Jonghwun Jung, Technical Research Laboratory, POSCO, 1, Goedong-dong, Nam-gu, Gyeongbuk 790-785, Pohang, South Korea and Isaac K. Gamwo, National Energy Technology Laboratory, U.S. Department of Energy, Pittsburgh, PA 15236-0940.
CO2 emissions from fossil fuels combustion in power plants have increased the concentration of atmospheric greenhouse gases, raising concerns on global climate change. The foresights show that fossil fuels will be the dominating energy source worldwide at short or medium term, which encourages the development of new technologies for CO2 capture and sequestration. Chemical looping combustion (CLC) is a good candidate for fossil fuel combustion with negligible atmospheric CO2 emissions. CLC produces a relatively pure stream of CO2 ready for compression and storage in geological settings. Furthermore, CLC also minimizes NOx emissions since the fuel combustion is flameless in the absence of nitrogen.
We previously simulated the fuel reactor behavior of a chemical looping combustion process. Here, we report on the effects of temperature on the fuel reactor behavior. We found that unburned fuel weight fraction was reduced by nearly half when the temperature increased from 690 0C to 950 0C indicating a substantial increase in the fuel conversion rate. The simulations also showed that the bubble size in the fuel reactor increases with temperature. This study clearly indicates the need to optimize the temperature in the fuel reactor with respect to the fuel conversion rate.