常温常压无催化剂CH_4与N_2等离子体合成新物质研究
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摘要
随着石油资源的日趋短缺，加之环境保护要求日益严格，天然气作为优质、高效、清洁能源，也是石油化学工业宝贵的原料，其开发利用越来越受到重视。本文结合国家自然科学基金重点资助项目“高气压下强电场电离气体的方法及其应用研究”以及当前国际国内甲烷化学的研究热点，在友好的常温常压、无催化剂的条件下，采用介质阻挡强电离放电方式对原料气体CH_4和N_2的等离子体合成进行研究。
强电场电离放电在等离子体发生器中建立折合电场强度大于400Td，电子平均能量大于12eV，电子密度大于10~(15)／cm~3的放电电场。高能电子通过与CH_4和N_2发生非弹性碰撞，将气体激发、电离和离解成N、N_2~+、CH_3、CH_2、CH、H等活性粒子，在等离子体反应腔内进行无任何环境污染的化学反应，再“定向装配”一步合成NH_3气态烃、液体燃料等高附加值的化工产品。通过改变单位面积放电功率、激励电压、放电频率、放电间隙等物理参数和气体的总流量、体积比、温度等工艺参数，考察其对甲烷转化和等离子体合成反应的影响规律。实验过程中用红外线分析仪、气相色谱仪和质谱仪检测合成产物。合成氨的浓度达到8000ppm，液体燃料的收率达20％，甲烷的转化率达90％。从收集到的液体燃料中检测出8种主要物质，分别为高级烯烃、炔烃、杂环化合物和多环有机物。
本实验采用的原料是自然界存在丰富的CH_4和N_2，在常温常压温和的反应条件下，不用任何催化剂，实现绿色合成氨和液体燃料，为天然气化工提供了一种低能耗的新技术，具有非常重要的学术和经济意义。
With the lessening of oil and strict environmental protection, the exploitation and using of natural gas, a high-quality, clean, effective energy sources and valuable chemical material, are becoming more and more important in our society. Following the key NSFC Project "Studies on Method and Application of Ionizing Gas Molecules with Strong Electric Field at High Pressure" and the internal and international focus of methane chemical, this paper studies CH4 and N2 plasma synthesis by strong dielectric barrier discharge at room temperature and atmospheric pressure without catalyst.
An electric field is formed by strong ionized discharge in the plasma reactor with reduced electric field intensity exceeding 400Td, average electron energy higher than 12eV and electron density more than 1015/cm3. Methane and nitrogen molecules are activated, ionized and dissociated into active particles such as N, N2+, CH3, CH2, CH and H by nonelastic collision with high energy electrons. The particles react each other in the reactor to synthesize chemically products of great additional value including ammonia, hydrocarbon gas and liquid fuel orientationally without any pollution. By changing the physical parameters such as discharge power per area, voltage, frequency and discharge gap and technical parameters such as total flow, volume ratio and gas temperature, we study how these parameters affect the conversion of methane and plasma synthesis. Infrared analyzer, gas chromatograph and mass spectrograph are used to detect the productions in the experiments. The concentration of ammonia reaches up to 8000p
pm, yield of liquid fuel conies up to 20 percent and the methane conversion attains 90 percent. And there are 8 kinds of main components in liquid fuel, which belong to higher olefine hydrocarbon, acetylene series, heterocyclic compound and polycyclic organic matter.
The experiments use CH4 and N2 as stuff, which are very abundant in the nature, realize green synthesizing of ammonia and liquid fuel at normal temperature and pressure without catalyst, provide a new technology with low energy consumption for natural gas industry, and have important meaning on science and economy.
强电场电离放电在等离子体发生器中建立折合电场强度大于400Td，电子平均能量大于12eV，电子密度大于10~(15)／cm~3的放电电场。高能电子通过与CH_4和N_2发生非弹性碰撞，将气体激发、电离和离解成N、N_2~+、CH_3、CH_2、CH、H等活性粒子，在等离子体反应腔内进行无任何环境污染的化学反应，再“定向装配”一步合成NH_3气态烃、液体燃料等高附加值的化工产品。通过改变单位面积放电功率、激励电压、放电频率、放电间隙等物理参数和气体的总流量、体积比、温度等工艺参数，考察其对甲烷转化和等离子体合成反应的影响规律。实验过程中用红外线分析仪、气相色谱仪和质谱仪检测合成产物。合成氨的浓度达到8000ppm，液体燃料的收率达20％，甲烷的转化率达90％。从收集到的液体燃料中检测出8种主要物质，分别为高级烯烃、炔烃、杂环化合物和多环有机物。
本实验采用的原料是自然界存在丰富的CH_4和N_2，在常温常压温和的反应条件下，不用任何催化剂，实现绿色合成氨和液体燃料，为天然气化工提供了一种低能耗的新技术，具有非常重要的学术和经济意义。
With the lessening of oil and strict environmental protection, the exploitation and using of natural gas, a high-quality, clean, effective energy sources and valuable chemical material, are becoming more and more important in our society. Following the key NSFC Project "Studies on Method and Application of Ionizing Gas Molecules with Strong Electric Field at High Pressure" and the internal and international focus of methane chemical, this paper studies CH4 and N2 plasma synthesis by strong dielectric barrier discharge at room temperature and atmospheric pressure without catalyst.
An electric field is formed by strong ionized discharge in the plasma reactor with reduced electric field intensity exceeding 400Td, average electron energy higher than 12eV and electron density more than 1015/cm3. Methane and nitrogen molecules are activated, ionized and dissociated into active particles such as N, N2+, CH3, CH2, CH and H by nonelastic collision with high energy electrons. The particles react each other in the reactor to synthesize chemically products of great additional value including ammonia, hydrocarbon gas and liquid fuel orientationally without any pollution. By changing the physical parameters such as discharge power per area, voltage, frequency and discharge gap and technical parameters such as total flow, volume ratio and gas temperature, we study how these parameters affect the conversion of methane and plasma synthesis. Infrared analyzer, gas chromatograph and mass spectrograph are used to detect the productions in the experiments. The concentration of ammonia reaches up to 8000p
pm, yield of liquid fuel conies up to 20 percent and the methane conversion attains 90 percent. And there are 8 kinds of main components in liquid fuel, which belong to higher olefine hydrocarbon, acetylene series, heterocyclic compound and polycyclic organic matter.
The experiments use CH4 and N2 as stuff, which are very abundant in the nature, realize green synthesizing of ammonia and liquid fuel at normal temperature and pressure without catalyst, provide a new technology with low energy consumption for natural gas industry, and have important meaning on science and economy.
引文
[1] 丁锋，我国油气资源勘探开发现状与对策，http://UNIT.CUGEDU.CN
[2] 刘洪岩，发展我国天然气化工的几点思考，http://ChemDevelop.com
[3] Pena M. A., New catalytic routes syngas and hydrogen production, Appl. Catal. A: General, 1996, 144: 7-57
[4] 徐占林，毕颖艳，甑开吉，甲烷催化二氧化碳重整制合成气反应研究进展，化学进展，2000，12(2)：121-130
[5] Jack H. Lunsford, Catalytic conversion of methane to more useful chemical and fuel: a challenge for 21st century, Catalysis Today, 2000, 63: 165-174
[6] 胡捷，贺德华，甲烷直接转化及制合成气研究进展，天然气化，2003，28：46-50
[7] 尚丽霞，谢为国，吕绍清，邱发礼，甲烷和空气部分氧化制合成气，合成化学，2001，9(2)：113-116
[8] 尹国川，奚祖威，曹国英，甲烷催化氧化制含氧化合物的研究，化学进展，1999，11(1)：21-29
[9] 王保伟，许根慧，刘昌俊，电促进甲烷偶联合成碳二烃研究进展，化工进展，2001，4：14-18
[10] 王保伟，许根慧，刘昌俊，等离子体在天然气中的应用，化工学报，2001，52(8)：659-665
[11] 朱爱民，张秀玲，宫为民，代斌，脉冲电晕等离子体作用下甲烷偶联反应的研究Ⅱ．反应添加气的影响，应用化学，1999，16(4)：70-73
[12] 张月萍，刘昌俊，许根慧，甲烷等离子体化学利用及其对新世纪能源、环境和化工的影响，化工进展，2001，(3)：51-56
[13] 张祥富，曾达权，天然气等离子体法制乙炔，天然气化工，1998，23(4)：39-43
[14] 罗义文，漆继红，印永祥，戴晓雁，热等离子体裂解甲烷的热力学与动力学分析，四川大学学报，2003，35(4)：33-37
[15] A. Oumghar, J. C. Legrand, A. M. Diamy, A Kinetic Study of Methane Conversion by a Dinitrogen Microwave Plasma, Plasma Chemistry and Plasma Processing,
1994，14(3)：229-249
[16] 陈栋梁，李庆，于作龙，甲烷和氮气在微波等离子体下的转化研究，天然气化工，2000，25：28-32
[17] Luk'yanov V B, Eremeev A P, Nesmeyanov An N. Synthesis of oxygen-containing organic compounds in electric discharges. Ⅺ. effect of the addition of argon and of the wall temperature on the formation of alde-hydes and carboxylic acids under the conditions of circulation, russian J of phys chem, 1974, 48(4): 531-533
[18] Finlayson D, Geoffrey J, Manufacture of aliphatic aldehydes, US Patent, 1987, (1): 881-885
[19] Changjun Liu, Abdulathim Marafee, Bobby Hill, Oxidative Coupling of Methane with ac and dc Corona Discharges, Ind. Eng. Chem. Res., 1996, 35: 3295-3301
[20] Thanyachotpaiboon K, Chavadej S, Caldwell T A, Conversion of methane to higher hydrocarbons in AC nonequilibrium plasma, AIChE Journal, 1998, 44(10): 2252-2257
[21] L. M. Zhou, B. Xue, U. Kogelschatz, Partial Oxidation of Methane with Oxygen or Air in a Nonequilibrium Discharge Plasma, Plasma Chemistry and Plasma Processing, 1998, 18(3):375-393
[22] Yanabe Shuji, Okitsu Kenji, Matsumoto Hiroshige, Profiles of methane dimerization with a glow discharge plasma system, Nagasaki Daigaku Kogakubu Kenkyu Hokoku, 1999, 29(53): 329-332
[23] 朱爱民，宫为民，张秀玲，周杰，脉冲电晕等离子体应用于甲烷偶联的探索研究，天然气化工，1997，22(2)：1-4
[24] 朱爱民，宫为民，张秀玲，张报安，脉冲电晕等离子体作用下甲烷偶联反应Ⅰ．无氧气氛下，中国科学(B辑)，2000，30(2)：167-173
[25] 朱爱民，张秀玲，宫为民，张报安，有氧气氛下等离子体甲烷偶联反应的研究，物理化学学报，2000，16(9)：839-843
[26] 朱爱民，张秀玲，李小松，宫为民，脉冲电晕等离子体作用下甲烷“超平衡”转化制乙炔和氢，中国科学(B辑)，2002，32(2)：179-185
[27] 李明伟，刘昌俊，许根慧，冷等离子体作用下CH_4—CO_2转化制合成气，应用化学，2000，17(6)：593-597
[28] 李明伟，温室气体冷等离子体反应制合成气基础研究，天津：天津大学化工学院，2000
[29] Mamoru Okumoto, Akira Mizuno, Conersion of methane for higher hydrocarbon fuel synthesis using pulsed discharge plasma method, Cstalysis Today, 2001, 71: 211-217
[30] Yun Yang, Methane Conversion and Reforming by Nonthermal Plasma on Pins, Ind Eng. Chem. Res., 2002, 41: 5918-5926
[31] Shigeru Kado, Kohei Urasaki, Yasushi Sekine, Kaoru Fujimoto, Direct conversion of methane to acetylene or syngas at room temperature using non-equilibrium discharge, Fuel, 2003, 82: 1377-1385
[32] Yue-ping Zhang, Yang Li, YU Wang, Plasam methane conversion in the Presence of carbon Dioxide using Dielectric-barrier discharge, Fuel Processing Technology, 2003, 83: 101-109
[33] Xu G H, Mallinson R G, Proceedings of the 1996 Asia-Pacific Chemical Reaction Engineering Forum, 1996, 1, 123
[34] 杜丽萍，许根慧，孙洪伟，何菲，电场增强等离子催化反应由天然气合成碳二烃，燃料化学学报，1997，25(4)：313-317
[35] 张劲松，Jeffrey K S Wan，曹丽华，微波诱导甲烷在活性炭／碳化硅上直接转化制C2烃，催化学报，1999，20(1)：45-50
[36] Chang-jun Liu, Richard Mallinson, Lance Lobban, Comparative investigation on plasma catalytic methane conversion to higher hydrocarbons over zeolites, Applied Catalysis A: General, 1999, 178: 17-27
[37] Yong Zhang, Wei Chu, Weimin Cao, A Plasma-Activated Ni/α-Al_2O_3 Catalyst for the conversion of CH_4 to syngas, Plasma chemistry and Plasma Processing, 2000: 137-144.
[38] Baldur Eliasson, Chang-jun Liu, Ulrich Kogelschatz, Direct Conversion of Methane
and Carbon Dioxide to Higher Hydrocarbons Using Catalytic Dielectric-Barrier Discharges with Zeolites, Ind. Eng. Chem. Res., 2000, 39: 1221-1227
[39] 代斌，张秀玲，宫为民，中国科学(B辑)，2001，44(2)：191-195
[40] M. Heintze, M. Magureanu, Methane Conversion into Aromatics in a Direct Plasma-Catalytic Process, Journal of Catalysis, 2002, 206: 91-97
[41] RADZIG A A, SMIRNOV B M, Reference Data on Atoms, Molecules, and Ions [M], Berlin: Springer-Verlag Berlin Heidelberg, 1985
[42] 李吕辉，物理化学，北京：高等教育出版社，1994
[43] 徐学基，诸定昌，气体物理，上海：复旦大学出版社，1996
[44] 白希尧，张芝涛，白敏冬，高气压强电离放电等离子体学科的形成及应用展望，自然杂志，2000，22(3)：156-161
[45] 菅井秀郎，等离子体电子工程学，北京：科学出版社，2002
[2] 刘洪岩，发展我国天然气化工的几点思考，http://ChemDevelop.com
[3] Pena M. A., New catalytic routes syngas and hydrogen production, Appl. Catal. A: General, 1996, 144: 7-57
[4] 徐占林，毕颖艳，甑开吉，甲烷催化二氧化碳重整制合成气反应研究进展，化学进展，2000，12(2)：121-130
[5] Jack H. Lunsford, Catalytic conversion of methane to more useful chemical and fuel: a challenge for 21st century, Catalysis Today, 2000, 63: 165-174
[6] 胡捷，贺德华，甲烷直接转化及制合成气研究进展，天然气化，2003，28：46-50
[7] 尚丽霞，谢为国，吕绍清，邱发礼，甲烷和空气部分氧化制合成气，合成化学，2001，9(2)：113-116
[8] 尹国川，奚祖威，曹国英，甲烷催化氧化制含氧化合物的研究，化学进展，1999，11(1)：21-29
[9] 王保伟，许根慧，刘昌俊，电促进甲烷偶联合成碳二烃研究进展，化工进展，2001，4：14-18
[10] 王保伟，许根慧，刘昌俊，等离子体在天然气中的应用，化工学报，2001，52(8)：659-665
[11] 朱爱民，张秀玲，宫为民，代斌，脉冲电晕等离子体作用下甲烷偶联反应的研究Ⅱ．反应添加气的影响，应用化学，1999，16(4)：70-73
[12] 张月萍，刘昌俊，许根慧，甲烷等离子体化学利用及其对新世纪能源、环境和化工的影响，化工进展，2001，(3)：51-56
[13] 张祥富，曾达权，天然气等离子体法制乙炔，天然气化工，1998，23(4)：39-43
[14] 罗义文，漆继红，印永祥，戴晓雁，热等离子体裂解甲烷的热力学与动力学分析，四川大学学报，2003，35(4)：33-37
[15] A. Oumghar, J. C. Legrand, A. M. Diamy, A Kinetic Study of Methane Conversion by a Dinitrogen Microwave Plasma, Plasma Chemistry and Plasma Processing,
1994，14(3)：229-249
[16] 陈栋梁，李庆，于作龙，甲烷和氮气在微波等离子体下的转化研究，天然气化工，2000，25：28-32
[17] Luk'yanov V B, Eremeev A P, Nesmeyanov An N. Synthesis of oxygen-containing organic compounds in electric discharges. Ⅺ. effect of the addition of argon and of the wall temperature on the formation of alde-hydes and carboxylic acids under the conditions of circulation, russian J of phys chem, 1974, 48(4): 531-533
[18] Finlayson D, Geoffrey J, Manufacture of aliphatic aldehydes, US Patent, 1987, (1): 881-885
[19] Changjun Liu, Abdulathim Marafee, Bobby Hill, Oxidative Coupling of Methane with ac and dc Corona Discharges, Ind. Eng. Chem. Res., 1996, 35: 3295-3301
[20] Thanyachotpaiboon K, Chavadej S, Caldwell T A, Conversion of methane to higher hydrocarbons in AC nonequilibrium plasma, AIChE Journal, 1998, 44(10): 2252-2257
[21] L. M. Zhou, B. Xue, U. Kogelschatz, Partial Oxidation of Methane with Oxygen or Air in a Nonequilibrium Discharge Plasma, Plasma Chemistry and Plasma Processing, 1998, 18(3):375-393
[22] Yanabe Shuji, Okitsu Kenji, Matsumoto Hiroshige, Profiles of methane dimerization with a glow discharge plasma system, Nagasaki Daigaku Kogakubu Kenkyu Hokoku, 1999, 29(53): 329-332
[23] 朱爱民，宫为民，张秀玲，周杰，脉冲电晕等离子体应用于甲烷偶联的探索研究，天然气化工，1997，22(2)：1-4
[24] 朱爱民，宫为民，张秀玲，张报安，脉冲电晕等离子体作用下甲烷偶联反应Ⅰ．无氧气氛下，中国科学(B辑)，2000，30(2)：167-173
[25] 朱爱民，张秀玲，宫为民，张报安，有氧气氛下等离子体甲烷偶联反应的研究，物理化学学报，2000，16(9)：839-843
[26] 朱爱民，张秀玲，李小松，宫为民，脉冲电晕等离子体作用下甲烷“超平衡”转化制乙炔和氢，中国科学(B辑)，2002，32(2)：179-185
[27] 李明伟，刘昌俊，许根慧，冷等离子体作用下CH_4—CO_2转化制合成气，应用化学，2000，17(6)：593-597
[28] 李明伟，温室气体冷等离子体反应制合成气基础研究，天津：天津大学化工学院，2000
[29] Mamoru Okumoto, Akira Mizuno, Conersion of methane for higher hydrocarbon fuel synthesis using pulsed discharge plasma method, Cstalysis Today, 2001, 71: 211-217
[30] Yun Yang, Methane Conversion and Reforming by Nonthermal Plasma on Pins, Ind Eng. Chem. Res., 2002, 41: 5918-5926
[31] Shigeru Kado, Kohei Urasaki, Yasushi Sekine, Kaoru Fujimoto, Direct conversion of methane to acetylene or syngas at room temperature using non-equilibrium discharge, Fuel, 2003, 82: 1377-1385
[32] Yue-ping Zhang, Yang Li, YU Wang, Plasam methane conversion in the Presence of carbon Dioxide using Dielectric-barrier discharge, Fuel Processing Technology, 2003, 83: 101-109
[33] Xu G H, Mallinson R G, Proceedings of the 1996 Asia-Pacific Chemical Reaction Engineering Forum, 1996, 1, 123
[34] 杜丽萍，许根慧，孙洪伟，何菲，电场增强等离子催化反应由天然气合成碳二烃，燃料化学学报，1997，25(4)：313-317
[35] 张劲松，Jeffrey K S Wan，曹丽华，微波诱导甲烷在活性炭／碳化硅上直接转化制C2烃，催化学报，1999，20(1)：45-50
[36] Chang-jun Liu, Richard Mallinson, Lance Lobban, Comparative investigation on plasma catalytic methane conversion to higher hydrocarbons over zeolites, Applied Catalysis A: General, 1999, 178: 17-27
[37] Yong Zhang, Wei Chu, Weimin Cao, A Plasma-Activated Ni/α-Al_2O_3 Catalyst for the conversion of CH_4 to syngas, Plasma chemistry and Plasma Processing, 2000: 137-144.
[38] Baldur Eliasson, Chang-jun Liu, Ulrich Kogelschatz, Direct Conversion of Methane
and Carbon Dioxide to Higher Hydrocarbons Using Catalytic Dielectric-Barrier Discharges with Zeolites, Ind. Eng. Chem. Res., 2000, 39: 1221-1227
[39] 代斌，张秀玲，宫为民，中国科学(B辑)，2001，44(2)：191-195
[40] M. Heintze, M. Magureanu, Methane Conversion into Aromatics in a Direct Plasma-Catalytic Process, Journal of Catalysis, 2002, 206: 91-97
[41] RADZIG A A, SMIRNOV B M, Reference Data on Atoms, Molecules, and Ions [M], Berlin: Springer-Verlag Berlin Heidelberg, 1985
[42] 李吕辉，物理化学，北京：高等教育出版社，1994
[43] 徐学基，诸定昌，气体物理，上海：复旦大学出版社，1996
[44] 白希尧，张芝涛，白敏冬，高气压强电离放电等离子体学科的形成及应用展望，自然杂志，2000，22(3)：156-161
[45] 菅井秀郎，等离子体电子工程学，北京：科学出版社，2002