阅读说明：本技术 以铜渣为循环床料的生物质双流化床催化气化联合循环发电方法及其系统 (Biomass double fluidized bed catalytic gasification combined cycle power generation method and system with copper slag as circulating bed material ) 是由 刘慧利 王�华 胡建杭 于 2019-09-11 设计创作，主要内容包括：本发明涉及一种以铜渣为循环床料的生物质双流化床催化气化联合循环发电方法及其系统,属于能源与环境技术领域；在该方法及其系统中,高温铜渣床料在流化床气化炉中加热生物质热解气化生成生物质燃气、生物质炭和焦油,铜渣床料催化焦油裂解,含少量焦油的生物质燃气净化后采用燃气轮机发电的方式进行利用；高温旋风分离器出来的铜渣床料和生物质炭进入流化床燃烧炉,生物质炭燃烧放热加热后的高温铜渣床料返回流化床气化炉；燃气轮机透平与高温旋风分离排放的高温烟气合并后采用余热锅炉和有机朗肯循环发电的方式回收余热；在整个过程中,铜渣床料具有热载体和催化焦油裂解的双重作用,采用燃气-有机工质联合循环发电的方式逐级利用热能。(the invention relates to a biomass double fluidized bed catalytic gasification combined cycle power generation method and a system thereof by taking copper slag as a circulating bed material, belonging to the technical field of energy and environment; in the method and the system thereof, high-temperature copper slag bed materials are heated in a fluidized bed gasification furnace to carry out pyrolysis and gasification on biomass to generate biomass gas, biomass charcoal and tar, the copper slag bed materials catalyze the cracking of the tar, and the biomass gas containing a small amount of tar is purified and then utilized in a gas turbine power generation mode; the copper slag bed material and the biomass charcoal from the high-temperature cyclone separator enter a fluidized bed combustion furnace, and the high-temperature copper slag bed material after heat release and heating of the biomass charcoal combustion returns to the fluidized bed gasification furnace; after being combined with high-temperature flue gas discharged by high-temperature cyclone separation, a gas turbine recovers waste heat by adopting a waste heat boiler and an organic Rankine cycle power generation mode; in the whole process, the copper slag bed material has double functions of a heat carrier and catalytic tar cracking, and the heat energy is utilized step by step in a gas-organic working medium combined cycle power generation mode.)

1. A biomass double fluidized bed catalytic gasification combined cycle power generation method taking copper slag as a circulating bed material is characterized by comprising the following specific steps:

(1) Biomass and steam or steam-air mixed gas in the fluidized bed gasification furnace are subjected to pyrolysis gasification reaction under the heating action of circulating bed material high-temperature copper slag to generate biomass gas, biomass charcoal and tar, and the tar is subjected to catalytic cracking reaction under the action of the copper slag bed material; the copper slag bed material and the biomass charcoal enter a high-temperature cyclone separator I for gas-solid separation under the carrying of biomass gas, the biomass gas containing a small amount of tar is sent into a gas purification device to obtain clean gas, and the mixture of the copper slag bed material and the biomass charcoal enters a fluidized bed combustion furnace through a material returning device;

(2) the biomass charcoal entering the fluidized bed combustion furnace in the step (1) and preheated air are subjected to oxidation combustion reaction, the released heat is used for heating copper slag bed materials, high-temperature flue gas generated by combustion carries the high-temperature copper slag bed materials to enter a high-temperature cyclone separator II, the separated high-temperature flue gas is subjected to waste heat recovery by a waste heat boiler, and the high-temperature copper slag bed materials enter a fluidized bed gasification furnace through a material returning device;

(3) Clean gas in the step (1) is sent into a gas turbine to drive a generator I to generate electricity, and high-temperature flue gas discharged by the gas turbine and high-temperature flue gas discharged by a high-temperature cyclone separator II are combined and then sent into a waste heat boiler to heat low-temperature heat conduction oil;

(4) the high-temperature heat conduction oil with the heated temperature increased in the step (3) enters an organic working medium evaporator to heat the liquid organic working medium, so that the organic working medium is heated and evaporated, and the heat conduction oil from the organic working medium evaporator is reduced in temperature and is sent to a waste heat boiler to be heated again;

(5) in the organic working medium evaporator in the step (4), the organic working medium absorbs the heat of the heat conducting oil and is heated and evaporated, the generated organic steam enters a turbine expander to expand and do work to drive a generator II to generate power, then the exhaust steam enters a condenser to be condensed, finally enters an organic working medium liquid storage tank, and the liquid organic working medium in the liquid storage tank is pressurized to evaporation pressure by a working medium pump and finally enters the organic working medium evaporator to be heated and evaporated again;

(6) And (4) preheating air in an air preheater by using medium-low temperature flue gas from the waste heat boiler in the step (4), then sending the preheated air into a fluidized bed combustion chamber, removing particles from the low-temperature flue gas from the air preheater by using a ceramic multi-tube dust remover and a bag-type dust remover, and then leading the low-temperature flue gas to a chimney for discharging.

2. the biomass double fluidized bed catalytic gasification combined cycle power generation method taking copper slag as circulating bed material according to claim 1, wherein the circulating bed material copper slag in the step (1) is one or more of closed blast furnace smelting slag, nandina smelting slag, buchekoff smelting slag, silver smelting slag, tenninite converter smelting slag, ostomate smelting slag, mitsubishi smelting slag and ottokumpu flash smelting slag, the content of Fe element in the copper slag is 29.0 ~ 45.9%, and the content of Fe element in the copper slag is Fe element₃O₄5-20.0% of SiO₂25.1 ~ 40.0% of CaO, 2.6 ~ 11.0% of CaO and 0.7 ~ 3.5% of MgO.

3. the biomass double fluidized bed catalytic gasification combined cycle power generation method taking copper slag as circulating bed material according to claim 2, characterized in that: the copper slag is copper slag raw slag and is pre-treated by calcinationthe treated copper slag or the copper slag after reduction pretreatment is calcined for 1 ~ 20H in the air, oxygen ~ enriched or pure oxygen atmosphere at 800 ~ 1050 ℃, and the copper slag reduction pretreatment is carried out in the H₂or reduction treatment is carried out for 1 ~ 10h at 600 ~ 1000 ℃ in CO reducing atmosphere.

4. the biomass dual fluidized bed catalytic gasification combined cycle power generation method taking copper slag as circulating bed material according to claim 2, characterized in that the particle size of the copper slag is 0.2 ~ 2.0 mm.

5. the biomass dual fluidized bed catalytic gasification combined cycle power generation method using copper slag as circulating bed material according ~ claim 1, wherein the temperature in the fluidized bed gasification furnace is 650 ~ 950 ℃, and the temperature in the fluidized bed combustion furnace is 800 ~ 1100 ℃.

6. The biomass double fluidized bed catalytic gasification combined cycle power generation system which takes copper slag as circulating bed material and realizes the method of claim 1 is characterized in that: the device comprises a biomass pretreatment device (1), a biomass bin (2), a fluidized bed gasification furnace (3), a high-temperature cyclone separator I (4), a high-temperature cyclone separator II (5), a fluidized bed combustion furnace (6), a gas purification device (7), a gas turbine combustion chamber (8), a gas compressor (9), a turbine (10), a generator I (11), a waste heat boiler (12), a heat-conducting oil circulating pump (13), an organic working medium evaporator (14), a turbine expander (15), a condenser (16), a liquid storage tank (17), a working medium pump (18), a generator II (19), an air preheater (20), a ceramic multi-pipe dust collector (21), a bag-type dust collector (22), an induced draft fan (23) and a chimney (24); a biomass fuel discharge port at the bottom of the biomass pretreatment device (1) is connected with a feed port of the biomass bin (2), the biomass pretreatment device (1) is connected with the biomass bin (2), a discharge port of the biomass bin (2) is connected with a feed port of the fluidized bed gasification furnace (3), a biomass fuel gas outlet at the top of the fluidized bed gasification furnace (3) is connected with a high-temperature cyclone separator I (4), and an air inlet is formed at the bottom of the fluidized bed gasification furnace (3); the bottom of a high-temperature cyclone separator I (4) is connected with a fluidized bed combustion furnace (6) through a material returning device, the top of the high-temperature cyclone separator I (4) is connected with an inlet of a gas purification device (7), an outlet of the gas purification device (7) is connected with a fuel inlet of a combustion chamber (8) of a gas turbine, an air outlet of a gas compressor (9) is connected with an air inlet of the combustion chamber (8) of the gas turbine, a heated working medium gas outlet of the combustion chamber (8) is connected with a turbine (10), the turbine (10) is connected with a generator I (11), a high-temperature flue gas outlet of the turbine (10) is connected with an outer layer pipeline in a waste heat boiler (12) through a high-temperature flue gas three-way valve, a high-temperature flue gas outlet at the top of the fluidized bed combustion furnace (6) is connected with a high-temperature cyclone separator II (5), and the bottom of the high-temperature cyclone separator II; a high-temperature flue gas outlet at the top of the high-temperature cyclone separator II (5) is connected with an outer layer pipeline in the waste heat boiler (12) through a high-temperature flue gas three-way valve; a heat conduction oil outlet of the waste heat boiler (12) is connected with an inlet of an organic working medium evaporator (14) through a heat conduction oil circulating pump (13), a low-temperature heat conduction oil outlet of the organic working medium evaporator (14) is connected with a heat conduction oil inlet of the waste heat boiler (12), a heated working medium steam outlet of the organic working medium evaporator (14) is connected with a turbine expander (15), the turbine expander (15) is connected with a generator II (19), an outlet of the turbine expander (15) is sequentially connected with a condenser (16) and a liquid storage tank (17), and the liquid storage tank (17) is connected with the organic working medium evaporator (14) through a working medium pump (18); the medium-low temperature smoke outlet of the waste heat boiler (12) is connected with an air preheater (20), the preheated air outlet of the air preheater (20) is connected with a fluidized bed combustion furnace (6), the low-temperature smoke outlet of the air preheater (20) is sequentially connected with a ceramic multi-tube dust remover (21) and a bag-type dust remover (22), and the low-temperature smoke outlet of the bag-type dust remover (22) is communicated with a chimney (24) through an induced draft fan (23).

Technical Field

The invention relates to a biomass double fluidized bed catalytic gasification combined cycle power generation method and system with copper slag as a circulating bed material, and belongs to the technical field of energy and environment.

Background

With the rapid development of social economy, the consumption of conventional energy sources such as coal, oil and natural gas is increasing day by day, and the environmental problems caused by the consumption are important problems which are generally concerned all over the world. Developing and utilizing resourcesRenewable energy with large reserves, cleanness and no pollution becomes an important outlet for relieving the energy problem. The biomass fuel is derived from organic matters generated by photosynthesis, the biomass resource storage capacity is large, the SOx emission generated in the utilization process is far lower than that of coal and heavy oil, the generation amount of NOx is low, and CO can be realized₂the energy is clean and renewable energy. The technology for preparing renewable gas fuel by biomass gasification is an important way for efficiently converting low-grade biomass energy into high-grade secondary energy.

At present, biomass gasification equipment mainly comprises a fixed bed gasification furnace, a fluidized bed gasification furnace and a fluidized bed gasification furnace. The double fluidized bed gasification furnace has the advantages of wide fuel adaptability, good heat transfer, high gasification strength and the like of common fluidized bed gasification, and improves the content of combustible components in product gas and the heat value of fuel gas because the pyrolysis gasification and combustion processes of biomass are separated. However, in the biomass gasification process, tar is an inevitable by-product, and the presence of tar not only reduces gasification efficiency and blocks a gas transfer pipe, but also damages gas equipment such as an internal combustion engine and a gas turbine, and therefore tar in the gas must be removed.

the tar content of the fuel gas generated by biomass gasification of the double fluidized bed is high and is generally 10 ~ 150 g/Nm³this portion of tar cannot be directly utilized and therefore measures must be taken to convert or remove the tar. Among various methods for converting and removing tar, the catalytic conversion method is the most suitable method for removing tar because of its advantages such as the ability to retain chemical energy of tar and high tar conversion rate. In a dual fluidized bed gasification system, catalytic conversion of tar can be achieved in two ways, one is by providing a catalytic reactor downstream of the gasification chamber, and the other is by using a material with catalytic action as a circulating bed material of the dual fluidized bed, which has the dual function of catalytic tar cracking and providing energy for biomass gasification in the gasification chamber of the dual fluidized bed as a heat carrier. The use of circulating bed materials with catalytic tar cracking is the most attractive option for a dual fluidized bed gasifier to reduce the tar content in the fuel gas. Currently, nickel-based, nickel-impregnated olivine and dolomite are dual fluidizedThe most common circulating bed material used for catalytic tar cracking in the bed. Nickel-based and nickel-impregnated olivines find use in applications where the catalyst is deactivated by carbon deposition, hydrogen sulfide, and alkali and chlorine compounds, and nickel-based catalysts are costly. Dolomite is very effective to the catalytic conversion of tar as the circulating bed material, but dolomite mechanical strength is low, easy wearing and tearing, produce a large amount of fine particles in the use, cause the adverse effect to the operation of double fluidized bed. Therefore, the research or development of the circulating bed material with high tar conversion rate and high mechanical strength is an important problem in the operation of the dual fluidized bed gasification furnace. In addition, the biomass gas generated by the double fluidized bed gasification furnace has high combustible component content and high heat value, is suitable for generating electricity by adopting a gas turbine generator set, and has room for improvement on how to further improve the generating efficiency of the system by adopting a gas turbine to match with combined circulation.

Disclosure of Invention

aiming at the problems and the defects in the prior art, the invention provides a biomass double fluidized bed catalytic gasification gas-organic working medium combined cycle power generation method taking copper slag as a circulating bed material.

The biomass double fluidized bed catalytic gasification combined cycle power generation method taking copper slag as a circulating bed material comprises the following specific steps:

(1) the biomass raw material is pretreated by crushing, drying and the like and then enters a biomass bin, the biomass in the bin is fed into a fluidized bed gasification furnace through a feeding device, steam or steam ~ air mixed gas which is used as a fluidized medium and participates in gasification reaction is fed from the bottom of the fluidized bed gasification furnace, the biomass raw material is subjected to pyrolysis gasification reaction under the heating action of circulating bed material high ~ temperature copper slag to generate biomass gas, biomass charcoal and tar, the temperature in the fluidized bed gasification furnace is 650 ~ 950 ℃, the tar is subjected to catalytic cracking reaction under the action of the copper slag bed material, the tar content in the biomass gas is reduced by 75 ~ 90%, the copper slag bed material and the biomass charcoal are carried by the biomass gas and then enter a high ~ temperature cyclone separator I for gas ~ solid separation, the biomass gas containing a small amount of tar enters a gas purification device for purification treatment for removing impurities such as tar, particles, moisture and the like, so as to obtain clean gas, and the mixture of the copper slag bed material and the biomass charcoal obtained by the gas ~ solid;

(2) in the step (1), the biomass charcoal entering the fluidized bed combustion furnace and the preheated air fed into the furnace are subjected to oxidation combustion reaction, the emitted heat is used for heating copper slag bed materials, the temperature in the fluidized bed combustion furnace is 800 ~ 1100 ℃, high ~ temperature flue gas generated by combustion carries the high ~ temperature copper slag bed materials to enter a high ~ temperature cyclone separator II, the high ~ temperature flue gas after gas ~ solid separation enters a waste heat boiler to recover flue gas waste heat, the temperature of the high ~ temperature flue gas is 650 ~ 1100 ℃, the high ~ temperature copper slag bed materials enter a fluidized bed gasification furnace through a return feeder, and the temperature of the high ~ temperature copper slag bed materials is 750 ~ 1050 ℃;

(3) Clean gas output by the gas purification device in the step (1) is sent into a combustion chamber of a gas turbine, a gas compressor sucks air from the atmospheric environment and compresses the air step by step to enable the temperature and the pressure of the air to be increased step by step and then the air is sent into the combustion chamber, the gas and the air are mixed and combusted in the combustion chamber to generate high-temperature and high-pressure gas, then the high-temperature and high-pressure gas enters a turbine to expand and do work to drive a generator to generate electricity, and high-temperature flue gas discharged by the turbine is combined with high-temperature flue gas discharged by a high-temperature cyclone;

(4) the temperature of the high ~ temperature flue gas entering the waste heat boiler in the step (3) is 700 ~ 950 ℃, the temperature of heat ~ conducting oil in the waste heat boiler is increased from 65 ~ 100 ℃ to 150 ~ 300 ℃, then the high ~ temperature heat ~ conducting oil enters an organic working medium evaporator to perform recuperative type countercurrent heat exchange with liquid organic working media, so that the organic working media are heated and evaporated, the organic working medium evaporator adopts a plate heat exchanger, the temperature of the heat ~ conducting oil coming out of the organic working medium evaporator is reduced, and the heat ~ conducting oil is pressurized by a heat ~ conducting oil circulating pump and enters the waste heat boiler to be heated again;

(5) In the organic working medium evaporator in the step (4), the organic working medium absorbs heat of the heat conducting oil and is heated and evaporated, the generated organic steam enters a turbine expander to expand and do work to drive a generator to generate power, then the exhaust steam enters a condenser to be condensed, and finally enters an organic working medium liquid storage tank, liquid organic working medium in the organic working medium liquid storage tank is pressurized to evaporation pressure through a working medium pump and finally enters the organic working medium evaporator to be heated and evaporated again, so that a cycle is formed;

(6) and (4) preheating the air by the medium ~ low temperature flue gas discharged from the waste heat boiler in the step (4) in an air preheater, wherein the temperature of the medium ~ low temperature flue gas is 300 ~ 400 ℃, the preheated air is fed into a fluidized bed combustion chamber, the temperature of the preheated air is 150 ~ 300 ℃, the particulate matters in the low ~ temperature flue gas discharged from the air preheater are removed by a ceramic multi ~ tube dust remover and a bag ~ type dust remover, the temperature of the flue gas is reduced to 120 ~ 175 ℃, and the flue gas is finally guided to a chimney through an induced draft fan and discharged.

the circulating bed material copper slag in the step (1) adopts closed blast furnace smelting slag, Norada smelting slag, Vanecov smelting slag, silver method smelting slag, Tenientt converter smelting slag, Osmant smelting slag, Mitsubishi smelting slag, Ottokitt flash smelting slag and the like, and the bed material of the copper slag contains 29.0 ~ 45.9% of Fe element, and Fe₃O₄5-20.0% of SiO₂25.1 ~ 40.0 percent of the slag, 2.6 ~ 11.0 percent of CaO, 0.7 ~ 3.5 percent of MgO, and the copper slag bed material is any one or a mixture of two or more of the copper slag.

in the step (1), the copper slag bed material is partially inactivated due to surface carbon deposition in the catalytic tar cracking process, after the copper slag bed material and the biomass carbon are conveyed to the fluidized bed combustion furnace through the material returning device, the carbon deposition on the surface of the bed material is removed in a combustion mode, and the copper slag bed material realizes the internal circulation regeneration of the system.

the copper slag bed material has the performances of high wear resistance, corrosion resistance, high hardness, high pressure resistance and the like, and the particle size of the copper slag bed material is 0.2 ~ 2.0 mm.

And (2) removing tar, particles and water in the biomass gas containing a small amount of tar in the step (1) in a gas purification device to obtain purified clean gas, wherein the main component of the clean gas is H₂、CO、CO₂、CH₄and small amounts of low molecular alkane, alkene and alkyne compounds.

the copper slag is raw copper slag, copper slag subjected to calcination pretreatment or copper slag subjected to reduction pretreatment, the copper slag calcination pretreatment method is to calcine the copper slag in air, oxygen ~ rich or pure oxygen atmosphere at 800 ~ 1050 ℃ for 1 ~ 20H, and the copper slag reduction pretreatment method is to calcine the copper slag in H₂or reduction treatment is carried out for 1 ~ 10h at 600 ~ 1000 ℃ in CO reducing atmosphere.

the invention also provides a biomass double fluidized bed catalytic gasification combined cycle power generation system which uses copper slag as a circulating bed material and completes the method, and the system comprises a biomass pretreatment device, a biomass bin, a fluidized bed gasification furnace, a high-temperature cyclone separator I, a high-temperature cyclone separator II, a fluidized bed combustion furnace, a gas purification device, a gas turbine combustion chamber, a gas compressor, a turbine, a generator I, a waste heat boiler, a heat conduction oil circulating pump, an organic working medium evaporator, a turbine expander, a condenser, a liquid storage tank, a working medium pump, a generator II, an air preheater, a ceramic multi-tube dust remover, a bag-type dust remover, an induced draft fan and a chimney; a biomass fuel discharge port at the bottom of the biomass pretreatment device is connected with a feed port of a biomass bin, the biomass pretreatment device is connected with the biomass bin, a discharge port of the biomass bin is connected with a feed port of the fluidized bed gasification furnace, a biomass gas outlet at the top of the fluidized bed gasification furnace is connected with the high-temperature cyclone separator I, and an air inlet is formed at the bottom of the fluidized bed gasification furnace; the bottom of the high-temperature cyclone separator I is connected with the fluidized bed combustion furnace through a material returning device, the top of the high-temperature cyclone separator I is connected with an inlet of a gas purification device, an outlet of the gas purification device is connected with a fuel inlet of a combustion chamber of a gas turbine, an air outlet of a gas compressor is connected with an air inlet of the combustion chamber of the gas turbine, a heated working medium gas outlet of the combustion chamber is connected with a turbine, the turbine is connected with a generator I, a high-temperature flue gas outlet of the turbine is connected with an outer layer pipeline in a waste heat boiler through a high-temperature flue gas three-way valve, a high-temperature flue gas outlet at the top of the fluidized bed combustion furnace is connected with a high-temperature cyclone separator II, and the; a high-temperature flue gas outlet at the top of the high-temperature cyclone separator II is connected with an outer layer pipeline in the waste heat boiler through a high-temperature flue gas three-way valve; a heat conduction oil outlet of the waste heat boiler is connected with an inlet of the organic working medium evaporator through a heat conduction oil circulating pump, a low-temperature heat conduction oil outlet of the organic working medium evaporator is connected with a heat conduction oil inlet of the waste heat boiler, a heated working medium steam outlet of the organic working medium evaporator is connected with a turbine expander, the turbine expander is connected with a generator II, an outlet of the turbine expander is sequentially connected with a condenser and a liquid storage tank, and the liquid storage tank is connected with the organic working medium evaporator through a working medium pump; the low-temperature smoke outlet of the waste heat boiler is connected with an air preheater, the preheated air outlet of the air preheater is connected with a fluidized bed combustion furnace, the low-temperature smoke outlet of the air preheater is sequentially connected with a ceramic multi-tube dust collector and a bag-type dust collector, and the low-temperature smoke outlet of the bag-type dust collector is communicated with a chimney through an induced draft fan.

the invention has the beneficial effects that:

(1) The copper slag is waste slag generated in the copper smelting process, has stable property, high mechanical strength, no toxicity and low cost, can reduce the exploitation of natural resources such as limestone, dolomite and the like, and has better economic benefit and environmental benefit;

(2) the copper slag bed material has double functions of a heat carrier and catalytic tar cracking, and can effectively reduce the tar content in the biomass gas;

(3) The carbon deposition of the inactivated copper slag bed material is removed in a fluidized bed combustion furnace in a combustion mode, and the bed material is recycled and regenerated in the system;

(4) The heat energy is utilized step by step in a gas-organic working medium combined cycle power generation mode, and the efficient and gradient utilization of the biomass energy is realized.

Drawings

FIG. 1 is a schematic process flow diagram of the process of the present invention;

FIG. 2 is a schematic structural diagram of a biomass double fluidized bed catalytic gasification combined cycle power generation system using copper slag as a circulating bed material according to the invention;

In the figure: 1-biomass pretreatment device, 2-biomass bin, 3-fluidized bed gasification furnace, 4-high temperature cyclone separator I, 5-high temperature cyclone separator II, 6-fluidized bed combustion furnace, 7-gas purification device, 8-gas turbine combustion chamber, 9-gas compressor, 10-turbine, 11-generator I, 12-waste heat boiler, 13-heat conducting oil circulating pump, 14-organic working medium evaporator, 15-turbine expander, 16-condenser, 17-liquid storage tank, 18-working medium pump, 19-generator II, 20-air preheater, 21-ceramic multi-pipe dust remover, 22-bag dust remover, 23-induced draft fan and 24-chimney.

Detailed Description

The invention is described in more detail below with reference to the figures and examples, without limiting the scope of the invention.