The fossil fuel consumption and pollutant emissions in a coal fired fluidized bed boiler could be reduced by biomass pyrolysis gas reburning.The influence of three kinds of biomass pyrolysis gases on the emission of N_2O in a laboratory scale fluidized bed was investigated using the mechanism of GRI3.0 in this paper.The results showed that:the effect of sawdust pyrolysis gas reburning on N_2O was more significant than that of rice husk and orange peel under the same conditions;the increase of initial oxygen content from 1% to 8% in flue gas would restrain the decomposition of N_2O;the N_2O decomposition was enhanced by increasing reaction temperature from 1073.15 K to 1323.15 K,and the decomposition rate may reach 99% at 1223.15 K.
HU XiaoYing DONG ChangQing YANG YongPing ZHANG JunJiao
The adsorption of C atoms on the α-Fe2O3（001） surface was studied based on density function theory（DFT） ,in which the exchange-correlation potential was chosen as the PBE（Perdew,Burke and Ernzerhof） generalized gradient approximation（GGA） with a plane wave basis set. Upon the optimization on different adsorption sites with coverage of 1/20 and 1/5 ML,it was found that the adsorption of C atoms on the α-Fe2O3（001） surface was chemical adsorption. The coverage can affect the adsorption behavior greatly. Under low coverage,the most stable adsorption geometry lied on the bridged site with the adsorption energy of about 3.22 eV; however,under high coverage,it located at the top site with the energy change of 8.79 eV. Strong chemical reaction has occurred between the C and O atoms at this site. The density of states and population analysis showed that the s,p orbitals of C and p orbital of O give the most contribution to the adsorption bonding. During the adsorption process,O atom shares the electrons with C,and C can only affect the outermost and subsurface layers of α-Fe2O3; the third layer can not be affected obviously.
