摘要
针对丙烷／丙烯的氨氧化体系分别进行热力学分析，计算主、副反应的标准摩尔反应焓变、标准摩尔反应吉布斯自由能变（△rGm）和热力学平衡常数（K），采用吉布斯自由能最小算法，用热力学HSC6．0软件计算主反应达到平衡状态时n（O2）：n（丙烷／丙烯）（氧比）对丙烷／丙烯平衡含量的影响。研究结果表明，在473～773K，丙烷／丙烯氨氧化主、副反应的△，繇均小于0，反应均可向正方向自发进行；在相同温度下对比主、副反应的△rGm，生成CO2、CO、氢氰酸和乙腈副反应的吉布斯自由能变值较小，且绝对值较大，热力学角度分析更有利于副产物的生成；与丙烯氨氧化相比，丙烷氨氧化主反应的△rGm较小，K较大，更有利于反应向正方向进行；在温度低于700K、主反应达到化学平衡时，氧比从2．0提高到5．0对丙烷／丙烯的平衡含量影响较小。
The thermodynamics of propane/propene ammoxidations to acrylonitrile was studied. The standard molar enthalpy changes, standard molar Gibbs free energy changes and thermodynamic equilibrium constants（K） of as well as sone side reactions were calculated, respectirely. The effects of n（O2）： n（propane/propene）（oxygen ratio） on the equilibrium contents of propane and propene were investigated by means of the Gibbs free energy minimization method and Software HSC 6.0. The results showed that, when reaction temperature was in the range of 473-773 K, the standard molar Gibbs free energy changes were all less than zero, so the reactions could occur spontaneously. At the same temperature, the standard molar Gibbs free energy changes of forming carbon dioxide, carbon monoxide, hydrogen cyanide and acetonitrile are smaller but their absolute value are greater, which means the side-products can form more easily. For the propane ammoxidation, the standard molar Gibbs free energy changes are smaller and the K values are greater than those of the propene ammoxidationm, so the propane ammoxidation easily occur thermodynamically. When the ammoxidation reached the chemical equilibrium below 700 K, the effects of the oxygen ratio, which increased from 2.0 to 5.0, on the equilibrium contents of propane and propene were small.
出处
《石油化工》
CAS
CSCD
北大核心
2016年第11期1315-1321,共7页
Petrochemical Technology
关键词
丙烷
丙烯
氨氧化
丙烯腈
热力学
平衡常数
profane
propene
ammoxidation
acrylonitrile
thermodynamics
equilibrium constant
