微界面强化重油浆态床低压加氢的传质基础

Mass transfer basis of low-pressure hydrogenation for heavy oil in microinterface-intensified slurry-bed reactor

每年将数亿吨重油加工成轻质馏分或化工原料关系到我国国家能源安全和能源资源的高效利用。然而传统的重油浆态床加氢反应器(TSR)一般都是在高压下运行,这会产生一系列负面影响。本文发展了一种新的加氢方法——微界面强化浆态床加氢反应器(MISR),构建了MISR中气泡Sauter平均直径d32和气-液相界面积a以及能量耗散率ε数学模型,并建立了冷模模拟实验体系d32和a的测试系统。理论计算结果表明,MISR中氢气传质速率远大于TSRs,这为MISR中重油高效、低压加氢提供了理论依据。实验研究表明,在实际操作条件下,当气液比(氢/油)从10变化到150时,MISR中d32在220~420μm范围内。与高压操作下的TSRs相比,MISR内气液界面面积和氢传质速率分别提高了20~100倍和20~50倍。分析显示,d32和a的理论计算结果与实测值的误差均在15%以内。

The processing of hundreds of millions of tons of heavy oil into light distillates or chemical raw materials every year is related to Chinese national energy security and efficient use of energy resources.However,the traditional slurry-bed reactor(TSRs)for heavy oil hydrogenation is generally operated at very high pressure which causes a series of negative effects.Herein a new hydrogenation method called microinterface-intensified slurry-bed reactor(MISR)was developed for the low-pressure hydrogenation.The mathematical models regarding bubble Sauter mean diameter d32 and gas-liquid interfacial area a as well as energy dissipation rateεin the MISR were proposed for predicting d32 and a.Also a cold-mode simulated experimental system was set up for the measurement of d32 and a.Theoretical results showed that the mass transfer rate of hydrogen and its amount from gas phase into liquid phase in the MISR are much bigger than those in the TSR,which provides a theoretical basis for the efficient and low-pressure hydrogenation of heavy oil in the MISR.Experimental study displayed that d32 in the MISR is in the range of 220—420μm when the gas-liquid ratio(hydrogen/oil)changes from 10 to 150 in the practical operation conditions.Compared with TSR under high pressure operation,the gas-liquid interface area and hydrogen mass transfer rate in MISR are increased by 20—100 times and 20—50 times,respectively.Analysis shows that the errors between the theoretical calculation results of d32 and a and the actual measured values are both within 15%.