Study On Catalytic Pyrolysis Of Biomass

Compared with fossil fuels, biomass has been gaining intense attention as its abundant, renewable and CO2neutral.Biomass pyrolysis is considered as one of the most promising technology among the various utilization ways.Pyrolysis experiments of peanut shell, lignin and pine sawdust have been performed, the pyrolysis behavior of these three kinds of biomass are investigated by Thermogravimetric Analysis(TGA), the influence factors of bio-oil yield are further explored on2kg/h bench-scale fluidized-bed, then the best reaction conditions are obtained, and the pyrolysis products are analyzed at last. Sand is used as bed material, fractional condensation and electrostatic precipitator (ESP) are used to collect bio-oil in pyrolysis experiments.The maximum yield of peanut shell bio-oil,54.7%,is obtained at the optimal condition. The highest content of peanut shell condensation1bio-oil and electric catching oil (e-oil),is phenols, followed by ketones, aldehydes, and acids compounds.The maximum yield of ligin bio-oil,30.9%,is obtained at the optimal condition. Lignin pyrolysis products are relatively simple, ketones and phenols are the main components of ligin condensation1bio-oil, while in the ligin e-oil it is phenols, also15.1%of2,3-Dihydrobenzofuran is detected in the e-oil.The maximum yield of pine sawdust bio-oil,60.1%,is obtained at the optimal conditions. Phenols, ketones and acids are the main components of condensation1sawdust oil, Phenols whose content is47.4%, play a leading role in pine sawdust e-oil, ketone and acid compounds reduce significantly,10.6%of amides and9.6%of ethers compounds are detected too.In view of the bio-oil coking problem when bio-oil is collected by fractional condensation,the bio-oil collection device is retrofited. The air condenser combined with ice-water condenser and(ESP)is used to collect bio-oil.The results indicate that bio-oil yield doesn’t change after the collection device is retrofited, but the bio-oil distribution is different. The bio-oil coking problem is solved effectively when some high boiling point and larger molecule organic compounds are collected by the air condenser.Based on pyrolysis experiment,red mud, dolomite and HZSM-5are used to pine sawdust catalytic pyrolysis experiment, and the catalytic effect on pyrolysis and pyroh’sis products is investigated by changing the volume ratio of sand and catalyst. In red mud catalytic pyrolysis experiments, the catalytic effect is best when the catalyst volume fraction is100%,phenols decrease and ketones increase significantly, and ketones take up nearly50%of condensation oil, while phenols increase obviously in the e-oil, reach70%or so, red mud has a good effect on compounds enrichment and separation. In dolomite catalytic pyrolysis experiments, dolomite calcined at different temperature are used as bed material and catalyst,800℃calcined dolomite has the best catalytic effect compared with the blankexperiment, it doesn’t change too much in condensation oil, while in e-oil amides and ethers are eliminated, phenols, acids, aldehydes and ketones increase to some extent. In HZSM-5catalytic pyrolysis experiments,the catalytic effect is best when the catalyst volume fraction is50%, phenols in both condensation oil and e-oil increase, also some hydrocarbons and esters are produced.Biological methods and thermochemical methods are the main utilization ways of biomass.Biomass waste based on the biological treatment methods is used as thermochemical methods raw material,which maximizes the conversion efficiency of biomass energy. Red mud is used as a catalyst of biomass pyrolysis, which has a effective separation and enrichment effect of b-oil compounds, meanwhile provides a new utilization way of red mud.