Advanced Coal Chemical-Looping combustion -AIMing at highest performanceChemical-looping combustion (CLC) for coal is a zero-emission technology, combining very low efficiency penalty (2-3%) and low CO2 capture cost, potentially as low as 10 €/ton CO2. Key issues for coal-CLC are:
Chemical looping combustion (CLC) has emerged as one of the most promising long-term technologies for low-cost CO2 capture for coal. The idea of CLC is to use a metal oxide to transport oxygen from air to the fuel, thus avoiding direct contact between fuel and air.
The process consists of an air reactor, where the metal is oxidized by the O2 content in the air, and a fuel reactor, where the metal oxide is reduced by the fuel that is converted to mainly CO2 and H2O. After condensing the steam, a stream of almost pure CO2 is obtained. The separation of CO2 is inherent in the process, resulting from the fact that combustion air and fuel are never mixed. Thus, no active separation of gases is needed, and there is no energy penalty for gas separation as in post-, pre- or oxy-combustion CO2 capture. Hence, the CLC process requires a uniquely low energy penalty of 2-3 percentage points, and CO2 capture costs are potentially as low as 10 €/ton of CO2 captured. The most promising approach for the two reactors is the fluidized bed technology that is widely applied to the conversion of coal.