Catalytic Pyrolysis Of Pinewood Over ZSM-5 And CaO For Aromatic Hydrocarbon

Lignocellulosic biomass is being studied globally as a feedstock for liquid biofuel and/or chemicals considering its large availability,carbon neutral and low cost.Up to date,several conversion routes have been studied to convert biomass to liquid fuel and chemicals,which involve various steps along with long residence times,and significantly increase the cost of biomass processing.Catalytic pyrolysis is a promising technology for yielding high selective aromatic hydrocarbon form biomass while the application of catalyst has been a hotspot for being capable to deoxygenate pyrolytic vapor and enhance its fuel properties.Catalytic fast pyrolysis of biomass involves the rapid heating?500?C/sec?under an inert atmosphere in the presence of catalyst whereas 400-600?C temperature needs to maintain.The main objective of this research is to find out the suitable biomass to catalyst ratio for yielding high selective aromatic hydrocarbon and improve its fuel properties.1)A higher amount of oxygenates is the main constraint for higher yield and quality of aromatics in catalytic pyrolysis while a study of hydrocarbon production with a balance of reactive species lies importance in the catalytic upgrading of pyrolytic vapor.Catalytic pyrolysis of pinewood sawdust over acidic?ZSM-5?and basic?CaO?catalyst was conducted by means of Py-GC/MS analysis to evaluate the effect of biomass to catalyst loading ratio on selective aromatic hydrocarbon production.Catalytic pyrolysis with four different biomass to catalyst ratios?0.25:1,0.5:1,1:1,and 2:1?and non-catalytic pyrolysis were conducted.It has been obtained that ZSM-5showed better catalytic activity in terms of a high fraction of aromatic hydrocarbon.The ZSM-5catalyst showed a potential on the aromatization as the yield of aromatic hydrocarbon increased with a higher amount of ZSM-5 catalyst and the highest yield of aromatics?42.19 wt.%?obtained for biomass to catalyst ratio of 0.25:1.On the other hand,basic CaO catalyst was not selective to aromatic hydrocarbon from pinewood sawdust but explored high deacidification reaction in pyrolytic vapor compared to ZSM-5 catalyst,whereas non-catalytic pyrolysis resulted in acidic species?13.45 wt.%?and phenolic?46.5 wt.%?.According to the results,ZSM-5 catalyst can only be suggested for catalytic pyrolysis of pinewood sawdust for aromatic hydrocarbon production.2)In order to promote aromatic hydrocarbon,catalytic pyrolysis of pinewood sawdust over combined catalyst was performed in Py-GC/MS and the effect of combined catalyst has been investigated.A maximum yield of 36 wt.%aromatic hydrocarbon was obtained from pyrolytic vapor of pinewood sawdust when the ratio of ZSM-5:CaO was 4:1.Large molecule compounds crack into small molecule compounds over combined catalyst.Addition of CaO significantly reduces the acidic species through deoxygenation reactions and converts oxygenates,like acid,aldehyde and ketone into aromatic hydrocarbon through hydrocarbon pool mechanism.It is noteworthy that catalytic pyrolysis of pinewood sawdust greatly influences the aromatic hydrocarbon yield over combined catalyst,whereas the presence of oxygenating species is minimal.Based on our result biomass to combined catalyst ratio 0.25:1?ZSM-5:CaO-4:1 wt.%?has been reported as suitable ratio for yielding high aromatic hydrocarbon and taken into account for further application.3)To explore the quality of bio-oil against the reported biomass to catalyst ratio,catalyticpyrolysis of pinewood sawdust over combined catalyst has been conducted in a fixed-bed reactor while all quality parameters have been addressed.The heating value,water content,acidity,viscosity,ash content,density,and solid content were 24.27±0.332 MJkg^-1,21±0.882%,4.1±0.145,17.29±0.328 mm²s^-1,0.06±0.001 wt.%,1.12±0.001 gcm^-3,and 0.21±0.012 wt.%,respectively,which indicates the quality of obtained bio-oil that meet the liquid biofuel standard ASTM D7544-12 for grade G biofuel.Based on our analysis and significance of this study,this research can be referred as a directory study or guideline for selection of suitable catalyst and biomass to catalyst ratio to maximize the aromatic production for future research.