γ-Al_2O_3负载型氯化铜基催化剂上乙烷氧氯化制氯乙烯
摘要
本文以廉价的乙烷替代乙烯,在氯化铜基催化剂的催化作用下氧氯化制得氯乙烯,填补了国内在乙烷氧氯化制氯乙烯方面的空白。采用浸渍法合成了氯化铜-助剂体系催化剂,并对其进行了较深入、细致的研究,通过XRD、EPR、XPS、UV-vis、TEM、TG-DTA、EPR、催化剂表面构织分析和ICP 等技术对催化剂的结构等特征进行了表征,全面考察了乙烷氧氯化制氯乙烯的反应性能。
经系列实验,选出最佳的催化剂组成、催化剂的制备条件和反应条件。在反应温度500℃,常压,催化剂1g,密度1000Kg/m3,V(C2H6):V(HCl):V(air)=1:3:5,空速2160h-1 的反应条件下:浸渍法制备的CuCl2-KCl-LaCl3/γ-Al2O3 催化剂(其中铜质量百分含量5%,钾质量百分含量6%,镧质量百分含量5%),乙烷转化率为97.5%,氯乙烯选择性52.8%。
研究结果表明,乙烷氧氯化反应的活性中心是高度分散在载体表面的CuCl2,助剂氯化钾的加入提高了表面氯化铜的含量,而且氯化钾可以与氯化铜形成低熔点混合盐,使得氯化铜更容易释放出氯,从而提高了乙烷的转化率和氯乙烯的选择性。由于氯化铜在反应温度下极易挥发,使催化剂失活,氯化钾和氯化镧的加入有效的提高了氯化铜的稳定性,上述浸渍法制备的催化剂经100h 寿命考察,对乙烷氧氯化的催化性能仍然无明显下降。这些研究结果在国内至今未见文献报道。
Because there has been a great demand for poly vinyl chloride (PVC), thevinyl chloride monomer (VCM) that is a raw material for producing PVC is animportant chemical product. There are three ways to produce VCM: acetyleneoxychlorination, ethylene oxychlorination and ethane oxychlorination.Acetylene oxychlorination is an old way to synthesize VCM, but it has beenused as a main route to manufacture VCM in our country. Now, ethyleneoxychlorination is used in most of foreign chemical companies. Ethyleneoxychlorination is a two-step way. In the first step ethylene is oxychlorinated to1, 2-dichloroethane. The dichloroethane is subsequently dehydrochlorinated atan elevated temperature to yield VCM and hydrogen chloride in the second step.The disadvantage of this way is its high cost. Ethane oxychlorination is thenewest way to produce VCM. European Vinyls Corporation has set upequipment producing 1000t VCM every year. However, in our country, no anyreport on this project is present. Because ethane can be obtained from naturegas, this route is a promising way to be used in chemical production and will
create essential economical benefits. Firstly, we investigated theγ-Al2O3 supported CuCl2 based catalystsprepared by impregnation and their catalytic properties for the ethaneoxychlorination, which were influenced by some factors. The results show thatγ-Al2O3 (made in Zibo petrochemical group, Shandong province) is goodsupport, and high ethane conversion and ethylene chloride selectivity areobtained over the catalysts which were made with this support. Copper chlorideis an active component for the topic reaction and the catalytic activity isaffected by the amount of dispersed copper chloride. The most suitable amountof supported copper is 5wt%. The preparation condition can affect the state of the active site. Thecalcination temperature is very important for obtaining catalysts with highcatalytic properties. High temperature would lead to change of the structure ofsupport and active species. A favorable temperature is 550℃for this catalyticsystem. Short impregnation and calcination time are disadvantageous to theinteraction between the CuCl2 and γ-Al2O3 and catalytic stability.Impregnation for 12h and calination for 4h are favor for preparing catalystswith high catalytic properties. The results of the reaction showed that the conversion of ethane can reach96.9% and the selectivity to ethylene chloride can reach 48.8% overCuCl2-KCl-LaCl3/γ-Al2O3 catalyst (having a Cu, K ,La content of 5wt%,6wt%, 0.74wt%, respectively) under following reaction condition: reactiontemperature 500℃, atmosphere, 2160h-1( GHSV) , V(C2H6):V (HCl): V(air)=1:3:5. Secondly, we prepared and investigated the catalysts containing 5wt%
copper with different K/Cu molar ration. The structure and the state of speciesover catalysts were studied by means of XRD, TPR, solubility test, UV-vis andTG-DTA. The results show that surface cupric chloride increases with additionof potassium chloride, and the ration of soluble copper to total copper increasesfrom 19.6% to 73%. The catalyst, in which molar ratio of K/Cu is 2, showedhigh ethane conversion and ethylene chloride selectivity. The potassiumchloride can promote dispersion of copper chloride and decrease the volatilityof copper chloride, so make the catalysts stable. The addition of potassiumchloride that makes catalysts molten at reaction temperature would increase thechlorine release from the CuCl2 particles owing to developing eutectic the saltmixture with CuCl2. The presence of KCl promotes the regeneration of cupricchloride by accelerating re-oxidation of Cu(Ⅰ) to Cu(Ⅱ). In addition, it wasfound that addition of KCl led to a decrease in apparent activation energy of thereaction. In a word, the addition of KCl not only enhanced the conversion ofethane and the selectivity of ethylene chloride but also decreased the volatilityof copper chloride. The catalyst CuCl2-KCl-LaCl3/ γ-Al2O3 shows a farther decreasingtendency to the volatility of CuCl2 and is more stable upon addition of LaCl3.We studied the catalytic stability change with the catalysts compose Cu content:5wt%, K content: 6wt%, La content: 0.74wt%, 3wt%, 5wt%, 7wt%, respectivelywhich are denoted as CuKXLa, where X represented weight percentage of La,for example, CuK3La stands for a catalyst containing 5wt% Cu, 6wt% K and3wt% La. The CuK5La catalyst shows the highest properties: ethane conversionwas 97.5% and ethylene chloride selectivity was 52.8%. Over the CuK7Lacatalyst used for 20h and CuK3La catalyst used for 10h carbon deposition was
经系列实验,选出最佳的催化剂组成、催化剂的制备条件和反应条件。在反应温度500℃,常压,催化剂1g,密度1000Kg/m3,V(C2H6):V(HCl):V(air)=1:3:5,空速2160h-1 的反应条件下:浸渍法制备的CuCl2-KCl-LaCl3/γ-Al2O3 催化剂(其中铜质量百分含量5%,钾质量百分含量6%,镧质量百分含量5%),乙烷转化率为97.5%,氯乙烯选择性52.8%。
研究结果表明,乙烷氧氯化反应的活性中心是高度分散在载体表面的CuCl2,助剂氯化钾的加入提高了表面氯化铜的含量,而且氯化钾可以与氯化铜形成低熔点混合盐,使得氯化铜更容易释放出氯,从而提高了乙烷的转化率和氯乙烯的选择性。由于氯化铜在反应温度下极易挥发,使催化剂失活,氯化钾和氯化镧的加入有效的提高了氯化铜的稳定性,上述浸渍法制备的催化剂经100h 寿命考察,对乙烷氧氯化的催化性能仍然无明显下降。这些研究结果在国内至今未见文献报道。
Because there has been a great demand for poly vinyl chloride (PVC), thevinyl chloride monomer (VCM) that is a raw material for producing PVC is animportant chemical product. There are three ways to produce VCM: acetyleneoxychlorination, ethylene oxychlorination and ethane oxychlorination.Acetylene oxychlorination is an old way to synthesize VCM, but it has beenused as a main route to manufacture VCM in our country. Now, ethyleneoxychlorination is used in most of foreign chemical companies. Ethyleneoxychlorination is a two-step way. In the first step ethylene is oxychlorinated to1, 2-dichloroethane. The dichloroethane is subsequently dehydrochlorinated atan elevated temperature to yield VCM and hydrogen chloride in the second step.The disadvantage of this way is its high cost. Ethane oxychlorination is thenewest way to produce VCM. European Vinyls Corporation has set upequipment producing 1000t VCM every year. However, in our country, no anyreport on this project is present. Because ethane can be obtained from naturegas, this route is a promising way to be used in chemical production and will
create essential economical benefits. Firstly, we investigated theγ-Al2O3 supported CuCl2 based catalystsprepared by impregnation and their catalytic properties for the ethaneoxychlorination, which were influenced by some factors. The results show thatγ-Al2O3 (made in Zibo petrochemical group, Shandong province) is goodsupport, and high ethane conversion and ethylene chloride selectivity areobtained over the catalysts which were made with this support. Copper chlorideis an active component for the topic reaction and the catalytic activity isaffected by the amount of dispersed copper chloride. The most suitable amountof supported copper is 5wt%. The preparation condition can affect the state of the active site. Thecalcination temperature is very important for obtaining catalysts with highcatalytic properties. High temperature would lead to change of the structure ofsupport and active species. A favorable temperature is 550℃for this catalyticsystem. Short impregnation and calcination time are disadvantageous to theinteraction between the CuCl2 and γ-Al2O3 and catalytic stability.Impregnation for 12h and calination for 4h are favor for preparing catalystswith high catalytic properties. The results of the reaction showed that the conversion of ethane can reach96.9% and the selectivity to ethylene chloride can reach 48.8% overCuCl2-KCl-LaCl3/γ-Al2O3 catalyst (having a Cu, K ,La content of 5wt%,6wt%, 0.74wt%, respectively) under following reaction condition: reactiontemperature 500℃, atmosphere, 2160h-1( GHSV) , V(C2H6):V (HCl): V(air)=1:3:5. Secondly, we prepared and investigated the catalysts containing 5wt%
copper with different K/Cu molar ration. The structure and the state of speciesover catalysts were studied by means of XRD, TPR, solubility test, UV-vis andTG-DTA. The results show that surface cupric chloride increases with additionof potassium chloride, and the ration of soluble copper to total copper increasesfrom 19.6% to 73%. The catalyst, in which molar ratio of K/Cu is 2, showedhigh ethane conversion and ethylene chloride selectivity. The potassiumchloride can promote dispersion of copper chloride and decrease the volatilityof copper chloride, so make the catalysts stable. The addition of potassiumchloride that makes catalysts molten at reaction temperature would increase thechlorine release from the CuCl2 particles owing to developing eutectic the saltmixture with CuCl2. The presence of KCl promotes the regeneration of cupricchloride by accelerating re-oxidation of Cu(Ⅰ) to Cu(Ⅱ). In addition, it wasfound that addition of KCl led to a decrease in apparent activation energy of thereaction. In a word, the addition of KCl not only enhanced the conversion ofethane and the selectivity of ethylene chloride but also decreased the volatilityof copper chloride. The catalyst CuCl2-KCl-LaCl3/ γ-Al2O3 shows a farther decreasingtendency to the volatility of CuCl2 and is more stable upon addition of LaCl3.We studied the catalytic stability change with the catalysts compose Cu content:5wt%, K content: 6wt%, La content: 0.74wt%, 3wt%, 5wt%, 7wt%, respectivelywhich are denoted as CuKXLa, where X represented weight percentage of La,for example, CuK3La stands for a catalyst containing 5wt% Cu, 6wt% K and3wt% La. The CuK5La catalyst shows the highest properties: ethane conversionwas 97.5% and ethylene chloride selectivity was 52.8%. Over the CuK7Lacatalyst used for 20h and CuK3La catalyst used for 10h carbon deposition was
引文
[1]蓝凤祥。聚氯乙烯,2001,3:1-17
[2]张凌霄。化工技术经济,2002,20:32-36
[3]董洪斌,张礼安,杨风文等。化工技术经济,2002,20(5):38
[4]蔡学文。经济师,2003,3:249
[5]徐兆瑜。塑料,2004,33(1):64
[6]徐彬。化工技术经济,2004,22(9):32
[7]吴铭。中国石油和化工,2004,5:14
[8]徐文渊,蒋长安。天然气利用手册,中国石化出版2002
[9]胡国埏。中国氯碱,2001,1:37
[10]郭亚军,代少勇,董红星,龚凡。化学与粘合,2002,6:277
[11]易华,徐明霞,景晓燕。化学工程师,2001,4:39
[12]王红霞。石油化工,2002,6:483
[13]李红海,吴天祥,苏保卫。化学反应工程与工艺,2004,20:167
[14]蓝凤祥,柯竹天,苏明耀等。聚氯乙烯生产与加工应用手册,北京:化学工业出版社,1996。
[15] Pierluigi F., Dario V., Andrea M., Single Stage Fixed Bed Oxychlorination of Ethylene [P]. GB 2294262,2001-01-30.
[16] Pierluigi F., Diego C., Andrea M., Oxychlorination of Ethylene in Two Stage FixBed Reactors Using Layers of Cupric Chloride Catalyst of Differing Activity [P]. GB 2298197,1996-08-28
[17] D·卡尔梅罗,P·法吐托,A·马尔色拉。乙烯在两级固定床反应器中的氧氯化反应[P]. CN1175938, 1998-03-11.
[18]黄凤刚。聚氯乙烯,1999,2:1-6
[19] Dipling K.R., Wenzeldr K., Manfred S., et al., Reactor for Oxychlorination of Ethylene to 1,2-Dichloroethane [P]. DE 4305001,1994-08-25.
[20]薛之化。聚氯乙烯,2000,4:9
[21] Carroll J., Berger W.F.,Borrelli T.C., et al., Chemosphere,1998,137:1957
[22] Clegg I. M., Hardman R. Catalytic Oxy-chlorination of Ethane to Vinyl Chloride Monomer-by Reacting Ethane with Chlorine Source and Incorporating Hydrogenation of Unsatd,by-prods for Recycling to Reaction. WO9507252-A.1995-03-16
[23] Tayin H.A., Chemistry and Industry, 1970,14:1468
[24] Scegbahm P.E.M., Blomberg M.R.A., Svensson M., J. Am. Chem. Soc., 1993,115:195
[25] Stoutland P.O., Bergman R.G., J. Am. Chem. Soc., 1985,107:4581
[26] Blomberg M.R.A., Siegbahu P.E.M., Nagashims U., et al., J. Am. Chem. Soc., 1991,113:424
[27] Mortensen M., Minet R.G., Tsotsis T.T., et al., Chem Eng Sci., 1996, 51(10): 2031
[28]赵新来。齐鲁石化,2003,31(1):37
[29]陶志华。天然气化工,1988(3):35
[30] Gelperin E. I., Shcheglova G. G., Catalyst for oxychlorination of ethane [P]. SU555906, 1977-4-30
[31] Magistro A.J., Ethylene and vinyl chloride from ethane [P]. US4100211, 1978-6-11
[32] Gelperin E.I., Kinet. Katal., 1978, 19(6):1527
[33] Shestakov G.K., Kinet.Katal.,1988 ,29(2):371
[34] Karo H., Vinyl chloride from natural gas [P]. JP61040231, 1986-2-26
[35] Zaidman O.A.,Method of preparing vinyl chloride [P].GB2036718, 1980-11-29
[36] Stauffer J.E.,Process for the chlorination of ethane [P].WO9008116, 1990-6-26
[37] Magistro A.J., Ctalyst composition for the preparation of ethlylene from ethane [P]. US5112793, 1992-5-12
[38] Clegg I.M., Hardman R., Manufacture of vinyl chloride monomer by catalytic oxychlorination of ethane [P]. WO9507251, 1995-5-16
[39]易小云。广东化工,2000,1:37
[40]蓝凤祥。化工科技动态,1995,3:6
[41]刘岭梅。中国氯碱,1997,5:20
[42]郑进。中国氯碱,2004,3:14
[43]高为华。石油化工,2004,33(增刊):1571
[2]张凌霄。化工技术经济,2002,20:32-36
[3]董洪斌,张礼安,杨风文等。化工技术经济,2002,20(5):38
[4]蔡学文。经济师,2003,3:249
[5]徐兆瑜。塑料,2004,33(1):64
[6]徐彬。化工技术经济,2004,22(9):32
[7]吴铭。中国石油和化工,2004,5:14
[8]徐文渊,蒋长安。天然气利用手册,中国石化出版2002
[9]胡国埏。中国氯碱,2001,1:37
[10]郭亚军,代少勇,董红星,龚凡。化学与粘合,2002,6:277
[11]易华,徐明霞,景晓燕。化学工程师,2001,4:39
[12]王红霞。石油化工,2002,6:483
[13]李红海,吴天祥,苏保卫。化学反应工程与工艺,2004,20:167
[14]蓝凤祥,柯竹天,苏明耀等。聚氯乙烯生产与加工应用手册,北京:化学工业出版社,1996。
[15] Pierluigi F., Dario V., Andrea M., Single Stage Fixed Bed Oxychlorination of Ethylene [P]. GB 2294262,2001-01-30.
[16] Pierluigi F., Diego C., Andrea M., Oxychlorination of Ethylene in Two Stage FixBed Reactors Using Layers of Cupric Chloride Catalyst of Differing Activity [P]. GB 2298197,1996-08-28
[17] D·卡尔梅罗,P·法吐托,A·马尔色拉。乙烯在两级固定床反应器中的氧氯化反应[P]. CN1175938, 1998-03-11.
[18]黄凤刚。聚氯乙烯,1999,2:1-6
[19] Dipling K.R., Wenzeldr K., Manfred S., et al., Reactor for Oxychlorination of Ethylene to 1,2-Dichloroethane [P]. DE 4305001,1994-08-25.
[20]薛之化。聚氯乙烯,2000,4:9
[21] Carroll J., Berger W.F.,Borrelli T.C., et al., Chemosphere,1998,137:1957
[22] Clegg I. M., Hardman R. Catalytic Oxy-chlorination of Ethane to Vinyl Chloride Monomer-by Reacting Ethane with Chlorine Source and Incorporating Hydrogenation of Unsatd,by-prods for Recycling to Reaction. WO9507252-A.1995-03-16
[23] Tayin H.A., Chemistry and Industry, 1970,14:1468
[24] Scegbahm P.E.M., Blomberg M.R.A., Svensson M., J. Am. Chem. Soc., 1993,115:195
[25] Stoutland P.O., Bergman R.G., J. Am. Chem. Soc., 1985,107:4581
[26] Blomberg M.R.A., Siegbahu P.E.M., Nagashims U., et al., J. Am. Chem. Soc., 1991,113:424
[27] Mortensen M., Minet R.G., Tsotsis T.T., et al., Chem Eng Sci., 1996, 51(10): 2031
[28]赵新来。齐鲁石化,2003,31(1):37
[29]陶志华。天然气化工,1988(3):35
[30] Gelperin E. I., Shcheglova G. G., Catalyst for oxychlorination of ethane [P]. SU555906, 1977-4-30
[31] Magistro A.J., Ethylene and vinyl chloride from ethane [P]. US4100211, 1978-6-11
[32] Gelperin E.I., Kinet. Katal., 1978, 19(6):1527
[33] Shestakov G.K., Kinet.Katal.,1988 ,29(2):371
[34] Karo H., Vinyl chloride from natural gas [P]. JP61040231, 1986-2-26
[35] Zaidman O.A.,Method of preparing vinyl chloride [P].GB2036718, 1980-11-29
[36] Stauffer J.E.,Process for the chlorination of ethane [P].WO9008116, 1990-6-26
[37] Magistro A.J., Ctalyst composition for the preparation of ethlylene from ethane [P]. US5112793, 1992-5-12
[38] Clegg I.M., Hardman R., Manufacture of vinyl chloride monomer by catalytic oxychlorination of ethane [P]. WO9507251, 1995-5-16
[39]易小云。广东化工,2000,1:37
[40]蓝凤祥。化工科技动态,1995,3:6
[41]刘岭梅。中国氯碱,1997,5:20
[42]郑进。中国氯碱,2004,3:14
[43]高为华。石油化工,2004,33(增刊):1571