A purification method for industrial waste gas resource utilization

Abstract

The present application belongs to the field of industrial waste gas purification, and particularly relates to a purification method for resource utilization of industrial waste gas. The method comprises the following steps: (1) dust removal and purification pretreatment of the industrial waste gas containing NH3 and high CO+CO2; (2) purification treatment of the industrial waste gas in a catalyst bed of an industrial waste gas purification catalyst under the condition of 230-400 DEG C; and (3) purification treatment of the industrial waste gas in a dechlorination agent bed under the condition of the same temperature. The industrial waste gas purification catalyst comprises A-type molecular sieve and MoO3 / WO3, NiO / CoO and V2O5 / CeO2 supported on the A-type molecular sieve. The content of molybdenum or tungsten is 3-12 wt% based on MoO3 or WO3, the content of nickel or cobalt is 3-7 wt% based on NiO or CoO, and the content of vanadium or cerium is 0.5-1.5 wt% based on V2O5 or CeO2. The molecular sieve further contains 55-75% alkali metal or alkaline earth metal which is not ion-exchanged. The catalyst can be used for purification of oxygen, olefin, HCN, complex sulfide and organic chlorine in the ammonia-containing and high CO+CO2 gas source, and the target purification effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of industrial waste gas, and in particular to a purification method for resource utilization of industrial waste gas, which is suitable for catalytic purification of oxygen, olefins, HCN, complex sulfides and organic chlorine in industrial waste gas such as blue coke gas and raw coal gas. Background Art

[0002] In recent years, due to environmental protection needs and cost advantages, the resource utilization of industrial waste gas has been accelerating. The types and range of impurities in industrial waste gas have far exceeded the purification technology and product application scope of coal chemical industry and petroleum and natural gas chemical industry that have developed and matured over the years. The purification of industrial waste gas has become a new research hotspot.

[0003] Industrial waste gases such as blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas, semi-coke gas, and raw coal gas are generated by various processes. These gases contain useful components such as CH4, CO, and H2, which can be purified and recycled. The purification of coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas has been extensively researched and has the most mature industrial applications. Large-scale industrial plants are also beginning to be used to recycle blast furnace gas and converter gas. In comparison, the purification of semi-coke gas and raw coal gas is more challenging.

[0004] The typical composition of semi-coke gas and raw coal gas is as follows:

[0005]

[0006] Both semi-coke gas and raw coal gas are tail gases from low-temperature dry distillation of coal. Due to the low dry distillation temperature (~600°C), the tail gas contains a large amount of impurities such as benzene, naphthalene, complex sulfides, oxygen, olefins, ammonia, HCN and organic chlorine. Among them, organic chlorine is mainly monochloromethane and dichloromethane, and complex sulfides are mainly thiophene, disulfide, mercaptan, sulfide and carbon disulfide.

[0007] In the past, semi-coke gas and raw coal gas were mainly burned as fuel gas due to their high nitrogen content, low content of useful components such as CH4, CO and H2, complex impurities, difficulty in purification, and low calorific value. Resource utilization was relatively late, but some resource utilization has begun. Some use non-catalytic partial oxidation technology to partially oxidize and burn methane in the gas source into CO and H2. After high-temperature treatment in this non-catalytic partial oxidation process, organic chlorine is decomposed into inorganic chlorine and hydrogen chloride. However, this process has a large loss of effective gas components and is not economical. Some use semi-coke gas and raw coal gas to separate methane and produce LNG (liquefied natural gas). At the same time, the purified CO and H2 are used to produce chemical products such as methanol and ethylene glycol. The traditional purification process used in these processes makes it impossible to remove impurities such as organic chlorine, which affects the subsequent conversion catalyst and causes short-term poisoning and deactivation, resulting in equipment shutdown and process failure.

[0008] There are two main methods for purifying organochlorine: physical adsorption and hydrogenation conversion. Physical adsorption uses porous materials to adsorb organochlorine to achieve purification effects. It is regenerable, but the purification accuracy and capacity are poor. Hydrogenation conversion is to hydrogenate organochlorine into inorganic hydrogen chloride and then use conventional dechlorination agents to remove it.

[0009] The purification of organic chlorine has traditionally only been involved in the purification of oil products, and is mainly removed by hydrogenation with a sulfide catalyst. In the traditional sense, in coal chemical industry, because the temperature of coal is high during gasification (900-1300°C), organic chlorine will not exist in a reducing atmosphere and is converted into inorganic chlorine, namely hydrogen chloride. Therefore, the dechlorination mentioned in coal chemical industry is dehydrochlorination. For the same reason, industrial waste gases such as blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas also have no organic chlorine in the impurities because they have passed through a high-temperature stage during the waste gas generation process.

[0010] In recent years, the resource utilization of chlorine-containing plastics has made the purification of organic chlorine a new hot topic, with a lot of research. The purification method is mainly hydrogenation conversion, and the research on active components is concentrated on reduced precious metals or transition metals and rare earth metals. Since these active components are easily poisoned by sulfur, these studies are not suitable for hydrodechlorination under working conditions containing high content of complex sulfides.

[0011] Hydrogenation treatment of impurities such as oxygen, olefins, HCN, complex sulfides, and organic chlorine is a conventional and effective purification method. Hydrodesulfurization, denitrification, and dechlorination catalysts are also widely and successfully used in the petrochemical industry. However, unlike oil products, industrial waste gases such as semi-coke gas and raw coal gas contain high levels of CO and CO2. When the hydrogenation catalyst is used at a temperature greater than 230°C, the high levels of CO and CO2 react with the H2 in the gas source to produce the following side reactions:

[0012] CO disproportionation reaction: 2CO==C(S)+CO2 (1)

[0013] CO reduction reaction: CO + H2 == C(S) + H2O (2)

[0014] CO methanation reaction: CO + 3H2 = = CH4 + H2O (3)

[0015] CO2 methanation reaction: CO2+4H2==CH4+2H2O(4)

[0016] Side reactions (1) and (2) will cause the catalyst to carbonize and become inactivated. Side reactions (3) and (4) are highly exothermic reactions, which will cause the catalyst bed to overheat. Overheating of the bed will aggravate the catalyst carbonization and inactivation. There have been many cases of dangerous accidents such as overheating and reactor burning caused by using purifiers in gas sources containing CO, CO2 and H2 at higher temperatures. Therefore, the hydrogenation catalysts traditionally widely used in oil purification cannot be used for hydrogenation purification of industrial gases such as lignite gas and raw coal gas. Currently, the hydrodesulfurization catalysts sold on the market at home and abroad all require CO+CO2≤10%. There are currently no organic chlorine hydrogenation catalysts on the market that can be used in gas sources containing CO and CO2.

[0017] At the same time, industrial waste gases such as semi-coke and raw coal gas contain tens to thousands of ppm of NH3. Existing catalysts for hydrogenation of impurities such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, and carbon disulfide require an inlet ammonia concentration of less than 0.1 ppm. These catalysts quickly deactivate when used under conditions where ammonia levels exceed this limit, creating an urgent need for hydrogenation catalysts suitable for use in ammonia-containing conditions. Furthermore, transition metal-containing catalysts can undergo varying degrees of FT reactions at high temperatures, generating a certain amount of multi-carbon chain macromolecular hydrocarbons. This not only increases feedstock consumption and impacts the normal operation of downstream PSA, low-temperature methanol washes, and cold boxes, but can also easily clog catalyst pores and cause carbon deposits, which should also be avoided. Summary of the Invention

[0018] The technical problem to be solved by this invention is to address the shortcomings of existing technologies and provide a purification method for resource utilization of industrial waste gas. This method can be used to purify oxygen, olefins, HCN, and complex sulfides such as thiophene, disulfide, mercaptan, sulfide, and CS2, as well as organic chlorine, from industrial waste gases containing ammonia and high levels of CO and CO2, such as semi-coke gas and raw coal gas, achieving the desired purification effect.

[0019] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0020] A purification method for resource utilization of industrial waste gas, comprising the following steps: (1) pre-processing industrial waste gas containing NH3 and high CO+CO2 to remove dust and purify the waste gas; (2) then entering an industrial waste gas purification catalyst bed for purification at 230-400°C; (3) then entering a dechlorination agent bed for removing inorganic chlorine at the same temperature for purification, wherein the industrial waste gas purification catalyst comprises a type A molecular sieve and MoO3 / WO3, NiO / CoO and V2O5 / CeO2 supported on the type A molecular sieve, wherein the content of molybdenum or tungsten is 3-12wt% in terms of MoO3 or WO3, the content of nickel or cobalt is 3-7wt% in terms of NiO or CoO, and the content of vanadium or cerium is 0.5-1.5wt% in terms of V2O5 or CeO2, and the molecular sieve further contains 55%-75% 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.

[0021] According to the above scheme, the dechlorinating agent used to remove inorganic chlorine is preferably a dechlorinating agent that can remove hydrogen chloride to less than 0.1 ppm.

[0022] According to the above method, in the above purification method, after pretreatment to meet standards to remove impurities such as tar, dust, benzene, naphthalene, etc., and pressurization, oxygen, olefins, HCN, complex sulfides, and organic chlorine are hydrogenated at 230-400°C to remove oxygen, saturate olefins, and purify HCN, thiophene, disulfide, mercaptan, sulfide, CS2, organic chlorine, etc. into ammonia, H2S, and hydrogen chloride. The hydrogen chloride is then purified and removed at the same temperature. The reactions involved are as follows:

[0023] O2+2H2==2H2O

[0024] C m H 2m +H2==C m H 2m+2

[0025] HCN+3H2==NH3+CH4

[0026] C4H4S+4H2==C4H 10 +H2S

[0027] RSH+H2==H2S+RH

[0028] RSR+2H2==H2S+2RH

[0029] RSSR+3H2==2H2S+2RH

[0030] CS2+4H2==2H2S+CH4

[0031] COS+H2==H2S+CO

[0032] CH3Cl+H2==CH4+HCl

[0033] CH2Cl2+2H2==CH4+2HCl

[0034] 2HCl+MO==MCl2+H2O

[0035] Furthermore, the ammonia-containing and high-CO+CO2 source gas has an NH3 content of 0.001% to 0.5% and a CO+CO2 content greater than 10%. Specifically, it can be industrial waste gas such as semi-coke gas or raw coal gas. The ammonia-containing and high-CO+CO2 source gas generally also contains H2. If necessary, hydrogen can be added to the gas source.

[0036] According to the above scheme, the tar content is less than 1 mg / Nm after step (1) pretreatment. 3 Benzene content <10mg / Nm 3 , naphthalene content <1mg / Nm 3 of purified gas.

[0037] According to the above scheme, the pretreatment includes decoking, water washing, temperature swing adsorption (TSA) treatment and pressurization treatment.

[0038] According to the above scheme, after step (2), the removal rates of oxygen, olefins, mercaptans, sulfides, disulfides, carbon disulfide, and organic chlorine are greater than 95%, and the removal rates of HCN and thiophene are greater than 90%; after step (3), the hydrogen chloride content is less than 0.1 ppm.

[0039] According to the above scheme, the space velocity of the catalytic reaction of industrial waste gas purification 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 0.01MPa~5MPa.

[0040] According to the above scheme, the sieve size of the A-type molecular sieve is

[0041] According to the above scheme, the type A molecular sieve can be commercially available 3A, 4A, or 5A molecular sieves.

[0042] Typical chemical composition of type A molecular sieve: Wherein M represents Na, K, and Ca.

[0043] Typical chemical composition of 3A molecular sieve: Typical chemical composition of 4A molecular sieve: Typical chemical composition of 5A molecular sieve:

[0044]

[0045] According to the above scheme, the industrial waste gas purification catalyst is to firstly pass 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, and calcium, and then loaded with Mo / W and V / Ce.

[0046] According to the above scheme, the preparation method of the above industrial gas purification catalyst specifically includes the following steps:

[0047] (1) ion exchange the type A molecular sieve with an ammonium salt solution at 80-100°C for 3-10 hours, repeat the exchange multiple times, filter, wash, and then calcine at 300-400°C for use;

[0048] (2) preparing a solution containing Ni / Co, stirring the solution with the powder obtained in step (1) at 80-100° C. for 5-8 hours, repeating the exchange multiple times, filtering, washing, and drying for later use;

[0049] (3) preparing a solution containing the active components Mo / W and V / Ce, impregnating equal amounts of the solution onto the powder obtained in step (2), and drying the solution for later use;

[0050] (4) Adding a binder to the powder obtained in step (3) and molding the powder, and activating the powder at 400-600° C. to complete the catalyst preparation.

[0051] According to the above scheme, after the ion exchange in steps (1) and (2), it is ensured that the molecular sieve still contains alkali metals and alkaline earth metals such as sodium, potassium, and calcium that have not been ion-exchanged in a molar ratio of 55% to 75%.

[0052] According to the above scheme, the ammonium salt includes but is not limited to ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0053] According to the above scheme, the active components in the solution containing the active components Mo / W, Ni / Co and V / Ce are all salts thereof, including but not limited to ammonium molybdate, ammonium metatungstate, nickel nitrate, cobalt nitrate, ammonium metavanadate, and cerium nitrate.

[0054] According to the above scheme, as needed, ammonia water can be used as a co-solvent in the preparation of the solutions of the active components Mo / W and V / Ce to prepare solutions of the active component salts.

[0055] According to the above scheme, the shaped dosage form can be spherical, bar-shaped or column-shaped.

[0056] The hydrodesulfurization, denitrification and dechlorination catalysts used in the petrochemical industry are used at 300-400℃. However, when the system contains a high CO+CO2 gas source, side reactions such as methanation and CO disproportionation at temperatures exceeding 230℃ can easily lead to catalyst overheating, carbon deposition and deactivation, and even burn the catalyst and reactor, resulting in safety accidents. At the same time, the 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.

[0057] The purification catalyst of the present invention can be applied to industrial waste gas containing NH3 and high CO+CO2, such as blue charcoal gas and raw coal gas, and can purify oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, CS2 and other complex sulfides and organic chlorine impurities in the gas source into water, saturated hydrocarbons, ammonia, H2S and hydrogen chloride at 230-400°C. At the same time, CO conversion and its reverse reaction will not occur, and side reactions such as CO disproportionation and methanation will be greatly reduced. No new C m H n (m≥3) and other hydrocarbon substances.

[0058] The purification catalyst of the present invention is used after sulfurization. The purification catalyst of the present invention is used to purify oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, CS2 and other complex sulfides and organic chlorine, with the removal rate of oxygen, olefins, mercaptan, sulfide, disulfide, CS2, and organic chlorine exceeding 95%, and the removal rate of HCN and thiophene exceeding 90%.

[0059] Hydrodesulfurization, denitrification, and dechlorination catalysts used in the petrochemical industry, such as those used in industrial waste gas containing high levels of CO and CO₂, can produce large quantities of multi-carbon chain macromolecules during the high-temperature hydrogenation process, compromising the safe operation of subsequent processes. Furthermore, conventional catalysts often incorporate acidic additives such as phosphorus or fluorine to increase the carrier acidity and enhance hydrogenation activity. However, acidic carriers cannot be used with ammonia-containing gas sources, as they rapidly lose activity. Furthermore, while enhancing hydrogenation activity, these acidic carriers can also lead to carbon deposition from CO disproportionation and methanation of CO and CO₂, causing catalyst temperature spikes and deactivation. Conventional cobalt-molybdenum catalysts supported on activated alumina, when used in gas sources containing H₂O, CO, CO₂, and H₂, inevitably undergo a CO shift reaction or its reverse reaction, altering the effective composition of CO and H₂ in the gas source. Furthermore, since the CO shift reaction is also highly exothermic, its occurrence can also alter the catalyst bed temperature. This, combined with the intense heat release from the aforementioned side reactions, such as CO disproportionation and methanation, can further complicate reaction control and increase the risk of safety incidents.

[0060] The purification catalyst used in this patent uses A-type molecular sieve to load active components, cleverly utilizes the 3-5 angstrom pore size distribution 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, it cooperates with the use of the remaining sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve to inhibit and reduce the occurrence of CO disproportionation, CO reduction and methanation of CO and CO2 and other side reactions, effectively avoiding catalyst runaway temperature 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.

[0061] The purification catalyst of the present invention effectively avoids the CO shift reaction or its reverse reaction, without changing 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, and organic chlorine at 230-400°C.

[0062] The main effects of this patent are:

[0063] (1) The present invention designs a segmented process. First, pretreatment is performed to meet standards to remove impurities such as tar, dust, benzene, and naphthalene. Then, the industrial waste gas purification catalyst of the present invention is used to hydrogenate oxygen, olefins, HCN, complex sulfides, and organic chlorine at 230-400°C to remove oxygen, saturate olefins, and purify HCN, thiophene, disulfide, mercaptan, sulfide, CS2, and organic chlorine into ammonia, H2S, and hydrogen chloride. Then, at the same temperature, the dechlorinating agent used to remove hydrogen chloride is used to purify and remove hydrogen chloride. After the above three steps, oxygen, olefins, HCN, and chlorine in the industrial waste gas are removed, and complex organic sulfur is hydrogenated into H2S. Subsequently, sulfur-resistant conversion, low-temperature methanol washing, or wet desulfurization followed by PSA for CO or hydrogen extraction can be performed according to the overall process requirements. The process of the present invention is segmented, fully considering the characteristics of the material to be purified, and achieving a good purification effect.

[0064] (2) Traditional hydrodesulfurization, denitrification, and dechlorination catalysts used in the petrochemical industry are used at 300-400°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, carbon deposition, and deactivation, and even burn the catalyst and reactor, resulting in safety accidents. At the same time, the 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 boxes, but also easily blocks the catalyst pores and causes carbon deposition. This patent is based on a newly developed industrial waste gas purification catalyst. It uses type A molecular sieve to load active components, cleverly utilizing the 3-5 angstrom pore size distribution of type A molecular sieve and the characteristics of the molecular sieve pore structure to inhibit the formation of multi-carbon chain macromolecules. At the same time, it cooperates with the use of alkali metals or alkaline earth metals such as sodium, potassium, and calcium remaining on the molecular sieve to selectively purify impurities, which can inhibit and reduce the occurrence of side reactions such as CO disproportionation, CO reduction, and methanation of CO and CO2, effectively avoiding catalyst runaway and carbon deposition deactivation. At the same time, the alkali metals or alkaline earth metals such as sodium, potassium, and calcium on the molecular sieve inhibit ammonia adsorption and can be used in NH3-containing gas sources (0.001% to 0.5%). In addition, alkali metals or alkaline earth metals such as sodium, potassium, and calcium are also good carbon removers, accelerating the elimination of small amounts of carbon precipitation in the catalyst due to CO disproportionation and preventing carbon accumulation on the catalyst support. It effectively avoids the occurrence of CO shift reaction or its reverse reaction without changing the content of effective components such as CO and H2 in the gas source.

[0065] (3) The process gas purification method of the present invention is used for the purification of complex sulfides and organic chlorine such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide, CS2, etc., and the removal rate of oxygen, olefins, mercaptan, sulfide, disulfide, CS2 and organic chlorine is greater than 95%, and the removal rate of HCN and thiophene is greater than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 Schematic diagram of the reaction process of the present invention. DETAILED DESCRIPTION

[0067] The following examples further illustrate the content of the present invention.

[0068] Example 1:

[0069] (1) Take 100 g of 3A molecular sieve and pour it into 1 L of prepared 2 mol / L ammonium chloride solution, place it in a 3 L container, stir and heat to increase the temperature, exchange at 90 ° C for 3 hours, filter, wash, and dry at 120 ° C. Repeat the exchange three times, filter, wash, dry, and roast at 300 ° C for 3 hours for use.

[0070] (2) Prepare 1 L of 0.2 mol / L nickel nitrate (nickel nitrate hexahydrate) solution, add the powder obtained in (1), place it in a 3-liter 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 use.

[0071] (3) Prepare a solution of 8 g of ammonium molybdate (ammonium heptamolybdate tetrahydrate) and 1 g of ammonium metavanadate (NH4VO3), add a small amount of ammonia water to dissolve it, and impregnate the powder obtained in (2) in equal amounts, and dry at 120°C for later use.

[0072] (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% MoO 3 , 3.3% NiO and 0.75% V 2 O 5 active components, and 73% of the alkali metals remained unexchanged on the 3A molecular sieve).

[0073] Example 2:

[0074] (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.

[0075] (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, filter, wash, and dry at 120 ° C for use.

[0076] (3) Prepare a solution of 10 g of ammonium molybdate (tetrahydrated ammonium heptamolybdate) and 1.5 g of cerium nitrate (cerium nitrate hexahydrate), add a small amount of ammonia water to dissolve it, and impregnate the powder obtained in (2) in equal amounts, and dry at 120°C for later use.

[0077] (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% MoO 3 , 5.2% CoO and 0.54% CeO 2 active components, and 65% of the alkali metals remained unexchanged on the 4A molecular sieve).

[0078] Example 3:

[0079] (1) Take 100 g of 5A molecular sieve and pour it into 1 L of prepared 2 mol / L ammonium nitrate solution, place it in a 3 L container, stir and heat to increase the temperature, exchange at 90 ° C for 5 hours, filter, wash, and dry at 120 ° C. Repeat the exchange three times, filter, wash, dry, and roast at 400 ° C for 3 hours for use.

[0080] (2) Prepare 1 L of 0.4 mol / L nickel nitrate (nickel nitrate hexahydrate) solution, add the powder obtained in (1), place it in a 3-liter 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.

[0081] (3) Take 7.5g of ammonium metatungstate ((NH4)6W 12 O 39 ·2H2O) and 0.7 g of ammonium metavanadate (NH4VO3) were prepared into a solution, a small amount of ammonia was added to aid dissolution, and an equal amount was impregnated onto the powder obtained in (2), and dried at 120°C for later use.

[0082] (4) After adding a binder, the material was extruded into strips with a diameter of 4 mm and activated at 550° C. for 3 hours to obtain the finished product A3 (containing 6.9% WO 3 , 6.4% NiO and 0.5% V 2 O 5 active components, and 59% of the alkali metals and alkaline earth metals remaining on the 5A molecular sieve were not exchanged).

[0083] Example 4:

[0084] (1) Pour 100 g of 3A molecular sieve into 1 L of prepared 2 mol / L ammonium nitrate solution in a 3 L container, stir and heat to raise the temperature, 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.

[0085] (2) Prepare 1 L of 0.3 mol / L cobalt nitrate (cobalt nitrate hexahydrate) solution, add the powder obtained in (1), place it in a 3-liter 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.

[0086] (3) Take 5g of ammonium metatungstate ((NH4)6W 12 O 39 Prepare a solution with 3 g of cerium nitrate (cerium nitrate hexahydrate) in 2H2O), add a small amount of ammonia water to dissolve it, and impregnate an equal amount of it on the powder obtained in (2), dry it at 120℃ and set aside.

[0087] (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 (which contained 4.5% WO3, 5.1% CoO and 1.1% CeO2 active components, and 63% of the alkali metals remained unexchanged on the 3A molecular sieve).

[0088] The catalyst samples prepared in Examples 1-4 above were subjected to a sulfurization treatment. The sulfurization treatment may specifically adopt the following sulfurization gas source and sulfurization steps:

[0089] The sulfide gas (in terms of volume fraction) consists of hydrogen sulfide (1%), hydrogen (10%), and the remainder is nitrogen.

[0090] Nitrogen was introduced into the reactor loaded with the catalyst sample, and the temperature was increased to sulfidation according to the conditions in Table 1. When the reactor temperature reached 200°C, the sulfidation process was switched to sulfide gas. At 400°C, the H2S volume fraction at the reactor inlet and outlet was analyzed until equilibrium was reached between the inlet and outlet H2S, indicating the end of the sulfidation process.

[0091] Table 1 Temperature-elevated vulcanization conditions

[0092]

[0093]

[0094] The sulfided catalyst samples are used for the treatment of typical industrial waste gases such as blue coke gas and raw coal gas.

[0095] (1) Typical raw gas with a volume composition of 18.5% CO, 9.5% CO2, 19.8% H2, 6.5% CH4, 45% N2, 0.3% C2H6, 0.2% O2, 0.1% C2H4, 0.1% H2S, 150ppm HCN, 500ppm NH3, 250ppm RSH (including various types of mercaptans), 11ppm dimethyl disulfide, 10ppm RSR (including methyl sulfide and ethyl sulfide), 8ppm CS2, 11ppm thiophene, 120ppm monochloromethane, 200mg / Nm3 tar, 300mg / Nm3 benzene, 70mg / Nm3 naphthalene, 20mg / Nm3 dust 30000Nm 3 / h, firstly after decoking, water washing, TSA and other pre-treatment, the tar content is less than 1mg / Nm 3 Benzene content <10mg / Nm 3 , naphthalene content <1mg / Nm 3 , dust content <1mg / Nm 3 , pressurized to 3.2MPa, then heated to 350℃ by heater, and then entered the 3 The 1# reactor bed is equipped with industrial waste gas purification catalyst. During the reaction process, the temperature entering the reactor can be adjusted to 350℃ by adjusting the gas volume passing through the heat exchanger and / or heating with a heater. The gas at the outlet of the 1# reactor then enters the 15m 3 The HCl content at the outlet of the 2# reactor of the commercially available inorganic chlorine-hydrogen chloride dechlorination agent is less than 0.1ppm. The outlet gas of the 2# reactor is heat-exchanged with the cold gas at the inlet of the 1# reactor and then enters the next process section. Figure 1 shown.

[0096] The four samples prepared above have a volume composition of 18.5% CO, 9.5% CO2, 19.8% H2, 6.5% CH4,

[0097] 45% N2, 0.3% C2H6, 0.2% O2, 0.1% C2H4, 0.1% H2S, 150ppmHCN, 500ppmNH3,

[0098] 250ppmRSH (including various types of mercaptans), 11ppm dimethyl disulfide, 10ppmRSR (including methyl sulfide and ethyl sulfide),

[0099] The evaluation results of typical raw gas containing 8ppm CS2, 11ppm thiophene, 120ppm methyl chloride, 200mg / Nm3 tar, 300mg / Nm3 benzene, 70mg / Nm3 naphthalene, and 20mg / Nm3 dust are shown in Table 2:

[0100] Table 2

[0101]

[0102]

[0103] 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 no C3 and above hydrocarbon substances C m H n (m≥3) is generated, and the CH4 increase is <0.1%.

[0104] (2) The volume composition is 12.5% ​​CO, 9.5% CO2, 23% H2, 7.5% CH4, 46.7% N2, 0.2% C2H6, 0.3% O2, 0.2% C2H4, 0.1% H2S, 250ppm HCN, 400ppm NH3, 180ppm RSH (including various types of mercaptans), 8ppm dimethyl disulfide, 9ppm RSR (including methyl sulfide and ethyl sulfide), 11ppm CS2, 5ppm thiophene, 50ppm monochloromethane, 60ppm dichloromethane, 200mg / Nm3 tar, 300mg / Nm3 benzene, 70mg / Nm3 naphthalene, 20mg / Nm3 dust. Typical blue carbon gas 100000Nm 3 / h, firstly after decoking, water washing, TSA and other pre-treatment, the tar content is less than 1mg / Nm 3 Benzene content <10mg / Nm 3 , naphthalene content <1mg / Nm 3 , dust content <1mg / Nm 3 , pressurized to 2.5MPa, then heated to 320℃ by heater, and then entered the 3The 1# reactor bed is equipped with industrial waste gas purification catalyst. During the reaction process, the temperature entering the reactor can be adjusted to 320℃ by adjusting the gas volume passing through the heat exchanger and / or heating with a heater. The gas at the outlet of the 1# reactor then enters the 40m 3 The HCl content at the outlet of the 2# reactor of the commercially available inorganic chlorine-hydrogen chloride dechlorination agent is less than 0.1ppm. The outlet gas of the 2# reactor is heat-exchanged with the cold gas at the inlet of the 1# reactor and then enters the next process section. Figure 1 shown.

[0105] The four samples prepared above have a volume composition of 12.5% ​​CO, 9.5% CO2, 23% H2, 7.5% CH4,

[0106] 46.7%N2, 0.2%C2H6, 0.3%O2, 0.2%C2H4, 0.1%H2S, 250ppmHCN, 400ppmNH3,

[0107] 180ppmRSH (including various types of mercaptans), 8ppm dimethyl disulfide, 9ppmRSR (including methyl sulfide and ethyl sulfide),

[0108] The evaluation results of typical blue carbon gas including 11ppm CS2, 5ppm thiophene, 50ppm chloromethane, 60ppm dichloromethane, 200mg / Nm3 tar, 300mg / Nm3 benzene, 70mg / Nm3 naphthalene and 20mg / Nm3 dust are shown in Table 3:

[0109] Table 3

[0110]

[0111]

[0112] 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. A purification method for resource utilization of industrial waste gas, characterized by: The method comprises the following steps: (1) pre-processing the industrial waste gas containing NH3 and high CO+CO2 to remove dust and purify the industrial waste gas containing NH3 and high CO+CO2, wherein the CO+CO2 content in the industrial waste gas containing NH3 and high CO+CO2 is greater than 10%; (2) then entering the industrial waste gas purification catalyst bed for purification treatment at 230-400°C; (3) then entering the dechlorination agent bed for removing inorganic chlorine under the same temperature conditions for purification treatment, wherein the industrial waste gas purification catalyst comprises a type A molecular sieve and MoO3 / WO3, NiO / CoO and V2O5 / CeO2 loaded on the type A molecular sieve, wherein the content of molybdenum or tungsten is 3-12wt% in terms of MoO3 or WO3, the content of nickel or cobalt is 3-7wt% in terms of NiO or CoO, and the content of vanadium or cerium is 0.5-1.5wt% in terms of V2O5 or CeO2, and the molecular sieve also contains 55%-75% of alkali metal or alkaline earth metal that has not been ion-exchanged, wherein the alkali metal or alkaline earth metal is sodium, potassium and calcium.

2. The purification method according to claim 1, wherein: The NH3 content in the industrial waste gas containing NH3 and high CO+CO2 is 0.001%~0.5%.

3. The purification method according to claim 1 or 2, characterized in that: The industrial waste gas is one or more of blue charcoal gas and raw coal gas.

4. The purification method according to claim 1, wherein: After step (1) pretreatment, the tar content is less than 1 mg / Nm 3 Benzene content <10mg / Nm 3 , naphthalene content <1mg / Nm 3 of purified gas.

5. The purification method according to claim 1, wherein: The pretreatment includes decoking, water washing, temperature swing adsorption (TSA) treatment and pressurization treatment.

6. The purification method according to claim 1, wherein: After step (2), the removal rates of oxygen, olefins, mercaptans, sulfides, disulfides, carbon disulfide, and organic chlorine are greater than 95%, and the removal rates of HCN and thiophene are greater than 90%. After step (3), the hydrogen chloride content is less than 0.1 ppm.

7. The purification method according to claim 1, wherein: 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.

8. The purification method according to claim 1, wherein: The pore size of the A-type molecular sieve is 3-5Å.

9. The purification method according to claim 1, wherein: The type A molecular sieve is 3A, 4A or 5A molecular sieve.

10. The purification method according to claim 1, wherein: The industrial waste gas purification catalyst is firstly to pass 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, and calcium, and then loaded with Mo / W and V / Ce.

Images