Stepped utilization device for fuel gas in alcohol-ammonia co-production process

Abstract

The utility model relates to the technical field of alcohol-ammonia co-production, in particular to a stepped utilization device for fuel gas in an alcohol-ammonia co-production process, which comprises a methanol expansion tank, a gasification furnace, a sulfur recovery incinerator, an electric heating boiler, a torch and a gas supply header pipe, and a purge gas pipeline is fixedly communicated between a gas outlet end of the methanol expansion tank and the gas supply header pipe. The gas supply header pipe is fixedly communicated with a liquid nitrogen washing system tail gas pipeline and a synthetic ammonia system tail gas pipeline, a gasification furnace gas supply pipeline is fixedly communicated between the gas supply header pipe and the gas inlet end of the gasification furnace, and a sulfur recovery gas supply pipeline is fixedly communicated between the gas supply header pipe and the gas inlet end of the sulfur recovery incinerator; an electric heating boiler gas supply pipeline is fixedly communicated between the gas supply main pipe and the gas inlet end of the electric heating boiler; and a methanol synthesis system tail gas pipeline is fixedly communicated on the gasification furnace gas supply pipeline. According to the utility model, the fuel gas is graded and utilized according to the heat value from high to low, so that the high-quality fuel gas is fully utilized, and the purposes of reducing cost and improving efficiency of enterprises are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of alcohol-ammonia co-production, and is a step-by-step utilization device for fuel gas in an alcohol-ammonia co-production process. Background Art

[0002] In the alcohol-ammonia co-production project, the mixed gas of the fuel gas pipeline network is the centralized collection of the tail gas containing flammable gas from each section. This part of the gas source mainly comes from the tail gas of the liquid nitrogen washing system, the vent gas of the methanol synthesis expansion tank, and the tail gas of the synthetic ammonia system. Among them, the vent gas of the methanol synthesis expansion tank and the tail gas of the methanol synthesis system are high calorific value fuel gases. After being discharged into the fuel gas pipeline network for centralized collection, the calorific value of some high calorific value gas sources is lowered. After part of it is used, the rest is discharged to the flare system for burning, causing great waste.

[0003] The requirements for fuel gas during gasification furnace baking are high calorific value, stable gas quality, and a maximum flow rate of 240Nm 3 / h. The mixed gas from the fuel gas network has a lower calorific value after mixing, resulting in the gasifier only being able to reach 650°C, far from the temperature requirement for standby furnaces. It is also necessary to use additional natural gas as a heat source for subsequent furnace baking and standby furnaces (650°C to 1100°C). In the existing design, the gasifier system uses a natural gas pipeline network to directly introduce the gas for furnace baking and standby furnaces, resulting in high economic expenditure. The sulfur recovery section also requires the fuel gas to have a high calorific value, stable gas quality, and be monitored and identified by ultraviolet and infrared monitoring instruments. The flow rate must reach 120Nm 3 / h. The current fire detection interlock of the sulfur recovery incinerator is unstable due to the mixed gas components of the fuel gas pipeline network. The fire detection flame cannot be detected during combustion, which poses a risk of system tripping and affects the safe and environmentally friendly operation of the system. Summary of the invention

[0004] The utility model provides a step-by-step utilization device for fuel gas in an alcohol-ammonia cogeneration process, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem that the mixed gas of the fuel gas pipeline network in the existing alcohol-ammonia cogeneration project cannot meet the requirements of some devices for fuel gas and the problem of waste of high calorific value fuel gas.

[0005] The technical scheme of the utility model is realized by the following measures: a step-by-step utilization device of fuel gas in the alcohol-ammonia co-production process, comprising a methanol expansion tank, a vaporizer, a sulfur recovery incinerator, an electric boiler, a flare and a gas supply main pipe, wherein the end of the gas supply main pipe is fixedly connected to the flare, a venting gas pipeline is fixedly connected between the gas outlet end of the methanol expansion tank and the first gas inlet end of the gas supply main pipe, a liquid nitrogen washing system tail gas pipeline is fixedly connected to the second gas inlet end of the gas supply main pipe, and a synthetic ammonia system tail gas pipeline is fixedly connected to the third gas inlet end of the gas supply main pipe. The gas supply pipeline of the vaporizer is fixedly connected between the gas supply main pipe between the purge gas pipeline and the tail gas pipeline of the liquid nitrogen washing system and the gas inlet end of the vaporizer, the gas supply main pipe between the gas supply pipeline of the vaporizer and the tail gas pipeline of the liquid nitrogen washing system and the gas inlet end of the sulfur recovery incinerator are fixedly connected with the sulfur recovery gas supply pipeline, the gas supply main pipe between the tail gas pipeline of the synthetic ammonia system and the flare and the gas inlet end of the electric boiler are fixedly connected with the electric boiler gas supply pipeline, and the gas supply pipeline of the vaporizer is fixedly connected with the tail gas pipeline of the methanol synthesis system.

[0006] The following are further optimizations and / or improvements to the above utility model technical solution:

[0007] The above-mentioned methanol synthesis system tail gas pipeline and the gasifier gas supply pipeline between the gasifier are fixedly connected with the first natural gas pipeline, the first natural gas pipeline and the sulfur recovery gas supply pipeline are fixedly connected with the second natural gas pipeline, and the second natural gas pipeline and the electric boiler gas supply pipeline are fixedly connected with the third natural gas pipeline.

[0008] A check valve is fixedly installed on the gas supply main pipe between the sulfur recovery gas supply pipeline and the tail gas pipeline of the liquid nitrogen washing system.

[0009] The above-mentioned cascade utilization device of fuel gas in the alcohol-ammonia co-production process also includes a first controller. A pressure gauge is fixedly installed on the gas supply main pipe between the sulfur recovery gas supply pipeline and the purge gas pipeline. A first solenoid valve is fixedly installed on the gas supply main pipe between the check valve and the tail gas line of the liquid nitrogen washing system. The first solenoid valve and the pressure gauge are both electrically connected to the first controller.

[0010] The step-by-step utilization device of the fuel gas of the alcohol-ammonia co-production process further includes a second controller, a third controller and a fourth controller. A second solenoid valve is fixedly installed on the gas supply pipeline of the vaporizer between the tail gas pipeline of the methanol synthesis system and the first natural gas pipeline, a third solenoid valve is fixedly installed on the first natural gas pipeline between the second natural gas pipeline and the gas supply pipeline of the vaporizer, and a fourth solenoid valve is fixedly installed on the tail gas pipeline of the methanol synthesis system. The second solenoid valve, the third solenoid valve, the fourth solenoid valve and the control end of the vaporizer are all electrically connected to the second controller; a fifth solenoid valve is fixedly installed on the sulfur recovery gas supply pipeline between the gas supply main and the second natural gas pipeline, a sixth solenoid valve is fixedly installed on the second natural gas pipeline between the third natural gas pipeline and the sulfur recovery gas supply pipeline, and the fifth solenoid valve, the sixth solenoid valve and the control end of the sulfur recovery incinerator are all electrically connected to the third controller, a seventh solenoid valve is fixedly installed on the gas supply pipeline of the electric boiler between the third natural gas pipeline and the gas supply main, an eighth solenoid valve is fixedly installed on the third natural gas pipeline, and the seventh solenoid valve, the eighth solenoid valve and the control end of the electric boiler are all electrically connected to the fourth controller.

[0011] The utility model utilizes fuel gas in grades from high to low according to calorific value, fully utilizes high-quality fuel gas, partially replaces the use of natural gas, reduces enterprise production costs, fully utilizes recyclable gas in production for reuse, and achieves the purpose of reducing costs and increasing efficiency for enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attached Figure 1 It is a schematic diagram of the process flow of the utility model.

[0013] The codes in the attached drawings are: 1 is a methanol expansion tank, 2 is a vaporizer, 3 is a sulfur recovery incinerator, 4 is an electric boiler, 5 is a torch, 6 is a gas supply main, 7 is a purge gas pipeline, 8 is a liquid nitrogen washing system tail gas pipeline, 9 is a synthetic ammonia system tail gas pipeline, 10 is a vaporizer gas supply pipeline, 11 is a sulfur recovery gas supply pipeline, 12 is an electric boiler gas supply pipeline, 13 is a methanol synthesis system tail gas pipeline, 14 is a first natural gas pipeline, 15 is a second natural gas pipeline, 16 is a third natural gas pipeline, 17 is a check valve, 18 is a first pressure gauge, 19 is a first solenoid valve, 20 is a second solenoid valve, 21 is a third solenoid valve, 22 is a fourth solenoid valve, 23 is a fifth solenoid valve, 24 is a sixth solenoid valve, 25 is a seventh solenoid valve, 26 is an eighth solenoid valve, 27 is a second pressure gauge, 28 is a first controller, 29 is a second controller, 30 is a third controller, and 31 is a fourth controller. DETAILED DESCRIPTION

[0014] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical solution of the present invention and actual conditions.

[0015] In the present invention, unless otherwise specified, the equipment and devices used are all the equipment and devices known and used in the art.

[0016] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached manual. Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0017] The utility model is further described below in conjunction with embodiments:

[0018] Example 1: Figure 1 As shown, the step-by-step utilization device of the fuel gas of the alcohol-ammonia co-production process comprises a methanol expansion tank 1, a vaporizer 2, a sulfur recovery incinerator 3, an electric boiler 4, a flare 5 and a gas supply main pipe 6. The end of the gas supply main pipe 6 is fixedly connected to the flare 5. A purge gas pipeline 7 is fixedly connected between the gas outlet end of the methanol expansion tank 1 and the first gas inlet end of the gas supply main pipe 6. A liquid nitrogen washing system tail gas pipeline 8 is fixedly connected to the second gas inlet end of the gas supply main pipe 6. A synthetic ammonia system tail gas pipeline 9 is fixedly connected to the third gas inlet end of the gas supply main pipe 6. The purge gas pipeline 7 is connected to the liquid nitrogen washing system tail gas pipeline 8. A gas supply pipeline 10 for the gasifier is fixedly connected between the gas supply main pipe 6 between the tail gas pipeline 8 of the system and the gas inlet end of the gasifier 2, a sulfur recovery gas supply pipeline 11 is fixedly connected between the gas supply main pipe 6 between the gasifier gas supply pipeline 10 and the tail gas pipeline 8 of the liquid nitrogen washing system and the gas inlet end of the sulfur recovery incinerator 3, an electric boiler gas supply pipeline 12 is fixedly connected between the gas supply main pipe 6 between the tail gas pipeline 9 of the synthetic ammonia system and the flare 5 and the gas inlet end of the electric boiler 4, and a methanol synthesis system tail gas pipeline 13 is fixedly connected to the gas supply pipeline 10 of the gasifier.

[0019] Example 2: Figure 1 As shown, as an optimization of the above-mentioned embodiment 1, the gasification furnace gas supply pipeline 10 between the methanol synthesis system tail gas pipeline 13 and the gasification furnace 2 is fixedly connected with a first natural gas pipeline 14, the first natural gas pipeline 14 and the sulfur recovery gas supply pipeline 11 are fixedly connected with a second natural gas pipeline 15, and the second natural gas pipeline 15 and the electric boiler gas supply pipeline 12 are fixedly connected with a third natural gas pipeline 16. When the high calorific value fuel gas that can be provided by the alcohol-ammonia co-production process is insufficient, or the system production requires high calorific value fuel gas, natural gas is used as a supplement to the system fuel gas.

[0020] Example 3: Figure 1 As shown, as an optimization of the above-mentioned embodiments 1 to 2, a check valve 17 is fixedly installed on the gas supply main pipe 6 between the sulfur recovery gas supply pipeline 11 and the liquid nitrogen washing system tail gas pipeline 8.

[0021] Example 4: Figure 1As shown, as an optimization of the above-mentioned embodiments 1 to 3, the step utilization device of the fuel gas in the alcohol-ammonia co-production process also includes a first controller 28, a first pressure gauge 18 is fixedly installed on the gas supply main pipe 6 between the sulfur recovery gas supply pipeline 11 and the purge gas pipeline 7, a first solenoid valve 19 is fixedly installed on the gas supply main pipe 6 between the check valve 17 and the tail gas pipeline 8 of the liquid nitrogen washing system, and the first solenoid valve 19 and the first pressure gauge 18 are both electrically connected to the first controller 28.

[0022] Example 5: Figure 1 As shown, as an optimization of the above-mentioned embodiments 1 to 2, the step-by-step utilization device of the fuel gas of the alcohol-ammonia co-production process further includes a second controller 29, a third controller 30 and a fourth controller 31, a second solenoid valve 20 is fixedly installed on the gasification furnace gas supply pipeline 10 between the tail gas pipeline 13 of the methanol synthesis system and the first natural gas pipeline 14, a third solenoid valve 21 is fixedly installed on the first natural gas pipeline 14 between the second natural gas pipeline 15 and the gasification furnace gas supply pipeline 10, a fourth solenoid valve 22 is fixedly installed on the tail gas pipeline 13 of the methanol synthesis system, and the second solenoid valve 20, the third solenoid valve 21, the fourth solenoid valve 22 and the control end of the gasification furnace 2 are all electrically connected to the second controller 29; a sulfur recovery gas supply pipeline 11 between the gas supply main 6 and the second natural gas pipeline 15 is fixedly installed on the first natural gas pipeline 14; A fifth solenoid valve 23 is fixedly installed, and a sixth solenoid valve 24 is fixedly installed on the second natural gas pipeline 15 between the third natural gas pipeline 16 and the sulfur recovery gas supply pipeline 11. The control ends of the fifth solenoid valve 23, the sixth solenoid valve 24 and the sulfur recovery incinerator 3 are all electrically connected to the third controller 30; a second pressure gauge 27 is fixedly installed on the gas supply main pipe 6 between the liquid nitrogen washing system tail gas pipeline 8 and the synthetic ammonia system tail gas pipeline 9, a seventh solenoid valve 25 is fixedly installed on the electric boiler gas supply pipeline 12 between the third natural gas pipeline 16 and the gas supply main pipe 6, and an eighth solenoid valve 26 is fixedly installed on the third natural gas pipeline 16. The second pressure gauge 27, the seventh solenoid valve 25, the eighth solenoid valve 26 and the control ends of the electric boiler 4 are all electrically connected to the fourth controller 31.

[0023] According to the needs, the pipelines and equipment of the step utilization device of the alcohol-ammonia co-production process fuel gas are equipped with conventional valves, thermometers and pressure gauges known in the art. The first controller 28, the second controller 29, the third controller 30 and the fourth controller 31 can all be CS3000 controllers produced by Yokogawa Corporation of Japan.

[0024] In the alcohol-ammonia co-production project, the fuel gas pipeline system collects the tail gas containing flammable gas from each section, mainly including the tail gas of the liquid nitrogen washing system, the methanol synthesis expansion tank purge gas, the tail gas of the methanol synthesis system and the tail gas of the synthetic ammonia system. Among them, the purge gas of the methanol synthesis expansion tank and the tail gas of the methanol synthesis system are high calorific value fuel gases. The gas supply volume of the methanol synthesis expansion tank purge gas is 0.39MPa and 280Nm3 / h, its main components are 50% hydrogen, 20% carbon monoxide, 6% methane, 4% nitrogen, 8% methanol, and 2% carbon dioxide. It is characterized by high combustion calorific value, stable components, and good quality. The tail gas of the methanol synthesis system has a gas supply of 4.6MPa and 100Nm 3 / h, the main components are 70% hydrogen, 28% carbon monoxide, 2% carbon dioxide, its characteristics are high calorific value and good quality. The fuel gas provided by the liquid nitrogen washing system has a gas supply of 3700Nm 3 / h, its main components are 50% nitrogen, 27% carbon monoxide, 15% hydrogen, and 8% methane. Nitrogen is an inert gas and does not burn. Its components vary greatly, which reduces the quality of the fuel gas network. Synthetic ammonia system: gas supply 0.2MPa, 20Nm 3 / h, the main components are 50% ammonia, 15% hydrogen, 10% water vapor, and 25% nitrogen. Features: ammonia is highly irritating, harmful to health, can form ammonium salt crystals, block flame arresters, and form safety hazards, and the thermal quality is average. The utility model refines the distribution of the above four parts of fuel gas, and supplies two parts of high calorific value fuel gas to the gasification furnace 2 and the sulfur recovery incinerator 3, which are two devices with high requirements for fuel gas, avoiding the waste of high calorific value fuel gas and realizing the step-by-step utilization of fuel gas in the alcohol-ammonia co-production process.

[0025] When the step-by-step utilization device of the fuel gas of the alcohol-ammonia co-production process is used, it includes a gas supply scheme for the gasifier 2, a gas supply scheme for the sulfur recovery incinerator 3 and a gas supply scheme for the thermal power boiler 4, wherein:

[0026] The gas supply scheme for gasifier 2 is: the gas supply flow rate of the methanol synthesis expansion tank purge gas is 200Nm 3 / h to 280Nm 3 / h, the tail gas supply flow rate of the methanol synthesis system is 0 to 100Nm 3 / h; when the methanol synthesis system is not in production, the fuel gas is provided by natural gas; during specific operation, the second controller 29 adjusts the second solenoid valve 20, the third solenoid valve 21, and the fourth solenoid valve 22 according to the temperature of the vaporizer 2 to control the gas supply flow.

[0027] The gas supply scheme of the sulfur recovery incinerator 3 is as follows: the gas supply flow rate of the methanol synthesis expansion tank purge gas is 0 to 120 Nm³ / h. When the methanol synthesis system is not in production, the fuel gas is provided by natural gas. During specific operation, the third controller 30 adjusts the fifth solenoid valve 23 and the sixth solenoid valve 24 according to the temperature of the sulfur recovery incinerator 3 to control the gas supply flow rate.

[0028] The gas supply scheme of the thermal power boiler 4 is as follows: when the pressure of the gas supply main 6 is normal (the pressure of the second pressure gauge 27 is ≥ 0.19MPa), the fuel gas is provided by the gas supply main 6, the tail gas supply flow rate of the synthetic ammonia system is 0 to 20Nm³ / h, the tail gas supply flow rate of the liquid nitrogen washing system is 3500Nm³ / h, and the gas supply flow rate of the methanol synthesis expansion tank purge gas is 0 to 240Nm³ / h. When the pressure of the gas supply main 6 is insufficient, natural gas is used as a supplement. During specific operation, the fourth controller 31 adjusts the seventh solenoid valve 25 and the eighth solenoid valve 26 according to the temperature of the thermal power boiler 4 and the pressure value of the second pressure gauge 27 to control the gas supply flow rate.

[0029] The utility model utilizes fuel gas in a graded manner from high to low according to calorific value, and uses the methanol synthesis expansion tank vent gas and the methanol synthesis system tail gas mainly for the gasifier to replace natural gas, meeting the requirement of a large amount of high calorific value fuel gas for temperature increase and heat storage during the gasifier baking or preparation process, and realizing full utilization of high-quality fuel gas. The methanol synthesis expansion tank vent gas is supplied to the sulfur recovery incinerator 3. The high quality characteristics of the methanol synthesis expansion tank vent gas make it easy for the probe to detect the fire, ensuring the safe and stable operation of the system. The liquid nitrogen washing system tail gas and the synthetic ammonia system tail gas are put into the thermal power boiler 4. These two parts of tail gas containing combustible gas are used in the thermal power boiler 4 to replace part of the coal combustion, and are discharged up to standard after being treated with flue gas desulfurization and denitrification, achieving energy saving and consumption reduction, green environmental protection, and reducing carbon emissions at the same time.

[0030] In summary, the utility model realizes the full utilization of various exhaust gases containing combustible gases in the alcohol-ammonia co-production project, partially replaces the use of natural gas, reduces the production cost of the enterprise, fully utilizes the recyclable gas in the production for reuse, and achieves the purpose of reducing costs and increasing efficiency of the enterprise.

[0031] The above technical features constitute the embodiments of the present utility model, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A step-by-step utilization device for fuel gas in an alcohol-ammonia co-production process, characterized in that It includes a methanol expansion tank, a vaporizer, a sulfur recovery incinerator, an electric boiler, a flare and a gas supply main. The end of the gas supply main is fixedly connected with the flare, a purge gas pipeline is fixedly connected between the gas outlet end of the methanol expansion tank and the first gas inlet end of the gas supply main, a liquid nitrogen washing system tail gas pipeline is fixedly connected at the second gas inlet end of the gas supply main, a synthetic ammonia system tail gas pipeline is fixedly connected at the third gas inlet end of the gas supply main, a vaporizer gas supply pipeline is fixedly connected between the purge gas pipeline and the liquid nitrogen washing system tail gas pipeline and the gas inlet end of the vaporizer, a sulfur recovery gas supply pipeline is fixedly connected between the gas supply pipeline of the vaporizer and the tail gas pipeline of the liquid nitrogen washing system and the gas inlet end of the sulfur recovery incinerator, an electric boiler gas supply pipeline is fixedly connected between the gas supply main between the tail gas pipeline of the synthetic ammonia system and the flare and the gas inlet end of the electric boiler, and a methanol synthesis system tail gas pipeline is fixedly connected on the gas supply pipeline of the vaporizer.

2. The step-by-step utilization device for the alcohol-ammonia co-production process fuel gas according to claim 1 is characterized in that The gasification furnace gas supply pipeline between the methanol synthesis system tail gas pipeline and the gasification furnace is fixedly connected with a first natural gas pipeline, the first natural gas pipeline and the sulfur recovery gas supply pipeline are fixedly connected with a second natural gas pipeline, and the second natural gas pipeline and the electric boiler gas supply pipeline are fixedly connected with a third natural gas pipeline.

3. The step-by-step utilization device for the fuel gas of the alcohol-ammonia co-production process according to claim 1 or 2, characterized in that A check valve is fixedly installed on the gas supply main pipe between the sulfur recovery gas supply pipeline and the tail gas pipeline of the liquid nitrogen washing system.

4. The stepwise utilization device for the fuel gas of the alcohol-ammonia co-production process according to claim 1 or 2, characterized in that It also includes a first controller. A pressure gauge is fixedly installed on the gas supply main pipe between the sulfur recovery gas supply pipeline and the purge gas pipeline. A first solenoid valve is fixedly installed on the gas supply main pipe between the check valve and the tail gas pipeline of the liquid nitrogen washing system. The first solenoid valve and the pressure gauge are both electrically connected to the first controller.

5. The step-by-step utilization device for the fuel gas of the alcohol-ammonia co-production process according to claim 3 is characterized in that It also includes a first controller. A pressure gauge is fixedly installed on the gas supply main pipe between the sulfur recovery gas supply pipeline and the purge gas pipeline. A first solenoid valve is fixedly installed on the gas supply main pipe between the check valve and the tail gas pipeline of the liquid nitrogen washing system. The first solenoid valve and the pressure gauge are both electrically connected to the first controller.

6. The stepwise utilization device for fuel gas in the alcohol-ammonia co-production process according to claim 2 or 5, characterized in that It also includes a second controller, a third controller and a fourth controller. A second solenoid valve is fixedly installed on the gas supply pipeline of the vaporizer between the tail gas pipeline of the methanol synthesis system and the first natural gas pipeline, a third solenoid valve is fixedly installed on the first natural gas pipeline between the second natural gas pipeline and the gas supply pipeline of the vaporizer, and a fourth solenoid valve is fixedly installed on the tail gas pipeline of the methanol synthesis system. The second solenoid valve, the third solenoid valve, the fourth solenoid valve and the control end of the vaporizer are all electrically connected to the second controller; a fifth solenoid valve is fixedly installed on the sulfur recovery gas supply pipeline between the gas supply main and the second natural gas pipeline, a sixth solenoid valve is fixedly installed on the second natural gas pipeline between the third natural gas pipeline and the sulfur recovery gas supply pipeline, the fifth solenoid valve, the sixth solenoid valve and the control end of the sulfur recovery incinerator are all electrically connected to the third controller, a seventh solenoid valve is fixedly installed on the gas supply pipeline of the electric boiler between the third natural gas pipeline and the gas supply main, an eighth solenoid valve is fixedly installed on the third natural gas pipeline, and the seventh solenoid valve, the eighth solenoid valve and the control end of the electric boiler are all electrically connected to the fourth controller.

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