Review of Bio-oil Upgrading Technologies and Experimental Study on Emulsification of Bio-oil and Diesel

Pyrolysis oil (also called bio-oils) produced from biomass is a promising substitute for fossil fuels. However, bio-oil has many shortcomings, such as high viscosity, high oxygenate content, low stability and low heating value. Therefore, it is hard for direct high-grade fuel utilization before upgrading. In this paper, bio-oil upgrading techniques, such as catalytic hydrogenation, catalytic cracking, catalytic steam reforming, catalytic esterification and emulsification, were first reviewed. Then, emulsification experiment between whole components bio-oil and 0# diesel was carried out. Bio-oil was obtained from Shabili timber on a fluidized fast pyrolysis reactor. Span and Tween series surfactants were used as emulsifiers. It was found that the optimal value of hydrophile and lipophile balance (HLB) value for bio-oil and diesel emulsification was approximate 6.