Study On The Enhanced Production Of 4-Ethyl Phenol From Catalytic Pyrolysis Of Biomass With 9,10-Dihydroanthracene

Fast pyrolysis technology can transform biomass into bio-oil containing a variety of high value-added chemicals,which opens up a new way for green chemical industry.However,the composition of bio-oil from conventional pyrolysis is complex and the yields of high-value products are generally low,which inhibits the application of bio-oil as chemical raw materials.Catalytic pyrolysis improves the economy of pyrolysis technology significantly by regulating the reaction process to selectively prepare high-value products.4-Ethylphenol(4-EP)is an important phenolic compound and widely used in chemical industry.Herbaceous biomass was used for selective production 4-EP under the catalysis of activated carbon(AC),but the yield was low.The fundamental reason is that biomass,with low hydrogen-carbon ratio,only provides limited hydrogen free radicals during pyrolysis,which is not conducive to the formation of saturated 4-EP.In addition,AC owns limited catalytic activity sites,which cannot catalyze the pyrolysis products adequately.Therefore,this paper proposes to add solid 9,10-dihydroanthracene(DHA)as hydrogen donor and nitrogen-doped biochar as catalyst to catalyze the pyrolysis of bagasse for 4-EP.1.Enhanced production of 4-EP from AC catalyzed fast pyrolysis of bagasse with DHA as a hydrogen donor.A novel way was put forward with DHA as a solid hydrogen donor to improve the selective production 4-EP from catalytic fast pyrolysis of bagasse over water activated rice husk carbon(RHAC)catalyst.Both pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and laboratory scale pyrolysis experiments were carried out on the 4-EP formation affected by various factors,in order to determine the optimal conditions for 4-EP production.The results indicated that DHA exhibited promising hydrogenation capabilities to improve 4-EP formation.In Py-GC/MS test,the 4-EP reached a maximal yield of 3.21 wt%with its corresponding selectivity of 22.96%at 350℃ under AC-to-bagasse(AC-to-BA)and DHA-to-bagasse(DHA-to-BA)ratios of 6:1 and 1:5,respectively.Whereas,the maximal 4-EP yield was only 2.18 wt%in the absence of DHA,indicating a yield increase of 47.2%by DHA.Moreover,laboratory scale experiments attained the highest 4-EP yield of 3.05 wt%and the corresponding selectivity of 16.31%.In addition,the possible hydrogenation mechanism of DHA in facilitating 4-EP formation was revealed.2.Enhanced production of 4-EP from N-doped biochar catalyzed fast pyrolysis of bagasse with DHA as a hydrogen donor.Based on hydrogen supply,nitrogen-doped biochar was prepared from walnut shell and used for catalytic pyrolysis of bagasse to produce 4-EP.RHAC,water activated walnut husk carbon(WSAC),and nitrogen-doped walnut husk carbon(N/WSAC)were tested on Py-GC/MS device to compare their catalytic activity for 4-EP.The results proved that N/WSAC possessed the best catalytic effect,which effectively promoted the hydrogenation of 4-Vinylphenol(4-VP)and its precursor,and almost completely transformed into 4-EP.In Py-GC/MS test,the 4-EP reached a maximal yield of 4.75 wt%at 350℃ under AC-to-BA and DHA-to-BA ratios of 3:1 and 7:20,respectively.Moreover,lab-scale experiments attained the highest 4-EP yield and the corresponding selectivity of 4.02 wt%and 25.53%with DHA.