CN101550056A - A thermal plasma coal cracking - gasification coupling process and reaction unit - Google Patents

Abstract

The invention discloses a thermal plasma coal cracking-gasification coupling process and a reaction device, which belong to the technical field of coal chemical industry. In the present invention, a gas-solid rapid separator and a coal gasification reactor are added after the plasma coal cracking reaction device. The high-level energy of pulverized coal forms a large amount of gas by-products, which improves the overall conversion rate of coal and the comprehensive value of the process. The present invention can make full use of the high-level energy carried by the reaction products of the plasma coal cracking process, especially the pulverized coal after the reaction, increasing By understanding the reaction time and course of pulverized coal, the overall conversion rate of pulverized coal can be improved, and a large number of gas by-products of the coal gasification reaction process, such as CO and H ₂ , can be obtained from the additional coal gasification reactor, and the comprehensive value of the plasma coal cracking process Compared with traditional technology, it will be greatly improved.

Description

A Thermal Plasma Coal Cracking-Gasification Coupling Process and Reaction Device

technical field

The invention belongs to the technical field of coal chemical industry, and in particular relates to a thermal plasma coal cracking-gasification coupling process and a reaction device.

Background technique

Acetylene is an important basic organic chemical raw material. The industrial methods for producing acetylene mainly include calcium carbide method, methane partial oxidation method and methane arc cracking method. Among them, the calcium carbide method acetylene process is mature and accounts for an absolute proportion in industrial production, but the pollution and energy consumption are relatively high.

Plasma pyrolysis of coal to acetylene is a new and promising route for direct chemical conversion of coal. The related research began in the 1960s at the University of Sheffield in the UK: in the arc thermal plasma jet with high temperature, high enthalpy and high reactivity, Coal volatiles and even fixed carbon can be directly converted to acetylene. Since then, a large number of studies have focused on the United Kingdom, the United States, Germany, India, the former Soviet Union and other countries. Since the 1990s, Chinese scholars and engineering technicians have carried out a lot of basic research and engineering research in this field. Because my country's oil and gas resources are relatively scarce, but coal resources are abundant, the process of plasma cracking coal to acetylene, as a clean and short-process coal conversion process, has important potential industrial prospects in the chemical utilization of coal.

AVCO Corporation of the United States completed the test of a 1MW industrial device in 1980. The input power of the plasma generator was 807kW, water was used as the quenching medium, and the unit production energy consumption before gas separation was 10.5kWh/kg acetylene. The German Huels company and Bergbau Forschung GmbH (German mining research company, now known as DMT) cooperated in the 1980s to build and test a 1.25MW pilot plant, and the obtained unit production energy consumption was 14-16kWh/kg acetylene.

my country's Xinjiang Tianye Group established 2MW and 5MW plasma cracking coal-to-acetylene device platforms from 2006 to 2009, and carried out experimental research work.

The test devices adopted by different research institutions at home and abroad have common features in system composition. The devices mainly include three common parts, namely plasma generator, reactor (including mixing and reaction section), quenching and separation device. The existing plasma coal cracking processes developed by various research institutions at home and abroad still have significant common limitations in terms of energy utilization efficiency, which is specifically reflected in the fact that after the millisecond-level contact and cracking reaction between coal powder and thermal plasma, the liquid Substances such as water, cold coal powder or low-carbon alkanes (such as propane) are used to achieve the quenching effect of the reaction product and ensure the yield of acetylene products; the temperature of the reaction product before quenching is usually within the range of 1400-2000K, and the reaction product after quenching When the temperature drops below 800K, the high-level energy carried by the reaction products, especially the pulverized coal after the reaction, is consumed in the form of rapid cooling, and its value is 30-60% of the total input electric power, which directly restricts the process that can be obtained. economic benefits.

The object of the present invention is to improve the existing plasma coal cracking device, comprehensively utilize the high-level energy of the reaction product of the process, and improve the overall conversion rate of coal and the comprehensive value of the process.

Contents of the invention

The object of the present invention is to provide a thermal plasma coal cracking-gasification coupling process and reaction device.

A thermal plasma coal cracking-gasification coupling reaction device, characterized in that a plasma generator 2 and a pulverized coal feeding device 3 are arranged at the upper end of the coal cracking reaction chamber 4, and a coal gasification reactor is arranged below the coal cracking reaction chamber 4 1. A coal cracking reaction chamber outlet 5 is set at the lower end of the coal cracking reaction chamber 4. The coal cracking reaction chamber outlet 5 is a constriction, and a quenching water nozzle 10 is placed around the outer wall of the coal cracking reaction chamber outlet 5 with a reduced diameter; the coal cracking reaction chamber outlet 5 The lower end is provided with a gas-solid quick separator 6, and the outlet 5 of the coal cracking reaction chamber and the upper end of the gas-solid quick separator 6 form a jacket structure 8, the gap of the jacket structure 8 is annular, and the jacket structure 8 is located between the quenching water nozzle 10 Next, a quenching water collection tank 12 is arranged around the gas-solid quick separator 6, the quenching water collection tank 12 divides the coal gasification reactor 1 into two parts, the upper part of the quenching water collection tank 12 is an air cooling chamber 9, and the quenching water collection tank 12 The lower part is the coal gasification reaction chamber 16, and the lower end of the gas-solid rapid separator 6 is the coal powder outlet 7 of the gas-solid rapid separator. 9 The cracked gas product outlet 11 is arranged around the outer wall, and the coal gasification product outlet 18 is arranged along the outer wall of the coal gasification reaction chamber 16; The cinder port 20 is connected to the water purifier 22 through the ash settler 21, and the coal gasification reactor 1 is provided with a liquid discharge port 23 in the supernatant liquid area of the liquid seal 19 at the bottom of the coal gasification reactor, and the liquid discharge port 23 is connected to the The water purifier 22 is connected; the quenching water collection tank 12 is connected with the steam-water separator 13, and one end of the steam-water separator 13 is connected with the coal gasification nozzle 17 through the circulating steam pipe 14, and the other end is connected with the water purifier 22 through the separator outlet 15, and the water The purifier 22 is connected to the quenching water nozzle 10 via a circulating water pump 24 .

There are 6-120 quenching water nozzles 10 .

The gas-solid rapid separation pulverized coal outlet 7 is columnar or conical.

There are 6-60 coal gasification nozzles 17 .

There are 2 to 12 cracked gas product outlets 11 .

The number of coal gasification product outlets 18 is 2-12.

A thermal plasma coal cracking-gasification coupling process, characterized in that the process steps are:

(1) The plasma enters the coal cracking reaction chamber 4 through the plasma generator 2, and reacts with the coal powder that enters the coal cracking reaction chamber 4 through the coal powder feeding device 3, and the reaction temperature in the coal cracking reaction chamber 4 is 2000-4000K, the reaction product is discharged through the outlet 5 of the coal cracking reaction section, the reaction product is a gas-solid mixture, the temperature of the gas-solid mixture is 1200-2000K, the gas-solid mixture enters the air-cooling chamber 9, the temperature in the air-cooling chamber 9 350 ~ 800K;

(2) The above reaction products pass through the gas-solid quick separator 6 to realize the separation of gas-solid two phases, the solid phase products and part of the gas phase products enter the coal gasification reaction chamber 16 through the pulverized coal outlet 7 of the gas-solid quick separator, and the remaining gas phase products pass through the coal gasification reaction chamber 16. The jacket structure 8 formed by the cracking reaction chamber outlet 5 and the gas-solid quick separator 6 is quenched by the quenching agent sprayed from the quenching water nozzle 10, and then discharged from the system through the cracking gas product outlet 11, and the quenching agent is collected by the quenching water collection tank 12 And enter the steam-water separator 13; the steam separated by the steam-water separator 13 is sent to the coal gasification nozzle 17 through the circulating steam pipe 14, and the liquid separated by the steam-water separator 13 enters the water purifier 22, and then passes through the circulating water pump 24 Deliver to the quenching water nozzle 10;

(3) The above-mentioned solid phase products and part of the gas phase products entering the coal gasification reaction chamber 16 through the pulverized coal outlet 7 of the gas-solid rapid separator, and the hot steam entering the coal gasification reaction chamber 16 through the coal gasification nozzle 17 undergo a coal gasification reaction; The reaction temperature in the gasification reaction chamber 16 is 800-2000K, and the gaseous products after the reaction are discharged from the system through the coal gasification product outlet 18; The gas-liquid interface of the coal gasification reactor is separated from the gas phase products, and is discharged from the system through the cinder port 20; the temperature of the liquid seal 19 at the bottom of the coal gasification reactor is 320-370K, and the supernatant in the area of the liquid seal 19 at the bottom of the coal gasification reactor passes through the liquid discharge port 23 is sent to the water purifier 22, and the water discharged from the cinder port 20 is collected by the ash settler 21 and sent to the water purifier 22, and the water in the water purifier 22 is sent to the quenching water nozzle 10 through the circulating water pump 24.

The coal powder is one of solid coal powder, a powdery mixture of coal and biomass or a powdery mixture of coal and petroleum coke.

The working gas of the plasma generator 2 is at least one of hydrogen, nitrogen, oxygen and water vapor.

The plasma is one of DC arc plasma, high frequency plasma or microwave plasma.

The beneficial effects of the present invention are: the present invention forms a new type of reaction device capable of realizing thermal plasma coal cracking-gasification coupling process by adding a gas-solid rapid separator and a coal gasification reactor after the plasma coal cracking reaction device , spray water steam in the added coal gasification reactor to continue the coal gasification reaction of pulverized coal, and then achieve the purpose of improving the overall conversion rate of the coal cracking device and the comprehensive value of the process. The present invention can make full use of the reaction products of the plasma coal cracking process In particular, the high energy carried by the pulverized coal after the reaction increases the reaction time and history of the pulverized coal, which can increase the overall conversion rate of the pulverized coal. A large amount of gas by-products of the coal gasification reaction process can be obtained from the additional coal gasification reactor, such as CO and H ₂ , the comprehensive value of plasma coal cracking process will be greatly improved compared with traditional technology.

Description of drawings

Fig. 1 is a schematic diagram of thermal plasma coal cracking-gasification coupling device;

Labels in the figure: 1-coal gasification reactor; 2-plasma generator; 3-coal powder feeding device; 4-coal cracking reaction chamber; 5-coal cracking reaction chamber outlet; 6-gas-solid rapid separator; 7 -Gas-solid quick separator pulverized coal outlet; 8-jacket structure; 9-air cooling chamber; 10-quench water nozzle; 11-cracking gas product outlet; 12-quench water collection tank; 13-steam water separator; Circulating steam pipe; 15-separator outlet; 16-coal gasification reaction chamber; 17-coal gasification nozzle; 18-coal gasification product outlet; 19-liquid seal at the bottom of coal gasification reactor; Device; 22-water purifier; 23-drainage port; 24-circulating water pump.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

Example 1

A thermal plasma coal cracking-gasification coupling reaction device, as shown in Figure 1, a plasma generator 2 and a pulverized coal feeding device 3 are arranged at the upper end of the coal cracking reaction chamber 4, and a coal gasification device is arranged at the lower end of the coal cracking reaction chamber 4 Reactor 1, the inner diameter of coal gasification reactor 1 is 300mm, coal cracking reaction chamber outlet 5 is set at the lower end of coal cracking reaction chamber 4, coal cracking reaction chamber outlet 5 is a constricted neck, at the periphery of coal cracking reaction chamber outlet 5 shrinking outer wall Install the quenching water nozzle 10; the lower end of the outlet 5 of the coal cracking reaction chamber is provided with a gas-solid quick separator 6, the outlet 5 of the coal cracking reaction chamber and the upper end of the gas-solid quick separator 6 form a jacket structure 8, and the gap between the jacket structure 8 is an annular gap shape, the thickness of the annular gap is 10 mm, the height of the annular gap is 50 mm, the jacket structure 8 is located under the quenching water nozzle 10, and at the periphery of the outer wall of the coal cracking reaction chamber outlet 5 that is 20, 40, and 60 mm away from the outlet of the jacket structure 8 Three layers of quenching water nozzles 10 are arranged, each layer has 12 nozzles, and the nozzles of adjacent layers are staggered by 10°. The cold water collecting tank 12 divides the coal gasification reactor 1 into two parts. The upper part of the quenching water collecting tank 12 is the air cooling chamber 9, the lower part of the quenching water collecting tank 12 is the coal gasification reaction chamber 16, and the lower part of the gas-solid quick separator 6 is the gas-solid The pulverized coal outlet 7 of the quick separator, the pulverized coal outlet 7 of the gas-solid quick separator is conical, the inner diameter of the opening is 120mm, and the distance from the outlet 5 of the coal cracking reaction chamber is 250mm, along the direction of the pulverized coal outlet 7 of the gas-solid quick separator Coal gasification nozzles 17 are arranged in the peripheral direction of the outer wall, and the coal gasification nozzles 17 are arranged at a distance of 10 mm above the pulverized coal outlet 7 of the gas-solid rapid separator. Four cracked gas product outlets 11 are arranged around the outer wall of the air cooling chamber 9, and four coal gasification product outlets 18 are arranged along the outer wall of the coal gasification reaction chamber 16; The distance between the pulverized coal outlet 7 of the quick separator and the liquid seal 19 at the bottom of the coal gasification reactor is 800mm. The lower part of the liquid seal 19 at the bottom of the coal gasification reactor is the cinder port 20, and the cinder port 20 passes through the ash settler 21 and the water purifier 22 connected, the coal gasification reactor 1 is provided with a drain port 23 in the supernatant liquid area of the liquid seal 19 at the bottom of the coal gasification reactor, and the drain port 23 is connected with the water purifier 22; the quenching water collection tank 12 is connected with the steam-water separator 13, One end of the steam-water separator 13 is connected to the coal gasification nozzle 17 through the circulating steam pipe 14 , and the other end is connected to the water purifier 22 through the separator outlet 15 , and the water purifier 22 is connected to the quenching water nozzle 10 through the circulating water pump 24 .

A thermal plasma coal cracking-gasification coupling process, using the above-mentioned device, the process steps are:

(1) The DC arc hydrogen plasma enters the coal cracking reaction chamber 4 through the plasma generator 2, and reacts with the dry coal powder particles with an average particle size of 60 μm entering the coal cracking reaction chamber 4 through the coal powder feeding device 3. , the reaction temperature in the coal cracking reaction chamber 4 is 2800-3500K, and the reaction product is discharged through the outlet 5 of the coal cracking reaction section. The reaction product is a gas-solid mixture, and the temperature of the gas-solid mixture is 1600-1800K. The cold chamber 9, the temperature in the air-cooled chamber 9 is 700-800K;

(2) The above reaction products pass through the gas-solid quick separator 6 to realize the separation of gas-solid two phases, the solid phase products and part of the gas phase products enter the coal gasification reaction chamber 16 through the pulverized coal outlet 7 of the gas-solid quick separator, and the remaining gas phase products pass through the coal gasification reaction chamber 16. The jacket structure 8 formed by the cracking reaction chamber outlet 5 and the gas-solid quick separator 6 is quenched by the quenching agent sprayed from the quenching water nozzle 10, and then discharged from the system through the cracking gas product outlet 11, and the quenching agent is collected by the quenching water collection tank 12 And enter the steam-water separator 13; the steam separated by the steam-water separator 13 is sent to the coal gasification nozzle 17 through the circulating steam pipe 14, and the liquid separated by the steam-water separator 13 enters the water purifier 22, and then passes through the circulating water pump 24 Deliver to the quenching water nozzle 10;

(3) The above-mentioned solid phase products and part of the gas phase products entering the coal gasification reaction chamber 16 through the pulverized coal outlet 7 of the gas-solid rapid separator, and the hot steam entering the coal gasification reaction chamber 16 through the coal gasification nozzle 17 undergo a coal gasification reaction; The reaction temperature in the gasification reaction chamber 16 is 1000-1300K, and the gaseous products after the reaction are discharged from the system through the coal gasification product outlet 18; The gas-liquid interface of the coal gasification reactor is separated from the gas phase products, and is discharged from the system through the cinder port 20; the temperature of the liquid seal 19 at the bottom of the coal gasification reactor is 350-370K, and the supernatant in the area of the liquid seal 19 at the bottom of the coal gasification reactor passes through the liquid discharge port 23 is sent to the water purifier 22, and the water discharged from the cinder port 20 is collected by the ash settler 21 and sent to the water purifier 22, and the water in the water purifier 22 is sent to the quenching water nozzle 10 through the circulating water pump 24.

The pressures of the bottom liquid seal 19 of the coal gasification reactor, the coal gasification product outlet 18 and the separator outlet 15 are all adjustable.

In this embodiment, the pressure at the plasma generator 2 is 140-150 kPa, the pressure at the cracked gas product outlet 11 is 100-105 kPa, and the pressure in the coal gasification reaction chamber 16 is 135-140 kPa.

Compared with the thermal plasma coal cracking device before improvement, the plasma coal cracking-gasification coupling reaction device: the overall conversion rate of coal powder is increased from 38-43% to 73-78%, which is close to the limit conversion of coal powder used rate of 81%; the ratio of the total generated heat of gas phase products and coal powder to the total input electric power has increased from 17-25% to 65-70%. The reaction heat required by the process, the total fraction of CO and _H2 in the reaction products of the coal gasification reaction process exceeds 80%; the specific energy consumption per unit mass of pulverized coal converted is reduced from 5.2 to 5.6 kWh/kg to 2.8 to 3.2 kWh /kg.

Claims (10)

1. A thermal plasma coal cracking-gasification coupling reaction device, characterized in that a plasma generator (2) and a pulverized coal feeding device (3) are arranged at the upper end of the coal cracking reaction chamber (4), and the coal cracking reaction The coal gasification reactor (1) is arranged under the chamber (4), and the coal cracking reaction chamber outlet (5) is arranged at the lower end of the coal cracking reaction chamber (4). (5) Quenching water nozzles (10) are placed on the periphery of the outer wall of the reduced diameter; a gas-solid quick separator (6) is arranged at the lower end of the outlet of the coal cracking reaction chamber (5), and the outlet of the coal cracking reaction chamber (5) is connected with the gas-solid quick separator ( 6) The upper end forms a jacket structure (8), the gap of the jacket structure (8) is annular, the jacket structure (8) is under the quenching water nozzle (10), and around the gas-solid quick separator (6) A quenching water collecting tank (12) is arranged, and the quenching water collecting tank (12) divides the coal gasification reactor (1) into two parts, and the upper part of the quenching water collecting tank (12) is an air cooling chamber (9), and the quenching water collecting tank ( 12) The lower part is the coal gasification reaction chamber (16), and the lower end of the gas-solid rapid separator (6) is the coal powder outlet (7) of the gas-solid rapid separator, along the peripheral direction of the outer wall of the gas-solid rapid separator coal powder outlet (7) The coal gasification nozzle (17) is arranged, the cracked gas product outlet (11) is arranged along the outer wall of the gas cooling chamber (9), and the coal gasification product outlet (18) is arranged along the outer wall of the coal gasification reaction chamber (16); the coal gasification reactor ( 1) The bottom of the coal gasification reactor is provided with a liquid seal (19) at the bottom, and the lower part of the liquid seal (19) at the bottom of the coal gasification reactor is the cinder port (20). The cinder port (20) passes through the ash settler (21) and the water purifier (22) are connected, and the coal gasification reactor (1) is provided with a drain port (23) in the supernatant liquid area of the liquid seal (19) at the bottom of the coal gasification reactor, and the drain port (23) is connected to the water purifier (22); The quenching water collection tank (12) is connected to the steam-water separator (13), one end of the steam-water separator (13) is connected to the coal gasification nozzle (17) through the circulating steam pipe (14), and the other end is connected to the water vaporizer through the outlet of the separator (15). Purifier (22) links to each other, and water purifier (22) links to each other with quenching water nozzle (10) through circulating water pump (24). 2. A thermal plasma coal cracking-gasification coupling reaction device according to claim 1, characterized in that there are 6-120 quenching water nozzles (10). 3. A thermal plasma coal cracking-gasification coupling reaction device according to claim 1, characterized in that the gas-solid rapid separation pulverized coal outlet (7) is cylindrical or conical. 4. A thermal plasma coal cracking-gasification coupling reaction device according to claim 1, characterized in that there are 6-60 coal gasification nozzles (17). 5. A thermal plasma coal cracking-gasification coupled reaction device according to claim 1, characterized in that there are 2-12 cracked gas product outlets (11). 6. A thermal plasma coal cracking-gasification coupling reaction device according to claim 1, characterized in that there are 2-12 coal gasification product outlets (18). 7. A thermal plasma coal cracking-gasification coupling process, characterized in that the process steps are: (1) The plasma enters the coal cracking reaction chamber (4) through the plasma generator (2), and reacts with the coal powder that enters the coal cracking reaction chamber (4) through the coal powder feeding device (3), and the coal cracking reaction occurs. The reaction temperature in the reaction chamber (4) is 2000-4000K, and the reaction product is discharged through the coal cracking reaction section outlet (5). The reaction product is a gas-solid mixture, and the temperature of the gas-solid mixture is 1200-2000K. The air-cooled chamber (9), the temperature in the air-cooled chamber (9) is 350-800K; (2) The gas-solid two-phase separation is realized through the gas-solid quick separator (6) for the above-mentioned reaction product, and the solid phase product and part of the gas phase product enter the coal gasification reaction chamber (16) through the gas-solid quick separator coal powder outlet (7). , the remaining gaseous products pass through the jacket structure (8) formed by the outlet of the coal cracking reaction chamber (5) and the gas-solid quick separator (6), and are quenched by the quenching agent ejected from the quenching water nozzle (10), and the cracked gas products The outlet (11) is discharged from the system, and the quenching agent is collected by the quenching water collection tank (12) and enters the steam-water separator (13); the steam separated by the steam-water separator (13) is sent to the coal gasification through the circulating steam pipe (14) Nozzle (17), the liquid that is separated by the steam-water separator (13) enters the water purifier (22), and is sent to the quenching water nozzle (10) through the circulating water pump (24) afterwards; (3) The solid phase products and part of the gas phase products entering the coal gasification reaction chamber (16) through the pulverized coal outlet (7) of the gas-solid rapid separator and the gasification reaction chamber (16) through the coal gasification nozzle (17) Coal gasification reaction occurs with hot steam; the reaction temperature in the coal gasification reaction chamber (16) is 800-2000K, and the gaseous products after the reaction are discharged from the system through the coal gasification product outlet (18); the solid phase products after the reaction are in the coal gasification reactor ( 1) Accumulated at the bottom, separated from the gas-phase product through the gas-liquid interface of the liquid seal (19) at the bottom of the coal gasification reactor, and discharged from the system through the coal slag port (20); the temperature of the liquid seal (19) at the bottom of the coal gasification reactor is 320 ~ 370K, the supernatant in the area of the liquid seal (19) at the bottom of the coal gasification reactor is sent to the water purifier (22) through the liquid discharge port (23), and the water discharged from the cinder port (20) is passed through the ash settler (21) Collection is sent to water purifier (22), and the water in water purifier (22) is delivered to quenching water nozzle (10) through circulating water pump (24). 8. A thermal plasma coal cracking-gasification coupling process according to claim 7, characterized in that the pulverized coal is solid pulverized coal, a powdery mixture of coal and biomass or a mixture of coal and petroleum coke One of the powder mixtures. 9. A thermal plasma coal cracking-gasification coupling process according to claim 7, characterized in that the working gas of the plasma generator (2) is at least one of hydrogen, nitrogen, oxygen and water vapor A sort of. 10. A thermal plasma coal cracking-gasification coupling process according to claim 7, characterized in that said plasma is one of DC arc plasma, high frequency plasma or microwave plasma.

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