Pyrolysis of Delonix regia using metal oxide catalysts and solvent effect on fuel fraction of bio-oil

Delonix regia (DR) lignocellulosic biomass waste contributes to large quantities of daily solid waste which is having high volatile matter that can be utilized for the production of bio-oil by pyrolysis. The pyrolytic raw bio-oil consists of both fuel and non-fuel fractions which can be separated by organic solvents. Further, application of mixed or individual metal oxide catalysts in pyrolysis reactor along with the feed reduces the corrosiveness and improves stability of pyrolytic bio-oil. Therefore, novelty statement includes catalytic pyrolysis of DR carried out in the presence of mixed metal oxide catalysts, TiO2 and ZnO; followed by separation of fuel and non-fuel fractions of pyrolytic bio-oil using dichloromethane and n-hexane solvents. The improvement of product qual-ity was realized by catalytic activity though the yield is almost unaffected compared to that of non-catalytic pyrolysis. Addition of solvents, helped improving quality of bio-oil by separating out non-fuel phase from it. Each experiment repeated thrice to ensure repeatability and reliability. Higher heating value (HHV) of pyrolytic raw liquid oil increased by 16.2% by the use of catalyst compared to that of non-catalytic pyrolytic raw liquid oil whereas the pH enhanced from 3.72 to 4.77, which indicated catalytic bio-oil has become less acidic. In addition, the physical and fuel properties of fuel fraction obtained by n-hexane are found to be superior to those obtained by dichloromethane. For instant, HHV of fuel portion separated with n-hexane is 23% higher than that obtained with dichloromethane. Density of fuel part obtained by n-hexane was found to be 0.74 g/ml (close to that of commercial gasoline) which is much low as compared to that obtained by using dichloromethane that is having density of 1.01 g/ml. Fourier -Transform InfraRed (FTIR) spectroscopy and proton Nuclear Magnetic Resonance (NMR) spectroscopy of fuel fraction of liquid product indicated partial deoxygenation of bio-oil by separating it with n-hexane.