Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 30 July 1999:
Vol. 285. no. 5428, pp. 712 - 715
DOI: 10.1126/science.285.5428.712
Prev | Table of Contents | Next

Reports

High Selectivities to Ethylene by Partial Oxidation of Ethane

A. S. Bodke, 1 D. A. Olschki, 1 L. D. Schmidt, 1* E. Ranzi 2

At least 85 percent selectivity to ethylene at greater than 70 percent conversion can be obtained by partial oxidation of ethane by adding large amounts of H2 to the reaction mixture and using a platinum-tin catalyst operating at 950°C with a contact time of ~10-3 seconds. This system almost totally shuts off the reactions that form undesired CO and CO2, which fall from 20 percent without H2 to 5 percent when H2 is added. Although a 2/1 H2/O2 mixture should be explosive at high temperatures, no flames or explosions occur in the presence of ethane. The successive reactions on the catalyst generate more H2 than used in the feed, so with recycle no additional H2 would be needed. These results are unexpected because ethylene is a nonequilibrium product and entropy considerations argue that all reaction channels open at high temperatures so the products should approach equilibrium, which predicts only a few percent ethylene. This process is promising for the replacement of steam cracking in the production of ethylene.

1 Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
2 Departmento di Chemica Industriale e Ingegneria Chemica, Politechnico di Milano, Milan, Italy.
*   To whom correspondence should be addressed.

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Toward Separation and Purification of Olefins Using Dithiolene Complexes: An Electrochemical Approach.
K. Wang and E. I. Stiefel (2001)
Science 291, 106-109
   Abstract »    Full Text »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)