Conversion method suitable for high carbon monoxide content

Abstract

The invention discloses a shift method suitable for high carbon monoxide content, and relates to the technical field of chemical engineering, the shift method suitable for high carbon monoxide content comprises the following steps: dividing a raw material gas into two parts, mixing the first part of the raw material gas with water vapor, feeding the mixture into a first-stage shift reaction furnace, and carrying out a shift reaction to obtain a first-stage shift gas; the first-stage converted gas is divided into two parts, the first part of the first-stage converted gas is mixed with water vapor and the second part of raw material gas, then a second-stage conversion reaction is conducted, and second-stage converted gas is obtained. By filling shift catalysts with different CuO contents, assisting in different water vapor amounts and controlling the reaction progress, the reaction point is expanded to the surface, so that the heat release amount of the reaction is effectively controlled, the hot-spot temperature of a catalyst bed layer is effectively controlled, the catalyst is prevented from being sintered at a high temperature, and the yield of the catalyst is improved. Therefore, the invention is especially suitable for conversion of feed gas containing high-concentration carbon monoxide.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technologies, and in particular to a conversion method applicable to a high carbon monoxide content. Background Art

[0002] With the rapid development of the world industry in recent years, the demand for oil and natural gas has been continuously increasing. In order to address the problem of energy resource shortage, chemical projects centered on clean coal gasification technologies have been vigorously developed. Among them, chemical projects based on coal energy are the main development direction of clean coal technologies. The development and large-scale industrial application of technologies for producing olefins from coal, coal-to-gas, and coal-to-diesel will break the technical boundaries between traditional coal chemical industries and petrochemical enterprises.

[0003] The CO conversion unit is an important part of the subsequent purification stage in the pulverized coal gasification process and is used to process the raw coal gas generated by the pulverized coal gasification device. Currently, most equipment adopts an advanced and mature medium-temperature shift series low-temperature shift sulfur-tolerant conversion process, in which CO and water vapor generated during the gasification process are converted into H2 and CO2 through a conversion catalyst.

[0004] U.S. Patent No. 6,033,634 discloses a plate-type high-temperature converter, which has a conversion reaction chamber filled with a high-temperature conversion catalyst; a cooling chamber with fillers to promote heat transfer, a cooling gas introduced into the cooling chamber, and a partition separating the conversion reaction chamber and the cooling chamber. The conversion reaction chamber has a light gas chamber separated by a plate-type partition composed of a porous plate and a palladium membrane permeable to hydrogen. Therefore, only the hydrogen generated in the conversion reaction chamber can enter the hydrogen chamber through the hydrogen permeable membrane.

[0005] CN1461730A discloses a carbon monoxide conversion process and a reactor. The process steps include: introducing the raw gas into the reactor tube of the reaction unit, the reactor tube having a fixed bed of a conversion catalyst located in the reaction zone; contacting the water raw gas with the catalyst under conversion reaction conditions that can effectively react carbon monoxide with water vapor to generate hydrogen; the cooling medium having a falling film form flowing along the outer shell side of the reactor tube, cooling the reaction through indirect heat exchange by the cooling medium, and removing the heated cooling medium from the falling film, so that the hydrogen generated by the conversion reaction reaches the permeation zone through a hydrogen selection membrane; withdrawing the hydrogen from the permeation zone and discharging the raw gas depleted of carbon monoxide from the reaction zone.

[0006] As an important section after coal chemical gasification, the CO conversion process has a mature process plan. Currently, most of them adopt two technologies: isothermal conversion and adiabatic conversion.

[0007] Gases such as coal gas, calcium carbide furnace tail gas, ferroalloy tail gas, and methanol purge gas contain a large amount of CO and impurities. Taking the large amount of tail gas generated during the production process of ferroalloy reduction electric furnace as an example, the effective fuel components such as CO, H2, and CH4 in the tail gas account for about 80% of the gas volume, mainly CO, and the calorific value is 2100 - 2400 kcal / Nm³. When carbon monoxide, especially high-concentration carbon monoxide, undergoes a shift reaction, a large amount of heat is released, resulting in a high hot spot temperature in the catalyst bed layer, and thus reducing the service life of the catalyst. Summary of the Invention

[0008] To solve the above problems, the present invention provides a shift method applicable to high carbon monoxide content.

[0009] The present invention provides a shift method applicable to high carbon monoxide content, as Figure 1 shown, the shift method applicable to high carbon monoxide content includes the following steps:

[0010] The raw material gas is divided into two parts. The first part of the raw material gas is mixed with steam and then enters the primary shift reaction furnace. After the shift reaction, the primary shift gas is obtained;

[0011] The primary shift gas is divided into two parts. The first part of the primary shift gas is mixed with steam and the second part of the raw material gas and then undergoes a secondary shift reaction to obtain the secondary shift gas;

[0012] The second part of the primary shift gas is mixed with the secondary shift gas and enters the post-treatment system to obtain the shifted product gas.

[0013] Further, the volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:(0 - 1.0), preferably 1:(0.5 - 1.0).

[0014] Further, the volume ratio of the second part of the primary shift gas to the first part of the primary shift gas is 1:(0 - 1.0), preferably 1:(0.2 - 0.5).

[0015] Further, the primary and secondary shift reaction furnaces adopt axial beds. The primary shift reaction and the secondary shift reaction are respectively carried out under the catalysis of a catalyst. In the primary shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3.

[0016] Further, the content of CuO in the low-activity catalyst is 10-15 wt%, the content of CuO in the high-activity catalyst is 40-45 wt%, and the content of CuO in the medium-activity catalyst is 25-30 wt%. The different activity copper oxide catalysts in the present invention can be conventional CuO catalysts obtained by loading CuO on carriers such as alumina and silica, and their activities are different only due to the different contents of CuO.

[0017] Further, based on the mass of the catalyst in the primary shift reaction, the feed space velocity of the primary shift reaction is 1000-2000 h -1 ; based on the mass of the catalyst in the secondary shift reaction, the feed space velocity of the secondary shift reaction is 1000-3000 -1 .

[0018] Further, a steam inlet is provided at the junction of the outer walls of the primary shift reaction furnace and the secondary shift reaction furnace corresponding to the loading of two different performance catalysts.

[0019] Further, in the raw material gas: the molar content of sulfide is less than 0.05 ppm, the molar content of chloride is less than 0.01 ppm, the molar content of arsenide is less than 0.01 ppm, and the molar content of oxygen is less than 0.02%.

[0020] Further, the inlet temperature of the primary isothermal shift reaction is 190-200 °C, preferably 195-200 °C, and the shift reaction pressure is 1.0-3.5 MPa, preferably 1.5-2.5 MPa.

[0021] Further, the inlet temperature of the secondary isothermal shift reaction is 190-200 °C, preferably 190-195 °C, and the shift reaction pressure is 1.0-3.5 MPa, preferably 1.5-2.5 MPa.

[0022] Further, the method further includes pre-treating the raw material gas before the primary shift reaction, and the pre-treatment includes desulfurization, dechlorination, dearsenication, deoxidation and preheating.

[0023] Further, the method further includes post-treating the secondary shift gas after the secondary shift reaction to obtain a shifted product gas, and the post-treatment includes cooling, gas-liquid separation and carbon dioxide removal.

[0024] Further, the raw material gas is derived from one or more mixtures of coal gas, calcium carbide furnace tail gas, ferroalloy tail gas or methanol purge gas.

[0025] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0026] An embodiment of the present invention provides a conversion method applicable to high carbon monoxide content. The present invention designs a process scheme from the perspective of reaction mechanism. By loading conversion catalysts with different CuO contents and assisting with different amounts of steam, the progress of the reaction is controlled, expanding the reaction from a point to a surface, thereby effectively controlling the heat release of the reaction, and further effectively controlling the hot spot temperature of the catalyst bed, avoiding sintering of the catalyst at high temperatures. Therefore, the present invention is particularly applicable to the conversion of raw gas containing high concentrations of carbon monoxide. Specifically:

[0027] 1) By loading conversion catalysts with different CuO contents, the reaction is expanded from a point to a surface, thus avoiding the concentrated reaction of the catalyst at a certain point, resulting in heat concentration.

[0028] 2) At the junction of the outer walls of the primary conversion reaction furnace and the secondary conversion reaction furnace corresponding to the loading of two different performance catalysts, there is an inlet for adding steam, which can effectively control the amount of steam added and control the progress of the reaction.

[0029] Thus, the heat release of the reaction is effectively controlled, and further the hot spot temperature of the catalyst bed is effectively controlled, avoiding sintering of the catalyst at high temperatures.

[0030] 3) Designing a process scheme from the perspective of reaction mechanism can be applicable to a mixture of one or more of raw gas from coal gas, calcium carbide furnace tail gas, ferroalloy tail gas or methanol purge gas, meeting the requirements for the conversion of raw gas with high carbon monoxide content. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments in line with the present invention, and are used together with the specification to explain the principles of the present invention.

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 It is a schematic flow chart of a conversion method applicable to high carbon monoxide content provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0035] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchases or prepared by existing methods.

[0036] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually determined in accordance with national standards. If there is no corresponding national standard, they are carried out in accordance with general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0037] Example 1

[0038] The raw material gas is sourced from the tail gas of an electric arc furnace. After desulfurization, dechlorination, dearsenization, and deoxidation, the molar composition is: H2 4.4%, CO 77.8%, CO2 6.2%, N2 11.9%, CH4 0.025%, sulfide 0.02 ppm, chloride 0.003 ppm, arsenide 0 ppm, O2 0.001 ppm.

[0039] The above raw material gas is preheated to 195°C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a first-stage isothermal conversion reaction at 2.5 MPa under the catalysis of a catalyst to obtain a first-stage converted gas. The reaction inlet temperature is 195°C and the outlet temperature is 280°C.

[0040] The first-stage converted gas is mixed with the second part of the raw material gas and undergoes a second-stage isothermal conversion reaction at 2.5 MPa under the catalysis of a conversion catalyst to obtain a second-stage converted gas. The reaction inlet temperature is 195°C and the outlet temperature is 280°C.

[0041] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:1.

[0042] The volume ratio of the second part of the first-stage converted gas to the first part of the first-stage converted gas is 1:0.5.

[0043] In the primary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. The CuO content of the low-activity catalyst is 12 wt%, the CuO content of the high-activity catalyst is 42 wt%, and the CuO content of the medium-activity catalyst is 28 wt%.

[0044] Based on the mass of the catalyst in the shift reaction, the feed space velocity of the primary shift reaction is 1500 h -1 , and the feed space velocity of the secondary shift reaction is 3000 -1 .

[0045] The composition of the primary shift gas is H2 69.41%, CO 1.7%, CO2 17.6%, N2 11.24%, CH4 0.027%.

[0046] The composition of the secondary shift gas is H2 69.52%, CO 1.6%, CO2 17.7%, N2 11.25%, CH4 0.028%.

[0047] The total carbon monoxide conversion rate of the primary shift reaction and the secondary shift reaction is 96.1%.

[0048] After the secondary shift gas is cooled, gas-liquid separated, and the carbon dioxide is removed by temperature swing adsorption, the shifted product gas is obtained. The composition of the shifted product gas is H2 89.317%, CO 1.24%, CO2 0.15%, N2 9.27%, CH4 0.023%.

[0049] Example 2

[0050] The raw material gas is sourced from the mixed gas of calcium carbide furnace tail gas and coal gas. After desulfurization, dechlorination, dearsenication, and deoxidation, the molar composition is: H2 4.1%, CO 70.7%, CO2 7.9%, N2 17.2%, CH4 0.021%, sulfide 0.02 ppm, chloride 0.003 ppm, arsenide 0 ppm, O2 0.001 ppm 。

[0051] The above raw material gas is preheated to 200 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a primary isothermal shift reaction at 2.0 MPa under the catalysis of a catalyst to obtain the primary shift gas. The reaction inlet temperature is 200 °C, and the outlet temperature is 280 °C.

[0052] The primary shift gas is mixed with the second part of the raw material gas and undergoes a secondary isothermal shift reaction at 2.0 MPa under the catalysis of a shift catalyst to obtain the secondary shift gas. The reaction inlet temperature is 190 °C, and the outlet temperature is 278 °C.

[0053] The volume ratio of the first part of the raw gas to the second part of the raw gas is 1:0.5.

[0054] The volume ratio of the second part of the primary reformed gas to the first part of the primary reformed gas is 1:0.2.

[0055] In the primary reforming reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary reforming reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. Among them, the CuO content of the low-activity catalyst is 10 wt%, the CuO content of the high-activity catalyst is 40 wt%, and the CuO content of the medium-activity catalyst is 30 wt%.

[0056] Based on the mass of the catalyst in the reforming reaction, the feed space velocity of the primary reforming reaction is 1000 h -1 , and the feed space velocity of the secondary reforming reaction is 2000 -1 .

[0057] The composition of the primary reformed gas is H2 67.22%, CO 3.7%, CO2 16.9%, N2 12.16%, CH4 0.026%.

[0058] The composition of the secondary reformed gas is H2 69.62%, CO 1.5%, CO2 17.7%, N2 11.25%, CH4 0.029%.

[0059] The total carbon monoxide conversion rate of the primary reforming reaction and the secondary reforming reaction is 96.0%.

[0060] After the secondary reformed gas is cooled, gas-liquid separated, and the carbon dioxide is removed by temperature swing adsorption, the reformed product gas is obtained. The composition of the reformed product gas is H2 89.217%, CO 1.26%, CO2 0.17%, N2 9.33%, CH4 0.023%.

[0061] Example 3

[0062] The raw gas is sourced from the mixed gas of ferroalloy electric furnace tail gas and coal gas. After desulfurization, dechlorination, dearsenication, and deoxidation, the molar composition is: H2 11.5%, CO 64.1%, CO2 5.3%, N2 13.6%, CH4 1.4%, sulfide 0.015 ppm, chloride 0.002 ppm, arsenide 0 ppm, O2 0.005 ppm.

[0063] Preheat the above raw material gas to 195°C and then divide it into two parts. The first part of the raw material gas is mixed with steam and undergoes a first-stage isothermal shift reaction at 1.5 MPa under the catalysis of a catalyst to obtain a first-stage shifted gas. The reaction inlet temperature is 195°C and the outlet temperature is 280°C.

[0064] The first-stage shifted gas is mixed with the second part of the raw material gas and undergoes a second-stage isothermal shift reaction at 1.5 MPa under the catalysis of a shift catalyst to obtain a second-stage shifted gas. The reaction inlet temperature is 190°C and the outlet temperature is 280°C.

[0065] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:1.

[0066] The volume ratio of the second part of the first-stage shifted gas to the first part of the first-stage shifted gas is 1:0.4.

[0067] In the first-stage shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the second-stage shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. Among them, the CuO content of the low-activity catalyst is 13 wt%, the CuO content of the high-activity catalyst is 42 wt%, and the CuO content of the medium-activity catalyst is 27 wt%.

[0068] Based on the mass of the catalyst in the shift reaction, the feed space velocity of the first-stage shift reaction is 1500 h -1 , and the feed space velocity of the second-stage shift reaction is 2000 -1 .

[0069] The composition of the first-stage shifted gas is H2 71.17%, CO 3.2%, CO2 11.5%, N2 12.4%, CH4 1.7%.

[0070] The composition of the second-stage shifted gas is H2 72.25%, CO 2.2%, CO2 12.4%, N2 11.9%, CH4 1.25%.

[0071] The total carbon monoxide conversion rate of the first-stage shift reaction and the second-stage shift reaction is 95.58%.

[0072] The second-stage shifted gas is cooled, gas-liquid separated, and undergoes temperature swing adsorption to remove carbon dioxide to obtain a shifted product gas. The composition of the shifted product gas is H2 88.513%, CO 1.93%, CO2 0.20%, N2 8.26%, CH4 1.10%.

[0073] Example 4

[0074] The raw material gas is sourced from coal gas. After desulfurization, dechlorination, dearsenification, and deoxidation, its molar composition is: H2 12.0%, CO 32.1%, CO2 5.3%, N2 47.4%, CH4 3.1%, sulfide 0.02 ppm, chloride 0.004 ppm, arsenide 0 ppm, O2 0.001 ppm.

[0075] The above raw material gas is preheated to 190 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a first-stage isothermal shift reaction at 3.0 MPa under the catalysis of a catalyst to obtain a first-stage shifted gas. The reaction inlet temperature is 190 °C and the outlet temperature is 280 °C.

[0076] The first-stage shifted gas is mixed with the second part of the raw material gas and undergoes a second-stage isothermal shift reaction at 3.0 MPa under the catalysis of a shift catalyst to obtain a second-stage shifted gas. The reaction inlet temperature is 190 °C and the outlet temperature is 278 °C.

[0077] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:1.

[0078] The volume ratio of the second part of the first-stage shifted gas to the first part of the first-stage shifted gas is 1:0.4.

[0079] In the first-stage shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the second-stage shift reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. Among them, the CuO content of the low-activity catalyst is 13 wt%, the CuO content of the high-activity catalyst is 42 wt%, and the CuO content of the medium-activity catalyst is 27 wt%.

[0080] Based on the mass of the catalyst in the shift reaction, the feed space velocity of the first-stage shift reaction is 1500 h -1 , and the feed space velocity of the second-stage shift reaction is 2000 -1 .

[0081] The composition of the first-stage shifted gas is H2 35.2%, CO 3.2%, CO2 10.2%, N2 48.5%, CH4 2.9%.

[0082] The composition of the second-stage shifted gas is H2 37.45%, CO 1.3%, CO2 12.9%, N2 45.5%, CH4 2.85%.

[0083] The total carbon monoxide conversion rate of the first-stage shift reaction and the second-stage shift reaction is 94.65%.

[0084] The secondary converted gas is cooled, subjected to gas-liquid separation and temperature swing adsorption to remove carbon dioxide, and the converted product gas is obtained. The composition of the converted product gas is H2 56.63%, CO 1.13%, CO2 0.20%, N2 39.56%, CH4 2.48%.

[0085] Example 5

[0086] The raw material gas is sourced from coal gas. After desulfurization, dechlorination, dearsenification and deoxidation, the molar composition is: H2 12.0%, CO 32.1%, CO2 5.3%, N2 47.4%, CH4 3.1%, sulfide 0.02 ppm, chloride 0.004 ppm, arsenide 0 ppm, O2 0.001 ppm.

[0087] The above raw material gas is preheated to 190 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a primary isothermal conversion reaction at 3.0 MPa under the catalysis of a catalyst to obtain the primary converted gas. The reaction inlet temperature is 190 °C and the outlet temperature is 280 °C.

[0088] The primary converted gas is mixed with the second part of the raw material gas and undergoes a secondary isothermal conversion reaction at 3.0 MPa under the catalysis of a conversion catalyst to obtain the secondary converted gas. The reaction inlet temperature is 190 °C and the outlet temperature is 278 °C.

[0089] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:0.

[0090] The volume ratio of the second part of the primary converted gas to the first part of the primary converted gas is 1:0.

[0091] In the primary conversion reactor, low-activity, high-activity and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary conversion reactor, low-activity, high-activity and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. The CuO content of the low-activity catalyst is 12 wt%, the CuO content of the high-activity catalyst is 42 wt%, and the CuO content of the medium-activity catalyst is 28 wt%.

[0092] Based on the mass of the catalyst in the conversion reaction, the feed space velocity of the primary conversion reaction is 1000 h -1 , and the feed space velocity of the secondary conversion reaction is 2000 -1 .

[0093] The composition of the primary converted gas is H2 29.3%, CO 10.2%, CO2 9.9%, N2 47.5%, CH4 3.1%.

[0094] The composition of the secondary converted gas is H2 37.45%, CO 1.3%, CO2 12.9%, N2 45.5%, CH4 2.85%.

[0095] The total carbon monoxide conversion rate of the primary conversion reaction and the secondary conversion reaction is 94.72%.

[0096] After the secondary converted gas is cooled, gas-liquid separated, and the carbon dioxide is removed by temperature swing adsorption, the converted product gas is obtained. The composition of the converted product gas is H2 56.63%, CO 1.13%, CO2 0.20%, N2 39.56%, CH4 2.48%.

[0097] Example 6

[0098] The raw material gas is sourced from the mixed gas of ferroalloy electric furnace tail gas and coal gas. After desulfurization, dechlorination, dearsenification, and deoxidation, the molar composition is: H2 11.5%, CO 64.1%, CO2 5.3%, N2 13.6%, CH4 1.4%, sulfide 0.015 ppm, chloride 0.002 ppm, arsenide 0 ppm, O2 0.005 ppm.

[0099] The above raw material gas is preheated to 190 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a primary isothermal conversion reaction at 3.0 MPa under the catalysis of a catalyst to obtain the primary converted gas. The reaction inlet temperature is 190 °C, and the outlet temperature is 280 °C.

[0100] The primary converted gas is mixed with the second part of the raw material gas and undergoes a secondary isothermal conversion reaction at 3.0 MPa under the catalysis of a conversion catalyst to obtain the secondary converted gas. The reaction inlet temperature is 190 °C, and the outlet temperature is 275 °C.

[0101] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:0.

[0102] The volume ratio of the second part of the primary converted gas to the first part of the primary converted gas is 1:0.

[0103] In the primary conversion reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary conversion reaction furnace, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. Among them, the CuO content of the low-activity catalyst is 12 wt%, the CuO content of the high-activity catalyst is 42 wt%, and the CuO content of the medium-activity catalyst is 28 wt%.

[0104] Based on the mass of the catalyst in the conversion reaction, the feed space velocity of the primary conversion reaction is 1000 h -1 , and the feed space velocity of the secondary conversion reaction is 2000-1 。

[0105] The composition of the primary converted gas is: H2 52.80%, CO 21.5%, CO2 11.8%, N2 12.6%, CH4 1.3%.

[0106] The composition of the secondary converted gas is: H2 72.25%, CO 2.2%, CO2 12.4%, N2 11.9%, CH4 1.25%.

[0107] The total carbon monoxide conversion rate of the primary conversion reaction and the secondary conversion reaction is 94.48%.

[0108] After the secondary converted gas is cooled, gas-liquid separated, and the carbon dioxide is removed by temperature swing adsorption, the converted product gas is obtained. The composition of the converted product gas is: H2 88.513%, CO 1.93%, CO2 0.20%, N2 8.26%, CH4 1.10%.

[0109] Example 7

[0110] The raw material gas is sourced from the mixed gas of ferroalloy electric furnace tail gas and coal gas. After desulfurization, dechlorination, dearsenication, and deoxidation, the molar composition is: H2 11.5%, CO 64.1%, CO2 5.3%, N2 13.6%, CH4 1.4%, sulfide 0.015 ppm, chloride 0.002 ppm, arsenide 0 ppm, O2 0.005 ppm.

[0111] The above raw material gas is preheated to 195 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a primary isothermal conversion reaction at 3.0 MPa under the catalysis of a catalyst to obtain the primary converted gas. The reaction inlet temperature is 195 °C, and the outlet temperature is 280 °C.

[0112] After the primary converted gas is mixed with the second part of the raw material gas, it undergoes a secondary isothermal conversion reaction at 3.0 MPa under the catalysis of a conversion catalyst to obtain the secondary converted gas. The reaction inlet temperature is 195 °C, and the outlet temperature is 275 °C.

[0113] The volume ratio of the first part of the raw material gas to the second part of the raw material gas is 1:0.4.

[0114] The volume ratio of the second part of the primary converted gas to the first part of the primary converted gas is 1:0.6.

[0115] In the primary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. The CuO content of the low-activity catalyst is 12 wt%, the CuO content of the high-activity catalyst is 45 wt%, and the CuO content of the medium-activity catalyst is 28 wt%.

[0116] Based on the mass of the catalyst in the shift reaction, the feed space velocity of the primary shift reaction is 1500 h -1 , and the feed space velocity of the secondary shift reaction is 2500 -1 .

[0117] The composition of the primary shift gas is H2 70.45%, CO 3.5%, CO2 11.9%, N2 13.26%, CH4 1.19%.

[0118] The composition of the secondary shift gas is H2 72.25%, CO 2.2%, CO2 12.4%, N2 11.9%, CH4 1.25%.

[0119] The total carbon monoxide conversion rate of the primary shift reaction and the secondary shift reaction is 94.51%.

[0120] The secondary shift gas is cooled, subjected to gas-liquid separation, and then undergoes temperature-variable adsorption to remove carbon dioxide to obtain the shifted product gas. The composition of the shifted product gas is H2 88.45%, CO 1.94%, CO2 0.21%, N2 8.28%, CH4 1.12%.

[0121] Example 8

[0122] The raw material gas is sourced from the mixed gas of ferroalloy electric furnace tail gas and coal gas. After desulfurization, dechlorination, dearsenization, and deoxidation, the molar composition is: H2 11.5%, CO 64.1%, CO2 5.3%, N2 13.6%, CH4 1.4%, sulfide 0.015 ppm, chloride 0.002 ppm, arsenide 0 ppm, O2 0.005 ppm.

[0123] The above raw material gas is preheated to 192 °C and then divided into two parts. The first part of the raw material gas is mixed with steam and undergoes a primary isothermal shift reaction at 1.0 MPa under the catalysis of a catalyst to obtain the primary shift gas. The reaction inlet temperature is 192 °C, and the outlet temperature is 275 °C.

[0124] The primary shift gas is mixed with the second part of the raw material gas and undergoes a secondary isothermal shift reaction at 1.0 MPa under the catalysis of a shift catalyst to obtain the secondary shift gas. The reaction inlet temperature is 192 °C, and the outlet temperature is 270 °C.

[0125] The volume ratio of the first part of the raw gas to the second part of the raw gas is 1:0.4.

[0126] The volume ratio of the second part of the primary converted gas to the first part of the primary converted gas is 1:0.6.

[0127] In the primary conversion reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:3; in the secondary conversion reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:3. Among them, the CuO content of the low-activity catalyst is 15wt%, the CuO content of the high-activity catalyst is 40wt%, and the CuO content of the medium-activity catalyst is 30wt%.

[0128] Based on the mass of the catalyst in the conversion reaction, the feed space velocity of the primary conversion reaction is 1500h -1 , and the feed space velocity of the secondary conversion reaction is 2500 -1 .

[0129] The composition of the primary converted gas is H2 70.15%, CO 4.1%, CO2 11.2%, N2 13.36%, CH4 1.21%.

[0130] The composition of the secondary converted gas is H2 72.09%, CO 2.3%, CO2 12.6%, N2 11.76%, CH4 1.25%.

[0131] The total carbon monoxide conversion rate of the primary conversion reaction and the secondary conversion reaction is 94.59%.

[0132] After the secondary converted gas is cooled, gas-liquid separated, and the carbon dioxide is removed by temperature swing adsorption, the converted product gas is obtained. The composition of the converted product gas is H2 88.45%, CO 1.94%, CO2 0.21%, N2 8.28%, CH4 1.12%.

[0133] It can be seen from the above embodiments that the present invention can be applied to a raw gas source that is one or more mixed gases of coal gas, calcium carbide furnace tail gas, ferroalloy tail gas, or methanol purge gas, and has the requirement for the conversion of raw gas with a high concentration of carbon monoxide.

[0134] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fractional or integer) within the indicated range.

[0135] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A conversion method applicable to a high carbon monoxide content, characterized in that, The shift conversion method applicable to a high carbon monoxide content comprises the following steps: The feed gas is divided into two parts. The first part of the feed gas is mixed with steam and then enters a primary shift reactor. After the shift reaction, a primary shifted gas is obtained. The primary shifted gas is divided into two parts. The first part of the primary shifted gas is mixed with steam and the second part of the feed gas and then undergoes a secondary shift reaction to obtain a secondary shifted gas. The second part of the primary shifted gas is mixed with the secondary shifted gas and enters a post-treatment system to obtain a shifted product gas.

2. The shift method applicable to a high carbon monoxide content according to claim 1, characterized in that, The volume ratio of the first part of the feed gas to the second part of the feed gas is 1:(0 - 1.0), and the volume ratio of the second part of the primary shifted gas to the first part of the primary shifted gas is 1:(0 - 1.0).

3. The shift method applicable to high carbon monoxide content according to claim 1, characterized in that, The volume ratio of the first part of the feed gas to the second part of the feed gas is 1:(0.5 - 1.0), and the volume ratio of the second part of the primary shifted gas to the first part of the primary shifted gas is 1:(0.2 - 0.5).

4. The shift method applicable to a high carbon monoxide content according to any one of claims 1 to 3, characterized in that, The primary and secondary shift reactors adopt axial beds. The primary shift reaction and the secondary shift reaction are respectively carried out under the catalysis of catalysts. In the primary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 3:4:

3. In the secondary shift reactor, low-activity, high-activity, and medium-activity catalysts are loaded in layers from top to bottom, and the loading volume ratio is 2:5:

3.

5. The shift method applicable to a high carbon monoxide content according to claim 4, characterized in that, The CuO content of the low-activity catalyst is 10 - 15 wt%, the CuO content of the high-activity catalyst is 40 - 45 wt%, and the CuO content of the medium-activity catalyst is 25 - 30 wt%.

6. The shift method applicable to a high carbon monoxide content according to claim 5, characterized in that, Based on the mass of the catalyst in the primary shift reaction, the feed space velocity of the primary shift reaction is 1000 - 2000 h -1 ; Based on the mass of the catalyst in the secondary conversion reaction, the feed space velocity of the secondary conversion reaction is 1000 - 3000 -1 .

7. The shift method applicable to high carbon monoxide content according to claim 6, characterized in that, Steam inlets are provided at the outer walls of the primary shift reactor and the secondary shift reactor corresponding to the junctions where two different performance catalysts are loaded. In the feed gas: the molar content of sulfide is less than 0.05 ppm, the molar content of chloride is less than 0.01 ppm, the molar content of arsenide is less than 0.01 ppm, and the molar content of oxygen is less than 0.02%.

8. The shift method applicable to a high carbon monoxide content according to claim 7, characterized in that, The inlet temperature of the primary isothermal shift reaction is 190 - 200 °C; the inlet temperature of the secondary isothermal shift reaction is 190 - 200 °C.

9. The shift method applicable to a high carbon monoxide content according to claim 8, characterized in that, The shift conversion method further comprises: Performing pre-treatment on the feed gas before the primary shift reaction. The pre-treatment includes desulfurization, dechlorination, dearsenication, deoxidation, and preheating. Performing post-treatment on the secondary shifted gas after the secondary shift reaction to obtain a shifted product gas. The post-treatment includes cooling, gas-liquid separation, and carbon dioxide removal.

10. The shift method applicable to high carbon monoxide content according to claim 9, wherein, The feed gas is sourced from one or more mixtures of coal gas, calcium carbide furnace tail gas, ferroalloy tail gas, or methanol purge gas.

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