煤加氢液化残渣的流变特性研究

煤加氢液化残渣的流变特性研究

  • 摘要: 采用从煤直接液化实验装置取得的液化残渣,研究了它的流变性及温度和油、沥青质、固体含量对其流变性的影响。液化残渣是剪切变稀的非牛顿型假塑性流体,非牛顿指数随温度升高而不断减小,温度越高越接近牛顿流体行为。液化残渣对温度非常敏感,在升温过程中其表观黏度下降很快,且没有出现黏度峰。在液化残渣中加入少量的循环油后其表观黏度大幅下降;而在加入少量沥青质后则表现出低温下黏度变大,高温下黏度变小的现象;固体含量则始终是黏度增大的因素,表明其黏度与油、沥青质和固体含量关系密切。液化残渣的黏度-温度关系符合Arrhenius关系式,但在升温过程中出现了拐点,低温段的黏流活化能比高温段的要大。

     

    Abstract: Coal liquefaction residue (CLR), coming from a direct coal liquefaction pilot plant, was used to investigate its rheological characteristics and the effects of temperature and oil, asphaltene, as well as solid content on its rheological characteristics. CLR is a kind of nonNewtonian pseudoplastic fluid, whose viscosity index decreases with increasing temperature, and approaches Newtonian fluid behavior at high temperature. The apparent viscosity of CLR drops greatly without peak as it is sensitive to temperature. After adding a little recycled oil (REC) into CLR, its apparent viscosity decreases remarkably. However, after the addition of a little asphaltene into CLR, its apparent viscosity increases at a low temperature and decreases at a high temperature. In addition, solid content is the factor of making the apparent viscosity increase all the time. All the results indicate that the apparent viscosity of CLR has a close relation with oil, asphaltene, and solid contents. The relationship between the apparent viscosity and temperature can be expressed by Arrhenius Equation. But there is a flex point during heating, and the viscous flow activation energy at the low temperature is greater than that at the high temperature.

     

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