Simple distillation to obtain bio-pitch from bio-oil for carbon anode production

Abstract

Utilizing renewable bio-pitch to replace coal tar pitch for carbon anode production is an attractive route away from fossil fuel dependence and environmental pollution. However, it is urgent but challenging for the quality to meet the standards of binder pitch. Herein, to improve the quinoline insoluble content and coking value, the distillation characteristics of two bio-oils as well as the effects of distillation temperature, time and additives on the physicochemical properties of bio-pitch were investigated. The results showed that when the temperature was increased from at 160 °C to 220 °C, the solid phase products of BO1 and BO2 bio-oil distillation decreased by 17.6 % and 14 %, respectively, and the toluene insoluble content, coking value, quinoline insoluble content, and the softening point of the bio-pitch gradually increased. Prolonged distillation time showed limited improvement in asphalt properties. The addition of appropriate amounts of styrene, isopropanol or biochar improved the coking value and quinoline insoluble content of bio-pitch. This work provided a reference for the preparation of bio-pitch that meets the criteria for binder use.