal from any one or more of the partial pyrolysis zone and/or the catalytic gasification zone of the gasifier to the gasifier. These feeding devices can include silos, rotating feed devices, and the necessary connecting pipes. Depending on whether the gasifier is gasified at atmospheric pressure or high pressure, the feed equipment can be operated at atmospheric or high pressure.

In another preferred embodiment, the gasifier of the present invention includes an apparatus for mixing a catalyst into pulverized coal and an apparatus for directly introducing the catalyst to the gasifier.

In another preferred embodiment, the gasifier of the present invention further comprises means for transporting at least partially pyrolyzed coal fines from the pyrolysis zone to the catalytic gasification zone, such as an overflow pipe, etc., and for use in coal The equipment for transporting the residue from the catalytic gasification zone to the residue gasification zone, such equipment may be a slagging apparatus known in the art. In a preferred embodiment, two slagging devices are arranged in series at the outlet of the bottom end of the gasifier, wherein a valve, a secondary slagging device and a primary slag are arranged between the primary slag discharging device and the gasification furnace. Valves are also provided between the devices, and both slag discharge devices are also provided with venting valves and filling gates. Row In the case of slag, the valve between the primary slagging device and the secondary slag discharging device is first closed, and the valve between the primary slag discharging device and the gasification furnace is opened, and the ash slag is discharged into the primary slag discharging device. After the quality of the ash received by the primary slagging device reaches a set threshold, the charging valve of the secondary slagging device is opened to charge the secondary slag discharging device, and the pressure of the secondary slag discharging device and the primary slag discharging When the pressure of the equipment is the same, the connection gate between the first-stage slagging equipment and the second-stage slagging equipment is opened, and the solid in the first-stage slagging equipment is sent to the second-stage slagging equipment, and the first-stage slagging equipment is closed. The communication valve between the slag discharge devices opens the venting valve of the secondary slagging device to relieve the pressure of the secondary slagging device, and discharges the ash from the secondary slag discharging device.

The sub-method for carrying out the invention using the gasifier of the present invention further comprises a pulverized coal preparation device, a mixing device for mixing the catalyst with the pulverized coal, a device for drying and pre-oxidizing the mixture, and a pulverized coal feeding device, which are They are all well known in the art.

The sub-method for carrying out the invention using the gasifier of the present invention further comprises a device for separating and purifying the methane-containing gas stream leaving the gasifier and a slagging device for discharging the ash from the bottom of the gasifier, and these devices are also It is well known in the art.

Second, the polygeneration sub-method and subsystem

The poly-produced sub-process is used to further utilize the synthesis gas obtained by separating the product of the multi-zone coal gasification process of the present invention from decane to produce methanol, decane, ethylene glycol, lower alcohol, diterpene ether. At least one method. The polygeneration method can be formulated with an appropriate amount of hydrogen or supplemented with carbon monoxide to adjust the hydrogen to carbon ratio. Methods and apparatus for producing these products using syngas are well known in the art.

Third, algae carbon absorption sub-method and subsystem

In order to achieve near zero emissions of carbon dioxide, the method of the present invention also includes an algae carbon uptake sub-process for absorbing the final remaining carbon dioxide of the integrated utilization of the coal.

The algae carbon absorption technology utilizes photosynthesis of algae to absorb the present invention. The carbon dioxide produced in the process produces both oxygen and biomass. The oxygen produced can be recycled back to the multi-zone coal gasification process. The biomass produced can be used to produce biodiesel, and can also be used to produce high value-added products such as astaxanthin, carotenoids, phycobiliproteins, and the resulting algae residues can be directly treated as fertilizers, and bio-fermentation can also produce methane. One or more of hydrogen or ethanol. The generated hydrogen can be fed back to the multi-zone coal gasification process and the multi-generation sub-process to form a recycling process.

Algae can absorb common algae such as algae, green algae, diatoms, algae, dinoflagellates, red algae, diatoms, chlamydia, yellow algae, brown algae or cyanobacteria. Of course, a mixture of various algae can also be used. .

Fourth, composite energy hydrogen generation method and subsystem

The process of the present invention also includes a composite energy hydrogen producer process to provide the hydrogen and/or oxygen required by the process of the present invention.

The composite energy hydrogen generation method is selected from the group consisting of hydrogen electrolysis hydrogen production, biological hydrogen production method, bioelectrochemical hydrogen production method or photoelectrochemical hydrogen production method.

The water electrolysis hydrogen production method can adopt a solid polymer electrolyte (SPE) electrolyzer system, or a conventional alkaline electrolysis cell system, and can also adopt solid polymerization. Electrolyte electrolytic cell system.

Among them, the water electrolysis system based on the solid polymer electrolyte can be divided into two parts as a whole: the process part and the circuit control part, in order to reduce the application of the explosion-proof element, the two parts can be separated and sealed. The process part generally includes an electrolysis module, a water supply module and a gas purification module. To ensure the safety of the electrolysis process, gas alarm devices and purging facilities are generally added in this part; the circuit control part generally includes a power supply module, an electric instrument control module and multiple stages. The switch module, in order to simplify this part, can generally be integrated with circuitry and controlled by a remote computer. The solid polymer electrolyte water electrolysis system (SPE-WE) technology can directly produce high purity (>99.9999%) and high pressure Ol OMPa ) Hydrogen, small in volume, high in hydrogen production, and can be combined with renewable energy power generation systems and fuel cell systems to form a green cycle of energy.

There are two main types of alkaline electrolysis cells: the traditional alkaline electrolysis cell (Alka l ine Electrolyzer) and the emerging solid polymer electrolysis cell. Since the 1970s, researchers have turned their attention to alkaline polymer electrolytes (Alkal ine Sol id Polymer Electrolyte, ASPE). ASPE conducts hydroxide ions instead of protons. The working environment changes from acidic to alkaline, acting as a separator for isolating hydrogen and oxygen, and conducting electricity by conducting hydroxide ions. ASPE alkaline electrolyzers use non-noble metals as catalysts. Currently, nickel-based catalysts are mainly used as binary or multi-component catalysts supplemented by other non-precious metal catalysts. In an alkaline cell, the catalyst is electroplated onto the bipolar plates. Therefore, the catalyst and the bipolar plate are integrated. In the case of bipolar plates, the alkaline cell uses a stainless steel bipolar plate that functions as both a plate and a catalyst substrate. Stainless steel is also chemically stable in alkaline systems. Compared with traditional alkaline electrolyzers, the new alkaline polymer electrolyte membranes are non-toxic, non-polluting, and have excellent mechanical properties, stability and cost. Instead of the toxic asbestos diaphragm, the electrolyte is replaced with deionized water by a 25-30wt% potassium hydroxide solution, which avoids the erosion of the lye, effectively increases the service life of the electrolyzer and reduces maintenance costs. In terms of current density, current efficiency is improved relative to alkaline cells. In electrode preparation, ASPE is used as a solid polymer electrolyte membrane, and a membrane electrode is required. At the same time, a stainless steel flow field is used as a plate, and an alkaline electrolytic cell is generally plated with a Ni-based non-precious metal catalyst on a stainless steel plate.

The biological hydrogen production technology includes, but is not limited to, using biomass as a raw material to utilize hydrogen physicochemical principles and techniques to produce hydrogen and to convert organic matter or water into hydrogen using a biological metabolic process. The latter include, but are not limited to, direct hydrogen production from photosynthetic organisms and hydrogen production from biomass fermentation.

Microbial species of biological hydrogen production include photosynthetic organisms (anaerobic photosynthetic bacteria, blue fine Bacteria and green algae), non-photosynthetic organisms (strictly anaerobic bacteria, facultative anaerobic bacteria and aerobic bacteria) and archaeal groups. Among them, cyanobacteria and green algae organisms can use the photosynthetic mechanism in the body to convert solar energy into hydrogen energy. Hydrogen production by photolysis of water is an ideal hydrogen production route, but in the photosynthetic hydrogen release, accompanied by the release of oxygen, in addition to the low hydrogen production efficiency, it is accompanied by the key problem of deactivation of hydrogenase by oxygen; anaerobic photosynthetic bacteria Oxygen photosynthetic hydrogen evolution process does not produce oxygen, simple process, high hydrogen production purity and hydrogen production efficiency; non-photosynthetic organisms can degrade the hydrogen production characteristics of macromolecular organics, making them biotransformable renewable energy materials (cellulose and its degradation products) And starch, etc.) to produce hydrogen energy.

The biological hydrogen production process can be divided into five categories: (1) biophotolysis of water using algae or blue-green bacteria; (2) photolysis of photosynthetic bacteria of organic compounds; (3) hydrogen production by fermentation of organic compounds; Hydrogen production by coupling of photosynthetic bacteria and fermenting bacteria; (5) Hydrogen production by enzyme catalysis. At present, fermenting bacteria have a higher hydrogen production rate and lower requirements on conditions, and have direct application prospects.

The bioelectrochemical hydrogen production technology is developed by microbial fuel cell (MFC) technology, which is based on microbial anaerobic respiration, that is, an electron transfer process in which a cathode is the sole electron acceptor. During the operation of MFC, some microorganisms first oxidize the organic substrate to generate electrons and protons. The electrons are transferred to the anode, which is received by the anode and then transmitted to the cathode through the wire. The protons permeate from the anode chamber to the cathode chamber through the cation exchange membrane. Oxygen and electrons form water, which produces electricity through a constant flow of electrons. In bioelectrochemical hydrogen systems, the operation near the anode is similar to that of MFC. The bacteria oxidize organic matter to form carbon dioxide, protons and electrons, electrons are transferred to the anode, and protons are transferred to the cathode. The operation of the cathode is quite different from that of the MFC. The cathode reaction chamber is sealed and maintains an oxygen-free environment. The external power source is used to enhance the potential of the cathode in the MFC circuit by electrochemical means, on the one hand, the energy required for the growth of part of the bacteria, and the other Aspects provide electrons to the cathode. In the cathode, protons are directly used as electron acceptors to generate hydrogen. This method uses organic matter to directly produce hydrogen, and electrolysis Compared to water, energy consumption is greatly reduced. The method utilizes a voltage greater than ll OmV (e.g., 300 mV to 400 mV), which theoretically produces hydrogen. This voltage is much lower than the voltage at which hydrogen is produced by electrolysis of water (theoretical 1210 mV, electrolyte pH is neutral).生物Using bioelectrochemical hydrogen production technology, hydrogen can be produced from fermentation products such as bio-hydrogen production, organic wastewater, and the like. 5〜5kWh。 The acetic acid is used as the substrate, the applied voltage is 250mV, the production of lm ³ hydrogen is only 0. 6kWh of electricity, and the electrolyzed water to produce lm ³ hydrogen is required to consume 4. 5 ~ 5kWh.

The photoelectrochemical hydrogen production technology is a low-cost hydrogen production technology that converts solar energy into hydrogen energy. In the process of converting solar energy into hydrogen energy, the synergistic effect of photoelectricity is used to achieve the purpose of increasing the light conversion rate. In the photoelectrochemical hydrogen production system, the semiconductor photocatalytic material acts as a photoanode, and the photoanode absorbs photons to generate electron-hole pairs. The holes have strong oxidizing ability, and the hydroxide ions in the water are oxidized to oxygen. Strong reduction ability, transferred to the cathode to reduce hydrogen to form hydrogen under external bias. V. Sub-methods and subsystems for recovering matter and energy

The method of the present invention also includes recovering the catalyst, water or steam in the multi-zone coal gasification process, recovering and recycling the solid material in the helium-containing gas stream, and utilizing waste heat or residual pressure in the process to generate electricity or Produce steam. Such an approach is implemented by a corresponding subsystem that implements the above process. Detailed ways

The following examples are given to illustrate the invention, which are not intended to be limiting.

Embodiment 1:

Referring to Figure 1, the gasifier in Figure 1 consists of three zones from top to bottom, respectively The pyrolysis zone 40, the catalytic gasification zone 41, and the residue gasification zone 42. The raw coal enters a portion of the pyrolysis zone 40 through a line 43, and the temperature of the partial pyrolysis zone 40 is 450 to 650. The gas stream from the catalytic gasification zone 41 heats the raw coal powder in a portion of the pyrolysis zone 40 to cause a portion thereof to occur. Pyrolysis and hydropyrolysis, obtaining methane-containing gas products, tar and pyrolysis of coal powder. The gaseous products and tar exit the gasifier from the outlet line 48 and enter the subsequent separation equipment. The pyrolyzed coal powder moves downward into the catalytic gasification zone 41. A further portion of the coal and catalyst enters the catalytic gasification zone from line 44 in the form of a mixture together with the pyrolyzed coal powder from the partial pyrolysis zone in the catalytic gasification zone 41 and from the residue gasification zone. The gas stream reacts and the reaction is as shown in the above reaction formulas (1) - (4) to form a gaseous product. There are mainly CH ₄ , C0, 11 ₂ and C0 ₂ , and a small amount of H ₂ S and NH ₃ and the like. These gaseous products move upward into a portion of the pyrolysis zone 40 to pyrolyze the coal. The temperature of the catalytic gasification zone 41 is 650-750. The coal residue which is not sufficiently reacted enters the residue gasification zone 42 downward, and the reaction represented by the above reaction formulas (5) to (8) occurs under the action of the superheated steam 46 and the oxygen gas 47 which are introduced, and the synthesis includes synthesis. The gas product and the solid ash, which are gas, move up to the catalytic gasification zone 41 for reaction, and the ash is discharged to the gasifier through the primary slagging device 50 and the secondary slagging device 51. 5MPa压力。 Under the pressure of 3. 5MPa. Embodiment 2:

Referring to Figure 4, the gas of the gasifier's outlet gas (mainly CH ₄ , C0, H ₂ and C0 ₂ , and a small amount of H ₂ S and ₃ ) is subjected to cyclone separation and isothermal dust filtration for gas-solid separation, solid phase dust. Returning to the gasification furnace for gasification reaction, the gas phase is separated by gas-liquid cooling separation unit to obtain low temperature tar. The crude syngas is subjected to a purification and separation device to remove acid gases such as carbon dioxide and hydrogen sulfide to obtain methane. The H ₂ S separated by the purification system is further processed to obtain sulfur. The remaining 11 ₂ and CO are fed into the polygeneration sub-method Preparation of decane, decyl alcohol, dioxane, etc. The steam produced by the polygeneration sub-method is used to generate electricity. Embodiment 3:

Referring to Figure 2, the synthesis gas produced by the multi-zone coal gasification process is purified by separation of methane (mainly H ₂ and CO) and the hydrogen and algae carbon uptake method of the hydrogen production process. The hydrogen is mixed and sent to the polygeneration process. A part of the direct decane is used to prepare the decane, and the by-product water is returned to the multi-zone coal gasification process; another part of the methanol is synthesized, and a part of the produced methanol is used to produce the diterpene ether, and the other part. Can be sold directly. The multi-zone coal gasification method and the carbon dioxide generated by the poly-generation method are fed into the algae carbon-absorbing sub-process to produce biodiesel, and co-production of oxygen. The algae residue is used to ferment one or more of the by-products hydrogen, methane or ethanol; the by-product hydrogen is returned to the polygeneration sub-method. The algae residue after fermentation and the wastewater generated in the system can also be used for bioelectrochemical hydrogen production. The hydrogen production method uses, for example, hydrogen production from electrolyzed water, and the generated oxygen is mixed with oxygen generated by the algae carbon absorption method, and sent to a multi-zone coal gasification method as a gasifying agent. Embodiment 4:

Referring to FIG. 3, the crude syngas produced by the multi-zone coal gasification method is subjected to purification and separation of hydrogen and hydrogen production method, and the hydrogen and algae carbon absorption sub-products are mixed with hydrogen produced by the residue fermentation, and returned to the multi-zone coal gasification subsystem. The gasifier is used to replenish hydrogen. The remaining H ₂ and CO and/or C0 _{2 are} fed into the polygeneration sub-method, and the hydrogen is chemically carbon-fixed, that is, the chemical reaction, a part of the direct dealkylation is used to prepare methane, and the by-product water is returned to the multi-zone coal gasification method; Methanol is synthesized, part of the sterol produced is used to produce diterpene ether, and the other part can be sold directly. The multi-zone coal gasification method and the carbon dioxide generated by the poly-generation method are fed into the algae carbon-absorbing sub-process to produce biodiesel, and co-production of oxygen. Algae residue used in fermentation to produce one of the by-products hydrogen, decane or ethanol One or more; by-product hydrogen return to the polygeneration sub-method. The algae residue after fermentation and the wastewater generated in the system can also be used for bioelectrochemical hydrogen production. The hydrogen production process can also use, for example, electrolysis of water to produce hydrogen, the oxygen produced is mixed with the oxygen produced by the algae carbon uptake process, and fed to a multi-zone coal gasification process for use as a gasification agent. Embodiment 5:

The carbon dioxide gas separated in the system is filtered to remove solid particles, collected into a gas storage tank and then introduced into the photobioreactor by a gas pump. The aeration device connected to the photobioreactor can be selected from a nozzle type, an aeration head type or the like. Types of. Under a certain temperature range (10 ~ 40, light intensity (300 ~ 40000 LUX), the algae cultured in the photobioreactor absorbs carbon dioxide, carries out photosynthesis, converts carbon dioxide into glucose under visible light irradiation, and then converts it into Nutrients such as proteins, fats, and vitamins, and release a large amount of oxygen. The algae are cultured and converted into biomass, and the biomass is bio-refined to produce one of biodiesel, astaxanthin, carotenoids, and phycobiliproteins. Various advantages of the present invention are as follows:

(1) retaining the characteristics and advantages of catalytic gasification, obtaining a higher content of methane, and overcome the difficulties of separate catalytic gasification, such as longer reaction time and higher carbon content of discharged ash;

(2) Multi-zone coupled gasification, the partial pyrolysis zone of the gasification furnace of the present invention uses the residual temperature of the catalytic gasification gas to heat the newly entered pulverized coal, partially pyrolyzes, and produces methane gas and the like, without increasing The decane and tar are added under the condition of energy consumption; the main reaction of catalytic gasification occurs in the catalytic gasification zone; the residual gasification zone passes through the gasification agent to gasify the remaining residue, and provides catalysis by burning and gasification of the residue. The heat required for gasification, while providing hydrogen and C0, is beneficial to the catalytic gasification reaction; (3) Compared with the two-step method for preparing methane, the device integrates multiple reactors to realize logistics coupling and heat coupling. The self-supply heat reduces the energy consumption of superheated steam, and solves the problem of carbon residue in the residue; The residence time increases the gas production capacity and increases the carbon conversion rate.

(4) From the whole process, the gasification of the multi-zone gasifier is used to prepare a gas rich in decane gas, which has high thermal efficiency, high solid phase processing depth, high decane content in the gas product, and simple and easy operation.

(5) Near zero emissions of carbon dioxide. On the one hand, it captures and absorbs carbon dioxide through algae carbon absorption technology, and on the other hand, it converts carbon monoxide or carbon dioxide into energy products through hydrogenation chemical carbon sequestration technology, thereby achieving near zero emission of carbon dioxide.

(6) Full price development of coal resources and optimal use of resources. Convert coal into decane, hydrogen, decyl alcohol, ethylene glycol, lower alcohol and/or diterpene ether; save energy by using composite energy hydrogen production technology; use biorefinery technology to obtain biodiesel, resource utilization efficiency More than 80%.

Claims

Rights request

1. A comprehensive utilization method of coal, comprising:

a. adding pulverized coal to a partial pyrolysis zone of a gasification furnace comprising a partial pyrolysis zone, a catalytic gasification zone and a residue gasification zone, where the pulverized coal is in contact with a gas stream from the catalytic gasification zone for partial heat Solving the coal powder to form a gas stream containing decane and partially pyrolyzed coal powder,

2. The method of claim 1 wherein at least a portion of the coal enters the gasifier from any one or more of a portion of the gasification zone and/or the catalytic gasification zone of the gasifier.

3. The method of claim 1 wherein a portion of the coal enters the gasifier from the residue gasification zone.

4. The method according to claim 1, wherein the catalyst is selected from the group consisting of: (1) an alkali metal or alkaline earth metal oxide, carbonate, hydroxide, acetate, nitrate, halide or a mixture thereof; Or (2) an oxide of a transition metal; or a mixture of (1) and (2) above.

5. The method of claim 1, wherein the temperature of the partial pyrolysis zone is in the range of 450-650, the temperature of the catalytic gasification zone is in the range of eso sox, and the temperature of the residue gasification zone is in the range of 800-1200, in the gasifier The pressure is in the range of 0.1 to 4 MPa.

6. The method according to claim 1, wherein the gasifying agent is introduced from the bottom of the gasifier, It contains oxygen as well as saturated steam or superheated steam.

0. 1 The weight ratio of the oxygen entering the gas to the gasifier is 0.1. -1. 0.

The method according to any one of claims 1 to 7, wherein the polygeneration method is to produce decyl alcohol, decane, and ethylene by syngas after separating decane from a gas stream of decane. A method of at least one of an alcohol, a lower alcohol, and a diterpene ether.

9. The method of claim 8 further comprising an algae carbonaceous sub-method.

10. The method according to claim 9, wherein said algae carbon uptake method absorbs the remaining carbon dioxide remaining by the integrated utilization method of said coal.

The method according to claim 9 or 10, wherein the algae carbon uptake method uses algae, green algae, Chara, algae, dinoflagellate, red algae, diatom, Chlamydomonas, yellow algae, brown algae, cyanobacteria Or a mixture of them.

12. The method according to claim 11, wherein the algae carbonaceous sub-process produces at least one of biodiesel, oxygen, hydrogen, decane, ethanol, astaxanthin, carotenes, phycobiliproteins.

13. The method of claim 8 further comprising a composite energy hydrogen generation process.

14. The method of claim 9 further comprising a composite energy hydrogen generation process.

The method according to claim 13 or 14, wherein the hydrogen generation method of the composite energy source is selected from the group consisting of a water electrolysis hydrogen generation method, a biological hydrogen production sub-method, a bioelectrochemical hydrogen production sub-method, or a photoelectrochemical hydrogen production sub-method.

16. The method of claim 8 further comprising recovering the catalyst, water or steam in the multi-zone coal gasification process and the poly-generation process, recovering the solid material in the methane-containing gas stream, and recycling, and The waste heat or residual pressure in the process is used to generate electricity or generate steam.

17. The method according to claim 15, wherein said composite energy hydrogen generation method The energy required in the solar energy, wind energy, hydro energy, geothermal energy, tidal energy, nuclear power, trough power, thermal power or electrical energy generated according to claim 16.

18. The method according to claim 4, wherein the transition metal is selected from the group consisting of iron, cobalt, nickel, molybdenum or a mixture thereof.

19. The method of claim 4, wherein the oxide of the transition metal is generated in situ by adding a decomposable salt or hydroxide of the transition metal to a gasifier.

20. A comprehensive utilization system for coal, comprising:

A gasification furnace and a polygeneration subsystem for producing a methane-containing gas by gasification, wherein the gasification furnace for preparing a gas containing decane by gasification includes, in order from top to bottom:

21. The system of claim 20, further comprising means for adding at least a portion of the coal to the gasifier from any one or more of the partial pyrolysis zone and/or the catalytic gasification zone of the gasifier.

22. The system of claim 20 or 21, further comprising an apparatus for mixing the catalyst into the pulverized coal and an apparatus for directly introducing the catalyst to the gasifier.

23. The system of claim 20 or 21, further comprising means for transporting partially pyrolyzed pulverized coal from the pyrolysis zone to the catalytic gasification zone and for gasifying the coal residue from the catalyst Equipment that is transported to the residue gasification zone.

24. The system of claim 20, wherein the polygeneration subsystem produces at least one of decyl alcohol, decane, ethylene glycol, lower alcohols, dioxins.

25. The system of claim 24, further comprising an algae carburizing subsystem.

26. The system of claim 25, wherein the algae carburizing subsystem absorbs carbon dioxide remaining in the integrated utilization system of the coal.

27. A system according to claim 24 or 25, further comprising a composite energy hydrogen generation subsystem.

28. The system of claim 27, wherein the composite energy hydrogen production subsystem is selected from the group consisting of a water electrolysis hydrogen production subsystem, a biohydrogen production subsystem, a bioelectrochemical hydrogen production subsystem, or a photoelectrochemical hydrogen production subsystem.

29. The system according to claim 24, further comprising an apparatus for recovering catalyst, water or steam in a gasification furnace for gasification to produce a gas containing decane, recovering the body material in the decane-containing gas stream and recycling Equipment, and equipment that uses the residual heat or residual pressure in the system to generate electricity or generate steam.

30. The system of claim 20, wherein the zones of the gasifier are separated by a porous distribution plate.

31. The system of claim 20, wherein the gasifier further includes an overflow tube for moving the coal downward.