Comprehensive recycling system for synthetic ammonia gas

Abstract

The invention provides a synthetic ammonia gas comprehensive recycling system, and relates to the technical field of synthetic ammonia. Comprising a synthetic ammonia raw material system for providing hydrogen and nitrogen raw materials for a synthetic ammonia production system, the synthetic ammonia production system for producing liquid ammonia according to the hydrogen and nitrogen raw materials and generating cold energy, and a synthetic ammonia carbon emission reduction system for producing a liquid carbon dioxide product by using tail gas of the synthetic ammonia raw material system and the cold energy provided by the synthetic ammonia production system, the synthetic ammonia tail gas recovery system uses tail gas of the synthetic ammonia production system as a raw material to produce a helium product, provides hydrogen and nitrogen raw materials for the synthetic ammonia production system and provides the methane-rich gas for the synthetic ammonia raw material system; and the adsorption efficiency is improved by using cold energy provided by a synthetic ammonia production system. The problems of low gas utilization value, low economical efficiency, high carbon emission, helium waste, high energy consumption and the like in the existing ammonia synthesis process are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic ammonia, and in particular to a comprehensive recovery and utilization system of synthetic ammonia gas. Background Art

[0002] Synthetic ammonia is an important chemical product, which is widely used in agriculture, industry, national defense, medicine, metallurgy and other fields, and is of great significance in the national economy. The energy consumption of synthetic ammonia production is roughly divided into two parts, namely raw material energy consumption and fuel energy consumption. A large amount of greenhouse gases methane and carbon dioxide will be produced in the process of synthetic ammonia. At the same time, as the reaction proceeds, components such as methane, helium, neon, argon, carbon dioxide, etc. that do not participate in the reaction gradually accumulate in the system, which will cause the pressure of the ammonia synthesis system to increase, the power consumption to increase, and the ammonia synthesis rate to decrease.

[0003] In order to reduce the content of non-reactive gases in the synthesis gas process and increase the ammonia synthesis rate, the enriched non-reactive gases must be discharged from the synthetic ammonia production system. At the same time, some of the nitrogen and hydrogen components of the synthetic ammonia raw materials, as well as the high-value helium that does not participate in the reaction, are also discharged, resulting in a waste of resources. In order to achieve energy-saving, consumption-reducing, clean and refined production, it is an important energy-saving, emission-reducing and efficiency-enhancing measure for synthetic ammonia enterprises to recycle and utilize the various components in the synthetic ammonia process. At present, the existing synthetic ammonia process has problems such as low gas utilization rate, single product, low recovery efficiency and high energy consumption. Moreover, it is difficult to remove neon from helium using technologies such as deep cooling and flash evaporation. Therefore, the development of comprehensive recycling and utilization of various gases in the synthetic ammonia process is very beneficial to reducing production consumption and environmental protection. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a comprehensive recovery and utilization system for synthetic ammonia gas.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A comprehensive recovery and utilization system for synthetic ammonia gas, comprising:

[0007] Synthetic ammonia production system, synthetic ammonia raw material system, synthetic ammonia carbon emission reduction system and synthetic ammonia tail gas recovery system;

[0008] The synthetic ammonia raw material system, the synthetic ammonia carbon emission reduction system and the synthetic ammonia tail gas recovery system are all connected to the synthetic ammonia production system; the synthetic ammonia carbon emission reduction system is connected to the synthetic ammonia raw material system, and the synthetic ammonia tail gas recovery system is connected to the synthetic ammonia raw material system;

[0009] The synthetic ammonia raw material system is used to provide hydrogen and nitrogen raw materials to the synthetic ammonia production system, and the synthetic ammonia production system is used to produce liquid ammonia and generate cold based on the hydrogen and nitrogen raw materials. The synthetic ammonia carbon emission reduction system uses the tail gas of the synthetic ammonia raw material system and the cold provided by the synthetic ammonia production system to produce liquid carbon dioxide products, and at the same time provides hydrogen-rich raw gas and methane-rich gas to the synthetic ammonia raw material system. The synthetic ammonia tail gas recovery system uses the tail gas of the synthetic ammonia production system as a raw material to produce helium products, and at the same time provides hydrogen and nitrogen raw materials to the synthetic ammonia production system and methane-rich gas to the synthetic ammonia raw material system, and uses the cold provided by the synthetic ammonia production system to improve adsorption efficiency.

[0010] Preferably, the synthetic ammonia raw material system comprises:

[0011] The first membrane unit and the first-stage reformer, the second-stage reformer, the carbon monoxide conversion unit and the primary decarbonization unit connected in sequence;

[0012] Compressed air is input into the input end of the first membrane unit, the permeate side of the first membrane unit is connected to the secondary reformer, and the retentate side of the first membrane unit is connected to the primary decarbonization unit.

[0013] Preferably, the synthetic ammonia carbon emission reduction system comprises:

[0014] a first compressor, a first pretreatment unit, a second membrane unit, a second compressor, a second pretreatment unit, a third pretreatment unit, a third membrane unit, a fourth membrane unit, a fifth membrane unit, a third compressor, and a condensation liquefaction unit;

[0015] One end of the first compressor is connected to the primary decarbonization unit of the synthetic ammonia raw material system, the other end of the first compressor is connected to one end of the first pretreatment unit, one end of the first pretreatment unit is connected to the retentate side of the fifth membrane unit, the other end of the first pretreatment unit is connected to the input end of the second membrane unit, the permeate side of the second membrane unit is connected to one end of the second compressor, the other end of the second compressor is connected to one end of the second pretreatment unit, the other end of the second pretreatment unit is connected to the input end of the fifth membrane unit, the permeate side of the fifth membrane unit is connected to one end of the third compressor, the other end of the third compressor is connected to the first input end of the condensation and liquefaction unit, the cold The second input end and the second output end of the condensation and liquefaction unit are both connected to the ammonia liquefaction unit of the synthetic ammonia production system, the first output end of the condensation and liquefaction unit is connected to one end of the second pretreatment unit, the third output end of the condensation and liquefaction unit outputs a liquid carbon dioxide product, the retentate side of the second membrane unit is connected to one end of the third pretreatment unit, the other end of the third pretreatment unit is connected to the input end of the third membrane unit, the retentate side of the third membrane unit is connected to the input end of the fourth membrane unit, the permeate side of the third membrane unit is connected to the primary decarbonization unit, the retentate side of the fourth membrane unit is connected to the first-stage reformer and the second-stage reformer, and the permeate side of the fourth membrane unit is connected to one end of the first compressor.

[0016] Preferably, the synthetic ammonia production system comprises:

[0017] Secondary decarbonization unit, ammonia synthesis unit, ammonia liquefaction unit and ammonia storage unit;

[0018] The input end of the secondary decarbonization unit is connected to the primary decarbonization unit of the synthetic ammonia raw material system, the output end of the secondary decarbonization unit is connected to the first input end of the ammonia synthesis unit, the second input end and the second output end of the ammonia synthesis unit are both connected to the synthetic ammonia tail gas recovery system, the first output end of the ammonia synthesis unit is connected to the first input end of the ammonia liquefaction unit, the first output end of the ammonia liquefaction unit is connected to the input end of the ammonia storage unit, the second input end of the ammonia liquefaction unit and the second output end of the ammonia liquefaction unit are respectively connected to the second output end of the condensation and liquefaction unit and the second input end of the condensation and liquefaction unit, and the output end of the ammonia storage unit is connected to the synthetic ammonia tail gas recovery system.

[0019] Preferably, the synthetic ammonia tail gas recovery system comprises:

[0020] A fourth pretreatment unit, a sixth membrane unit, a fifth pretreatment unit, an electrochemical hydrogen pump unit, a sixth pretreatment unit, a seventh membrane unit, a fourth compressor, a seventh pretreatment unit, an eighth membrane unit, a ninth membrane unit, a turbine compressor, a sixth compressor, an eleventh membrane unit, a tenth membrane unit, an eighth pretreatment unit, a fifth compressor, a heat exchanger, and a deep purification adsorption unit;

[0021] The input end of the fourth pretreatment unit is connected to the output end of the ammonia storage unit and the second output end of the ammonia synthesis unit, the output end of the fourth pretreatment unit is connected to the input end of the sixth membrane unit, the retentate side of the sixth membrane unit is connected to the first input end of the turbine compressor, the permeate side of the sixth membrane unit is connected to one end of the fifth pretreatment unit, the other end of the fifth pretreatment unit is connected to the input end of the electrochemical hydrogen pump unit, the first output end of the electrochemical hydrogen pump unit is connected to the second input end of the ammonia synthesis unit, and the second output end of the electrochemical hydrogen pump unit is connected to One end of the sixth pretreatment unit is connected, the other end of the sixth pretreatment unit is connected to the input end of the seventh membrane unit, the retentate side of the seventh membrane unit is connected to the input end of the ninth membrane unit, the permeate side of the seventh membrane unit is connected to one end of the fourth compressor, the other end of the fourth compressor is connected to one end of the seventh pretreatment unit, the other end of the seventh pretreatment unit is connected to the input end of the eighth membrane unit, the retentate side of the eighth membrane unit is connected to the input end of the seventh membrane unit, the permeate side of the eighth membrane unit is connected to one end of the fifth compressor, and the fifth compressor is connected to one end of the seventh pretreatment unit. The other end of the machine is connected to the first input end of the heat exchanger, the first output end of the heat exchanger is connected to the input end of the deep purification adsorption unit, the second input end of the heat exchanger is connected to the first output end of the turbine compressor, the second output end of the heat exchanger is connected to one end of the eighth pretreatment unit, the first output end of the deep purification adsorption unit is used to output the helium product, the second output end of the deep purification adsorption unit is used to connect to the second input end of the turbine compressor, the second output end of the turbine compressor is connected to the input end of the seventh membrane unit, and the other end of the eighth pretreatment unit is connected to the The input end of the tenth membrane unit is connected, the retentate side of the tenth membrane unit is connected to the input end of the eleventh membrane unit, the permeate side of the tenth membrane unit is connected to the first-stage reformer and the second-stage reformer, the retentate side of the eleventh membrane unit is connected to the second input end of the ammonia synthesis unit, the permeate side of the eleventh membrane unit is connected to one end of the sixth compressor, the other end of the sixth compressor is connected to one end of the eighth pretreatment unit, the retentate side of the ninth membrane unit is connected to the input end of the eleventh membrane unit, and the permeate side of the ninth membrane unit is connected to the third input end of the turbine compressor.

[0022] Preferably, the first membrane unit is one of polydimethylsiloxane, polyurethane, polycellulose or polyethernitrile;

[0023] The third membrane unit, the fourth membrane unit, the sixth membrane unit, the seventh membrane unit, the eighth membrane unit and the ninth membrane unit are all polyimide membranes with an operating temperature range of 40°C to 100°C; the second membrane unit, the fifth membrane unit, the tenth membrane unit and the eleventh membrane unit are all polydimethylsiloxane membranes with an operating temperature range of -10°C to 80°C.

[0024] Preferably, the helium concentration in the tail gas of the synthetic ammonia production system is 0.001 vol% to 40 vol%; the amount of helium processed by the deep purification adsorption unit of the synthetic ammonia tail gas recovery system is less than 20% of the amount of helium in the tail gas of the synthetic ammonia production system, and the helium concentration of the helium product is ≥99.9999 vol%; the concentration of the carbon dioxide product is ≥95 vol%.

[0025] Preferably, the operating temperature range of the deep purification adsorption unit in the synthetic ammonia tail gas recovery system is 40°C to -220°C, and the operating temperature range of the electrochemical hydrogen pump unit is 10°C to 100°C.

[0026] Preferably, the oxygen concentration on the permeate side of the first membrane unit in the synthetic ammonia raw material system is higher than 25 vol%, and the nitrogen concentration on the retentate side is higher than 85 vol%.

[0027] The present invention discloses the following technical effects:

[0028] The invention provides a synthetic ammonia gas comprehensive recovery and utilization system, comprising: a synthetic ammonia production system, a synthetic ammonia raw material system, a synthetic ammonia carbon emission reduction system and a synthetic ammonia tail gas recovery system; the synthetic ammonia raw material system, the synthetic ammonia carbon emission reduction system and the synthetic ammonia tail gas recovery system are all connected to the synthetic ammonia production system; the synthetic ammonia carbon emission reduction system is connected to the synthetic ammonia raw material system, and the synthetic ammonia tail gas recovery system is connected to the synthetic ammonia raw material system; the synthetic ammonia raw material system is used to provide hydrogen and nitrogen raw materials for the synthetic ammonia production system, the synthetic ammonia production system is used to produce liquid ammonia and generate cold according to the hydrogen and nitrogen raw materials, the synthetic ammonia carbon emission reduction system uses the tail gas of the synthetic ammonia raw material system as a raw material and uses the cold provided by the synthetic ammonia production system to produce liquid carbon dioxide products, and at the same time provides hydrogen-rich raw material gas and methane-rich gas for the synthetic ammonia raw material system, the synthetic ammonia tail gas recovery system uses the tail gas of the synthetic ammonia production system as a raw material to produce helium products, and at the same time provides hydrogen and nitrogen raw materials for the synthetic ammonia production system and methane-rich gas for the synthetic ammonia raw material system, and uses the cold provided by the synthetic ammonia production system to improve adsorption efficiency. The present invention takes the synthetic ammonia production system as the core, and comprehensively recycles and utilizes the gases of various systems in the synthetic ammonia process, which not only saves the natural gas of the synthetic ammonia raw material system, but also can achieve the productization of near-zero emissions of greenhouse gases methane and carbon dioxide, and at the same time, the hydrogen in each hydrogen-containing gas of the synthetic ammonia is recycled at a high value, thereby improving the utilization rate of hydrogen in the synthetic ammonia production process. The high-value helium contained in the synthetic ammonia tail gas recovery system is extracted, further increasing the comprehensive utilization value of the synthetic ammonia process gas. Through the optimization of the coupling form of the developed unique non-phase change multi-stage membrane technology and hydrogen pump technology, not only can the helium concentration be increased step by step, but also the components such as methane, nitrogen and neon can be effectively removed synchronously, so that the gas entering the deep purification adsorption unit reaches the industrial grade helium standard, and further passes through the deep purification adsorption unit to produce electronic grade helium products. Low energy consumption production is achieved by graded utilization of oxygen and nitrogen, and comprehensive utilization of the cold provided by the synthetic ammonia production system and the turbine process of the synthetic ammonia tail gas recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 A schematic diagram of the structure of a comprehensive recovery and utilization system for synthetic ammonia gas provided by an embodiment of the present invention;

[0031] Figure 2A detailed schematic diagram of a synthetic ammonia gas comprehensive recovery and utilization system provided in an embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 1. Synthetic ammonia production system; 2. Synthetic ammonia carbon reduction system; 3. Synthetic ammonia raw material system; 4. Synthetic ammonia tail gas recovery system; M-1, first membrane unit; M-2, second membrane unit; M-3, third membrane unit; M-4, fourth membrane unit; M-5, fifth membrane unit; M-6, sixth membrane unit; M-7, seventh membrane unit; M-8, eighth membrane unit; M-9, ninth membrane unit; M-10, tenth membrane unit; M-11, eleventh membrane unit; RP-1, first pretreatment unit; RP-2, second pretreatment unit; RP-3, third Pretreatment unit; RP-4, fourth pretreatment unit; RP-5, fifth pretreatment unit; RP-6, sixth pretreatment unit; RP-7, seventh pretreatment unit; RP-8, eighth pretreatment unit; EHP, electrochemical hydrogen pump unit; CS-1, condensation liquefaction unit; He-PSA, deep purification adsorption unit; E-1, heat exchanger; K-1, first compressor; K-2, second compressor; K-3, third compressor; K-4, fourth compressor; K-5, fifth compressor; K-6, sixth compressor; TK-1, turbine compressor. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 As shown, the present invention provides a comprehensive recovery and utilization system for synthetic ammonia gas, comprising:

[0037] Synthetic ammonia production system 1, synthetic ammonia raw material system 3, synthetic ammonia carbon emission reduction system 2 and synthetic ammonia tail gas recovery system 4;

[0038] The synthetic ammonia raw material system 3, the synthetic ammonia carbon emission reduction system 2 and the synthetic ammonia tail gas recovery system 4 are all connected to the synthetic ammonia production system 1; the synthetic ammonia carbon emission reduction system 2 is connected to the synthetic ammonia raw material system 3, and the synthetic ammonia tail gas recovery system 4 is connected to the synthetic ammonia raw material system 3;

[0039] The synthetic ammonia raw material system 3 is used to provide hydrogen and nitrogen raw materials to the synthetic ammonia production system 1. The synthetic ammonia production system 1 is used to produce liquid ammonia and generate cold energy based on the hydrogen and nitrogen raw materials. The synthetic ammonia carbon reduction system 2 uses the tail gas of the synthetic ammonia raw material system 3 and the cold energy provided by the synthetic ammonia production system 1 to produce liquid carbon dioxide products, and at the same time provides the synthetic ammonia raw material system 3 with hydrogen-rich raw gas with a hydrogen concentration greater than 60 vol% and a calorific value greater than 10.0 MJ / Nm 3 The synthetic ammonia tail gas recovery system 4 uses the tail gas of the synthetic ammonia production system 1 as a raw material to produce helium products, and at the same time provides hydrogen and nitrogen raw materials for the synthetic ammonia production system 1 and provides methane-rich gas for the synthetic ammonia raw material system 3, wherein the methane-rich gas is the enriched methane gas.

[0040] Further, such as Figure 2 As shown, the synthetic ammonia raw material system 3 includes:

[0041] The first membrane unit M-1 and the first-stage reformer, the second-stage reformer, the carbon monoxide conversion unit and the primary decarbonization unit connected in sequence;

[0042] Compressed air is input to the input end of the first membrane unit M-1, the permeate side of the first membrane unit M-1 is connected to the secondary reformer, and the retentate side of the first membrane unit M-1 is connected to the primary decarbonization unit.

[0043] Specifically, the raw gas after the primary reforming and desulfurization is mixed with water vapor at a gas (water vapor) carbon (methane) ratio of 2.7 and then enters the primary reformer. The reforming reaction causes the water vapor and hydrocarbons to react under the action of a catalyst to generate hydrogen and carbon oxides. There is about 30% (mole, dry basis) of unconverted methane in the outlet gas of the primary reformer, and the outlet gas is sent to the top of the secondary reformer.

[0044] The following is an introduction to the two-stage reformer:

[0045] In the upper section of the second-stage reformer, oxygen in the air reacts with the outlet gas of the first-stage reformer to generate carbon oxides and water; the large amount of heat energy released raises the gas temperature to about 800°C; the nitrogen brought in by the air is used as the raw material for synthesizing ammonia.

[0046] Furthermore, the synthetic ammonia carbon emission reduction system 2 comprises:

[0047] a first compressor K-1, a first pretreatment unit RP-1, a second membrane unit M-2, a second compressor K-2, a second pretreatment unit RP-2, a third pretreatment unit RP-3, a third membrane unit M-3, a fourth membrane unit M-4, a fifth membrane unit M-5, a third compressor K-3, and a condensation and liquefaction unit CS-1;

[0048] One end of the first compressor K-1 is connected to the primary decarbonization unit, the other end of the first compressor K-1 is connected to one end of the first pretreatment unit RP-1, one end of the first pretreatment unit RP-1 is connected to the retentate side of the fifth membrane unit M-5, the other end of the first pretreatment unit RP-1 is connected to the input end of the second membrane unit M-2, the permeate side of the second membrane unit M-2 is connected to one end of the second compressor K-2, the other end of the second compressor K-2 is connected to one end of the second pretreatment unit RP-2, the other end of the second pretreatment unit RP-2 is connected to the input end of the fifth membrane unit M-5, the permeate side of the fifth membrane unit M-5 is connected to one end of the third compressor K-3, the other end of the third compressor K-3 is connected to the first input end of the condensation and liquefaction unit CS-1, The second input end and the second output end of the condensation and liquefaction unit CS-1 are both connected to the synthetic ammonia production system 1, the first output end of the condensation and liquefaction unit CS-1 is connected to one end of the second pretreatment unit RP-2, the third output end of the condensation and liquefaction unit CS-1 outputs a liquid carbon dioxide product, the retentate side of the second membrane unit M-2 is connected to one end of the third pretreatment unit RP-3, the other end of the third pretreatment unit RP-3 is connected to the input end of the third membrane unit M-3, the retentate side of the third membrane unit M-3 is connected to the input end of the fourth membrane unit M-4, the permeate side of the third membrane unit M-3 is connected to the primary decarbonization unit, the retentate side of the fourth membrane unit M-4 is connected to the first stage reformer and the second stage reformer, and the permeate side of the fourth membrane unit M-4 is connected to one end of the first compressor K-1.

[0049] Furthermore, the synthetic ammonia production system 1 comprises:

[0050] Secondary decarbonization unit, ammonia synthesis unit, ammonia liquefaction unit and ammonia storage unit;

[0051] The input end of the secondary decarbonization unit is connected to the primary decarbonization unit, the output end of the secondary decarbonization unit is connected to the first input end of the ammonia synthesis unit, the second input end and the second output end of the ammonia synthesis unit are both connected to the synthetic ammonia tail gas recovery system 4, the first output end of the ammonia synthesis unit is connected to the first input end of the ammonia liquefaction unit, the first output end of the ammonia liquefaction unit is connected to the input end of the ammonia storage unit, the second input end of the ammonia liquefaction unit and the second output end of the ammonia liquefaction unit are respectively connected to the second output end of the condensation and liquefaction unit CS-1 and the second input end of the condensation and liquefaction unit CS-1, and the output end of the ammonia storage unit is connected to the synthetic ammonia tail gas recovery system 4.

[0052] Furthermore, the synthetic ammonia tail gas recovery system 4 comprises:

[0053] The fourth pretreatment unit RP-4, the sixth membrane unit M-6, the fifth pretreatment unit RP-5, the electrochemical hydrogen pump unit EHP, the sixth pretreatment unit RP-6, the seventh membrane unit M-7, the fourth compressor K-4, the seventh pretreatment unit RP-7, the eighth membrane unit M-8, the ninth membrane unit M-9, the turbine compressor TK-1, the sixth compressor K-6, the eleventh membrane unit M-11, the tenth membrane unit M-10, the eighth pretreatment unit RP-8, the fifth compressor K-5, the heat exchanger E-1 and the deep purification adsorption unit He-PSA;

[0054] The input end of the fourth pretreatment unit RP-4 is connected to the output end of the ammonia storage unit and the second output end of the ammonia synthesis unit, the output end of the fourth pretreatment unit RP-4 is connected to the input end of the sixth membrane unit M-6, the retentate side of the sixth membrane unit M-6 is connected to the first input end of the turbine compressor TK-1, the permeate side of the sixth membrane unit M-6 is connected to one end of the fifth pretreatment unit RP-5, the other end of the fifth pretreatment unit RP-5 is connected to the input end of the electrochemical hydrogen pump unit EHP, the first output end of the electrochemical hydrogen pump unit EHP is connected to the second input end of the ammonia synthesis unit, and the second output end of the electrochemical hydrogen pump unit EHP is connected to the sixth membrane unit M-6. The sixth pretreatment unit RP-6 is connected to one end of the pretreatment unit RP-6, the other end of the sixth pretreatment unit RP-6 is connected to the output end of the seventh membrane unit M-7, the retentate side of the seventh membrane unit M-7 is connected to the input end of the ninth membrane unit M-9, the permeate side of the seventh membrane unit M-7 is connected to one end of the fourth compressor K-4, the other end of the fourth compressor K-4 is connected to one end of the seventh pretreatment unit RP-7, the other end of the seventh pretreatment unit RP-7 is connected to the input end of the eighth membrane unit M-8, the retentate side of the eighth membrane unit M-8 is connected to the input end of the seventh membrane unit M-7, the permeate side of the eighth membrane unit M-8 is connected to one end of the fifth compressor K-5, and the second end of the fourth compressor K-4 is connected to one end of the seventh pretreatment unit RP-7. The other end of the fifth compressor K-5 is connected to the first input end of the heat exchanger E-1, the first output end of the heat exchanger E-1 is connected to the input end of the deep purification adsorption unit He-PSA, the second input end of the heat exchanger E-1 is connected to the first output end of the turbine compressor TK-1, the second output end of the heat exchanger E-1 is connected to one end of the eighth pretreatment unit RP-8, the first output end of the deep purification adsorption unit He-PSA is used to output helium products, the second output end of the deep purification adsorption unit He-PSA is used to connect to the second input end of the turbine compressor TK-1, the second output end of the turbine compressor TK-1 is connected to the seventh membrane unit M-7 The other end of the eighth pretreatment unit RP-8 is connected to the input end of the tenth membrane unit M-10, the retentate side of the tenth membrane unit M-10 is connected to the input end of the eleventh membrane unit M-11, the permeate side of the tenth membrane unit M-10 is connected to the first-stage reformer and the second-stage reformer, the retentate side of the eleventh membrane unit M-11 is connected to the second input end of the ammonia synthesis unit, the permeate side of the eleventh membrane unit M-11 is connected to one end of the sixth compressor K-6, the other end of the sixth compressor K-6 is connected to one end of the eighth pretreatment unit RP-8, the retentate side of the ninth membrane unit M-9 is connected to the input end of the eleventh membrane unit M-11,The permeate side of the ninth membrane unit M-9 is connected to the third input end of the turbo compressor TK-1.

[0055] Specifically, compressed air passes through an oxygen-enriched membrane separation unit (the first membrane unit M-1) to obtain oxygen-enriched gas on the permeate side, and the oxygen-enriched gas enters the second-stage reformer to achieve oxygen-enriched combustion. Nitrogen-rich gas is obtained on the retentate side, and carbon dioxide is initially removed from the nitrogen-rich gas through the primary decarbonization unit. The nitrogen and hydrogen mixed gas removed from the carbon dioxide by the primary decarbonization unit enters the secondary decarbonization unit for deep removal of carbon dioxide, and a high-purity nitrogen and hydrogen mixed gas is obtained for use as a raw material for synthetic ammonia. The desorbed gas of the primary decarbonization unit is separated from carbon dioxide and hydrogen by the second membrane unit M-2, and the hydrogen-rich gas is further enriched with hydrogen by the third membrane unit M-3, and the enriched hydrogen enters the primary decarbonization unit. The nitrogen-rich and hydrogen-rich mixed gas streams after decarbonization enter the secondary decarbonization unit as a raw material for synthetic ammonia, and the retentate gas of the third membrane unit M-3 is separated from methane and carbon dioxide by the fourth membrane unit M-4, and the methane-rich gas enters the reformer (preferably a first-stage reformer) as fuel, and the carbon dioxide-rich gas and the desorbed gas of the primary decarbonization unit are mixed and recycled. The permeate gas of the second membrane unit M-2 is further enriched with carbon dioxide through the fifth membrane unit M-5. The permeate gas of the fifth membrane unit M-5 is passed through the condensation and liquefaction unit CS-1 to obtain liquid carbon dioxide products. The permeate gas of the fifth membrane unit M-5 is recycled as hydrogen-containing tail gas. The liquid ammonia of the synthetic ammonia unit provides cold for the condensation and liquefaction unit CS-1. The hydrogen-rich and helium-rich tail gas produced in the synthetic ammonia process enters the sixth membrane unit M-6 through the pretreatment unit PR-4. The permeate side of the sixth membrane unit M-6 is hydrogen-rich and helium-rich gas. The hydrogen-rich and helium-rich gas enters the electrochemical hydrogen pump unit EHP through the pretreatment unit PR-5 to separate hydrogen and helium. The high-purity hydrogen obtained at the cathode of the electrochemical hydrogen pump unit EHP is used as a raw material for synthetic ammonia or sold as a product. The anode of the electrochemical hydrogen pump unit EHP is helium-rich gas. After the pretreatment unit PR-6, the helium-rich gas enters the seventh membrane unit M-7 for preliminary enrichment of helium. The permeate gas of the seventh membrane unit M-7 enters the eighth membrane unit M-8 after pressurization and pretreatment. The eighth membrane unit M-8 realizes further enrichment of helium. The permeate gas of the eighth membrane unit M-8 is pressurized and heat-exchanged, and then deeply purified and adsorbed by the deep purification adsorption unit He-PSA to produce electronic-grade helium products. The retentate gas of the eighth membrane unit M-8 is recycled. The retentate gas of the seventh membrane unit M-7 is enriched with helium by the ninth membrane unit M-9, and the permeate gas of the ninth membrane unit M-9 and the desorbed gas of the deep purification adsorption unit He-PSA are mixed and pressurized for recycling. The retentate gas of the sixth membrane unit M-6 enters the tenth membrane unit M-10 after passing through the turbine compressor TK-1, the heat exchanger E-1 and the eighth pretreatment unit PR-8, mainly to achieve the separation of methane and nitrogen. The methane-rich gas on the permeate side of the tenth membrane unit M-10 is returned to the converter (preferably a first-stage converter) of the synthetic ammonia raw material system as fuel, and the nitrogen-rich retentate gas enters the eleventh membrane unit M-11 to further achieve the separation of methane and nitrogen. The nitrogen-rich gas is obtained on the retentate side as the raw material for the synthetic ammonia unit, and the methane-rich gas is recycled on the permeate side.

[0056] Further, the first membrane unit is one of polydimethylsiloxane, polyurethane, polycellulose or polyethernitrile;

[0057] The third membrane unit, the fourth membrane unit, the sixth membrane unit, the seventh membrane unit, the eighth membrane unit and the ninth membrane unit are all polyimide membranes with an operating temperature range of 40°C to 100°C; the second membrane unit, the fifth membrane unit, the tenth membrane unit and the eleventh membrane unit are all polydimethylsiloxane membranes with an operating temperature range of -10°C to 80°C.

[0058] Furthermore, the helium concentration in the tail gas of the synthetic ammonia production system is 0.001 vol% to 40 vol%; the amount of helium treated by the deep purification adsorption unit He-PSA of the synthetic ammonia tail gas recovery system is less than 20% of the amount of helium in the tail gas of the synthetic ammonia production system, and the helium concentration of the helium product is ≥99.9999 vol%; the concentration of the carbon dioxide product is ≥95 vol%.

[0059] Furthermore, the operating temperature range of the deep purification adsorption unit He-PSA in the synthetic ammonia tail gas recovery system is 40°C to -220°C, and the operating temperature range of the electrochemical hydrogen pump unit is 10°C to 100°C.

[0060] Furthermore, in the synthetic ammonia raw material system, the oxygen concentration on the permeate side of the first membrane unit M-1 is higher than 25 vol%, and the nitrogen concentration on the retentate side is higher than 85 vol%.

[0061] Specifically, the corresponding operating temperatures in this embodiment are all achieved through the cooling capacity provided by the heat exchanger E-1 and the synthetic ammonia production system, which ensures that the operation of this system is carried out at a low temperature.

[0062] More specifically, the pretreatment unit (first pretreatment unit to eighth pretreatment unit): removes fixed particles and liquid mist through a precision filter; the compression unit (first compressor to sixth compressor) mainly uses a reciprocating compressor for boosting; the condensation and liquefaction unit uses liquid ammonia to provide cooling to liquefy carbon dioxide;

[0063] The compressed air parameter is 5000Nm 3 / h, 30°C, 2.0MPa; the composition of the compressed air is 78.96vol% nitrogen, 21.0vol% oxygen, and 0.04vol% carbon dioxide;

[0064] The parameters of the tail gas of the primary decarbonization unit are 8000Nm 3 / h, 30℃, 0.1MPa; the composition of the tail gas of the primary decarbonization unit is 13.16vol% methane, 1.65vol% nitrogen, 59.96vol% carbon dioxide, and 25.23vol% hydrogen;

[0065] The tail gas parameters of the synthetic ammonia production system are 3000Nm 3 / h, 40°C, 10MPa; the composition of the tail gas of the synthetic ammonia production system is 12.75vol% methane, 27vol% nitrogen, 0.25vol% helium, and 60vol% hydrogen;

[0066] More specifically, the following are the limitations on the parameters of each membrane unit:

[0067] The membrane material of the first membrane unit M-1 is polyurethane, and the membrane area is 85m 2 ;

[0068] The membrane materials of the third membrane unit M-3, the fourth membrane unit M-4, the sixth membrane unit M-6, the seventh membrane unit M-7, the eighth membrane unit M-8 and the ninth membrane unit M-9 are all polyimide membranes, and the operating temperature is 80°C. Among them, the membrane area of ​​the third membrane unit M-3 is 580m 2 The membrane area of ​​the fourth membrane unit M-4 is 390m 2 The membrane area of ​​the sixth membrane unit M-6 is 680m 2 The membrane area of ​​the seventh membrane unit M-7 is 180m 2 The membrane area of ​​the eighth membrane unit M-8 is 9m 2 The membrane area of ​​the ninth membrane unit M-9 is 280m 2 ;

[0069] The membrane materials of the second membrane unit M-2, the fifth membrane unit M-5, the tenth membrane unit M-10, and the eleventh membrane unit M-11 are all polydimethylsiloxane membranes, and the operating temperature is -5°C. The membrane area of ​​the second membrane unit M-2 is 725m 2 The membrane area of ​​the fifth membrane unit M-5 is 740m 2 The membrane area of ​​the tenth membrane unit M-10 is 45m 2 The membrane area of ​​the eleventh membrane unit M-11 is 39m 2 ;

[0070] The following are the limitations on various compressor parameters:

[0071] The power parameter of the first compressor K-1 is 1330kW; the power parameter of the second compressor K-2 is 990kW; the power parameter of the third compressor K-3 is 1061kW; the power parameter of the fourth compressor K-4 is 10kW; the power parameter of the fifth compressor K-5 is 3kW; the power parameter of the sixth compressor K-6 is 83kW; the power parameter of the turbo compressor TK-1 is 20kW;

[0072] The following is an introduction to the working principle, materials used and helium concentration of the deep purification adsorption unit He-PSA:

[0073] The adsorbent of the deep purification adsorption unit He-PSA is 13X molecular sieve, and the deep purification adsorption unit He-PSA is a four-tower adsorption layout; the operating temperature is -200°C; the helium concentration entering the deep purification adsorption unit He-PSA is 98.5vol%;

[0074] The following is an introduction to the materials and products of the electrochemical hydrogen pump unit EHP:

[0075] The material of the electrochemical hydrogen pump unit EHP is Nafion membrane; the operating temperature is 40°C.

[0076] The following is an introduction to the gas parameters at each location:

[0077] The calorific value of the methane-rich gas on the permeate side of the fourth membrane unit M-4 is 20.2MJ / Nm 3 The calorific value of the methane-rich gas on the permeate side of the tenth membrane unit M-10 is 25.3MJ / Nm 3 ; Nitrogen concentration 85.50vol%, recovery rate 66.18%;

[0078] The hydrogen concentration at the cathode of the electrochemical hydrogen pump unit EHP is 99.999 vol%, the hydrogen concentration in the permeate gas of the third membrane unit M-3 is 65 vol%, and the overall hydrogen recovery rate is 93.23%;

[0079] Carbon dioxide concentration 98.52 vol%, yield 65.23%;

[0080] The helium product of the deep purification adsorption unit He-PSA is 99.9999 vol% helium, and the helium recovery rate is 94.31%.

[0081] The oxygen concentration in the oxygen-rich gas on the permeate side of the first membrane unit M-1 is 38.95 vol%, and the yield is 72%.

[0082] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0083] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A comprehensive recovery and utilization system for synthetic ammonia gas, characterized in that: include: Synthetic ammonia production system, synthetic ammonia raw material system, synthetic ammonia carbon emission reduction system and synthetic ammonia tail gas recovery system; The synthetic ammonia raw material system, the synthetic ammonia carbon emission reduction system and the synthetic ammonia tail gas recovery system are all connected to the synthetic ammonia production system; the synthetic ammonia carbon emission reduction system is connected to the synthetic ammonia raw material system, and the synthetic ammonia tail gas recovery system is connected to the synthetic ammonia raw material system; The synthetic ammonia raw material system is used to provide hydrogen and nitrogen raw materials to the synthetic ammonia production system, and the synthetic ammonia production system is used to produce liquid ammonia and generate cold based on the hydrogen and nitrogen raw materials. The synthetic ammonia carbon emission reduction system uses the tail gas of the synthetic ammonia raw material system and the cold provided by the synthetic ammonia production system to produce liquid carbon dioxide products, and at the same time provides hydrogen-rich raw gas and methane-rich gas to the synthetic ammonia raw material system. The synthetic ammonia tail gas recovery system uses the tail gas of the synthetic ammonia production system as a raw material to produce helium products, and at the same time provides hydrogen and nitrogen raw materials to the synthetic ammonia production system and methane-rich gas to the synthetic ammonia raw material system, and uses the cold provided by the synthetic ammonia production system to improve adsorption efficiency.

2. A comprehensive recovery and utilization system for synthetic ammonia gas according to claim 1, characterized in that: The synthetic ammonia raw material system comprises: The first membrane unit and the first-stage reformer, the second-stage reformer, the carbon monoxide conversion unit and the primary decarbonization unit connected in sequence; Compressed air is input into the input end of the first membrane unit, the permeate side of the first membrane unit is connected to the secondary reformer, and the retentate side of the first membrane unit is connected to the primary decarbonization unit.

3. A comprehensive recovery and utilization system for synthetic ammonia gas according to claim 2, characterized in that: The synthetic ammonia carbon emission reduction system comprises: a first compressor, a first pretreatment unit, a second membrane unit, a second compressor, a second pretreatment unit, a third pretreatment unit, a third membrane unit, a fourth membrane unit, a fifth membrane unit, a third compressor, and a condensation liquefaction unit; One end of the first compressor is connected to the primary decarbonization unit of the synthetic ammonia raw material system, the other end of the first compressor is connected to one end of the first pretreatment unit, one end of the first pretreatment unit is connected to the retentate side of the fifth membrane unit, the other end of the first pretreatment unit is connected to the input end of the second membrane unit, the permeate side of the second membrane unit is connected to one end of the second compressor, the other end of the second compressor is connected to one end of the second pretreatment unit, the other end of the second pretreatment unit is connected to the input end of the fifth membrane unit, the permeate side of the fifth membrane unit is connected to one end of the third compressor, the other end of the third compressor is connected to the first input end of the condensation and liquefaction unit, the cold The second input end and the second output end of the condensation and liquefaction unit are both connected to the ammonia liquefaction unit of the synthetic ammonia production system, the first output end of the condensation and liquefaction unit is connected to one end of the second pretreatment unit, the third output end of the condensation and liquefaction unit outputs a liquid carbon dioxide product, the retentate side of the second membrane unit is connected to one end of the third pretreatment unit, the other end of the third pretreatment unit is connected to the input end of the third membrane unit, the retentate side of the third membrane unit is connected to the input end of the fourth membrane unit, the permeate side of the third membrane unit is connected to the primary decarbonization unit, the retentate side of the fourth membrane unit is connected to the first-stage reformer and the second-stage reformer, and the permeate side of the fourth membrane unit is connected to one end of the first compressor.

4. A comprehensive recovery and utilization system for synthetic ammonia gas according to claim 3, characterized in that: The synthetic ammonia production system comprises: Secondary decarbonization unit, ammonia synthesis unit, ammonia liquefaction unit and ammonia storage unit; The input end of the secondary decarbonization unit is connected to the primary decarbonization unit of the synthetic ammonia raw material system, the output end of the secondary decarbonization unit is connected to the first input end of the ammonia synthesis unit, the second input end and the second output end of the ammonia synthesis unit are both connected to the synthetic ammonia tail gas recovery system, the first output end of the ammonia synthesis unit is connected to the first input end of the ammonia liquefaction unit, the first output end of the ammonia liquefaction unit is connected to the input end of the ammonia storage unit, the second input end of the ammonia liquefaction unit and the second output end of the ammonia liquefaction unit are respectively connected to the second output end of the condensation and liquefaction unit and the second input end of the condensation and liquefaction unit, and the output end of the ammonia storage unit is connected to the synthetic ammonia tail gas recovery system.

5. A comprehensive recovery and utilization system for synthetic ammonia gas according to claim 4, characterized in that: The synthetic ammonia tail gas recovery system comprises: A fourth pretreatment unit, a sixth membrane unit, a fifth pretreatment unit, an electrochemical hydrogen pump unit, a sixth pretreatment unit, a seventh membrane unit, a fourth compressor, a seventh pretreatment unit, an eighth membrane unit, a ninth membrane unit, a turbine compressor, a sixth compressor, an eleventh membrane unit, a tenth membrane unit, an eighth pretreatment unit, a fifth compressor, a heat exchanger, and a deep purification adsorption unit; The input end of the fourth pretreatment unit is connected to the output end of the ammonia storage unit and the second output end of the ammonia synthesis unit, the output end of the fourth pretreatment unit is connected to the input end of the sixth membrane unit, the retentate side of the sixth membrane unit is connected to the first input end of the turbine compressor, the permeate side of the sixth membrane unit is connected to one end of the fifth pretreatment unit, the other end of the fifth pretreatment unit is connected to the input end of the electrochemical hydrogen pump unit, the first output end of the electrochemical hydrogen pump unit is connected to the second input end of the ammonia synthesis unit, and the second output end of the electrochemical hydrogen pump unit is connected to One end of the sixth pretreatment unit is connected, the other end of the sixth pretreatment unit is connected to the input end of the seventh membrane unit, the retentate side of the seventh membrane unit is connected to the input end of the ninth membrane unit, the permeate side of the seventh membrane unit is connected to one end of the fourth compressor, the other end of the fourth compressor is connected to one end of the seventh pretreatment unit, the other end of the seventh pretreatment unit is connected to the input end of the eighth membrane unit, the retentate side of the eighth membrane unit is connected to the input end of the seventh membrane unit, the permeate side of the eighth membrane unit is connected to one end of the fifth compressor, and the fifth compressor is connected to one end of the seventh pretreatment unit. The other end of the machine is connected to the first input end of the heat exchanger, the first output end of the heat exchanger is connected to the input end of the deep purification adsorption unit, the second input end of the heat exchanger is connected to the first output end of the turbine compressor, the second output end of the heat exchanger is connected to one end of the eighth pretreatment unit, the first output end of the deep purification adsorption unit is used to output the helium product, the second output end of the deep purification adsorption unit is used to connect to the second input end of the turbine compressor, the second output end of the turbine compressor is connected to the input end of the seventh membrane unit, and the other end of the eighth pretreatment unit is connected to the The input end of the tenth membrane unit is connected, the retentate side of the tenth membrane unit is connected to the input end of the eleventh membrane unit, the permeate side of the tenth membrane unit is connected to the first-stage reformer and the second-stage reformer, the retentate side of the eleventh membrane unit is connected to the second input end of the ammonia synthesis unit, the permeate side of the eleventh membrane unit is connected to one end of the sixth compressor, the other end of the sixth compressor is connected to one end of the eighth pretreatment unit, the retentate side of the ninth membrane unit is connected to the input end of the eleventh membrane unit, and the permeate side of the ninth membrane unit is connected to the third input end of the turbine compressor.

6. A synthetic ammonia gas comprehensive recovery and utilization system according to claim 5, characterized in that: The first membrane unit is one of polydimethylsiloxane, polyurethane, polycellulose or polyethernitrile; The third membrane unit, the fourth membrane unit, the sixth membrane unit, the seventh membrane unit, the eighth membrane unit and the ninth membrane unit are all polyimide membranes with an operating temperature range of 40°C to 100°C; the second membrane unit, the fifth membrane unit, the tenth membrane unit and the eleventh membrane unit are all polydimethylsiloxane membranes with an operating temperature range of -10°C to 80°C.

7. A synthetic ammonia gas comprehensive recovery and utilization system according to claim 6, characterized in that: The helium concentration in the tail gas of the synthetic ammonia production system is 0.001 vol% to 40 vol%; the amount of helium processed by the deep purification adsorption unit of the synthetic ammonia tail gas recovery system is less than 20% of the amount of helium in the tail gas of the synthetic ammonia production system, the helium concentration of the helium product is ≥99.9999 vol%; the concentration of the carbon dioxide product is ≥95 vol%.

8. The comprehensive recovery and utilization system of synthetic ammonia gas according to claim 5, characterized in that: The operating temperature range of the deep purification adsorption unit in the synthetic ammonia tail gas recovery system is 40°C to -220°C, and the operating temperature range of the electrochemical hydrogen pump unit is 10°C to 100°C.

9. The comprehensive recovery and utilization system of synthetic ammonia gas according to claim 2, characterized in that: The oxygen concentration on the permeate side of the first membrane unit in the synthetic ammonia raw material system is higher than 25 vol%, and the nitrogen concentration on the retentate side is higher than 85 vol%.

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