Experimental Study on Co-Pyrolysis Characteristics of Lignite Mixed with Biomass Mixture

Co-pyrolysis characteristics of lignite mixed with biomass mixture in different proportions were studied with a thermogravimetric analyzer,in which the latter one is prepared with 13 kinds of biomass in a certain proportion,such as straw,rice hull,maize cob,saw dust,branch and leaves of salix psammophia and salix mastud,alfalfa,bulrush,windryegrass etc.;critical temperature below which biomass volatiles stop separation is calculated while the separation temperature of lignite volatiles reasonably defined.Test results show that under co-pyrolysis conditions,the generation rate of pyrolytic product is basically the weighted average of the concerned matter's under each independent pyrolysis condition.In case the biomass mixture accounts for 20%～40%,the volatile releasing temperature of lignite will be lower than that under its singular pyrolysis condition,due to the promotion function of high alkali metal and CaO content and large H/C ratio contained in biomass.While if the biomass mixture accounts for 50%,the volatile releasing temperature of lignite will obviously be higher than its independent pyrolysis,due to the inhibiting function of biomass,which is low in density and easy to get soft,therefore restrictiing the release and diffusion of lignite volatiles.Figs 5,tables 3 and refs 17.