Effects of the Components of Coal Hydro-liquefaction Residue on Its Rheological Characteristics

Abstract

Four kinds of typical coal liquefaction residue samples, coming from Shenhua coal liquefaction pilot plant, were used to investigate the effects of components of residue, separation time, and temperature on its rheological characteristics. Coal liquefaction residue is a non-Newtonian pseudoplastic fluid whose apparent viscosity decreases with increasing shear rate. Moreover, the residue has high viscosity at the initial softening temperature, and its viscosity drops greatly with increasing temperature. The oil content in residue has a great effect on the decline of the apparent viscosity of residue. The asphaltene can increase the apparent viscosity at lower temperatures but decrease it at higher temperatures. However, the solid only increases the apparent viscosity as it can be neither softened nor dissolved to become fluid. After simulating the separation condition, it is found that prolonging the separation time and enhancing the separation temperature will increase the apparent viscosity of residue, which is bad for preventing pipes from being blocked. So choosing the right separation time and separation temperature is necessary to actual industrial production.