Industrial gas purification method

Abstract

The invention belongs to the field of industrial gas purification, and particularly relates to an industrial gas purification method. Comprising the following steps: industrial gas containing NH3 and high CO + CO2 enters an industrial gas purification catalyst bed layer at 230-450 DEG C for purification treatment; the industrial gas enters the same industrial gas purification catalyst bed layer for purification treatment at the temperature of 80-200 DEG C, the industrial gas purification catalyst comprises an A-type molecular sieve and MoO3 / WO3 and NiO / CoO loaded on the A-type molecular sieve, the content of molybdenum or tungsten is 3-12 wt% in terms of MoO3 or WO3, the content of nickel or cobalt is 3-7 wt% in terms of NiO or CoO, and the content of cobalt is 3-7 wt% in terms of NiO or CoO. And the molecular sieve also contains 55-75% of alkali metal or alkaline earth metal which is not subjected to ion exchange according to the molar ratio. The device can be used for purifying industrial gas containing ammonia and high CO + CO2, and the target purification effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of industrial gas purification, and in particular to an industrial gas purification method, which is suitable for catalytic purification of industrial gases containing ammonia and oxygen, olefins, HCN and complex sulfides, COS, etc. in high CO+CO2 gas sources such as coal gasification, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas and other industrial waste gases. Background Art

[0002] In recent years, domestic coal chemical industry has developed rapidly, and the products produced have greatly surpassed the traditional synthetic ammonia, urea and methanol. In many cases, the raw coal gas from the gasifier no longer needs to be converted, but directly extracted from the coal gas by low-temperature methanol washing and cold box deep cold separation to produce different chemical products. The unconverted raw coal gas contains impurities such as oxygen, olefins, HCN and complex sulfides, which need to be purified before entering the low-temperature methanol washing and cold box to remove oxygen, saturate olefins, convert HCN into NH3, and convert complex sulfides into hydrogen sulfide.

[0003] In addition, the comprehensive utilization of blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas and calcium carbide tail gas has become a new trend. In addition to useful components such as CH4, CO and H2, these industrial waste gases also contain impurities such as oxygen, olefins, HCN and complex sulfides that need to be purified.

[0004] Hydrogenation treatment of impurities such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide and carbon disulfide is a conventional and effective purification method. At the same time, cobalt-molybdenum hydrogenation catalysts are also widely and successfully used in the natural gas industry. However, industrial waste gases such as raw coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas are different from natural gas. They contain high content of CO and CO2. High content of CO and CO2 will produce the following side reactions with H2 in the gas source when the cobalt-molybdenum hydrogenation catalyst is used at a temperature greater than 230°C:

[0005] CO disproportionation reaction: 2CO==C(S)+CO2 (1)

[0006] CO reduction reaction: CO+H2==C(S)+H2O (2)

[0007] CO methanation reaction: CO+3H2==CH4+H2O (3)

[0008] CO2 methanation reaction: CO2+4H2==CH4+2H2O(4)

[0009] Side reactions (1) and (2) will cause the catalyst to carbonize and deactivate. Side reactions (3) and (4) are highly exothermic reactions and will cause the catalyst bed to overheat. Overheating of the bed will aggravate the catalyst carbonization and deactivation. There have been many cases of dangerous accidents such as overheating and reactor burning caused by the use of purifiers in gas sources containing CO, CO2 and H2 at relatively high temperatures. Therefore, the cobalt-molybdenum catalyst traditionally widely used in the hydrodesulfurization and deolefination of natural gas cannot be used for hydrogenation purification of crude coal gas and industrial gases such as blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas. Currently, the hydrogenation catalysts sold on the market at home and abroad all require CO+CO2≤10%. The market is in urgent need of a hydrogenation catalyst that can be used in high-content CO+CO2 conditions.

[0010] At the same time, industrial gases such as raw coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas contain tens to thousands of ppm of NH3. The existing catalysts for hydrogenation treatment of impurities such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide and carbon disulfide require inlet ammonia <0.1ppm, and they are quickly deactivated when used under conditions of excessive ammonia. In order to simplify the process, the market is in urgent need of hydrogenation catalysts that can be used in ammonia-containing conditions.

[0011] In addition, transition metal-containing catalysts can also undergo varying degrees of FT reaction under high temperature conditions to generate a certain amount of multi-carbon chain macromolecular hydrocarbon substances, which not only increases raw material consumption and affects the normal operation of downstream PSA, low-temperature methanol washing and cold box, but also easily blocks the catalyst pores and causes carbon deposition, which should be avoided as much as possible. Summary of the invention:

[0012] The technical problem to be solved by the present invention is to provide an industrial gas purification method in view of the deficiencies of the prior art. The method can be used to purify oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, CS2 and other complex sulfides and COS in industrial gases containing ammonia and high CO+CO2, and achieve the target purification effect.

[0013] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0014] A new method for purifying industrial gas comprises the following steps: (1) industrial gas containing NH3 and high CO+CO2 first enters an industrial gas purification catalyst bed at 230-450°C for purification treatment; (2) then enters the same industrial gas purification catalyst bed at 80-200°C for purification treatment, wherein the industrial gas purification catalyst comprises a type A molecular sieve and MoO3 / WO3 (MoO3 or WO3) and NiO / CoO (NiO or CoO) loaded on the type A molecular sieve, wherein the content of molybdenum or tungsten is 3-12wt% based on MoO3 or WO3, and the content of nickel or cobalt is 3-7wt% based on NiO or CoO, and the molecular sieve also contains 55%-75% of alkali metal or alkaline earth metal that has not been ion-exchanged by molar ratio, wherein the alkali metal or alkaline earth metal is sodium, potassium or calcium.

[0015] According to the above method, in the above purification method, oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, carbon disulfide and other organic sulfur (complex sulfide) impurities other than COS in the gas source are first hydrogenated at 230-450°C to remove oxygen, olefins are saturated, HCN and thiophene, disulfide, mercaptan, sulfide, CS2 and the like are purified into ammonia and H2S, and the impurity COS in the gas source is purified into H2S at 80-200°C. The reactions involved in this process are as follows:

[0016] O2+2H2==2H2O

[0017] C m H 2m +H2==C m H 2m+2

[0018] HCN+3H2==NH3+CH4

[0019] C4H4S+4H2==C4H 10 +H2S

[0020] RSH+H2==H2S+RH

[0021] RSR+2H2==H2S+2RH

[0022] RSSR+3H2==2H2S+2RH

[0023] CS2+4H2==2H2S+CH4

[0024] COS+H2==H2S+CO

[0025] COS+H2O==H2S+CO2

[0026] Furthermore, the ammonia-containing and high CO+CO2 gas source has an NH3 content of 0.001% to 0.5% and a CO+CO2 content of >10%, and can specifically be industrial gases such as raw coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas, etc. The ammonia-containing and high CO+CO2 gas source generally also contains H2, and if necessary, hydrogen can be added to the gas source.

[0027] According to the above scheme, the industrial gas is heated and / or used as the cold gas at the inlet of the first reactor and heat exchanged with the outlet gas of the first reactor before entering the first reactor filled with an industrial gas purification catalyst bed for reaction. The hot gas at the outlet of the first reactor is cooled to the required temperature and enters the second reactor for reaction over the same industrial gas purification catalyst, and then the reacted gas is discharged. The treatment temperature of the first reactor is 230-450°C; the treatment temperature of the second reactor is 80-200°C.

[0028] According to the above scheme, the hot gas at the outlet of the first reactor is heat exchanged with the cold gas at the inlet and / or cooled to the required temperature of the second reactor.

[0029] According to the above scheme, the reaction temperature of the first reactor is adjusted by adjusting the gas volume and temperature rise degree of the outlet gas of the first reactor and the cold gas at the inlet of the first reactor for heat exchange; the reaction temperature in the second reactor is adjusted by adjusting the gas volume and cooling degree of the outlet gas of the first reactor and the cold gas at the inlet of the first reactor for heat exchange.

[0030] According to the above scheme, the reaction temperature in the first reactor is regulated according to the content of complex sulfides such as exported oxygen, olefins, HCN and thiophene, disulfide, mercaptan, sulfide, CS2, etc. during the reaction.

[0031] According to the above scheme, after the reaction, the removal rates of oxygen, olefins, mercaptans, sulfides, disulfides, and carbon disulfide are greater than 95%, and the removal rates of HCN, COS, and thiophene are greater than 90%.

[0032] According to the above scheme, the space velocity of the industrial gas purification catalytic reaction in the reactor is 500-20000h -1 ; When the reaction is carried out in the reactor, the pressure of the reaction system is controlled to be 0.01MPa~5MPa.

[0033] According to the above scheme, the mesh size of the A-type molecular sieve is

[0034] According to the above scheme, the type A molecular sieve can be commercially available 3A, 4A, 5A molecular sieves.

[0035] Typical chemical composition of type A molecular sieve: Wherein M represents Na, K, and Ca.

[0036] Typical chemical composition of 3A molecular sieve: Typical chemical composition of 4A molecular sieve: Typical chemical composition of 5A molecular sieve:

[0037]

[0038] According to the above scheme, the industrial gas purification catalyst is firstly to react the A-type molecular sieve with NH4 + Ion exchange, roasting to remove ammonia, and then ion exchange loading Ni / Co, so that the molecular sieve still contains 55% to 75% of alkali metal or alkaline earth metal that has not been ion exchanged, the alkali metal or alkaline earth metal is sodium, potassium, calcium, and then loaded with Mo / W to obtain.

[0039] According to the above scheme, the preparation method of the above industrial gas purification catalyst specifically includes the following steps:

[0040] (1) using an ammonium salt solution to stir the A-type molecular sieve at 80-100° C. for 3-10 hours, repeating the exchange multiple times, filtering, washing, and then calcining at 300-400° C. for later use;

[0041] (2) preparing a Ni / Co solution, stirring the solution with the powder obtained in step (1) at 80-100° C. for ion exchange for 5-8 hours, repeating the exchange multiple times, filtering, washing, and drying for later use;

[0042] (3) preparing a solution containing active components Mo / W, impregnating an equal amount of the solution onto the powder obtained in step (2), and drying the solution for later use;

[0043] (4) Adding a binder to the powder obtained in step (3) and molding it into a spherical, bar or columnar shape, and activating it at 400-600° C. to complete the catalyst preparation.

[0044] According to the above scheme, after the ion exchange in steps (1) and (2), the molecular sieve still contains alkali metals and alkaline earth metals such as sodium, potassium, and calcium in a molar ratio of 55% to 75% that have not been ion exchanged.

[0045] According to the above scheme, the ammonium salt includes but is not limited to ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0046] According to the above scheme, the active components in the solution containing the active components Mo / W and Ni / Co are all salts thereof, including but not limited to ammonium molybdate, ammonium metatungstate, nickel nitrate, and cobalt nitrate.

[0047] According to the above scheme, as required, ammonia water can be used as a co-solvent in the solution preparation of the active component Mo / W to prepare a solution of the active component salt.

[0048] According to the above scheme, the shaped dosage form can be spherical, bar-shaped or column-shaped.

[0049] Traditional cobalt-molybdenum hydrogenation catalysts used in natural gas chemical industry adopt activated alumina carrier. In order to hydrogenate and purify oxygen, olefins, and complex sulfides such as thiophene, mercaptan, and disulfide, they must be used above 350°C. However, when the system contains a high CO+CO2 gas source, side reactions such as methanation and CO disproportionation at temperatures exceeding 230°C can easily lead to catalyst overheating and carbon deposition and deactivation, and even burn the catalyst and reactor, causing safety accidents. At the same time, FT reaction occurs to generate multi-carbon chain macromolecular hydrocarbons, which not only increases raw material consumption and affects the normal operation of downstream PSA, low-temperature methanol washing and cold box, but also easily blocks the catalyst pores and causes carbon deposition.

[0050] The industrial gas purification catalyst of the present invention can be applied to industrial gases containing NH3 and high CO+CO2, such as raw coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas and other industrial waste gases, to purify oxygen, olefins, HCN and thiophene, disulfide, mercaptan, sulfide, CS2 and other complex sulfide impurities in the gas source into water, saturated hydrocarbons, ammonia and H2S at 230-450°C, and purify COS impurities into H2S at 80-200°C, while no CO conversion and its reverse reaction occur, and side reactions such as CO disproportionation and methanation are greatly reduced, and no new C m H n (m≥3) and other hydrocarbon substances.

[0051] The industrial gas purification catalyst of the present invention is used after sulfurization. The industrial gas purification catalyst of the present invention is used for the purification of complex sulfides such as oxygen, olefins, HCN and thiophene, disulfide, mercaptan, sulfide, CS2 and / or COS, and the removal rate of oxygen, olefins, mercaptan, sulfide, disulfide, CS2 is greater than 95%, and the removal rate of HCN, COS, thiophene is greater than 90%.

[0052] Traditional cobalt-molybdenum catalysts used in natural gas chemical industry use activated alumina as carriers, which produce a large number of multi-carbon chain macromolecules during high-temperature hydrogenation, affecting the safe operation of the subsequent stages. In addition, traditional molybdenum catalysts used in oil hydrogenation in the petrochemical industry usually add acidic additives such as phosphorus or fluorine to increase the acidity of the carrier to improve the hydrogenation activity. However, on the one hand, the acidic carrier cannot be used under the condition of ammonia-containing gas source, otherwise it will quickly lose its activity. On the other hand, while improving the hydrogenation activity, the acidic carrier is prone to CO disproportionation to produce carbon deposition and CO and CO2 methanation side reactions, which will cause the catalyst to overheat and deactivate. Traditional cobalt-molybdenum catalysts with activated alumina as carriers, when used in gas sources containing H2O, CO, CO2 and H2, will inevitably produce CO shift reaction or its reverse reaction, resulting in changes in the effective composition of CO, H2 and other components in the gas source. At the same time, since the CO shift reaction is also a strong exothermic reaction, the occurrence of the CO shift reaction or its reverse reaction will also change the catalyst bed temperature. In addition, the violent exothermicity of the aforementioned side reactions such as CO disproportionation and methanation makes the reaction more difficult to control and prone to safety accidents.

[0053] The industrial gas purification catalyst used in this patent uses A-type molecular sieve to load active components, cleverly utilizes the pore size distribution of 3 to 5 angstroms of A-type molecular sieve, and utilizes the characteristics of the molecular sieve pore structure to inhibit the generation of multi-carbon chain macromolecules. At the same time, the remaining sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve can inhibit and reduce the occurrence of CO disproportionation, CO reduction and methanation of CO and CO2 and other side reactions, effectively avoiding catalyst runaway and carbon deposition deactivation. At the same time, the sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve inhibit the adsorption of ammonia and can be used in a gas source containing NH3 (0.001% to 0.5%). In addition, sodium, potassium, calcium and other alkali metals or alkaline earth metals are also good carbon removers, which accelerate the elimination of a small amount of carbon precipitation in the catalyst due to CO disproportionation and avoid carbon accumulation on the catalyst carrier.

[0054] The industrial gas purification catalyst of the present invention effectively avoids the occurrence of CO conversion reaction or its reverse reaction, and does not change the content of effective components such as CO and H2 in the gas source. It also has the function of purifying oxygen, olefins, HCN and complex sulfides such as thiophene, disulfide, mercaptan, sulfide, CS2 at 230-450°C and purifying COS at 80-200°C.

[0055] The main effects of this patent are:

[0056] (1) The present invention designs a segmented process, using the same industrial gas purification catalyst to purify under two different temperature conditions, which can completely solve the current industrial application of oxygen, olefins, HCN and complex organic sulfides, and meet the post-stage requirements of PSA, low-temperature methanol washing and low-temperature cold box. Specifically, the patent design first purifies oxygen, olefins, HCN and thiophene, disulfide, mercaptan, sulfide, carbon disulfide and other organic sulfurs other than COS through the first reactor, and then cools down and uses the same industrial gas purification catalyst to hydrolyze COS into H2S at 80-200°C. Limited by the thermodynamic equilibrium constant, the COS hydrogenation equilibrium concentration is greater than the COS hydrolysis equilibrium concentration. COS cannot meet the purification requirements directly through the industrial gas purification catalyst in the first reactor at 230-450°C. Sometimes the concentration will increase after high-temperature purification. The process of the present invention is designed in segments, fully considering the characteristics of the object to be purified, and achieving a better purification effect.

[0057] (2) Traditional cobalt-molybdenum hydrogenation catalysts must be used at temperatures above 280°C in order to hydrogenate and purify oxygen, olefins, and complex sulfides such as thiophene, mercaptan, and disulfide. However, when used in high CO+CO2 gas sources, side reactions such as methanation and CO disproportionation may cause the catalyst to overheat, become deactivated by carbon deposition, and even burn out the catalyst and reactor, leading to safety accidents. This patent is based on a newly developed industrial gas purification catalyst, uses type A molecular sieve to load active components, and cleverly utilizes the 3-5 angstrom pore size distribution of type A molecular sieve. The characteristics of the molecular sieve pore structure can inhibit the generation of multi-carbon chain macromolecules. When using the remaining sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve, the impurities can be selectively purified and treated, which can inhibit and reduce the occurrence of side reactions such as CO disproportionation, CO reduction and methanation of CO and CO2, and effectively avoid catalyst overheating and carbon deposition deactivation. At the same time, the sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve inhibit the adsorption of ammonia and can be used in NH3-containing gas sources (0.001% to 0.5%). In addition, sodium, potassium, calcium and other alkali metals or alkaline earth metals are also good carbon removers, which accelerate the elimination of a small amount of carbon precipitation in the catalyst due to CO disproportionation and avoid carbon accumulation on the catalyst carrier. It effectively avoids the occurrence of CO shift reaction or its reverse reaction, and does not change the content of effective components such as CO and H2 in the gas source.

[0058] (3) The process gas purification method of the present invention is used for the purification of complex sulfides and COS such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, CS2, etc. The removal rates of oxygen, olefins, mercaptan, sulfide, disulfide, and CS2 are greater than 95%, and the removal rates of HCN, COS, and thiophene are greater than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the reaction process of the present invention. DETAILED DESCRIPTION

[0060] The content of the invention is further illustrated by examples below.

[0061] Embodiment 1:

[0062] (1) Pour 100 g of 3A molecular sieve into 1 L of prepared 2 mol / L ammonium chloride solution, place in a 3 L container, stir and heat, exchange at 90°C for 3 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, filter, wash, dry, and calcine at 300°C for 3 hours for use.

[0063] (2) Prepare 1 L of 0.2 mol / L nickel nitrate (nickel nitrate hexahydrate) solution, add the powder obtained in (1), place in a 3 L container, stir and heat to 90° C., continue stirring for 5 hours, filter, wash, and dry at 120° C. Repeat the exchange three times, then filter, wash, and dry at 120° C. for later use.

[0064] (3) Take 8 g of ammonium molybdate (ammonium heptamolybdate tetrahydrate) to prepare a solution, add a small amount of ammonia water to dissolve it, and impregnate an equal amount of the solution onto the powder obtained in (2), and dry it at 120°C for later use.

[0065] (4) After adding a binder to the material, it was extruded into strips with a diameter of 3 mm and activated at 500° C. for 3 hours to obtain the finished product A1 (which contained 6.3% MoO3 and 3.3% NiO active components, and 73% alkali metals remained on the 3A molecular sieve without exchange).

[0066] Embodiment 2:

[0067] (1) Take 100 g of 4A molecular sieve and pour it into 1 L of prepared 1 mol / L ammonium sulfate solution, place it in a 3 L container, stir and heat to increase the temperature, exchange at 90°C for 6 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, filter, wash, dry, and roast at 350°C for 3 hours for use.

[0068] (2) Prepare 1 L of 0.3 mol / L cobalt nitrate (cobalt nitrate hexahydrate) solution, add the powder obtained in (1), place in a 3 L container, stir and heat to 90°C, continue stirring for 7 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, then filter, wash, and dry at 120°C for later use.

[0069] (3) Take 10 g of ammonium molybdate (ammonium heptamolybdate tetrahydrate) to prepare a solution, add a small amount of ammonia water to dissolve it, and impregnate an equal amount of the solution onto the powder obtained in (2), and dry it at 120°C for later use.

[0070] (4) After adding a binder to the material, it was extruded into strips with a diameter of 5 mm and activated at 500° C. for 3 hours to obtain the finished product A2 (which contained 7.8% MoO3 and 5.2% CoO active components, and 65% alkali metal remained on the 4A molecular sieve without exchange).

[0071] Embodiment 3:

[0072] (1) Pour 100 g of 5A molecular sieve into 1 L of prepared 2 mol / L ammonium nitrate solution, place in a 3 L container, stir and heat, exchange at 90°C for 5 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, filter, wash, dry, and calcine at 400°C for 3 hours for use.

[0073] (2) Prepare 1 L of 0.4 mol / L nickel nitrate (nickel nitrate hexahydrate) solution, add the powder obtained in (1), place in a 3 L container, stir and heat to 90° C., continue stirring for 8 hours, filter, wash, and dry at 120° C., repeat the exchange three times, then filter, wash, and dry at 120° C. for use.

[0074] (3) Take 7.5 g of ammonium metatungstate ((NH4)6W 12 O 39 ·2H2O) to prepare a solution, add a small amount of ammonia water to help dissolution, and impregnate an equal amount onto the powder obtained in (2), and dry at 120℃ for later use.

[0075] (4) After adding a binder to the material, it was extruded into strips with a diameter of 4 mm and activated at 550° C. for 3 hours to obtain the finished product A3 (which contained 6.9% WO3 and 6.4% NiO active components, and 59% alkali metals and alkaline earth metals remained on the 5A molecular sieve without exchange).

[0076] Embodiment 4:

[0077] (1) Pour 100 g of 3A molecular sieve into 1 L of prepared 2 mol / L ammonium nitrate solution, place in a 3 L container, stir and heat, exchange at 90°C for 9 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, filter, wash, dry, and calcine at 300°C for 3 hours for use.

[0078] (2) Prepare 1 L of 0.3 mol / L cobalt nitrate (cobalt nitrate hexahydrate) solution, add the powder obtained in (1), place in a 3 L container, stir and heat to 90°C, continue stirring for 8 hours, filter, wash, and dry at 120°C. Repeat the exchange three times, then filter, wash, and dry at 120°C for later use.

[0079] (3) Take 5 g of ammonium metatungstate ((NH4)6W 12 O 39 ·2H2O) to prepare a solution, add a small amount of ammonia water to help dissolution, and impregnate an equal amount onto the powder obtained in (2), and dry at 120℃ for later use.

[0080] (4) After adding a binder to the material, it was extruded into strips with a diameter of 3 mm and activated at 450° C. for 6 hours to obtain the finished product A4 (containing 4.5% WO3 and 5.1% CoO active components, and 63% alkali metals remaining on the 3A molecular sieve were not exchanged).

[0081] The catalyst samples prepared in the above Examples 1-4 are subjected to sulfidation treatment. The sulfidation treatment may specifically adopt the following sulfidation gas source and sulfidation steps:

[0082] The sulfide gas (by volume fraction) is composed of hydrogen sulfide (1%), hydrogen (10%), and the rest is nitrogen.

[0083] Nitrogen was introduced into the reactor loaded with the catalyst sample, and the temperature was raised to perform sulfurization according to the conditions in Table 1. When the reactor temperature rose to 200°C, the sulfurization was started by switching to sulfurized gas; at 400°C, the volume fraction of H2S at the inlet and outlet of the reactor was analyzed until the inlet and outlet H2S were balanced, and the sulfurization was completed.

[0084] Table 1 Temperature vulcanization conditions

[0085]

[0086] The sulfided catalyst samples are used for the treatment of typical industrial gases such as crude coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas, etc.

[0087] (1) The volume composition is 14% CO, 33% CO2, 39% H2, 12% CH4, 1% H2O, 0.4% C2H6, 0.2% O2, 0.1% C2H4, 0.2% H2S, 150ppm HCN, 150ppm COS, 300ppm NH3, 250ppm RSH (including various types of mercaptans), 11ppm dimethyl disulfide, 10ppm RSR (including methyl sulfide and ethyl sulfide), 8ppm CS2, 11ppm thiophene. The crude gas after typical Lurgi furnace cooling and separation at 40℃ is 30000Nm 3 / h, pressure 3.8MPa, at the initial start-up, the temperature is raised to 350℃ by the heater, and the 10m 3 The 1# reactor bed of the industrial gas purification catalyst described in this patent can adjust the temperature of the reactor to 350°C by adjusting the gas volume passing through the heat exchanger and / or heating with a heater during the reaction process. The outlet gas of the 1# reactor exchanges heat with the inlet cold gas and passes through a gas cooler to reduce the temperature to 150°C before entering a 15m 3 The 2# reactor bed of the industrial gas purification catalyst described in this patent, the outlet gas enters the next stage, such as Figure 1 shown.

[0088] The four samples prepared above have a volume composition of 14% CO, 33% CO2, 39% H2, 12% CH4, 1% H2O,

[0089] 0.4%C2H6, 0.2%O2, 0.1%C2H4, 0.2%H2S, 150ppmHCN, 150ppmCOS, 300ppmNH3,

[0090] 250ppmRSH (including various types of mercaptans), 11ppm dimethyl sulfide, 10ppmRSR (including methyl sulfide and ethyl sulfide),

[0091] The evaluation results of 8ppm CS2 and 11ppm thiophene in typical Lurgi furnace raw gas are shown in Table 2:

[0092] Table 2

[0093]

[0094] At the same time, the composition of the outlet gas source was detected. The contents of CO, CO2, H2, and H2O did not change, indicating that no CO shift reaction and its reverse reaction occurred, and there was no C3 or higher hydrocarbon substance C m H n (m≥3) is generated, and the CH4 increase is <0.1%.

[0095] (2) Volume composition is 8% CO, 3% CO2, 53% H2, 27% CH4, 6.5% N2, 1.5% H2O, 0.3% C2H6, 0.4% O2, 0.1% C2H4, 0.1% H2S, 500ppm HCN, 100ppm COS, 400ppm NH3, 120ppm RSH (including various types of mercaptans), 11ppm dimethyl disulfide, 8ppm RSR (including methyl sulfide and ethyl sulfide), 9ppm CS2, 5ppm thiophene. Typical coke oven gas 100000Nm 3 / h, pressure 2.5MPa, at the initial start-up, after heat exchange with the outlet gas of the 1# reactor and heating to 320℃ through the heater as needed, it first enters the 40m 3 The 1# reactor bed of the industrial gas purification catalyst described in this patent exchanges heat between the reactor outlet gas and the inlet cold gas. During the reaction operation, the reactor temperature can be adjusted to 320°C by adjusting the gas volume through the heat exchanger and / or heating by the heater. After the heat exchange between the reactor outlet gas and the inlet cold gas, the temperature is reduced to 120°C through the gas cooler and enters the 40m 3 The 2# reactor bed of the industrial gas purification catalyst described in this patent, the outlet gas enters the next stage, such as Figure 1 shown.

[0096] The four samples prepared above have a volume composition of 8% CO, 3% CO2, 53% H2, 27% CH4, 6.5% N2, 1.5% H2O, 0.3% C2H6, 0.4% O2, 0.1% C2H4, 0.1% H2S, 500ppm HCN, 100ppm COS,

[0097] The evaluation results of 400ppm NH3, 120ppm RSH (including various types of mercaptans), 11ppm dimethyl ether, 8ppm RSR (including methyl sulfide and ethyl sulfide), 9ppm CS2, and 5ppm thiophene in typical coke oven gas are shown in Table 3:

[0098] Table 3

[0099]

[0100] At the same time, the composition of the outlet gas source was detected, and the contents of CO, CO2, H2, and H2O did not change, indicating that no CO shift reaction and its reverse reaction occurred, no C3 and above hydrocarbons were generated, and the CH4 increase was <0.1%.

[0101] (3) Volume composition is 74% CO, 6% CO2, 10% H2, 0.5% CH4, 6.5% N2, 2% H2O, 0.4% C2H6, 0.3% O2, 0.1% C2H4, 0.05% H2S, 300ppm HCN, 150ppm COS, 400ppm NH3, 45ppm RSH (including various types of mercaptans), 7ppm dimethyl disulfide, 5ppm RSR (including methyl sulfide and ethyl sulfide), 21ppm CS2 Typical calcium carbide gas 50000Nm 3 / h, pressure 2.8MPa, at the initial start-up, the temperature is raised to 370℃ by the heater, and the 10m 3 The 1# reactor bed of the industrial gas purification catalyst described in this patent can heat exchange the reactor outlet gas and the inlet cold gas during the reaction operation, adjust the gas volume through the heat exchanger and / or adjust the reactor temperature to 370°C by heating with a heater. After the heat exchange between the reactor outlet gas and the inlet cold gas, the temperature is reduced to 200°C through a gas cooler and enters a 50m 3 The 2# reactor bed of the industrial gas purification catalyst described in this patent, the outlet gas enters the next stage, such as Figure 1 shown.

[0102] The four samples prepared above have a volume composition of 74% CO, 6% CO2, 10% H2, 0.5% CH4, 6.5% N2, 2% H2O, 0.4% C2H6, 0.3% O2, 0.1% C2H4, 0.05% H2S, 300ppm HCN, 150ppm COS,

[0103] The evaluation results of 400ppm NH3, 45ppm RSH (including various types of mercaptans), 7ppm dimethyl ether, 5ppm RSR (including methyl sulfide and ethyl sulfide), and 21ppm CS2 in typical calcium carbide gas are shown in Table 4:

[0104] Table 4

[0105]

[0106] At the same time, the composition of the outlet gas source was detected, and the contents of CO, CO2, H2, and H2O did not change, indicating that no CO shift reaction and its reverse reaction occurred, no C3 and above hydrocarbons were generated, and the CH4 increase was <0.1%.

Claims

1. An industrial gas purification method, characterized in that: The following steps are involved: (1) Industrial gas containing NH3 and high CO+CO2 first enters an industrial gas purification catalyst bed for purification treatment at 230-450°C; (2) then enters the same industrial gas purification catalyst bed for purification treatment at 80-200°C, wherein the industrial gas purification catalyst comprises a type A molecular sieve and MoO3 / WO3 and NiO / CoO loaded on the type A molecular sieve, wherein the content of molybdenum or tungsten is 3-12wt% based on MoO3 or WO3, and the content of nickel or cobalt is 3-7wt% based on NiO or CoO, and the molecular sieve also contains 55%-75% by mole of alkali metal or alkaline earth metal that has not been ion exchanged, wherein the alkali metal or alkaline earth metal is sodium, potassium, or calcium.

2. The purification method according to claim 1, characterized in that: The industrial gas containing ammonia and high CO+CO2 has an NH3 content of 0.001% to 0.5% and a CO+CO2 content of more than 10%.

3. The purification method according to claim 2, characterized in that: The industrial gas is one or more of raw coal gas, blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas and calcium carbide tail gas.

4. The purification method according to claim 1, characterized in that: The industrial gas is heated and / or used as the cold gas at the inlet of the first reactor and heat exchanged with the outlet gas of the first reactor before entering the first reactor filled with an industrial gas purification catalyst bed for reaction. The hot gas at the outlet of the first reactor is cooled to the required temperature and enters the second reactor for reaction over the same industrial gas purification catalyst, and then the reacted gas is discharged. The treatment temperature of the first reactor is 230-450°C; the treatment temperature of the second reactor is 80-200°C.

5. The purification method according to claim 4, characterized in that: The hot gas at the outlet of the first reactor is heat exchanged with the cold gas at the inlet and / or cooled down to the required temperature of the second reactor.

6. The purification method according to claim 4, characterized in that: The reaction temperature of the first reactor is adjusted by adjusting the gas volume and temperature rise degree of the outlet gas of the first reactor and the cold gas at the inlet of the first reactor for heat exchange; the reaction temperature in the second reactor is adjusted by adjusting the gas volume and cooling degree of the outlet gas of the first reactor and the cold gas at the inlet of the first reactor for heat exchange.

7. The purification method according to claim 1, characterized in that: During the reaction, the reaction temperature in the first reactor is regulated according to the contents of outlet oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, and CS2 sulfide; after the reaction, the removal rates of oxygen, olefins, mercaptan, sulfide, disulfide, and carbon disulfide are greater than 95%, and the removal rates of HCN, COS, and thiophene are greater than 90%.

8. The purification method according to claim 1, characterized in that: The space velocity of the industrial gas purification catalytic reaction in the reactor is 500~20000h -1 ; When the reaction is carried out in the reactor, the pressure of the reaction system is controlled to be 0.01MPa~5MPa.

9. The purification method according to claim 1, characterized in that: The sieve size of the A-type molecular sieve is It is 3A, 4A or 5A molecular sieve.

10. The purification method according to claim 1, characterized in that: The industrial gas purification catalyst is firstly to purify the A-type molecular sieve through NH4 + Ion exchange, roasting to remove ammonia, and then ion exchange loading Ni / Co, so that the molecular sieve still contains 55% to 75% of alkali metal or alkaline earth metal that has not been ion exchanged, the alkali metal or alkaline earth metal is sodium, potassium, calcium, and then loaded with Mo / W to obtain.

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