Chemical-Looping Combustion of Solid Fuels – What is Needed to Reach Full-Scale?,
Conference contribution, 2016
Because the CO2 capture is inherent in chemical-looping combustion (CLC), thus ideally avoiding costly gas separation, this process has a potential for uniquely low costs of CO2 capture. So what is needed to get to the realization of this technology? The purpose of the paper is to discuss the status of the technology, barriers to the implementation of the technology, and also to suggest routes for the critical path from successful testing in small pilots to implementation in commercial-sized units.
Thus, operational experiences with oxygen carriers and chemical-looping with solid fuels are discussed, as well as large scale design and important technology challenges. Moreover, possible routes to scale-up are suggested. One way of lowering the costs of intermediate scale-up steps is to build CLC plants without CO2 purification/compression and oxygen production, because CO2 capture normally only makes sense in large scale. Another way to avoid or minimize the cost of the air reactor, would be by using a CFBB (circulating fluidized bed boiler) as the air reactor. This could either be an existing CFBB which is not in operation or can be taken out of operation for a period, or a designed dual purpose air reactor/CFBB where the CFBB can be used as a stand-alone unit after the testing period with CLC.