Viscosity reduction of heavy crude oil by co-heating with hydrothermal liquid product of cotton stalk

Abstract

Hydrothermal process (HT) is an economical and simple method in upgrading agriculture wastes. The liquid product obtained from HT is interesting because of abundant active chemical group. The present work tried to co-heat the HT liquid product of cotton stalk (CS) with heavy crude oil to reduce its viscosity. The optimization study was performed to obtain the best condition of co-heating and mechanism study was completed by comparing the viscosity reduction efficiency and analyzing group composition of crude oil before and after co-heating with HT liquid products of CS, cellulose, hemicellulose and lignin. The results show that the crude oil viscosity reduced obviously after co-heating with CS-HT liquid product under the optimized condition (220°C, 1 h, 3 g treatment liquid, 30 ml crude oil). The preliminary mechanism study results suggest that the main function component of CS that cause viscosity reduction of heavy oil is lignin. The current work provides a new idea of lignocellulosic biomass upgrading and heavy crude oil viscosity reduction.