Study On The Reaction Performance For Chemical Looping Combustion

The crisises caused by the global warming have attracted more and more attention. In order to control the CO2 emission, a new combustion technology for CO2 capture without special CO2 separation equipment or more energy consumption is proposed. According to the principle of zero emission, chemical looping combustion could not only availably enrich CO2 concentration, but also increase the energy conversion efficiency and decrease the emission of various pollutants. The reaction performance of chemical looping combustion was examined by a fixed-bed reactor.After investigating the former-research of oxygen carriers in chemical looping combustion, a fixed-bed reactor and an infrared gas analyzer was designed according to our test. Eight kinds of sol-gel-derived Fe2O3/Al2O3 oxygen carriers were produced by the sol-gol method based on the primary Ni-based oxygen carriers and one in which was selected for the experiment later.NiO/NiAl2O4 oxygen carriers have been used for circular reaction with char/air and hydrogen/air in a fixed-bed reactor. We have analyzed the chemical mechanism by off-gas and oxygen carriers after circular reaction with XRD, ESEM and BET. The results show that: both Ni-based and Fe-based oxygen carriers reacted with CO2 and H2 rapidly. When they are reacted with CH4, the carbon deposit can be solved by controlling the reducing time of reaction. In the char/air cycle reaction, Ni-based oxygen carriers are good at the reaction velocity and Fe-based oxygen carriers are good at the reaction conversion ratio. Because of the low CO concentration in the flue gas, CO2 capture will be easier, which testifies the feasibility of chemical looping combustion of coal. The honeycomb structure of ash and the magnetism of Fe-based oxygen carriers provide the basis of separating the ash and the oxygen carriers. There isn't any sintering between different oxygen carriers. The oxygen carrier remains its beehive form.