Coal Based Clean Energy is Not Just a Dream

September 27, 2010 — Increasing dependence on international energy resources has made domestic fossil fuels more attractive. Estimated reserves of coal in Wyoming are 68.7 billion tons, sufficient to contribute to the US energy portfolio for 60 years. Wyoming coal has been considered to be a dependable candidate as possible gasification feedstock. People are increasingly interested in using coal for more diversified products, such as transportation fuels, hydrogen (H2), as well as for improved electricity generation.

Recognizing that enormous research and development is necessary to address technical as well as environmental issues of clean coal technologies, the State of Wyoming has launched a major initiative to make the University of Wyoming a leader in coal science, technology, and education. This initiative engages the College of Engineering and Applied Science, especially its Department of Chemical and Petroleum Engineering (CPE), and the School of Energy Resources (SER).

Engineering Associate Professor Maohong Fan has been working with his research colleagues on various clean coal technologies associated with both conventional coal-fired and future integrated gasification combined cycle (IGCC) based power generation systems. These works are being supported by various federal funding resources (e.g., the National Science Foundation), state agencies (e.g., SER and California Energy Commission), and major industrial companies (notably FMC Inc.). Funding of his currently contracted research projects at UW total more than $4M. One of his current research activities in his labs is the development of a cost-effective catalytic gasification process for future IGCC based power generation systems. IGCC plays a major role in coal-based H2 production and utilization. It involves two operational systems, gasification and combined cycle. The inputs of gasification unit are coal, oxygen/air and steam. Outputs of gasification unit are acidic syngas and ash.

The syngas is cooled, cleaned and processed through water gas shift reaction to produce clean H2 for combined cycle unit. The heat recovered through gas cooling system can not only be used to generate steam which is sent to steam turbine to generate electricity but also sent to gasification unit for use. The cleaned H2 can be used to produce chemicals or sent to gas turbine in combined cycle to generate electricity.

Significant progress has been made with gasification. However, a major problem with coal gasification is the high demand for heat (thereby making the gasification energy intensive). It is a problem that has not been satisfactorily overcome. Dr. Fan’s group is interested in using catalysis as an effective tool to reduce the gasification reaction temperature, and increase the rates of gasification reactions. The catalysts to be used should be readily available and inexpensive. This feasibility of requirement has yet to be determined. In this regard, Dr. Fan’s group is working with FMC Inc. in testing Trona based products as potentially major components of composite catalysts for coal gasification.

Dr. Fan’s research group is also developing an inexpensive bimetallic gasification catalyst, expected to take the corresponding advantages of individual metal based catalysts while avoiding their disadvantages. Specifically, the bimetallic catalyst is expected to increase gas production, stay active for a longer period, is more resistant to poisoning. The synergetic effects of the bimetallic catalyst could be tuned by controlling its composition to increase the activity of coal and the selectivity of reactions towards preferred coal gasification products. Dr. Tiberiu Popa, a former NSF Graduate Fellow and a current postdoc, is doing this research.

Another research effort involving Dr. Fan and his group is the search for new generation of water gas shift reaction (WGSR) catalysts or nanocatalysts. WGSR is an important process in IGCC system used for generating H2 from the syngas resulting from coal gasification with the set-up shown in the photo above. Dr. Zhijian Mei and Ying Li (a Ph.D. student) are doing this development.

 

Ph.D. student Ying Li (left) and Dr. Zhijian Mei conduct research on water gas shift reaction, used for generating H2 from the syngas resulting from coal gasification, UW photo.