Raw gas shift system and process for preparing synthesis gas by using same

Abstract

The invention provides a raw gas shift system and a process for preparing synthesis gas by adopting the raw gas shift system. The raw gas conversion system comprises a conversion device, a first waste heat boiler, a detoxification tank, a second waste heat boiler and heat exchange equipment. The conversion device is provided with an inlet and an outlet; the inlet of the conversion device is connected with a raw gas source; the first waste heat boiler is provided with an inlet and an outlet, and the inlet of the first waste heat boiler is connected with a raw gas source; the detoxification tank is provided with an inlet and an outlet; the inlet of the detoxification tank is connected with the outlet of the first waste heat boiler; the second waste heat boiler is provided with an inlet and an outlet, and the inlet of the second waste heat boiler is connected with the outlet of the detoxification tank; the heat exchange equipment is provided with an inlet and an outlet; the inlet of the heat exchange equipment is connected with the outlet of the second waste heat boiler; along the direction from the inlet to the outlet of the detoxification tank, the detoxification tank internally comprises a first area and a second area which are sequentially communicated, the first area is filled with a hydrolytic agent, and the second area is filled with a shift catalyst. The conversion system can realize high-load production of more than 100%.

Description

Technical Field

[0001] The present invention relates to the technical field of coal chemical industry, and in particular to a raw coal gas conversion system and a process for preparing synthesis gas by using the same. Background Art

[0002] At present, most coal chemical processes use coal gasification to produce synthesis gas. The synthesis gas is sent to the synthesis unit to prepare chemical products such as natural gas, olefins, methanol and oil products after conversion and purification. Water-gas shift is an indispensable process in coal chemical process, and its main function is to adjust the hydrogen-carbon ratio of synthesis gas. The principle of the shift reaction is to make CO and H2O(g) in the process gas undergo a shift reaction to generate H2 and CO2 under certain pressure and temperature conditions under the action of a catalyst.

[0003] The reaction formula is as follows:

[0004] CO+H2O=CO2+H2+Q△H=-41.1kJ / mol

[0005] Q=10861-1.44T-0.4×10-4T 2 +8×18-8T 3

[0006] Since the shift reaction can reduce the carbon monoxide content in the synthesis gas and generate more H2, the shift reaction can not only adjust the hydrogen-carbon ratio, but also meet different production requirements. Therefore, water-gas shift is crucial for downstream industrial synthesis.

[0007] The conversion devices in modern large-scale coal chemical plants are divided into conversion systems and non-conversion systems. The conversion system is equipped with a conversion furnace, which is the place where carbon monoxide reacts with water vapor. The conversion furnace is equipped with a sulfur-resistant conversion catalyst. The non-conversion system is equipped with a detoxification tank, which is equipped with a hydrolyzing agent, and its main purpose is to remove carbonyl sulfide and other organic sulfur in the raw coal gas. The non-conversion system does not undergo a carbon monoxide conversion reaction.

[0008] However, in the production process, if the process is not changed and the gas volume of the conversion system and the non-conversion system is directly increased, the conversion device can only maintain 100% full load operation at most and the load cannot be further increased. In addition, if the load is directly increased, the pressure drop of the conversion device will increase and exceed the design value, and the pressure of the system will increase, which may cause the syngas in the gasification section to be vented. Summary of the invention

[0009] The main purpose of the present invention is to provide a raw coal gas conversion system and a process for preparing synthesis gas using the same, so as to solve the problem in the prior art that it is difficult to increase the load of the conversion device to more than 100%.

[0010] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a raw gas conversion system is provided, which comprises: a conversion device, a first waste heat boiler, a detoxification tank, a second waste heat boiler and a heat exchange device, the conversion device having a conversion device inlet and a conversion device outlet, the conversion device inlet is connected to a raw gas source, the conversion device is used to perform a first conversion reaction on part of the raw gas to obtain a first conversion gas; the first waste heat boiler having a first waste heat boiler inlet and a first waste heat boiler outlet, the first waste heat boiler inlet is connected to the raw gas source, the first waste heat boiler is used to perform a first condensation on the remaining part of the raw gas to obtain condensed raw gas; the detoxification tank having a detoxification tank inlet and a detoxification tank outlet, the detoxification tank inlet is connected to the first waste heat boiler outlet, the detoxification tank is used to perform a first conversion reaction on the condensed raw gas The second conversion reaction is performed to obtain a detoxified gas including a detoxified unconverted gas and a detoxified converted gas; the second waste heat boiler has a second waste heat boiler inlet and a second waste heat boiler outlet, the second waste heat boiler inlet is connected to the detoxification tank outlet, and the second waste heat boiler is used to perform a second condensation on the detoxified gas to obtain a condensed gas; the heat exchange equipment has a heat exchange equipment inlet and a heat exchange equipment outlet, the heat exchange equipment inlet is connected to the second waste heat boiler outlet, and the heat exchange equipment is used to perform heat exchange on the condensed gas to obtain an unconverted gas and a second converted gas; the first converted gas, the unconverted gas and the second converted gas are introduced into a synthesis gas unit to prepare a synthesis gas; wherein, along the direction from the detoxification tank inlet to the detoxification tank outlet, the detoxification tank includes a first area and a second area which are connected in sequence, the first area is filled with a hydrolyzing agent, and the second area is filled with a conversion catalyst.

[0011] Furthermore, the inlet temperature of the detoxification tank is 200-230°C; and / or, when the load of the conversion device is greater than 80%, the detoxification tank includes one or more detoxification tanks arranged in parallel, preferably two detoxification tanks arranged in parallel, and each detoxification tank can be switched.

[0012] Furthermore, the raw coal gas conversion system also includes a newly added waste heat boiler, which is arranged in parallel with the second waste heat boiler; and / or the inner diameter of the inlet pipeline of the second waste heat boiler is 105-115 cm, and the inner diameter of the outlet pipeline of the second waste heat boiler is 95-105 cm; and / or the temperature of the second waste heat boiler is 240-260°C, and / or the pressure of the second waste heat boiler is 3.6-4.5 MPa; and / or the inner diameter of the inlet pipeline of the newly added waste heat boiler is 100-110 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler is 90-100 cm.

[0013] Furthermore, the inner diameter of the inlet pipeline of the first waste heat boiler is 120-135 cm, and the inner diameter of the outlet pipeline of the first waste heat boiler is 110-122 cm; and / or, the temperature of the first waste heat boiler is 200-220° C., and / or, the pressure of the first waste heat boiler is 4-4.4 MPa.

[0014] Furthermore, the temperature of the conversion device is 200-460° C., and / or the pressure of the conversion device is 3.6-4.4 MPa; and / or the water-gas ratio of the first conversion gas is 0.3-0.65:1.

[0015] Furthermore, the inlet temperature of the heat exchanger is 240-260°C, and / or the outlet temperature of the heat exchanger is 30-60°C; and / or the water-gas ratio of the unconverted gas is 0.4-0.8:1; and / or the water-gas ratio of the second converted gas is 0.35-0.7:1.

[0016] According to one aspect of the present invention, there is provided a process for producing synthesis gas using the above-mentioned crude gas conversion system, the process comprising: the crude gas is composed of a part of the crude gas and a remaining part of the crude gas; the part of the crude gas is subjected to a first conversion reaction to obtain a first conversion gas; the remaining part of the crude gas is subjected to a first condensation to obtain a condensed crude gas; under the action of a conversion catalyst and a hydrolyzing agent, the condensed crude gas is subjected to a second conversion reaction to obtain a detoxified gas including a detoxified unconverted gas and a detoxified converted gas; the detoxified gas is subjected to a second condensation to obtain a condensed gas; the condensed gas is subjected to heat exchange to obtain an unconverted gas and a second converted gas; and the first converted gas, the unconverted gas and the second converted gas are used as raw materials for synthesis gas.

[0017] Furthermore, the volume ratio of the above-mentioned part of the raw gas and the remaining part of the raw gas is 3-4:2-3, and / or the water-gas ratio of the raw gas is 0.6-0.85:1, and / or the volume ratio of the first conversion gas, the detoxified unconverted gas and the detoxified conversion gas is 4-6:2-3:2-3.

[0018] Furthermore, relative to 50000~100000m 3 The volume of the condensed raw gas is 10-20m 3 The volume of the hydrolyzing agent is 10 to 18 m 3 ; The volume ratio of the hydrolyzing agent to the conversion catalyst is 1 to 1.3:1; and / or the conversion catalyst is selected from any one or more of an iron-chromium conversion catalyst, a copper-zinc conversion catalyst and a cobalt-molybdenum conversion catalyst; and / or the active component of the hydrolyzing agent is an alkali metal.

[0019] Further, the temperature of the first shift reaction is 250-450°C; and / or the space velocity of the first shift reaction is 4500-6500h -1 ; and / or, the temperature of the second shift reaction is 230-460°C; and / or, the space velocity of the second shift reaction is 2000-3000h -1 .

[0020] By applying the technical solution of the present invention, the present application can reduce the gas distribution ratio of the conversion device by loading the conversion catalyst in the detoxification tank, so that the unconverted gas, i.e., the condensed raw gas, undergoes a partial conversion reaction, thereby reducing the pressure drop of the conversion device, and further increasing the load of the raw gas conversion system, achieving a load exceeding 100%, or even a high-load production of up to 110%. Specifically, part of the raw gas fully undergoes the first conversion reaction in the conversion device to obtain conversion gas; the remaining part of the raw gas undergoes the first condensation in the first waste heat boiler, which can not only adjust the temperature of the raw gas, thereby meeting the temperature requirements of the subsequent second conversion reaction, avoiding the deactivation of the conversion catalyst in the detoxification tank due to excessive temperature, but also remove impurities in the raw gas. According to the above-mentioned method, the hydrolyzing agent and the conversion catalyst are loaded in the detoxification tank, and the composition of the condensed raw gas can be pre-adjusted under the action of the hydrolyzing agent, and the conditions of the second conversion reaction can be optimized, thereby facilitating the second conversion reaction of CO and H2O in the condensed raw gas under the action of the conversion catalyst and improving the reaction efficiency of the second conversion reaction, thereby reducing the gas distribution ratio of the conversion device and reducing the pressure drop of the conversion device. At the same time, the hydrolyzing agent can also remove carbonyl sulfide and other organic sulfur in the condensed raw coal gas. The detoxified gas is subjected to a second condensation in the second waste heat boiler, which can not only separate the water vapor produced by the second shift reaction, thereby reducing the moisture in the gas, but also adjust the temperature of the gas; the condensed gas is subjected to heat exchange in the heat exchange equipment, which can further reduce the temperature of the gas to meet the needs of the subsequent synthesis process. The above-mentioned first shifted gas, unshifted gas and second shifted gas are introduced into the synthesis gas unit to prepare high-quality synthesis gas, thereby obtaining high-quality chemical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 A schematic diagram of a raw gas conversion system of the present application is shown.

[0023] Among them, the above drawings include the following reference numerals:

[0024] 1. Conversion device; 2. First waste heat boiler; 3. Detoxification tank; 4. Second waste heat boiler; 5. Heat exchange equipment; 6. New waste heat boiler; 31. First detoxification tank; 32. Second detoxification tank. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] As analyzed in the background technology of this application, there is a problem in the prior art that it is difficult to increase the load of the conversion device to higher than 100%. In order to solve the above problem, this application provides a raw coal gas conversion system and a process for producing synthesis gas using the same.

[0027] In a typical embodiment of the present application, a raw gas conversion system is provided, such as Figure 1 As shown, the raw gas conversion system includes: a conversion device 1, a first waste heat boiler 2, a detoxification tank 3, a second waste heat boiler 4 and a heat exchange device 5, the conversion device 1 has a conversion device inlet and a conversion device outlet, the conversion device inlet is connected to the raw gas source, the conversion device 1 is used to perform a first conversion reaction on part of the raw gas to obtain a first conversion gas; the first waste heat boiler 2 has a first waste heat boiler inlet and a first waste heat boiler outlet, the first waste heat boiler inlet is connected to the raw gas source, the first waste heat boiler 2 is used to perform a first condensation on the remaining part of the raw gas to obtain condensed raw gas; the detoxification tank 3 has a detoxification tank inlet and a detoxification tank outlet, the detoxification tank inlet is connected to the first waste heat boiler outlet, the detoxification tank 3 is used to perform a second conversion reaction on the condensed raw gas to obtain a raw gas including detoxification. Detoxified gas of unconverted gas and detoxified converted gas; the second waste heat boiler 4 has a second waste heat boiler inlet and a second waste heat boiler outlet, the second waste heat boiler inlet is connected to the detoxification tank outlet, and the second waste heat boiler 4 is used to perform a second condensation on the detoxified gas to obtain condensed gas; the heat exchange equipment 5 has a heat exchange equipment inlet and a heat exchange equipment outlet, the heat exchange equipment inlet is connected to the second waste heat boiler outlet, and the heat exchange equipment 5 is used to perform heat exchange on the condensed gas to obtain unconverted gas and a second converted gas; the first converted gas, the unconverted gas and the second converted gas are introduced into the synthesis gas unit to prepare synthesis gas; wherein, along the direction from the detoxification tank inlet to the detoxification tank outlet, the detoxification tank 3 includes a first area and a second area connected in sequence, the first area is filled with a hydrolyzing agent, and the second area is filled with a conversion catalyst.

[0028] The present application can reduce the gas distribution ratio of the conversion device 1 by loading the conversion catalyst in the detoxification tank 3, so that the unconverted gas, i.e., the condensed raw gas, undergoes a partial conversion reaction, thereby reducing the pressure drop of the conversion device 1, and further increasing the load of the raw gas conversion system, achieving a load exceeding 100%, or even a high-load production of up to 110%. Specifically, part of the raw gas fully undergoes the first conversion reaction in the conversion device 1 to obtain the conversion gas; the remaining part of the raw gas undergoes the first condensation in the first waste heat boiler 2, which can not only adjust the temperature of the raw gas, thereby meeting the temperature requirements of the subsequent second conversion reaction, avoiding the deactivation of the conversion catalyst in the detoxification tank 3 due to excessive temperature, but also remove impurities in the raw gas. According to the above method, the hydrolyzing agent and the conversion catalyst are loaded in the detoxification tank 3, and the composition of the condensed raw gas can be pre-adjusted under the action of the hydrolyzing agent, and the conditions of the second conversion reaction can be optimized, thereby facilitating the second conversion reaction of CO and H2O in the condensed raw gas under the action of the conversion catalyst and improving the reaction efficiency of the second conversion reaction, thereby reducing the gas distribution ratio of the conversion device 1 and reducing the pressure drop of the conversion device 1. At the same time, the hydrolyzing agent can also remove carbonyl sulfide and other organic sulfur in the condensed raw coal gas. The detoxified gas is subjected to a second condensation in the second waste heat boiler 4, which can not only separate the water vapor produced by the second conversion reaction, thereby reducing the moisture in the gas, but also adjust the temperature of the gas; the condensed gas is subjected to heat exchange in the heat exchange equipment 5, which can further reduce the temperature of the gas to meet the needs of the subsequent synthesis process. The above-mentioned first conversion gas, unconverted gas and second conversion gas are introduced into the synthesis gas unit to prepare high-quality synthesis gas, thereby obtaining high-quality chemical products.

[0029] In one embodiment of the present application, the inlet temperature of the detoxification tank 3 is 200-230°C; and / or, when the load of the conversion device 1 is greater than 80%, the detoxification tank 3 includes one or multiple detoxification tanks 3 arranged in parallel, preferably two detoxification tanks 3 arranged in parallel, and each detoxification tank 3 can be switched.

[0030] It is preferred to control the inlet temperature of the detoxification tank 3 within the above range, which helps the condensed raw gas to fully carry out the second conversion reaction under the action of the conversion catalyst, thereby further improving the reaction efficiency of the second conversion reaction. At the same time, when the load of the conversion device 1 is greater than 80%, a second detoxification tank 32 is arranged in parallel with the first detoxification tank 31 in the detoxification tank 3, which can meet the high-load operation of the raw gas conversion system. When the load of the conversion device 1 is reduced, the two detoxification tanks are operated at the same time, and there may be a risk of overheating. Therefore, a single detoxification tank (for example, the first detoxification tank 31) can be operated, and the other detoxification tank (for example, the second detoxification tank 32) is in a hot standby state.

[0031] In one embodiment of the present application, the raw gas conversion system also includes a newly added waste heat boiler 6, which is arranged in parallel with the second waste heat boiler 4; and / or, the inner diameter of the inlet pipeline of the second waste heat boiler 4 is 105-115 cm, and the inner diameter of the outlet pipeline of the second waste heat boiler 4 is 95-105 cm; and / or, the temperature of the second waste heat boiler 4 is 240-260°C, and / or, the pressure of the second waste heat boiler 4 is 3.6-4.5 MPa; and / or, the inner diameter of the inlet pipeline of the newly added waste heat boiler 6 is 100-110 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler 6 is 90-100 cm.

[0032] Since the condensed raw coal gas undergoes a second conversion reaction under the action of the conversion catalyst, the gas temperature will increase, thereby increasing the heat load of the second waste heat boiler 4. By setting a new waste heat boiler 6 in parallel with the second waste heat boiler 4, and controlling the inner diameter of the inlet pipeline, the inner diameter of the outlet pipeline of the second waste heat boiler 4 and the new waste heat boiler 6 and the temperature of the second waste heat boiler 4 within the above-mentioned range, the heat load of the second waste heat boiler 4 and the new waste heat boiler 6 can be balanced, thereby reducing the safety risk of equipment operation.

[0033] In one embodiment of the present application, the inner diameter of the inlet pipeline of the first waste heat boiler 2 is 120-135 cm, and the inner diameter of the outlet pipeline of the first waste heat boiler 2 is 110-122 cm; and / or, the temperature of the first waste heat boiler 2 is 200-220°C, and / or, the pressure of the first waste heat boiler 2 is 4-4.4 MPa.

[0034] It is preferred to control the inlet pipeline inner diameter, outlet pipeline inner diameter, temperature and pressure of the first waste heat boiler 2 within the above ranges, which helps to adjust the temperature, pressure and flow of the raw coal gas, thereby facilitating the subsequent second shift reaction.

[0035] In one embodiment of the present application, the temperature of the conversion device 1 is 200-460° C., and / or the pressure of the conversion device 1 is 3.6-4.4 MPa; and / or the water-gas ratio of the first conversion gas is 0.3-0.65:1.

[0036] It is preferred to control the temperature and pressure of the conversion device 1 within the above range, which helps the raw coal gas to fully undergo the first conversion reaction, thereby helping to increase the CO conversion rate and H2 production, and obtain the first conversion gas with a water-gas ratio within the above range.

[0037] In one embodiment of the present application, the inlet temperature of the heat exchange device 5 is 240-260°C, and / or the outlet temperature of the heat exchange device 5 is 30-60°C; and / or the water-gas ratio of the unconverted gas is 0.4-0.8:1; and / or the water-gas ratio of the second converted gas is 0.35-0.7:1.

[0038] It is preferred to control the inlet temperature and outlet temperature of the heat exchange device 5 within the above range, which helps to control the temperature and water-gas ratio of the unconverted gas and the second converted gas, thereby facilitating the use of the unconverted gas and the second converted gas in the subsequent synthesis gas process.

[0039] In another typical embodiment of the present application, a process for producing synthesis gas using the above-mentioned crude gas conversion system is provided, and the process includes: the crude gas is composed of part of the crude gas and the remaining part of the crude gas; part of the crude gas is subjected to a first conversion reaction to obtain a first conversion gas; the remaining part of the crude gas is subjected to a first condensation to obtain a condensed crude gas; under the action of a conversion catalyst and a hydrolyzing agent, the condensed crude gas is subjected to a second conversion reaction to obtain a detoxified unconverted gas and a detoxified converted gas; the detoxified unconverted gas and the detoxified converted gas are subjected to a second condensation to obtain a condensed gas; the condensed gas is subjected to heat exchange to obtain an unconverted gas and a second converted gas; and the first converted gas, the unconverted gas and the second converted gas are used as raw materials for synthesis gas.

[0040] The present invention provides a process for preparing synthesis gas using the above-mentioned raw gas conversion system. By dividing the raw gas into two parts, a part of the raw gas and the remaining part of the raw gas, the part of the raw gas is subjected to a first conversion reaction, which can reduce the content of CO in the first conversion gas and increase the content of H2. The remaining part of the raw gas is subjected to a first condensation, which can not only adjust the temperature of the raw gas, thereby meeting the temperature requirements of the subsequent second conversion reaction, but also remove impurities in the raw gas. The condensed raw gas can remove carbonyl sulfide and other organic sulfur in the condensed raw gas under the action of a hydrolyzing agent, and then CO and H2O in the condensed raw gas undergo a second conversion reaction under the action of a conversion catalyst, thereby improving the reaction efficiency of the second conversion reaction, and further reducing the content of CO in the detoxified unconverted gas and the detoxified conversion gas. The detoxified gas is subjected to a second condensation, which can not only separate the water vapor generated by the second conversion reaction, thereby reducing the moisture in the gas, but also adjust the gas temperature. The condensed gas is subjected to heat exchange, which can further reduce the temperature of the gas to meet the requirements of being a raw material for synthesis gas.

[0041] In one embodiment of the present application, the volume ratio of part of the raw coal gas and the remaining part of the raw coal gas is 3-4:2-3, and / or the water-gas ratio of the raw coal gas is 0.6-0.85:1, and / or the volume ratio of the first conversion gas, the detoxified unconverted gas and the detoxified conversion gas is 4-6:2-3:2-3.

[0042] It is preferred to control the volume ratio of part of the crude gas and the remaining part of the crude gas and the water-gas ratio of the crude gas within the above-mentioned range, which helps the part of the crude gas and the remaining part of the crude gas to undergo conversion reactions respectively, thereby reducing the content of CO and H2O in the synthesis gas; it is preferred to control the volume ratio of the first conversion gas, the detoxified unconverted gas and the detoxified conversion gas within the above-mentioned range, which helps to regulate the gas distribution ratio of part of the crude gas and the remaining part of the crude gas, thereby helping to reduce the pressure drop on the first conversion gas side, and further helping to make the load of the above-mentioned crude gas conversion system higher than 100%, and even the load of the crude gas conversion system can reach 110%.

[0043] In one embodiment of the present application, relative to 50000~100000m 3 The volume of the condensed raw gas is 10-20m 3 The volume of the hydrolyzing agent is 10 to 18 m 3 ; The volume ratio of the hydrolyzing agent to the conversion catalyst is 1 to 1.3:1; and / or the conversion catalyst is selected from any one or more of an iron-chromium conversion catalyst, a copper-zinc conversion catalyst and a cobalt-molybdenum conversion catalyst; and / or the active component of the hydrolyzing agent is an alkali metal.

[0044] It is preferred that the type, volume and volume ratio of the conversion catalyst and the hydrolyzing agent are within the above ranges, which helps carbonyl sulfide and water to react at a lower temperature under the action of the hydrolyzing agent, thereby purifying the raw coal gas; helps carbon monoxide and water to react under the action of the conversion catalyst, thereby adjusting the hydrogen-carbon ratio; and helps the hydrolyzing agent and the conversion catalyst to better exert their catalytic effects, thereby increasing the load of the entire system.

[0045] In one embodiment of the present application, the temperature of the first shift reaction is 250-450° C.; and / or the space velocity of the first shift reaction is 4500-6500 h -1 ; and / or, the temperature of the second shift reaction is 230-460°C; and / or, the space velocity of the second shift reaction is 2000-3000h -1 .

[0046] It is preferred to control the temperature and space velocity of the first conversion reaction within the above range, which helps to increase the reaction rate of part of the raw coal gas in the first conversion reaction, thereby helping to increase the CO conversion rate and H2 content; it is preferred to control the temperature and space velocity of the second conversion reaction within the above range, which helps to ensure sufficient contact between the condensed raw coal gas and the conversion catalyst, thereby improving the reaction efficiency of the second conversion reaction.

[0047] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0048] Example 1

[0049] Use Figure 1The crude gas conversion system shown in the figure converts the crude gas into synthesis gas. Specifically, the crude gas with a water-gas ratio of 0.6 is converted from 60m 3 Part of the raw gas and 50m 3 The remaining part of the crude gas is composed of; part of the crude gas is introduced into the conversion device 1 through the conversion device inlet for the first conversion reaction to obtain 40m 3 The first conversion gas, wherein the temperature of the conversion device 1 is 200° C., the pressure of the conversion device 1 is 3.6 MPa, and the water-gas ratio of the first conversion gas is 0.3:1.

[0050] The remaining raw coal gas is introduced into the first waste heat boiler 2 through the first waste heat boiler inlet for the first condensation to obtain 45m 3 The raw coal gas is condensed, wherein the inner diameter of the inlet pipeline of the first waste heat boiler 2 is 120 cm, the inner diameter of the outlet pipeline of the first waste heat boiler 2 is 110 cm, the temperature of the first waste heat boiler 2 is 200° C., and the pressure of the first waste heat boiler 2 is 4 MPa.

[0051] The condensed raw coal gas is output from the outlet of the first waste heat boiler and is respectively introduced into the first detoxification tank 31 and the second detoxification tank 32 which are arranged in parallel through the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 in the detoxification tank 3. In the direction from the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 to the detoxification tank outlet, the first detoxification tank 31 and the second detoxification tank 32 each include a first area and a second area which are connected in sequence, and the first area is each filled with 10m 3 Alkali metal series hydrolyzing agent, the second area is filled with 10m 3 Cobalt-molybdenum series shift catalyst. Under the action of the shift catalyst and the hydrolyzing agent, the condensed raw coal gas undergoes the second shift reaction to obtain 30m 3 Detoxified unconverted gas and 20m 3 Detoxification gas of detoxification conversion gas, wherein the inlet temperature of the detoxification tank 3 is 200°C, the temperature of the second conversion reaction is 230°C, and the space velocity of the second conversion reaction is 2000h -1 .

[0052] After the detoxified gas is output from the detoxification tank outlets of the first detoxification tank 31 and the second detoxification tank 32, it is passed through the second waste heat boiler inlet and the inlet of the newly added waste heat boiler 6 into the second waste heat boiler 4 and the newly added waste heat boiler 6 arranged in parallel for a second condensation to obtain condensed gas, wherein the inner diameter of the inlet pipeline of the second waste heat boiler 4 is 105 cm, the inner diameter of the outlet pipeline of the second waste heat boiler 4 is 95 cm, the temperature of the second waste heat boiler 4 is 340°C, the pressure of the second waste heat boiler 4 is 3.6 MPa, the inner diameter of the inlet pipeline of the newly added waste heat boiler 6 is 100 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler 6 is 90 cm.

[0053] After the condensed gas is output from the outlet of the second waste heat boiler and the outlet of the newly added waste heat boiler 6, it is passed into the heat exchange device 5 through the heat exchange device inlet for heat exchange, and 25m 3 Unchanged gas and 15m 3 The second conversion gas, wherein the inlet temperature of the heat exchange device 5 is 240°C, the outlet temperature of the heat exchange device 5 is 30°C, the water-gas ratio of the unconverted gas is 0.4:1, and the water-gas ratio of the second conversion gas is 0.35:1.

[0054] The first converted gas is output from the outlet of the conversion device, the unconverted gas and the second converted gas are output from the outlet of the heat exchange device, and the first converted gas, the unconverted gas and the second converted gas are introduced into the synthesis gas unit to prepare synthesis gas.

[0055] Example 2

[0056] Use Figure 1 The crude gas conversion system shown in the figure converts the crude gas into synthesis gas. Specifically, the crude gas with a water-gas ratio of 0.6 is converted from 70m 3 Part of the raw gas and 50m 3 The remaining part of the crude gas is composed of 45m 3 The first shift gas, wherein the temperature of the shift device 1 is 350°C, the pressure of the shift device 1 is 4 MPa, and the space velocity of the first shift reaction is 5500 h -1 The water-gas ratio of the first conversion gas is 0.5:1.

[0057] The remaining raw coal gas is introduced into the first waste heat boiler 2 through the first waste heat boiler inlet for the first condensation to obtain 45m 3 The raw coal gas is condensed, wherein the inner diameter of the inlet pipeline of the first waste heat boiler 2 is 128 cm, the inner diameter of the outlet pipeline of the first waste heat boiler 2 is 116 cm, the temperature of the first waste heat boiler 2 is 210° C., and the pressure of the first waste heat boiler 2 is 4.2 MPa.

[0058] The condensed raw coal gas is output from the outlet of the first waste heat boiler and is respectively introduced into the first detoxification tank 31 and the second detoxification tank 32 which are arranged in parallel through the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 in the detoxification tank 3. In the direction from the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 to the detoxification tank outlet, the first detoxification tank 31 and the second detoxification tank 32 each include a first area and a second area which are connected in sequence, and the first area is each filled with 10m 3 Alkali metal series hydrolyzing agent, the second area is filled with 10m 3 Cobalt-molybdenum series shift catalyst. Under the action of the shift catalyst and the hydrolyzing agent, the condensed raw coal gas undergoes a second shift reaction to obtain 35m 3Detoxified unconverted gas and 25m 3 Detoxification gas of detoxification conversion gas, wherein the inlet temperature of detoxification tank 3 is 215°C, the temperature of the second conversion reaction is 355°C, and the space velocity of the second conversion reaction is 2500h -1 .

[0059] After the detoxified gas is output from the detoxification tank outlets of the first detoxification tank 31 and the second detoxification tank 32, it is passed through the second waste heat boiler inlet and the inlet of the newly added waste heat boiler 6 into the second waste heat boiler 4 and the newly added waste heat boiler 6 arranged in parallel for a second condensation to obtain condensed gas, wherein the inner diameter of the inlet pipeline of the second waste heat boiler 4 is 110 cm, the inner diameter of the outlet pipeline of the second waste heat boiler 4 is 100 cm, the temperature of the second waste heat boiler 4 is 250°C, the pressure of the second waste heat boiler 4 is 4 MPa, the inner diameter of the inlet pipeline of the newly added waste heat boiler 6 is 105 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler 6 is 95 cm.

[0060] The condensed gas is output from the outlet of the second waste heat boiler and the outlet of the newly added waste heat boiler 6, and then passes through the heat exchange device inlet into the heat exchange device 5 for heat exchange, thereby obtaining 28m 3 Unchanged gas and 18m 3 The second conversion gas, wherein the inlet temperature of the heat exchange device 5 is 260°C, the outlet temperature of the heat exchange device 5 is 45°C, the water-gas ratio of the unconverted gas is 0.6:1, and the water-gas ratio of the second conversion gas is 0.55:1.

[0061] The first converted gas is output from the outlet of the conversion device, the unconverted gas and the second converted gas are output from the outlet of the heat exchange device, and the first converted gas, the unconverted gas and the second converted gas are introduced into the synthesis gas unit to prepare synthesis gas.

[0062] Example 3

[0063] Use Figure 1 The crude gas conversion system shown in the figure converts the crude gas into synthesis gas. Specifically, the crude gas with a water-gas ratio of 0.6 is converted from 60m 3 Part of the raw gas and 50m 3 The remaining part of the crude gas is composed of; part of the crude gas is introduced into the conversion device 1 through the conversion device inlet for the first conversion reaction to obtain 40m 3 The first shift gas, wherein the temperature of the shift device 1 is 460°C, the pressure of the shift device 1 is 4.4 MPa, and the space velocity of the first shift reaction is 6500 h -1 The water-gas ratio of the first conversion gas is 0.65:1.

[0064] The remaining raw coal gas is introduced into the first waste heat boiler 2 through the first waste heat boiler inlet for the first condensation to obtain 45m 3The raw coal gas is condensed, wherein the inner diameter of the inlet pipeline of the first waste heat boiler 2 is 135 cm, the inner diameter of the outlet pipeline of the first waste heat boiler 2 is 122 cm, the temperature of the first waste heat boiler 2 is 220° C., and the pressure of the first waste heat boiler 2 is 4.4 MPa.

[0065] The condensed raw coal gas is output from the outlet of the first waste heat boiler and is respectively introduced into the first detoxification tank 31 and the second detoxification tank 32 which are arranged in parallel through the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 in the detoxification tank 3. In the direction from the detoxification tank inlets of the first detoxification tank 31 and the second detoxification tank 32 to the detoxification tank outlet, the first detoxification tank 31 and the second detoxification tank 32 each include a first area and a second area which are connected in sequence, and the first area is each filled with 10m 3 Alkali metal series hydrolyzing agent, the second area is filled with 10m 3 Cobalt-molybdenum series shift catalyst. Under the action of the shift catalyst and the hydrolyzing agent, the condensed raw coal gas undergoes the second shift reaction to obtain 30m 3 Detoxified unconverted gas and 20m 3 Detoxification gas of detoxification conversion gas, wherein the inlet temperature of the detoxification tank 3 is 230°C, the temperature of the second conversion reaction is 460°C, and the space velocity of the second conversion reaction is 3000h -1 .

[0066] After the detoxified gas is output from the detoxification tank outlets of the first detoxification tank 31 and the second detoxification tank 32, it is passed through the second waste heat boiler inlet and the inlet of the newly added waste heat boiler 6 into the second waste heat boiler 4 and the newly added waste heat boiler 6 arranged in parallel for a second condensation to obtain condensed gas, wherein the inner diameter of the inlet pipeline of the second waste heat boiler 4 is 115 cm, the inner diameter of the outlet pipeline of the second waste heat boiler 4 is 105 cm, the temperature of the second waste heat boiler 4 is 260°C, the pressure of the second waste heat boiler 4 is 4.5 MPa, the inner diameter of the inlet pipeline of the newly added waste heat boiler 6 is 105 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler 6 is 95 cm.

[0067] After the condensed gas is output from the outlet of the second waste heat boiler and the outlet of the newly added waste heat boiler 6, it is passed into the heat exchange device 5 through the heat exchange device inlet for heat exchange, and 25m 3 Unchanged gas and 15m 3 The second conversion gas, wherein the inlet temperature of the heat exchange device 5 is 260°C, the outlet temperature of the heat exchange device 5 is 60°C, the water-gas ratio of the unconverted gas is 0.8:1, and the water-gas ratio of the second conversion gas is 0.7:1.

[0068] The first converted gas is output from the outlet of the conversion device, the unconverted gas and the second converted gas are output from the outlet of the heat exchange device, and the first converted gas, the unconverted gas and the second converted gas are introduced into the synthesis gas unit to prepare synthesis gas.

[0069] Example 4

[0070] The difference from Example 1 is that the volume ratio of part of the crude coal gas and the remaining part of the crude coal gas is 4:3, and synthesis gas is finally prepared.

[0071] Example 5

[0072] The difference from Example 1 is that the volume ratio of part of the crude coal gas and the remaining part of the crude coal gas is 3:4, and synthesis gas is finally prepared.

[0073] Example 6

[0074] The difference from Example 1 is that the volume ratio of the first conversion gas, the detoxified unconverted gas and the detoxified conversion gas is 6:2:3, and synthesis gas is finally prepared.

[0075] Example 7

[0076] The difference from Example 1 is that the volume ratio of the first shifted gas, the detoxified unshifted gas and the detoxified shifted gas is 1:1:1, and synthesis gas is finally prepared.

[0077] Example 8

[0078] The difference from Example 1 is that the volume ratio of the hydrolyzing agent to the conversion catalyst is 1.3:1, and synthesis gas is finally prepared.

[0079] Example 9

[0080] The difference from Example 1 is that the volume ratio of the hydrolyzing agent to the conversion catalyst is 1:2, and synthesis gas is finally prepared.

[0081] Comparative Example 1

[0082] The difference from Example 1 is that the detoxification tank 3 is not filled with a shift catalyst.

[0083] Test Method

[0084] The calculation method of the load of the raw gas conversion system is: the actual gas volume of the raw gas / the designed gas volume of the raw gas. The actual gas volume of the raw gas is measured by the flow meter at the inlet of the conversion device.

[0085] Table 1

[0086] Example / Comparative Example load(%) Example 1 108 Example 2 110 Example 3 108 Example 4 105 Example 5 100 Example 6 103 Example 7 102 Example 8 103 Example 9 101 Comparative Example 1 95

[0087] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0088] The present application can reduce the gas distribution ratio of the conversion device by loading the conversion catalyst in the detoxification tank, so that the unconverted gas, i.e., the condensed raw gas, undergoes a partial conversion reaction, thereby reducing the pressure drop of the conversion device, and further increasing the load of the raw gas conversion system, achieving a load exceeding 100%, or even a high-load production of up to 110%. Specifically, part of the raw gas fully undergoes the first conversion reaction in the conversion device to obtain conversion gas; the remaining part of the raw gas undergoes the first condensation in the first waste heat boiler, which can not only adjust the temperature of the raw gas, thereby meeting the temperature requirements of the subsequent second conversion reaction, avoiding the deactivation of the conversion catalyst in the detoxification tank due to excessive temperature, but also remove impurities in the raw gas. According to the above method, the hydrolyzing agent and the conversion catalyst are loaded in the detoxification tank, and the composition of the condensed raw gas can be pre-adjusted under the action of the hydrolyzing agent, and the conditions of the second conversion reaction can be optimized, thereby facilitating the second conversion reaction of CO and H2O in the condensed raw gas under the action of the conversion catalyst and improving the reaction efficiency of the second conversion reaction, thereby reducing the gas distribution ratio of the conversion device and reducing the pressure drop of the conversion device. At the same time, the hydrolyzing agent can also remove carbonyl sulfide and other organic sulfur in the condensed raw coal gas. The detoxified gas is subjected to a second condensation in the second waste heat boiler, which can not only separate the water vapor produced by the second shift reaction, thereby reducing the moisture in the gas, but also adjust the temperature of the gas; the condensed gas is subjected to heat exchange in the heat exchange equipment, which can further reduce the temperature of the gas to meet the needs of the subsequent synthesis process. The above-mentioned first shifted gas, unshifted gas and second shifted gas are introduced into the synthesis gas unit to prepare high-quality synthesis gas, thereby obtaining high-quality chemical products.

[0089] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A crude gas conversion system, It is characterized in that The raw gas conversion system comprises: A conversion device (1) having a conversion device inlet and a conversion device outlet, wherein the conversion device inlet is connected to a raw coal gas source, and the conversion device (1) is used to perform a first conversion reaction on a portion of the raw coal gas to obtain a first conversion gas; a first waste heat boiler (2), having a first waste heat boiler inlet and a first waste heat boiler outlet, wherein the first waste heat boiler inlet is connected to the raw coal gas source, and the first waste heat boiler (2) is used to perform a first condensation on the remaining portion of the raw coal gas to obtain condensed raw coal gas; A detoxification tank (3) having a detoxification tank inlet and a detoxification tank outlet, wherein the detoxification tank inlet is connected to the outlet of the first waste heat boiler, and the detoxification tank (3) is used to perform a second shift reaction on the condensed raw coal gas to obtain detoxified gas including detoxified unshifted gas and detoxified shifted gas; A second waste heat boiler (4) has a second waste heat boiler inlet and a second waste heat boiler outlet, wherein the second waste heat boiler inlet is connected to the outlet of the detoxification tank, and the second waste heat boiler (4) is used to perform a second condensation on the detoxified gas to obtain condensed gas; A heat exchange device (5) having a heat exchange device inlet and a heat exchange device outlet, wherein the heat exchange device inlet is connected to the outlet of the second waste heat boiler, and the heat exchange device (5) is used to perform heat exchange on the condensed gas to obtain unconverted gas and second converted gas; Passing the first shifted gas, the unshifted gas and the second shifted gas into a synthesis gas unit to prepare synthesis gas; Wherein, along the direction from the detoxification tank inlet to the detoxification tank outlet, the detoxification tank (3) includes a first area and a second area which are connected in sequence, the first area is filled with a hydrolyzing agent, and the second area is filled with a conversion catalyst.

2. The crude gas shift system according to claim 1, It is characterized in that The inlet temperature of the detoxification tank (3) is 200-230° C.; and / or, when the load of the conversion device (1) is greater than 80%, the detoxification tank (3) includes one or a plurality of detoxification tanks (3) arranged in parallel, preferably two detoxification tanks (3) arranged in parallel, and each of the detoxification tanks (3) can be switched.

3. The raw gas shift system according to claim 1 or 2, It is characterized in that The raw coal gas conversion system further comprises a newly added waste heat boiler (6), wherein the newly added waste heat boiler (6) and the second waste heat boiler (4) are arranged in parallel; and / or the inner diameter of the inlet pipeline of the second waste heat boiler (4) is 105 to 115 cm, and the inner diameter of the outlet pipeline of the second waste heat boiler (4) is 95 to 105 cm; and / or the temperature of the second waste heat boiler (4) is 240 to 260° C., and / or the pressure of the second waste heat boiler (4) is 3.6 to 4.5 MPa; and / or the inner diameter of the inlet pipeline of the newly added waste heat boiler (6) is 100 to 110 cm, and the inner diameter of the outlet pipeline of the newly added waste heat boiler (6) is 90 to 100 cm.

4. The crude gas shift system according to any one of claims 1 to 3, It is characterized in that The inner diameter of the inlet pipeline of the first waste heat boiler (2) is 120 to 135 cm, and the inner diameter of the outlet pipeline of the first waste heat boiler (2) is 110 to 122 cm; and / or the temperature of the first waste heat boiler (2) is 200 to 220° C., and / or the pressure of the first waste heat boiler (2) is 4 to 4.4 MPa.

5. The crude gas shift system according to any one of claims 1 to 4, It is characterized in that The temperature of the conversion device (1) is 200 to 460° C., and / or the pressure of the conversion device (1) is 3.6 to 4.4 MPa; and / or the water-gas ratio of the first conversion gas is 0.3 to 0.65:

1.

6. The raw gas shift system according to any one of claims 1 to 5, It is characterized in that The inlet temperature of the heat exchange device (5) is 240-260°C, and / or the outlet temperature of the heat exchange device (5) is 30-60°C; and / or the water-gas ratio of the unconverted gas is 0.4-0.8:1; and / or the water-gas ratio of the second converted gas is 0.35-0.7:

1.

7. A process for producing synthesis gas using the raw gas shift system according to any one of claims 1 to 6, It is characterized in that The process comprises: The crude coal gas is composed of a part of the crude coal gas and a remaining part of the crude coal gas; Performing a first shift reaction on the portion of the raw coal gas to obtain a first shifted gas; performing a first condensation on the remaining portion of the crude coal gas to obtain condensed crude coal gas; Under the action of a shift catalyst and a hydrolyzing agent, the condensed raw coal gas is subjected to a second shift reaction to obtain a detoxified gas including a detoxified unshifted gas and a detoxified shifted gas; The detoxified gas is subjected to a second condensation to obtain condensed gas; The condensed gas is subjected to heat exchange to obtain unconverted gas and second converted gas; The first shifted gas, the unshifted gas, and the second shifted gas are used as raw materials of synthesis gas.

8. The process according to claim 7, It is characterized in that The volume ratio of the part of the raw gas to the remaining part of the raw gas is 3-4:2-3, and / or the water-gas ratio of the raw gas is 0.6-0.85:1, and / or the volume ratio of the first converted gas, the detoxified unconverted gas and the detoxified converted gas is 4-6:2-3:2-3.

9. The process according to claim 7 or 8, It is characterized in that Relative 50000~100000m 3 The condensed raw coal gas, the volume of the conversion catalyst is 10 to 20 m 3 The volume of the hydrolyzing agent is 10 to 18 m 3 ; The volume ratio of the hydrolyzing agent to the conversion catalyst is 1 to 1.3:1; and / or the conversion catalyst is selected from any one or more of an iron-chromium conversion catalyst, a copper-zinc conversion catalyst and a cobalt-molybdenum conversion catalyst; and / or the active component of the hydrolyzing agent is an alkali metal.

10. The process according to any one of claims 7 to 9, It is characterized in that The temperature of the first shift reaction is 250-450°C; and / or the space velocity of the first shift reaction is 4500-6500h -1 ; and / or, the temperature of the second shift reaction is 230-460°C; and / or, the space velocity of the second shift reaction is 2000-3000h -1 .

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