NSF Award
0944555
This Small Business Innovation Research Phase I project seeks to develop a novel high temperature catalyst for the oxidation of methane present in coal mine ventilation air. Referred to as ventilation air methane (VAM), VAM emissions contain between 0.2% and 1.2% CH4 plus ppm levels of sulfur gases (H2S, SO2 and COS). While the sulfur levels are low, these levels are sufficient to rapidly deactivate traditional oxidation catalysts employed in the control of CH4 emissions. In order to be successful, the catalyst must be operated at high temperatures in order to avoid the formation of palladium sulfates, plus employ a catalyst support material that is able to maintain its integrity in the high temperature environment in the presence of water vapor and sulfur gases. This project seeks to use a patented high temperature (700°C) catalyst capable of destroying perfluorocompounds (e.g. C2F6 and SF6) present in semiconductor manufacturing emissions. The success of the catalyst, a Co/ZrO2-Al2O3, stems from the formation of cobalt-spinel complexes, which prevent acid gases from forming the corresponding aluminum fluorides and sulfates. It is the objective of this effort to employ this material as a basis for a high temperature CH4 oxidation catalyst for the treatment of VAM emissions.<br/><br/>The broader/commercial impact of this project, if successful, will be the direct conversion of CH4 to CO2 and H2O would reduce the overall a global warming potential (GWP) by over 90%. Greenhouse gas emissions are coming under increased scrutiny due to their link to climate change. CH4 is a key contributor to greenhouse gas emissions with a global warming potential (GWP) of 21 times that of CO2. Thus, VAM accounts for 10% of the anthropogenic methane emissions in the US. Low cost, reliable technologies are sought for the treatment of these emissions. Reverse-flow thermal oxidation systems have been proposed to treat these emissions. These processes operate at extreme temperatures, are large and require moving parts (valves and louvers) that operate at high temperatures. As a result, the reverse-flow process is expensive and unreliable. Catalytic processes offer significant advantages in terms of reduced size, lower energy input and greatly enhanced reliability. However, catalysts capable of treating VAM emissions are not available on the commercial market, due to durability issues associated with the operating conditions. If successful, a catalytic process would offer a low-cost alternative to the treatment of VAM emissions.
