Reports: ND956382-ND9: Understanding and Improving the Direct Conversion of Methane to Ethylene

William Ciurtis Conner, PhD, University of Massachusetts, Amherst

Since receiving this grant, we have accomplished the following:

A Fe/SiO2 catalyst as tested in the initial Science article has been synthesize (or tried to be synthesized) and tested by conventional and microwave heating. On line mass spectral analyses, MS, indicated selective production of C-2 products with hydrogen. The selectivity and yield were not easily quantified with the MS analyses. Subsequently, we have added on-line gas chromatographic analyses. We also initially observed coke formation for both processes (conventional and microwave heating) based on the formation of black deposits on the quartz reactor surfaces. Fortunately, this problem was apparently solved by increasing the purity of the CH4 (natural gas) feed to 99.99% purity or even just employing a liquid nitrogen trap on the inlet stream.  No deposits were then apparently formed!

Our initial microwave system was limited to 600 Watt microwave exposure. CEM Corporation was approached and readily agreed to help us design a new higher power system that would enable studies for exposure to 1400 Watts with higher reactor temperatures as suggested in our proposal. We also helped develop two approaches to on-line temperature measurements (bot infrared and via a thermocouple).

We are now preparing to bring all of the  pieces together and we have made a new Fe/SiO2 catalyst with the new high temperature and power microwave reactor coupled with the on line GC and MS and both temperature measurement and analytical systems.  We will see if additional in situ preheating of the CH4 is needed.