Study On Ca-based Oxygen Carrier For Chemical-looping Combustion Fueled By Gas

The emissions of CO2from fossil fuel combustion have made great impact on globalwarming, which is also the main reason to leading to global warming. Because of its use ofenergy cascade、improving the thermal efficiency of the system、the eradication of emissionof thermal NOx and internal separation of CO2, chemical-looping combustion technologyaroused widespread concern. CaSO4is considered to be the most potential oxygen carrierfor application because of its large oxygen capacity, low cost, environmentally friendlycharacteristic, etc. Simulative and experimental study of calcium-based oxygen carrier inchemical-looping combustion application have been done in this paper.The reaction between CaSO4and syngas has been simulated and calculated. Theresults showed that: the fuel has better conversion rates while reducing the release of sulfurwhen FR temperature was915℃, ΦFR=1, under atmospheric pressure condition. We canalso suppress the release of SO2and formation of CaO by introduced excess air intoAR.CaSO4oxygen carrier containing lots of CaO is tested in fixed bed CO CLC testunder different temperatures and reduction atmospheres to study the release of SO2, COS.In high CO2concentration conditions, as the temperature increases, the release of SO2increases with decreasing of concentration of COS. At low CO2concentration conditions,as the temperature rises, the concentration of SO2and COS will both increase. Under sametemperature condition, as CO/CO2atmosphere increases, SO2release decreases, and therelease of COS increases. The higher the temperature, reaction between CaSO4and COproduce more CaO and SO2, leading to inactivation of oxygen carrier. Samples containingCaO particles under conditions of927℃, played a good desulfurization effect.CaSO4oxygen carrier containing lots of CaO is tested in fixed bed CH4CLC testunder different temperatures to study the release of SO2,COS,H2S. There should be asuitable temperature so that the reaction can not only obtain a high conversion rate, also it ispossible to effectively suppress the emission of sulfur contaminants.