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In-situ Gasification Chemical-Looping Combustion (iG-CLC) with coal has been proposed as a low-cost process for the capture of CO 2 during the energy generation. Previous experimental works have highlighted that high CO 2 capture efficiency, close to 100 %, can be achieved. However, a certain amount of unburnt gases (mainly CH 4 , CO and H 2) are present in the CO 2 stream. These gases can be treated in an oxygen polishing step placed downstream from the CLC unit where they are burnt with pure oxygen, which defines the so-called oxygen demand for the process. The aim of this work was to optimize the performance of the iG-CLC process with coal in order to minimize oxygen demand while maintaining CO 2 capture at high levels. Ilmenite was used as the oxygen carrier to burn a bituminous coal in a 50 kW th CLC unit, which consisted of a fuel reactor, an air reactor and a carbon stripper unit between them. The fuel reactor temperature, solids inventory in the fuel reactor, solids circulation rate, coal feeding rate and carbon stripper efficiency were varied, and the CO 2 capture efficiency and oxygen

Chemical Looping with Oxygen Uncoupling (CLOU) is a Chemical Looping Combustion (CLC) process that allows the combustion of solid fuels through the use of a solid oxygen carrier that release gaseous oxygen inside the fuel reactor. The aim of this work was to study the fate of elements potentially pollutant present in fuel during CLOU combustion, i.e. S, N and Hg. Experiments using lignite as fuel were carried out in a continuously operated 1.5 kW th CLOU unit during more than 35 h of coal combustion. Novel particles containing 50 wt. % CuO, 10 wt. % Fe 2 O 3 an 40 wt. % MgAl 2 O 4 , prepared by spray drying, were used as oxygen carrier in the CLOU process. The temperature in the fuel reactor varied between 885 and 945 ºC. Both the reactivity and oxygen transport capacity of the oxygen carrier were unaffected during operation with a high sulphur content fuel, and agglomeration problems did not occur. Complete combustion of the fuel to CO 2 and H 2 O was found in all experiments. Sulphur, NO X and Hg emissions from fuel and air reactor streams in the process were analyzed. Most of the sulphur introduced with the fuel exited as SO 2 at the fuel reactor outlet, although a small amount of SO 2 was

Chemical Looping Combustion (CLC) involves the use of a solid oxygen carrier to transport the oxygen from the air to a fuel. Attention has recently been focused on oxygen carriers based on Mn-Fe mixed oxides because they are cheap materials that are able to release oxygen at high temperature, the so-called oxygen uncoupling step. The aim of this work was to assess the use of (Mn 0.77 Fe 0.23) 2 O 3 material as an oxygen carrier with the ability to transport oxygen both by reduction with gaseous fuels and by oxygen uncoupling, i.e. typical mechanisms in CLC and in Chemical Looping with Oxygen Uncoupling (CLOU), respectively. The particles prepared by mechanical mixing were screened to obtain particles of sufficient reactivity and mechanical strength for use in a fluidized bed

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