Conversion of CO2 into Commercial Materials Using Carbon Feedstocks
- Research Triangle Institute (RTI), Research Triangle Park, NC (United States)
In this project, our research focused on developing reaction chemistry that would support using carbon as a reductant for CO2 utilization that would permit CO2 consumption on a scale that would match or exceed anthropomorphic CO2 generation for energy production from fossil fuels. Armed with the knowledge that reactions attempting to produce compounds with an energy content greater than CO2 would be thermodynamically challenged and/or require significant amounts of energy, we developed a potential process that utilized a solid carbon source and recycled the carbon to effectively provide infinite time for the carbon to react. During testing of different carbon sources, we found a wide range of reaction rates. Biomass-derived samples had the most reactivity and coals and petcoke had the lowest. Because we had anticipated this challenge, we recognized that a catalyst would be necessary to improve reaction rates and conversion. From the data analysis of carbon samples, we recognized that alkali metals improved the reaction rate. Through parametric testing of catalyst formulations we were able to increase the reaction rate with petcoke by a factor of >70. Our efforts to identify the reaction mechanism to assist in improving the catalyst formulation demonstrated that the catalyst was catalyzing the extraction of oxygen from CO2 and using this extracted oxygen to oxidize carbon. This was a significant discovery in that if we could modify the catalyst formulation to permit controlled the oxidation, we would have a very power selective oxidation process. With selective oxidation, CO2 utilization could be effective used as one of the process steps in making many of the large volume commodity chemicals that support our modern lifestyles. The key challenges for incorporating these functionalities into the catalyst formulation were to make the oxidation selective and lower the temperature required for catalytic activity. We identified four catalyst families that had the potential to meet these challenges. Initial screening of the catalyst families did show that the reduction/oxidation activity did occur at lower temperatures and that these catalysts were able to cause carbon chain growth as well as C—C cleavage. A preliminary techno-economic feasibility of using petcoke/catalyst to produce a CO-rich syngas product was completed and showed significant economic promise. Testing of the different catalyst families demonstrated that Catalyst A was able to stably produce 5 sccm of ethylene/gram of catalyst at 900°C for one hour. For dry methane reforming, our Catalyst 4 was able to achieve production rates of > 10 sccm of CO and > 3 sccm of H2 per gram of catalyst at 600°C and 350 psig. Based on these developments, the potential for CO2 utilization in the production of large volume commodity chemicals is very promising.
- Research Organization:
- Research Triangle Institute (RTI), Research Triangle Park, NC (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FE0004329
- OSTI ID:
- 1177781
- Country of Publication:
- United States
- Language:
- English
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