Chemical-looping with oxygen uncoupling (CLOU) is a novel method to burn fuels in gas-phase oxygen without the need for an energy-intensive air separation unit. The carbon dioxide from the combustion is obtained separated from the nitrogen in the combustion air. The technique is based on chemical-looping combustion (CLC) but does not involve any direct reaction between the fuel and oxygen carrier. Instead, the CLOU process uses three steps in two reactors, one air reactor where a metal oxide captures oxygen from the combustion air (step 1), and a fuel reactor where the metal oxide releases oxygen (step 2) and where this oxygen reacts with a fuel (step 3). This means that the fuel burns directly with gaseous O 2 . In this work CaMn 0.875 Ti 0.125 O 3 will be used as oxygen carrier. Experiments were first performed with a thermogravimetric analyzer (TGA). Here the sintering temperature, and thereby the porosity, for the produced granulates was varied and optimized. The substitution of Ti on Mn sites in CaMnO 3 was chosen since this material showed no coke formation even in dry CH 4 at high temperatures. This was followed by fluidized bed experiments with both methane and petroleum coke as fuel. The CaMn 0.875 Ti 0.125 O 3 particles showed promising results both for the tests performed in TGA and in fluidized bed experiments. CaMn 0.875 Ti 0.125 O 3 released O 2 both in inert and reducing atmosphere, making it a possible candidate as oxygen carrier in CLOU.
No takes yet. Share an insight, caveat, or question.
Leion et al. (2009) studied this question.