| Viscosity characteristic of coal-oil slurry plays an essential part in direct coal liquefaction process and has big influences on the abilities of coal-oil slurry transportation and liquefaction, as well as the designs of pipeline and preheater. For guiding the industrial production application of ShenHua direct coal liquefaction, the viscosity changes of four types ShenHua coal-oil slurries with different contents of inertinite (SHV, SHB, SHG, SHI) were observed on the condition of rising temperature and atmosphere. The effects of temperature, solvent property, coal kind and coal concentration on the viscosity of coal-oil slurry were investigated. Besides that, the possibility of improving slurry's viscosity through coal blending, the effect of pre-swelling treatment at atmosphere on coal-oil slurry viscosity and the swelling rates of different slurries were observed. Base on the collected data, the fitted equations for predicting the coal-oil slurry viscosity during the process of slurrying and high temperature heating were derived.The results indicate that:the temperature, coal kind, solvent character and the swelling property are the main factors influencing the viscosity of coal-oil slurry. Because of the highest inertinite content, SHI-oil slurry has the biggest viscosity in all four kinds of coal-oil slurries, and due to the highest moisture content and large inertinite contents, SHG-oil slurry has bigger viscosity and lower swelling rate than SHB/SHV-oil slurry on the same condition. The coal blending test of SHB and SHG can improve the viscosity of SHG-oil slurry in a certain extent, especially at high temperature. During the heating at atmosphere, the solvent character plays a important role in effecting the viscosity changes of coal-oil slurry during the low temperature period (eg.≤80℃), then the co-action of swelling and solvent loss is the main factor influencing the viscosity changes of coal-oil slurry at high temperature period (eg.≥120℃). |
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