Direct Methane Conversion to Acetylene and Ethylene in a Corona Discharge Reactor: Energy Evaluation

Document Type : Research Paper

Authors

Gas Research Division, Research Institute of Petroleum Industry

Abstract

Methane was directly converted to ethylene, acetylene, and synthesis gas using non-equilibrium plasma. The process was performed at room temperature and atmospheric pressure employing a quarts tube reactor with an outer diameter of 9 mm and an ac electrical discharge of 50 Hertz. Methane conversion was normally more than 50% with high selectivity to C2 hydrocarbons and synthesis gas. The experimental results show that, by applying higher voltages to the reactor, the conversion of methane and oxygen was increased. High selectivity to acetylene and synthesis gas was obtained at a higher level of voltage applied to the electrodes of the discharge zone. Introducing He to the feed stream enhanced the conversion of CH4 and O2; in this condition the yield of C2 hydrocarbons was as high as 27% with the energy efficiency of 0.26 mmol/kJ, which was the highest value obtained in this study. When CH4 partial pressure was increased in the feed it caused a decrease in the overall methane conversion while increased selectivity to acetylene productions. The energy efficiency was improved smoothly by increasing the CH4 partial pressure. Finally, the interactions of high energy electrons with various species available in non- thermal plasma were thoroughly discussed.
 

Keywords

References

[1]. Jun Liu C., Marafee A., Hill B., Mallinson R. and Lobban L., “oxidative coupling of methane with ac and dc Corona Discharges”. Ind.Eng, Chem. Res., Vol. 35, pp. 3295-3305, 1996.
[2]. Jun Liu C., Mallinson R., and Lobban L., “Comparative investigation on plasma catalytic methane conversion to higher hydrocarbons over zeolites” , Applied Catalysis, Vol .178(A: General), pp.17-27, 1999.
[3]. Jun Liu C., M arafee A., Mallinson R., and Lobban, L., “Methane conversion to higher hydrocarbons in a corona discharge over metal oxide catalysts with OH groups”, Applied Catalysis, Vol.164(A: General),pp.21-26,1997.
[4]. Thanyachotpaiboon K., Chavadej S., Caldwell T. A., Lobban L. and Mallinson R. G., “Conversion of methane to higher hydrocarbons in AC non -equilibrium plasmas”, AIChE Journal, Vol. 44, pp. 2252-2260, 1998.
[5]. Zhou L. M., Xue B., Kogelschatz U., and Eliasson B., “Partial Oxidation of Methane to Methanol with Oxygen or Air in a Nonequilibrium Discharge Plasma”, Plasma Chemistry and Plasma Processing, Vol.18, NO.3, pp.375-393, 1998.
[6].  Aghamir F. M., Seyed Matin N., Jalili A. H., Esfarayeni M. H., Khodagholi M . A. and Ahmadi R., “Conversion of methane to methanol in an ac dielectric barrier discharge”, Plasma Sources Sci. Technol., Vol.13, pp.707-712, 2004.
7]. خداقلی، م. ع.، ناصر، س. م.، و جلیلی، ا. ح.، تبدیل متان به هیدروکربن های بالاتر و متانول با پلاسمای مانع  دی- الکتریک، نشریه علوم دانشگاه تربیت معلم، جلد 7، شماره2، 1386.
[8]. Shuiliang Y., Nakayama A. and Suzuki E., “Methane conversion using a high-frequency pulsed plasma: Important factors” AlChE Journal, Vol.47, No.2, pp. 413-418 ,2001.
[9]. Shuiliang Y., Nakayama A., “A novel pulsed plasma for chemical conversion”., Thin Solid Films, Vol. 390, No. 1-2, pp. 165-169, 2001.
[10]. Jiang T., Liu, Yang, L., Chang – jun, Gen – hui, Xu., Eliason, B. and Xue, B., “Plasma methane conversion using dielectric-barrier discharges with zeolite A”., Catalysis Today, Vol. 72, pp. 229-235, 2002.
[11]. Ghorbanzadeh A. M., Matin N.S., “Methane Conversion to Hydrogen and Higher Hydrocarbons by Double Pulsed Glow Discharge”., Plasma Chemistry and Plasma Processing, Vol. 25, No.1, pp. 19-29, 2005.
[12]. Tarverdi H., Mortazavi M. S. and Khodadadi A. A., “Synergetic Effects of Plasma, Temperature and Diluents on Nonoxidative Conversion of Methane to C2+ Hydrocarbons in a Dielectric Barrier Discharge Reactor.”, IJCCE. Vol. 24, No. 4, pp. 63-68, 2004.
[13]. خداقلی، م. ع.، و ناصر، س. م.، تبدیل متان به هیدروکربن های سنگین تر در رآکتور تخلیه هاله مثبت، نشریه علوم دانشگاه تربیت معلم، جلد 3 شماره 2 صفحه 228 – 215 ، 1382.
[14]. خداقلی، م. ع.، و ناصر،س. م.، تبدیل متان به هیدروکربن های بالاتر با پلاسمای الکتریکی، مجله علوم دانشگاه آزاد اسلامی، دوره 14، شماره 52، تابستان 1383.
 
Journal of Petroleum Research
Volume 23, Issue 73 - Serial Number 73
July and August 2013
Pages 113-123

Files

Share

How to cite

Statistics