煤与生物油的成浆性能研究

利用不同煤种的煤和生物油制备了不同浓度的生物油煤浆,考察了生物油煤浆的成浆浓度、表观黏度、流变特性和稳定性。结果表明,生物油煤浆是具有一定屈服应力的非牛顿流体,其流变特性可用宾汉姆方程来描述;生物油煤浆的屈服应力和表观黏度都随着固体浓度的增加而增大;随着剪切速率的增加,生物油煤浆的表观黏度减小;四种煤中,无烟煤的成浆浓度最高,可达42%,其含碳量高达49%,相当于同种煤制成的74%的水煤浆含量。烟煤次之,褐煤最低;生物油与煤粉之间能够形成絮凝性的大分子网络结构,使得生物油煤浆存在屈服应力并能够保持良好的静态稳定性,4.0~5.0 d天没有软沉淀产生,数月没有硬沉淀产生。

Properties of coal and bio-oil slurry

Coal bio-oil slurries (CBS) with different coal concentrations were prepared by mixing different type of coal and bio-oil. The apparent viscosity, rheological properties, maximum solid concentration and static stability of the prepared CBS were examined. The result shows that CBS are non-Newtonian fluid with a certain yield stress, and the rheological behavior of CBS can be described by the Bingham plastic fluid model. Both the apparent viscosity and the yield stress of CBS increase with increasing of solid concentrations. The apparent viscosity decreases with increasing of shear rates. The solid concentration of stable CBS prepared by Yangquan anthracite can reach as high as 42% without any additives, followed by bituminous coal and lignite. The flocculation network structure formed by coal particles in the bio-oil can keep good static stability of CBS for 4.0~5.0 days without formation of soft sediment, and for months without hard sediment.