Microstructure Characterization And Physicochemical Properties Of Biochar

Study on the properties of biochar is the focus of the research work.It is well known that various of raw materials and carbonization technology is the main cause of the variability of the physicochemical properties.Thus,this article took 31 kinds of various biomass wastes such as maize straw,peanut shell and pine sawdust et al.as raw material,produce 264 kinds of biochars with difference physicochemical properties,from difference carbonization parameters and took these biochars as research subject to study its properties by using Standardized Product Definition and Product Testing Guidelines for Biochar recommended by IBI.Constructing a database of basic properties,and then carry out systemic research on the influence mechanism of raw material types and carbonization parameters on physicochemical properties of biochar.Results of this study provide a theoretical basis for the selection and design of biochar according to the actual demands.The researching results were as follows:During carbonization of biomass,the color of biochars become darker,the volume shrinkage,porous structure clear,multilayer structure of cell wall disappear.The morphology and microstructure are the main basis for identification of biochars and biochars analogues.The rang of biochars yield from 22.83%-96.96%and the average value is 40.66%.Biomass of high lignin content and process parameters(HTT>500? and RT>30min)should be selected to produce biochars with yield maximum value.The rang of biochars pH from 3.18-12.71 and the average value is 9.06.Biomass of high lignin content and process parameters(HTT?500?C and RT?30min)should be selected to produce biochars with pH maximum value.The rang of biochars pH from 43.40%-85.90%and the average value is 64.60%.Biomass of high lignin content and high carbonization temperature should be selected to improve biochars stability.With the HTT rises,the safty of biochars decreased.Biomass with low content of heavy meatal as well as low carbonization temperature(or HTT=700?)should be selected to improve biochars safty.Due to the less nutrient value in biochars(0%mineral nitrogen,0.10%P2O5,1.79%K2O),it should be used cooperatively with fertilizer to increase crop yield.