Calcium carbide method acetylene purification post-treatment method

Abstract

The invention provides a calcium carbide process acetylene purification post-treatment method, H2S and PH3 in acetylene gas are treated by sequentially adopting wet catalytic oxidation and an adsorbent adsorption method, an oxidizing agent for wet catalytic oxidation is a mixed solution of ferric sulfate and sulfuric acid, a water-soluble manganese salt and a water-soluble tungstate are also added into the mixed solution, and the water-soluble manganese salt and the water-soluble tungstate are added into the mixed solution. The adsorbent is a cerium-zirconium solid solution loaded with copper oxide. Mn < 2 + > dissociated from manganese salt is introduced into a catalytic oxidation system and forms a bi-component catalytic center with original Fe < 3 + > / Fe < 2 + >, so that the regeneration rate of Fe < 2 + > to Fe < 3 + > can be remarkably accelerated, and the oxidation of the catalyst on hydrogen sulfide and hydrogen phosphide is greatly improved; tungstate is introduced to effectively prevent elemental sulfur from depositing and blocking on the filler and equipment by changing the crystal form of the elemental sulfur, so that the system is guaranteed, PH3 molecules are catalyzed to generate hydrolysis reaction, and phosphorous acid which is easier to oxidize is generated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of purification methods, more particularly to a method for post-treatment of calcium carbide method acetylene purification. BACKGROUND

[0002] Acetylene gas, especially crude acetylene gas prepared by calcium carbide method, is an important raw material for chemical products such as polyvinyl chloride (PVC). However, crude acetylene gas prepared by calcium carbide method usually contains harmful impurities such as phosphine (PH3) and hydrogen sulfide (H2S). The presence of these impurities not only reduces the purity of acetylene products, but more seriously, causes irreversible poisoning of the catalyst in the subsequent polymerization process, resulting in catalyst deactivation and affecting the stability and economy of the entire production line. In addition, PH3 and H2S themselves are highly toxic and corrosive, and their direct discharge can cause serious harm to the environment and human health.

[0003] Currently, the main purification methods for acetylene gas in industry include sodium hypochlorite oxidation method and concentrated sulfuric acid method. Although the sodium hypochlorite method has a certain purification effect, it has a major safety hazard of producing explosive chloroacetylene, and a large amount of chlorinated wastewater generated during operation can easily cause secondary environmental pollution. The concentrated sulfuric acid method requires extremely harsh concentration of sulfuric acid (usually higher than 98%), and is prone to carbonization of sulfuric acid due to the presence of impurities such as olefins during operation, resulting in a large amount of waste acid that is difficult to handle, and serious corrosion of equipment, with high maintenance costs.

[0004] Therefore, further improvement and development are needed. SUMMARY

[0005] In view of the various deficiencies of the prior art, in order to solve the above problems, a method for post-treatment of calcium carbide method acetylene purification is proposed, and the following technical solutions are provided. A method for post-treatment of calcium carbide method acetylene purification, comprising treating H2S and PH3 in acetylene gas by wet catalytic oxidation and adsorbent adsorption method in sequence, the oxidizing agent of the wet catalytic oxidation is a mixed solution of iron sulfate and sulfuric acid, water-soluble manganese salt and water-soluble tungstate are also added in the mixed solution, and the adsorbent is cerium-zirconium solid solution loaded with copper oxide.

[0006] Further, the molar ratio of Fe 3+ in the iron sulfate to Mn 2+ in the manganese salt is (5-10):1.

[0007] Further, the concentration of iron ions in the mixed solution is 0.5-0.7 mol / L, and the pH of the mixed solution is 2.5-4.

[0008] Further, the molar ratio of Fe 3+ in the iron sulfate to WO4 2-The molar ratio is (40-60): 1.

[0009] Further, the mixed solution further comprises a complexing agent EDTA, and the mass ratio of the complexing agent to the ferric sulfate is (3-4): 1.

[0010] Further, the water-soluble manganese salt is manganese sulfate, and the water-soluble tungstate is sodium tungstate.

[0011] Further, the reaction temperature of the wet wet oxidation is 35-40 DEG C.

[0012] Further, in the wet wet oxidation, a spraying method is used to spray the mixed solution to contact with acetylene gas.

[0013] Further, the loading amount of copper oxide in the cerium-zirconium solid solution loaded with copper oxide is 3wt%-8wt%.

[0014] Further, the cerium-zirconium solid solution loaded with copper oxide is prepared from cerium nitrate, zirconyl nitrate and copper nitrate and ammonia water, and the preparation process is as follows: The mixed aqueous solution of cerium nitrate, zirconyl nitrate and copper nitrate and ammonia water are respectively and simultaneously dropped into the reactor, the end point pH value of the precipitation process is controlled to be stable at 9-10, after the precipitation is completed, the filter cake is washed by suction filtration until the filtrate is neutral, and the washed filter cake is dried and calcined, so that the cerium-zirconium solid solution loaded with copper oxide is finally obtained.

[0015] Due to the above technical solutions, the application has the following beneficial technical effects: 1. The Mn 2+ dissociated from the manganese salt in the catalytic oxidation system of the application 3+ / Fe 2+ constitutes a two-component catalytic center, which can significantly accelerate the regeneration rate of Fe 2+ to Fe 3+ , greatly improves the oxidation of hydrogen sulfide and phosphine, and introduces tungstate to effectively prevent the deposition and blockage of elemental sulfur on the filler and equipment by changing the crystal form of elemental sulfur, thereby ensuring the system and catalyzing the hydrolysis reaction of PH3 molecules to generate phosphorous acid which is more easily oxidized. 2. This invention first uses wet catalytic oxidation to efficiently treat H2S and PH3 in acetylene gas, oxidizing most of them into elemental sulfur and phosphoric acid. This stage has low processing cost and large processing capacity. Then, an adsorbent adsorption method is used to remove trace amounts of H2S and PH3 remaining after wet treatment, as well as acid mist that may be carried or generated by the wet system. The surface of the cerium-zirconium solid solution is rich in Lewis acid sites, which can absorb acidic molecules such as sulfuric acid through strong coordination. At the same time, the excellent oxygen storage and redox capabilities of the cerium-zirconium solid solution can continuously provide active oxygen, deeply oxidizing hydrogen sulfide and phosphine into elemental sulfur and phosphoric acid. Copper oxide provides chemical adsorption and oxidation sites with high activity for hydrogen sulfide and phosphine, which can deeply clean acetylene gas. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application.

[0017] A method for post-treatment of acetylene purified by the calcium carbide method, wherein crude acetylene gas prepared by the calcium carbide method is treated sequentially by wet catalytic oxidation and adsorption to remove H2S and PH3 from the acetylene gas. The oxidant in the wet catalytic oxidation is a mixed solution of ferric sulfate and sulfuric acid, and manganese sulfate and sodium tungstate are also added to the mixed solution. In the wet catalytic oxidation, the mixed solution is sprayed to contact the acetylene gas. The adsorbent is a cerium-zirconium solid solution loaded with copper oxide.

[0018] In this invention, manganese salt is introduced into the catalytic oxidation system, and the Mn released from the manganese salt... 2+ With the original Fe 3+ / Fe 2+ Constitutes a two-component catalytic center, Mn 2+ Not only can it promote the generation of hydroxyl radicals through a Fenton-like reaction, but more importantly, it reacts with Fe... 3 + / Fe 2+ There is an electronic cooperative effect between the cycles, which can significantly accelerate Fe 2+ To Fe 3+ The regeneration rate ensures the main catalyst Fe 3+ The high concentration of sulfur supplied significantly enhances its oxidation of hydrogen sulfide and phosphine. The introduction of tungstate not only effectively prevents the deposition and blockage of elemental sulfur in packings and equipment by altering the crystal form of elemental sulfur, ensuring long-term stable system operation, but also releases WO4 from the tungstate. 2-The ions can act as a surface catalytic site, preferentially adsorb and catalyze the hydrolysis reaction of PH3 molecules to generate phosphorous acid which is more easily oxidized. This process effectively reduces the reaction energy barrier of direct oxidation of PH3, and in combination with the aforementioned "double catalytic oxidation cycle", a double guarantee of "hydrolysis pretreatment and deep oxidation" is formed, thereby realizing the deep and efficient removal of the stubborn pollutant PH3. In summary, through the ingenious compounding of manganese salt, tungstate and ferric sulfate-sulfuric acid system, the present application realizes the perfect synergy of catalytic oxidation, product form regulation and system anti-clogging ability, and finally achieves the high-efficiency and economical deep purification effect of H2S and PH3, and the comprehensive performance is significantly better than any single component or traditional binary system.

[0019] The adsorbent used in the adsorbent adsorption method in the present application is a cerium-zirconium solid solution loaded with copper oxide, and the loading amount of copper oxide in the cerium-zirconium solid solution loaded with copper oxide is 3wt%-8wt%; the cerium-zirconium solid solution loaded with copper oxide is prepared from cerium nitrate, zirconyl nitrate and copper nitrate and ammonia water as raw materials, and the preparation process is as follows: The mixed aqueous solution of cerium nitrate, zirconyl nitrate and copper nitrate and ammonia water are respectively loaded into two constant-pressure dropping funnels, and under the stirring of 400-600 rpm, the two solutions are simultaneously and slowly dropped into a beaker containing deionized water as a bottom liquid; the end point pH value of the precipitation process is controlled to be stable at 9-10, the beaker is maintained at 60-70 DEG C in a water bath, and the whole process lasts for 1-2 hours; After the precipitation is completed, the obtained suspension is aged for 2-4 hours under the same temperature and stirring, and then the suspension is subjected to suction filtration and washed with ethanol for 4-6 times until the filtrate is neutral; The washed filter cake is dried in an oven at 100-120 DEG C for 12 hours, and the dried powder is calcined in a muffle furnace, the muffle furnace is raised to 400-500 DEG C at a temperature rising rate of 2-5 DEG C / min, and is kept at this temperature for 3-5 hours, and finally the cerium-zirconium solid solution loaded with copper oxide is obtained.

[0020] The present application efficiently treats H2S and PH3 in acetylene gas by wet catalytic oxidation, and most of them are oxidized into elemental sulfur and phosphoric acid. This stage has low treatment cost and large treatment capacity. Then, an adsorbent adsorption method is used to remove trace amounts of H2S, PH3 and acid mist that may be entrained or generated in the wet treatment system. The cerium-zirconium solid solution surface is rich in Lewis acid sites, which can absorb acidic molecules such as sulfuric acid through strong coordination. At the same time, the cerium-zirconium solid solution has excellent oxygen storage and redox capacity, which can continuously provide active oxygen to deeply oxidize hydrogen sulfide and phosphine into elemental sulfur and phosphoric acid. The oxidation of copper provides chemical adsorption and oxidation sites, which has high activity for hydrogen sulfide and phosphine, and can deeply clean acetylene gas.

[0021] Example 1 Wet catalytic oxidation step mixed solution preparation: deionized water was taken as the solvent, iron sulfate (Fe2(SO4)3) and concentrated sulfuric acid were added, and the solution was adjusted to make the iron ion (Fe 3+ ) concentration 0.6 mol / L and the pH value 3.0. Manganese sulfate (MnSO4·H2O) was added to control the molar ratio of Fe 3+ to Mn 2+ 8:1. Sodium tungstate (Na2WO4·2H2O) was added to control the molar ratio of Fe 3+ to WO4 2- 50:1. The complexing agent EDTA (ethylenediaminetetraacetic acid) was added with a mass ratio of 3.5:1 to iron sulfate. The solution was stirred until completely dissolved to obtain an oxidant mixed solution.

[0022] Adsorbent preparation: cerium nitrate (Ce(NO3)3·6H2O), zirconyl nitrate (ZrO(NO3)2·6H2O), and copper nitrate (Cu(NO3)2·3H2O) were dissolved in 1.8 L deionized water to obtain a mixed aqueous solution with a mass ratio of 9.19:7.18:1, and the copper oxide loading was controlled at 5 wt%. The mixed aqueous solution and ammonia water (concentration 10%) were simultaneously added to the reactor (containing deionized water bottom liquid) through constant pressure dropping funnels, and the end point pH value was controlled to be stable at 9.5 under 500 rpm stirring. The reaction temperature was maintained at 65°C, and the dropping time was 1.5 hours. After the precipitation was completed, it was aged at 65°C for 3 hours, then filtered and washed with ethanol for 5 times until the filtrate was neutral. The filter cake was dried in an oven at 110°C for 12 hours, and then calcined in a muffle furnace at a temperature rising rate of 3°C / min to 450°C for 4 hours to obtain a cerium-zirconium solid solution adsorbent loaded with copper oxide.

[0023] The above prepared mixed solution was placed in a spray tower, and crude acetylene gas (from calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner through a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0024] 100 g of the above prepared adsorbent was filled into an adsorption tower, and the above wet treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas detection tube was used to analyze the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet of the adsorption tower at regular intervals, and the results were recorded.

[0025] Example 2 Preparation of mixed solution for wet catalytic oxidation step: Use deionized water as solvent, add ferric sulfate (Fe2(SO4)3) and concentrated sulfuric acid, and adjust the solution to make the iron ion concentration (Fe2(SO4)3) equal to that of Fe2(SO4)3. 3+ The concentration was 0.5 mol / L, and the pH was 3.0. Manganese sulfate (MnSO4·H2O) was added to control the Fe content. 3+ With Mn 2+ The molar ratio is 10:1. Sodium tungstate (Na₂WO₄·2H₂O) is added to control the Fe content. 3+ With WO4 2- The molar ratio of the components is 60:1. Add the complexing agent EDTA (ethylenediaminetetraacetic acid), with a mass ratio of 4:1 to ferric sulfate. Stir the solution until completely dissolved to obtain a mixed solution of oxidizing agents.

[0026] Adsorbent Preparation: Cerium nitrate (Ce(NO3)3·6H2O), zirconium oxynitrate (ZrO(NO3)2·6H2O), and copper nitrate (Cu(NO3)2·3H2O) were dissolved in 1.8 L of deionized water at a mass ratio of 9.19:7.18:1 to obtain a mixed aqueous solution, with the copper oxide loading controlled at 5 wt%. The mixed aqueous solution and ammonia water (10% concentration) were simultaneously added dropwise to the reactor (containing the deionized water bottom solution) through a constant pressure dropping funnel. The pH value was stabilized at 9.5 at the endpoint under stirring at 500 rpm. The reaction temperature was maintained at 65℃, and the dropping time was 1.5 hours. After precipitation, the mixture was aged at 65℃ for 3 hours, then filtered and washed 5 times with ethanol until the filtrate was neutral. The filter cake was dried in an oven at 110℃ for 12 hours, and then calcined in a muffle furnace at a temperature increased to 450℃ at 3℃ / min for 4 hours to obtain the cerium-zirconium solid solution adsorbent loaded with copper oxide.

[0027] The prepared mixed solution was placed in a spray tower, and crude acetylene gas (from the calcium carbide process, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was sprayed counter-currently with the acetylene gas through the spray system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m / s. 3 The liquid circulation flow rate is 50 L / min, and the contact time is 10 seconds.

[0028] 100g of the adsorbent prepared above was packed into an adsorption tower, and the acetylene gas after the above wet treatment was passed into the adsorption tower. The adsorption temperature was controlled at room temperature (25℃), and the gas space velocity was 1000 h⁻¹. -1 At the outlet of the adsorption tower, use a gas detection tube to periodically analyze the gas concentrations of hydrogen sulfide, phosphine, and acid mist, and record the results.

[0029] Example 3 Wet catalytic oxidation step mixed solution preparation: deionized water was taken as the solvent, iron sulfate (Fe2(SO4)3) and concentrated sulfuric acid were added, and the solution was adjusted to make the iron ion (Fe 3+ ) concentration 0.6 mol / L and the pH value 3.0. Manganese sulfate (MnSO4·H2O) was added to control the molar ratio of Fe 3+ to Mn 2+ 5:1. Sodium tungstate (Na2WO4·2H2O) was added to control the molar ratio of Fe 3+ to WO4 2- 40:1. The complexing agent EDTA (ethylenediaminetetraacetic acid) was added with a mass ratio of 3:1 to iron sulfate. The solution was stirred until completely dissolved to obtain an oxidant mixed solution.

[0030] Adsorbent preparation: cerium nitrate (Ce(NO3)3·6H2O), zirconyl nitrate (ZrO(NO3)2·6H2O), and copper nitrate (Cu(NO3)2·3H2O) were dissolved in 1.8 L deionized water to obtain a mixed aqueous solution with a mass ratio of 9.19:7.18:1, and the copper oxide loading was controlled at 5 wt%. The mixed aqueous solution and ammonia water (concentration 10%) were simultaneously added to the reactor (containing deionized water bottom liquid) through constant pressure dropping funnels, and the end point pH value was controlled to be stable at 9.5 under 500 rpm stirring. The reaction temperature was maintained at 65°C, and the dropping time was 1.5 hours. After the precipitation was completed, it was aged at 65°C for 3 hours, then filtered and washed with ethanol for 5 times until the filtrate was neutral. The filter cake was dried in an oven at 110°C for 12 hours, and then calcined in a muffle furnace at a temperature rising rate of 3°C / min to 450°C for 4 hours to obtain a cerium-zirconium solid solution adsorbent loaded with copper oxide.

[0031] The above prepared mixed solution was placed in a spray tower, and crude acetylene gas (from calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner through a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0032] 100 g of the above prepared adsorbent was filled into an adsorption tower, and the above wet treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas detection tube was used at the outlet of the adsorption tower to analyze the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet at regular intervals, and the results were recorded.

[0033] Example 4 Wet catalytic oxidation step mixed solution preparation: deionized water was taken as the solvent, iron sulfate (Fe2(SO4)3) and concentrated sulfuric acid were added, and the solution was adjusted to make the iron ion (Fe 3+ ) concentration 0.6 mol / L and the pH value 3.0. Manganese sulfate (MnSO4·H2O) was added to control the molar ratio of Fe 3+ to Mn 2+ 8:1. Sodium tungstate (Na2WO4·2H2O) was added to control the molar ratio of Fe 3+ to WO4 2- 50:1. The complexing agent EDTA (ethylenediaminetetraacetic acid) was added with a mass ratio of 3.5:1 to iron sulfate. The solution was stirred until completely dissolved to obtain an oxidant mixed solution.

[0034] Adsorbent preparation: cerium nitrate (Ce(NO3)3·6H2O), zirconyl nitrate (ZrO(NO3)2·6H2O), and copper nitrate (Cu(NO3)2·3H2O) were dissolved in 1.8 L deionized water to obtain a mixed aqueous solution with a mass ratio of 15.7:12.2:1, and the copper oxide loading was controlled at 5 wt%. The mixed aqueous solution and ammonia water (concentration 10%) were simultaneously added to the reactor (containing deionized water bottom liquid) through constant pressure dropping funnels, and the end point pH value was controlled to be stable at 9.5 under 500 rpm stirring. The reaction temperature was maintained at 65°C, and the dropping time was 1.5 hours. After the precipitation was completed, it was aged at 65°C for 3 hours, then filtered and washed with ethanol for 5 times until the filtrate was neutral. The filter cake was dried in an oven at 110°C for 12 hours, and then calcined in a muffle furnace at a temperature rising rate of 3°C / min to 450°C for 4 hours to obtain a cerium-zirconium solid solution adsorbent loaded with copper oxide.

[0035] The above prepared mixed solution was placed in a spray tower, and crude acetylene gas (from calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner through a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0036] 100 g of the above prepared adsorbent was filled into an adsorption tower, and the above wet treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas detection tube was used at the outlet of the adsorption tower to analyze the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet at regular intervals, and the results were recorded.

[0037] Example 5 Wet catalytic oxidation step mixed solution preparation: Deionized water was taken as the solvent, and iron sulfate (Fe2(S04)3) and concentrated sulfuric acid were added. The solution was adjusted to make the iron ion (Fe 3+ ) concentration 0.6 mol / L and the pH value 3.0. Manganese sulfate (MnS04-H20) was added to control the molar ratio of Fe 3+ to Mn 2+ 8:1. Sodium tungstate (Na2WO4-2H2O) was added to control the molar ratio of Fe 3+ to WO4 2- 50:1. The complexing agent EDTA (ethylenediaminetetraacetic acid) was added with a mass ratio of 3.5:1 to iron sulfate. The solution was stirred until completely dissolved to obtain an oxidant mixed solution.

[0038] Adsorbent preparation: Cerium nitrate (Ce(N03)3-6H2O), zirconyl nitrate (ZrO(N03)2-6H2O), and copper nitrate (Cu(N03)2-3H2O) were dissolved in 1.8 L of deionized water to obtain a mixed aqueous solution with a mass ratio of 5.56:4.35:1, and the copper oxide loading was controlled at 5 wt%. The mixed aqueous solution and ammonia water (concentration 10%) were simultaneously added to the reactor (containing deionized water bottom liquid) through constant pressure dropping funnels, and the end point pH value was controlled to be stable at 9.5 under 500 rpm stirring. The reaction temperature was maintained at 65°C, and the dropping time was 1.5 hours. After the precipitation was completed, aging was carried out at 65°C for 3 hours, then suction filtration was performed and ethanol washing was carried out 5 times until the filtrate was neutral. The filter cake was dried in an oven at 110°C for 12 hours, and then calcined in a muffle furnace at a temperature rising rate of 3°C / min to 450°C for 4 hours to obtain a cerium-zirconium solid solution adsorbent loaded with copper oxide.

[0039] The above prepared mixed solution was placed in a spray tower, and crude acetylene gas (from calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner through a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0040] 100 g of the above prepared adsorbent was filled into an adsorption tower, and the above wet treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas detection tube was used to analyze the gas concentrations of outlet hydrogen sulfide, phosphine, and acid mist at the outlet of the adsorption tower at regular intervals, and the results were recorded.

[0041] Comparative Example 1 This comparative example used 98% concentrated sulfuric acid as the oxidant in the wet catalytic oxidation step in the prior art.

[0042] The prepared mixed solution was introduced into a spray tower, and crude acetylene gas (from the calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner by a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, the contact time was 10 seconds, and the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet were analyzed in real time using a gas detection tube at the outlet of the spray tower, and the results were recorded.

[0043] Comparative Example 2 The only difference between this comparative example and Example 1 is that the mixed solution in the wet wet oxidation step does not contain a water-soluble manganese salt.

[0044] The prepared mixed solution was introduced into a spray tower, and crude acetylene gas (from the calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner by a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, the contact time was 10 seconds, and the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet were analyzed in real time using a gas detection tube at the outlet of the spray tower, and the results were recorded.

[0045] The prepared adsorbent 100 g was filled into an adsorption tower, and the above wet-treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet were analyzed in real time using a gas detection tube at the outlet of the adsorption tower, and the results were recorded.

[0046] Comparative Example 3 The only difference between this comparative example and Example 1 is that the mixed solution in the wet wet oxidation step does not contain a water-soluble tungstate salt.

[0047] The prepared mixed solution was introduced into a spray tower, and crude acetylene gas (from the calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was contacted with the acetylene gas in a countercurrent manner by a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, the contact time was 10 seconds, and the gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet were analyzed in real time using a gas detection tube at the outlet of the spray tower, and the results were recorded.

[0048] The prepared adsorbent 100 g was filled into an adsorption tower, and the above wet-treated acetylene gas was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 . The gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet were analyzed in real time using a gas detection tube at the outlet of the adsorption tower, and the results were recorded.

[0049] Comparative Example 4 The only difference between this comparative example and Example 1 is that the mixed solution in the wet wet oxidation step does not contain EDTA.

[0050] The mixed solution prepared above was placed in a spray tower, and crude acetylene gas (from the calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was brought into countercurrent contact with the acetylene gas in a spray manner by a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0051] The adsorbent prepared above was filled into an adsorption tower, and the acetylene gas treated by the wet method above was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 The gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet of the adsorption tower were analyzed in real time using a gas detection tube, and the results were recorded.

[0052] Comparative Example 5 The only difference between this comparative example and Example 1 is that the adsorbent in the adsorption step is activated carbon loaded with copper oxide.

[0053] The mixed solution prepared above was placed in a spray tower, and crude acetylene gas (from the calcium carbide method, containing H2S and PH3 impurities) was introduced into the spray tower. The mixed solution was brought into countercurrent contact with the acetylene gas in a spray manner by a spraying system, and the reaction temperature was maintained at 37°C. The gas flow rate was controlled at 100 m 3 / h, the liquid circulation flow rate was 50 L / min, and the contact time was 10 seconds.

[0054] The adsorbent prepared above was filled into an adsorption tower, and the acetylene gas treated by the wet method above was introduced into the adsorption tower. The adsorption temperature was controlled at room temperature (25°C), and the gas space velocity was 1000 h -1 The gas concentrations of hydrogen sulfide, phosphine, and acid mist at the outlet of the adsorption tower were analyzed in real time using a gas detection tube, and the results were recorded.

[0055] Table 1 Gas detection results at the outlet of the adsorption tower in Examples 1-5 and Comparative Examples 1-5 Example 1 exhibits the best overall performance: the highest removal rate (>99.9% H2S, >99.9% PH3), and the system is stable and free of plugging. Examples 2-3 are slightly less effective in removing H2S and PH3 than Example 1 but are still better than each of the comparative examples. Examples 4-5 are slightly less effective in absorbing acid mist than Example 1 but are still better than the comparative examples, and are slightly less effective in removing H2S and PH3 than Example 1, but are better than Examples 2-3 and Comparative Examples 1-5. Comparative Example 1 uses conventional means to clean acetylene gas, which will have obvious elemental sulfur deposition, with the risk of plugging the walls of the container; using concentrated sulfuric acid to absorb H2S and PH3 requires high corrosion resistance of the reactor, and after long-term use, the sulfuric acid concentration will decrease, resulting in poor cleaning effect. Comparative Example 2 (without manganese salt): the removal rate of H2S and PH3 is significantly reduced, and the time to reach 90% removal rate is greatly extended. This is because Mn 2+ As a co-catalyst, it significantly accelerates the regeneration cycle of Fe2+ to Fe3+, thereby greatly improving the overall oxidation reaction rate and efficiency, and without Mn 2+ , the catalytic cycle is slow. Comparative Example 3 (without tungstate salt): although the removal rate is acceptable, the system has serious elemental sulfur plugging after operation. This is because WO4 2- By changing the crystal form of elemental sulfur, it prevents its deposition and plugging of equipment, ensuring the long-term stable operation of the system; at the same time, the removal rate of PH3 decreases compared to Example 1, which confirms the promotion of WO4 2- hydrolysis of PH3. Comparative Example 5 has some acid mist removal ability, but its acid mist removal rate is about 70%, because the activated carbon is acidified, resulting in a decrease in adsorption performance.

[0056] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each example can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for post-treatment of acetylene purified using the calcium carbide method, characterized in that, H2S and PH3 in acetylene gas were treated sequentially by wet catalytic oxidation and adsorption. The oxidant in the wet catalytic oxidation was a mixed solution of ferric sulfate and sulfuric acid, and water-soluble manganese salt and water-soluble tungstate were also added to the mixed solution. The adsorbent was a cerium-zirconium solid solution loaded with copper oxide.

2. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, Fe in ferric sulfate 3+ With Mn in manganese salt 2+ The molar ratio is (5-10):

1.

3. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The concentration of iron ions in the mixed solution is 0.5-0.7 mol / L, and the pH of the mixed solution is 2.5-4.

4. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, Fe in ferric sulfate 3+ With WO4 in tungstate 2- The molar ratio is (40-60):

1.

5. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The mixed solution also contains the complexing agent EDTA, and the mass ratio of the complexing agent to ferric sulfate is (3-4):

1.

6. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The water-soluble manganese salt is manganese sulfate, and the water-soluble tungstate is sodium tungstate.

7. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The reaction temperature for the wet oxidation process is 35-40℃.

8. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, In the wet oxidation process, a mixed solution is sprayed to contact acetylene gas.

9. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The copper oxide loading in the cerium-zirconium solid solution loaded with copper oxide is 3wt%-8wt%.

10. A method for post-treatment of acetylene purified by the calcium carbide method according to claim 1, characterized in that, The copper oxide-loaded cerium-zirconium solid solution was prepared from cerium nitrate, zirconium oxynitrate, copper nitrate, and ammonia water as raw materials, and the preparation process is as follows: A mixed aqueous solution of cerium nitrate, zirconium oxynitrate, and copper nitrate was simultaneously added dropwise to a reactor along with ammonia to produce a precipitate. The pH value at the end of the reaction was controlled at 9-10. The solution was then filtered, washed, dried, and calcined to obtain a cerium-zirconium solid solution loaded with copper oxide.

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