Experimental Study On Preparation Of Aromatics Of Catalytic Pyrolysis Of Nannochloropsis Sp./palm Kernel Shell

With the depletion of oil resources and the gradual increase of environmental pollution problems,it is imminent to develop green and environment-friendly renewable energy,catalytic pyrolysis of biomass provides a reliable way to produce high-value chemicals such as aromatics.The current research on the production of aromatics from lignocellulosic biomass has made great progresses,however,the steady supply of raw materials is the biggest obstacle to its large-scale application.As the representative of third generation biomass energy,the high value utilization of Nannochloropsis sp.received extensive attention from researchers.However,there are relatively hardly studies on the pyrolysis of aromatics by using Nannochloropsis sp.pyrolysis in the existing literature.The characteristics of mixed py roly si s of Nannochloropsis sp.and lignocellulosic biomass to produce aromatics need studying urgently.The main research content of this article are as follows.Taking Nannochloropsis sp.(NS)and palm kernel shell(PKS)as the experimental material,and using walnut shell(WS),pine(P),straw(S)as comparison raw material of lignocellulosic biomass,then the effects of mass ratio(1:0,7:3,1:1,3:7,0:1),heating rates(10,20,30,40 ?/min)on the mixed pyrolysis characteristics from NS/lignocellulosic biomass mixed pyrolysis were studied.TG-DSC was used to analyze the thermal coupling effect during the main weightlessness phase of mixed pyrolysis of Nannochloropsis sp.and lignocellulosic biomass,the results show that the pyrolysis process of Nannochloropsis sp.,lignocellulosic biomass and their mixture can be divided into four stages:dehydration,slow weight loss,rapid pyrolysis;Compared with the theoretical value,the experimental results of the weight loss and the rate of weight loss of NS/PKS mixed pyrolysis was improved,and the improvement degree is obviously superior to the other three lignocellulosic biomass.A synergistic effect was observed upon co-pyrolysis of NS/PKS.At different heating rates,the overall performance of walnut shell,palm kernel shell,pine,straw pyrolysis both took on the endothermic effect with thermal demanding values of 378.56-596.45 kJ·kg-1,160.35-704.55 k·kg-1,184.93-203.29 kJ·kg-1,126.19-1019.36 kJ·kg-1,respectively.An endothermic peak was obtained from Nannochloropsis sp.pyrolysis at 280-450 ?,the overall performance of Nannochloropsis sp.pyrolysis took on exothermic effect with thermal demanding values of(-814.76)-(-1191.52)kJ·kg-1.The pyrolysis of Nannochloropsis sp./lignocellulosic biomass presented low exothermic effect with thermal demanding values of(-95.14)-(-356.08)kJ·kg-1,indicating that the mixed pyrolysis achieved thermal coupling.The effects of mass ratio(1:0,7:3,1:1,3:7,0:1),reaction temperature(500,550,600,650,700 ?),and catalysts(Cu/HZSM-5,HZSM-5,CaO+HZSM-5)on the preparation of aromatic hydrocarbons from Nannochloropsis sp./lignocellulosic biomass mixed pyrolysis were studied in a fixed-bed reactor.It showed that the mixed pyrolysis of Nannochloropsis sp./shell biomass showed obvious synergistic effect on the preparation of aromatics,and the mixed pyrolysis effect of Nannochloropsis sp.and palm kernel shell is excellent.The optimum condition for aromatics preparation with a value of 30.39 area%was achieved at a temperature of 600 ? and a Nannochloropsis sp./palm kernel shell mass ratio of 1:1.By introducing Cu/HZSM-5 catalyst,the relative content of aromatics was further improved(42.65 area%).Such study provides a new approach for high-value utilization of Nannochloropsis sp.and palm kernel shell.