Experimental Study On Co-pyrolysis Of Biomass And Waste Cooking Oil With Upgrading Process Of Bio-oil

A new two-stage fixed-bed reactor for pyrolysis of biomass is designed in thispaper for the pyrolysis of biomass and waste cooking oil. Impact factors on thepyrolysis products would be researched in the reactor.Experiments of single pyrolysis of corn-cob and co-pyrolysis of corn-cob/wastecooking oil are conducted in the fixed-reactor. Results show that some synergy effectsoccurred during the co-pyrolysis of corn-cob and waste cooking oil. The liquidproduct (also can be called bio-oil) yield raised from44.68wt%under thesingle-pyrolysis condition to63.53wt%under co-pyrolysis condition; on the otherhand，the solid and gaseous products decreased. The HHV of liquid product fromco-pyrolysis condition higher than that from single-pyrolysis, but their coke productsenjoy almost the same HHV. GC-MS and GC-FID analysis of liquid product show:bio-oil is consisted of various complex organic components. Concentration of tolueneand PX in the co-pyrolysis condition are higher than that in the single-pyrolysis, butlower concentration of acetic acid, furan and oleic acid; GC-TCD analysis of gaseousproduct show: non-condensable gases of the pyrolysis vapours have the potential to beused as city gas.Further studies focus on the factors affecting the co-pyrolysis products. It hasbeen proven that carrier gas flow rate have small impact on the yields and quality ofpyrolysis products. In the experiments of two factors with three levels (WCO tocorn-cob mass ratio varies from0.1to1and reaction temperature changes from500℃to600℃). Some conclusions have been obtained, liquid product yield increased withthe enhancement of WCO:corn-cob mass ratio,70.62wt%is achieved as the highestyield. Compared with WCO:corn-cob mass ratio, temperature has slighter influenceson pyrolysis products. Within the same reaction temperature,550℃is verified to bethe optimal temperature for producing bio-oil. Yield of solid product reduced with theincreasing of WCO:corn-cob mass ratio and temperature. Oxygen content in thebio-oil decreased with the increasing of WCO:corn-cob mass ratio and temperature.While oxygen content of coke products have little association with the two factors.GC-MS analysis of bio-oil shows: with the enhancement of WCO:corn-cob massratio, both the relative amounts of hydrocarbons and carboxylic acid increased andtheir increasing rate reduced; Relative amounts of phenols, alcohols and acetone decreased apparently while other constituents changed slightly. The same constituentchanged largely with different temperature under different WCO:corn-cob mass ratio,it may due to the WCO:corn-cob mass ratio have more impacts on pyrolysisproduction than that of temperature.An optimal operating condition was proposed to be upgraded by HY online. Theresult shows: with the addition of HY zeolite, the oxygen content of bio-oil decreasedsignificantly, HHV of bio-oil enhanced visibly while the yield decreased a little.With the addition of HY, relative amounts of hydrocarbons and acetone in thebio-oil raised greatly; Relative amounts of acetic acid and phenols decreasedapparently. But what is astonishing is:1,1-diethoxy-ethane increased significantlyfrom1.11%without HY to17.01%with HY which maybe due to the complexreaction among aldehydes, acetones and ester. While compared bio-oil fromco-pyrolysis with bio-oil from conventional pyrolysis, quality of former bio-oil isbetter who enjoys a higher relative amounts of hydrocarbons and heating value. Whatis more, after upgrading by HY zeolite, the upgraded bio-oil have more potentials tobe alternative fuels. In the end, an innovative route of bio-oil refining was proposed.