Purification method for resource utilization of industrial waste gas

Abstract

The invention belongs to the field of industrial waste gas purification, and particularly relates to a purification method for resource utilization of industrial waste gas. Comprising the following steps: (1) carrying out dust removal and purification pretreatment on the industrial waste gas containing NH3 and high CO + CO2; (2) entering an industrial waste gas purification catalyst bed layer at 230-400 DEG C for purification treatment; and (3) the industrial waste gas enters a dechlorinating agent bed layer for removing inorganic chlorine under the same temperature condition for purification treatment, the industrial waste gas purification catalyst comprises an A-type molecular sieve and MoO3 / WO3, NiO / CoO and V2O5 / CeO2 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, the content of vanadium or cerium is 0.5-1.5 wt% in terms of V2O5 or CeO2, the content of vanadium or cerium is 0.5-1.5 wt% in terms of V2O5 or CeO2, and the content of vanadium or cerium is 0.5-1.5 wt% in terms of V2O5 or CeO2. And the molecular sieve also contains 55-75% of alkali metal or alkaline earth metal which is not subjected to ion exchange. The catalyst can be used for purifying oxygen, olefin, HCN, complex sulfides and organic chlorine in an 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 ranges 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] Due to different processes, industrial waste gases such as blast furnace gas, converter gas, coke oven gas, yellow phosphorus tail gas, calcium carbide tail gas, blue coke gas, and raw coal gas are produced. These industrial waste gases contain useful components such as CH4, CO, and H2, which can be purified and recycled. Among them, the purification of coke oven gas, yellow phosphorus tail gas, and calcium carbide tail gas has been studied more, and the industrial application is also the most mature. Blast furnace gas and converter gas have also begun to have large-scale industrial devices for resource utilization. In comparison, the purification of blue coke gas and raw coal gas is more difficult.

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

[0005]

[0006] Both lignite gas and raw coal gas are tail gases from low-temperature carbonization of coal. Due to the low carbonization 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 methyl chloride and dichloromethane, and complex sulfides are mainly thiophene, disulfide, mercaptan, sulfide and carbon disulfide.

[0007] Semi-coke gas and crude coal gas are mainly burned as fuel gas in the past because of their high nitrogen content, low content of useful components such as CH4, CO and H2, complex impurities, high purification difficulty and low calorific value. Resource utilization is relatively late. At present, some resource utilization has begun. Some adopt non-catalytic partial oxidation process 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 composition and is not economical. Some use semi-coke gas and crude coal gas to separate methane and produce LNG (liquefied natural gas), and use the purified CO and H2 to produce chemical products such as methanol and ethylene glycol. The traditional purification process is used, which makes it impossible to remove impurities such as organic chlorine, which affects the short-term poisoning and deactivation of subsequent conversion catalysts, and the device is shut down, and the process cannot be opened.

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

[0009] Traditionally, the purification of organic chlorine is only involved in the purification of oil products, and it is mainly removed by hydrogenation with a sulfide catalyst. In the traditional sense, 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, i.e., 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, due to the resource utilization of chlorine-containing plastics, the purification of organic chlorine has become a new hot spot and has been widely studied. 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 levels 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. At the same time, hydrodesulfurization, denitrification, and dechlorination catalysts have also been widely and successfully used in the petrochemical industry. However, industrial waste gases such as semi-coke gas and waste gas are different from oil products. They contain high levels of CO and CO2. High levels of CO and CO2 react with H2 in the gas source under the condition that the hydrogenation catalyst is used at a temperature greater than 230°C, resulting in 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 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 hydrogenation catalysts traditionally widely used in oil purification cannot be used for hydrogenation purification of industrial gases such as lignite gas and waste gas. Currently, the hydrodesulfurization catalysts sold on the market both at home and abroad 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 gas and waste gas contain tens to thousands of ppm of NH3. The existing catalysts for hydrogenation of impurities such as oxygen, olefins, HCN, thiophene, disulfide, mercaptan, sulfide and carbon disulfide require inlet ammonia <0.1ppm. They are quickly deactivated when used under conditions of excessive ammonia. The market is in urgent need of hydrogenation catalysts that can be used in ammonia-containing conditions. In addition, catalysts containing transition metals 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 boxes, but also easily clogs the catalyst pores and causes carbon deposition, which should also be avoided as much as possible. Summary of the invention:

[0018] The technical problem to be solved by the present invention is to provide a purification method for resource utilization of industrial waste gas 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 organic chlorine in industrial waste gas containing ammonia and high CO+CO2 such as blue coke gas and raw coal gas, and achieve the target 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-treatment of industrial waste gas containing NH3 and high CO+CO2 with dust removal and purification; (2) then entering an industrial waste gas purification catalyst bed for purification at 230-400°C; (3) then entering a dechlorinating 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 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 or calcium.

[0021] According to the above scheme, the dechlorinating agent used for removing inorganic chlorine is preferably a dechlorinating agent capable of removing hydrogen chloride to less than 0.1 ppm.

[0022] According to the above method, in the above purification method, after pretreatment to meet the 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 and thiophene, disulfide, mercaptan, sulfide, CS2, organic chlorine, etc. into ammonia, H2S and hydrogen chloride, and then hydrogen chloride is 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 gas source has an NH3 content of 0.001% to 0.5% and a CO+CO2 content of >10%, and can specifically be industrial waste gas such as blue charcoal gas and waste gas. The ammonia-containing and high CO+CO2 gas source generally also contains H2, and if necessary, hydrogen can be added to the gas source.

[0036] According to the above scheme, 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.

[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 be 0.01MPa~5MPa.

[0040] According to the above scheme, the mesh 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, 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 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 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) 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;

[0048] (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;

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

[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 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 required, ammonia water can be used as a co-solvent in the solution preparation of the active components Mo / W and V / Ce to prepare the solution 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, denitrogenation 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, 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.

[0057] The purification catalyst of the present invention can be applied to industrial waste gas containing NH3 and high CO+CO2, such as blue carbon gas and crude gas, to 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, 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.

[0058] The purification catalyst of the present invention is used after sulfurization. The purification catalyst 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%.

[0059] Hydrodesulfurization, denitrification, and dechlorination catalysts used in the petrochemical industry, such as those used in industrial waste gas with high CO+CO2 content, will produce a large number of multi-carbon chain macromolecules during the high-temperature hydrogenation process, affecting the safe operation of the subsequent stage. In addition, acidic additives such as phosphorus or fluorine are usually added to traditional catalysts 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 reactions or their reverse reactions, resulting in changes in the effective composition of CO, H2, etc. 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 CO disproportionation, methanation and other side reactions makes the reaction more difficult to control and prone to safety accidents.

[0060] The 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.

[0061] The 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. At the same time, it has the function of purifying oxygen, olefins, HCN and thiophene, disulfide, mercaptan, sulfide, CS2 and other complex sulfides 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 pre-treatment to meet the standards to remove impurities such as tar, dust, benzene, naphthalene, etc., 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 and thiophene, disulfide, mercaptan, sulfide, CS2, organic chlorine, etc. into ammonia, H2S and hydrogen chloride, and then the hydrogen chloride is purified and removed at the same temperature using a dechlorinating agent for removing 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 CO or hydrogen extraction can be performed according to the overall process requirements. The process of the present invention is designed in segments, fully considering the characteristics of the object 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, causing 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. This patent is based on a newly developed industrial waste gas purification catalyst. It 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, it cooperates with the remaining sodium, potassium, calcium and other alkali metals or alkaline earth metals on the molecular sieve to selectively purify and treat impurities, 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 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 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.

[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. The removal rates of oxygen, olefins, mercaptan, sulfide, disulfide, CS2 and organic chlorine are greater than 95%, and the removal rates of HCN and thiophene are greater than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic diagram of the reaction process of the present invention. DETAILED DESCRIPTION

[0067] The content of the invention is further illustrated by examples below.

[0068] Embodiment 1:

[0069] (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.

[0070] (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.

[0071] (3) Take 8 g of ammonium molybdate (ammonium heptamolybdate tetrahydrate) and 1 g of ammonium metavanadate (NH4VO3) to prepare a solution, add a small amount of ammonia water to help 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.

[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% MoO3, 3.3% NiO and 0.75% V2O5 active components, and 73% alkali metals remained on the 3A molecular sieve without exchange).

[0073] Embodiment 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, then filter, wash, and dry at 120°C for later use.

[0076] (3) Prepare a solution by taking 10 g of ammonium molybdate (ammonium heptamolybdate tetrahydrate) and 1.5 g of cerium nitrate (cerium nitrate hexahydrate), add a small amount of ammonia water to assist dissolution, and impregnate an equal amount of the solution onto the powder obtained in (2), 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% MoO3, 5.2% CoO and 0.54% CeO2 active components, and 65% of the alkali metals remaining on the 4A molecular sieve were not exchanged).

[0078] Embodiment 3:

[0079] (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.

[0080] (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.

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

[0082] (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, 6.4% NiO and 0.5% V2O5 active components, and 59% alkali metals and alkaline earth metals remained on the 5A molecular sieve without exchange).

[0083] Embodiment 4:

[0084] (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.

[0085] (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.

[0086] (3) Take 5 g of ammonium metatungstate ((NH4)6W 12 O 39 ·2H2O) 3 g cerium nitrate (cerium nitrate hexahydrate) is prepared into a solution, a small amount of ammonia water is added to aid dissolution, an equal amount is impregnated onto the powder obtained in (2), and dried at 120°C for later use.

[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 (containing 4.5% WO3, 5.1% CoO and 1.1% CeO2 active components, and 63% alkali metals remaining on the 3A molecular sieve were not exchanged).

[0088] 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:

[0089] The sulfide gas (by volume fraction) is composed of hydrogen sulfide (1%), hydrogen (10%), and the rest is nitrogen.

[0090] 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.

[0091] Table 1 Temperature rise vulcanization conditions

[0092]

[0093]

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

[0095] (1) Typical waste 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 pretreatment, the tar content is less than 1mg / Nm 3 , benzene content <10mg / Nm 3 , naphthalene content <1mg / Nm 3 , Dust content <1mg / Nm 3 , the pressure is raised to 3.2MPa, and then the temperature is raised to 350℃ by a heater, and then the 10m 3 The 1# reactor bed layer is equipped with industrial waste gas purification catalyst. During the reaction operation, the temperature entering the reactor can be adjusted to 350°C by adjusting the gas volume passing through the heat exchanger and / or heating with a heater. The outlet gas of the 1# reactor then enters the 15m 3 The 2# reactor bed layer of the commercially available inorganic chlorine-hydrochlorine dechlorination agent has a HCl content of less than 0.1ppm at the outlet of the 2# reactor bed layer. 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 stage. 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 waste gas with 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 there was no C3 or higher hydrocarbon substance 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 pretreatment, 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 a heater, and then entered a 40m 3The 1# reactor bed layer is equipped with industrial waste gas purification catalyst. During the reaction operation, the temperature entering the reactor can be adjusted to 320°C by adjusting the gas volume passing through the heat exchanger and / or heating with a heater. The outlet gas of the 1# reactor then enters the 40m 3 The 2# reactor bed layer of the commercially available inorganic chlorine-hydrochlorine dechlorination agent has a HCl content of less than 0.1ppm at the outlet of the 2# reactor bed layer. 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 stage. 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 11ppm CS2, 5ppm thiophene, 50ppm methyl chloride, 60ppm dichloromethane, 200mg / Nm3 tar, 300mg / Nm3 benzene, 70mg / Nm3 naphthalene, and 20mg / Nm3 dust in typical blue carbon gas 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 in that: The invention comprises the following steps: (1) pre-treating industrial waste gas containing NH3 and high CO+CO2 to remove dust; (2) then entering an industrial waste gas purification catalyst bed for purification at 230-400°C; (3) then entering a dechlorinating 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 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 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 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, characterized in that: Step (1) After 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, characterized in that: The pretreatment includes decoking, water washing, temperature swing adsorption (TSA) treatment and pressurization treatment.

6. The purification method according to claim 1, characterized in that: 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, 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.

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

10. The purification method according to claim 1, characterized in that: The industrial waste 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 and V / Ce.

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