费托合成产物分布的热力学平衡分析  

Thermodynamic equilibrium analysis of product distribution for Fischer-Tropsch synthesis

作　　者：高军虎[1,2,3] 吴宝山[1,3] 杨勇[1,3] 郝栩[1,3] 李永旺[1,3] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室 [2]中国科学院研究生院,北京100049 [3]中国科学院山西煤炭化学研究所煤间接液化国家工程实验室,山西太原030001

出　　处：《计算机与应用化学》2013年第1期71-75,共5页Computers and Applied Chemistry

基　　金：国家杰出青年科学基金(20625620);中科院知识创新项目(KJCX2-YW-N41)

摘　　要：费托合成通常被认为是个动力学控制的反应过程,因此对其热力学平衡的研究很少报道。本文基于Aspen Plus软件建立了费托合成产物物性数据库和热力学平衡分析模型,对费托合成的全局和局部热力学平衡进行了详细研究。结果表明:热力学上乙烯较其它长链烯烃更难生成,是解释实验观察乙烯偏低的重要原因;热力学平衡预测的总产物分布及烯烃、烷烃、醇的各组分分布均符合ASF分布规律,与实验观察的产物分布非常相似;若假定反应处于局部热力学平衡,则预测的产物分布链增长因子和烯烷比很接近实验观察值;热力学预测的反应条件对产物分布的影响也与实验结果基本一致。由此可见,热力学平衡是影响费托合成产物分布的重要因素,对反应机理研究至关重要。Fischer-Tropsch synthesis （FTS） has been generally considered as a kinetic-controlled reaction and thus its thermodynamic equilibrium investigations were seldom reported. Based on Aspen Plus software, a physical properties database and a thermodynamic equilibrium model for FTS were established in this study. The simulated results show that ethylene formation is not favored in thermodynamics compared to other long chain u-olefins, which may be a reason to explain the lower ethylene content in experimental product distribution. The estimated product distributions of total hydrocarbons, olefins, paraffins and alcohols are similar to experimental ones and essentially follow Anderson-Schulz-Flory distribution pattern. As a local thermodynamic equilibrium is assumed for the formation of hydrocarbon product, the chain growth parameter and olefirdparaffin ratio are very close to their experimental values under same reaction conditions. Accordingly, thermodynamic equilibrium is highly important to the reaction mechanism study of Fischer-Tropsch synthesis.

关 键 词：费托合成 产物分布 热力学 ASPEN PLUS 烯烷比 

分 类 号：O643[理学—物理化学] O642[理学—化学]