Abstract:
Chemical looping combustion (CLC) is the promising process which is expected to capture carbon in form of CO2 and low operating costs. This research studied the effects of Fe2O3 addition to CaSO4 oxygen carrier which are cheap material, provide high amount of oxygen, reacted with methane and coal in combustion reaction and suitable for fixed bed gaseous combustion and fluidized bed coal combustion. The effects of Fe2O3 loading was examined by performing CLC of CH4 using a lab-scale fixed-bed reactor. The result revealed that 20 wt.% Fe2O3/CaSO4 and reaction temperature at at 950oC gave the best efficiency result in term of carbon dioxide generation. The 20 wt.% Fe2O3/CaSO4 was selected and then applied to CLC of coal in lab-scale fluidized bed system. For the CLC of coal, the reaction temperature is optimal at 950oC. The reduction reaction was rapidly occur within 60 min. SEM and XRD were used to analyze the solid composition and morphology of spent oxygen carrier showed the morphology and structure of carries oxygen before and after used, found calcium ferrite structure which can promote the combustion reaction by XRD and small particle size agglomeration of oxygen carrier occurred by SEM. The result of recyclability of mixed oxygen carrier in fixed bed reactor, the regeneration reaction weigh lost and gain at the first to fourth are stable and reduction reaction in fluidized bed reactor is rapidly occurred in 30 minutes by the first reduction reaction test give the highest amount and rate of carbon dioxide. Concluding that 20 wt.% Fe2O3/CaSO4 could be used in CLC process of both gaseous and solid fuels.