Effect Of Microwave Pretreatment On The Pyrolysis Characteristics Of Biomass And Municipal Sludge

With the rapid development of modern society,the requirement for energy is getting stronger.However,fossil energy is a kind of non-renewable energy source.In order to alleviate the coming of the energy crisis,it is urgent to conduct in-depth research on pyrolysis to produce bio-oil,a technology that recycles waste biomass into energy.Based on the biomass pyrolysis,microwave pretreatment method is studied in this paper,and the pyrolysis characteristics of the biomass(water hyacinth,pine sawdust)pyrolysis,water hyacinth and municipal sludge catalytic co-pyrolysis under microwave pretreatment are further studied.In this paper,the effects of microwave pretreatment conditions are analyzed by liquid phase product distribution,kinetic parameters and blending ratio.This article uses several experiments to study the process and reaction products of the co-pyrolysis under microwave pretreatment,as follows:(1)In the microwave pretreatment of biomass pyrolysis experiment,microwave pretreated water hyacinth catalytic pyrolysis experiments showed that pretreatment effectively damaged the cellulose surface and made it easier for volatile components to escape from the inside and it also cause a repolymerization reaction inside the water hyacinth.Microwave pretreatment will also increase the activation energy of water hyacinth,from 69.21 to 89.78kJ/mol.Most of the pyrolysis liquid products are ketones,followed by phenols and sugars.With the deepening of microwave pretreatment,the relative content of acid increased from 0%to 9.25%and then decreased to 4.28%.Although microwave pretreatment can promote the decomposition of pine sawdust,too long microwave treatment time can easily cause the repolymerization of pine sawdust,which will cause a small DTG peak between 400?450?.The relative content of ketones in the microwave pretreated pine sawdust catalytic pyrolysis products reached 55.80%.Pretreatment conditions with quality improvement in the product appeared in P567T10CaO,the relative content of phenol increased from 3.63%to 23.95%,and the relative content of aldehydes increased from 0%to 5.99%(2)Under microwave pretreatment conditions,the co-pyrolysis of water hyacinth and municipal sludge is promoted.When water hyacinth accounts for 50%,it shows the best synergy effect.Most of the liquid phase products are aldehydes,phenols,ketones and aliphatic hydrocarbons.When the sludge accounted for 100%,it had the highest relative content of aliphatic hydrocarbons,reaching 18.67%.The presence of acid was not detected in the co-pyrolysis experiments,which benefit for the subsequent utilization of bio-oil.The microwave pretreatment power and processing time will affect the co-pyrolysis of water hyacinth and municipal sludge.As the degree of microwave pretreatment getting stronger,the performance of co-pyrolysis also gets promoted,and the oxygen content of the pyrolysis liquid product can be continuously reducedIn summary,microwave pretreatment can effectively improve the catalytic co-pyrolysis characteristics of water hyacinth and municipal sludge,reduce the viscosity and oxygen content of bio-oil,and cut down the cost of storage and transportation,which has good practical prospects.