关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">甲醇, 正庚烷, 催化裂解, 吉布斯自由能, 平衡常数, 反应转化率, 烯烃产物, 平衡收率

Abstract: The thermodynamic model for the initial activation reaction of n-heptane before and after adding methanol is established according to the reaction mechanism of methanol activating n-alkanes. The enthalpy change, Gibbs free energy change, and equilibrium constant of each reaction at different temperatures are calculated using the five-parameter method. The thermodynamic system of methanol coupled n-heptane catalytic pyrolysis reaction is simulated using Aspen Plus software, and the effects of methanol addition amount, temperature, and pressure on the equilibrium composition of the coupled reaction are studied. The calculation results show that: compared with the initial activation cracking reaction of n-heptane, the methanol activation of n-heptane reaction has lower energy consumption, the heat absorption is about 15 kJ/mol, and the reaction is irreversible. Adding an appropriate amount of methanol is beneficial to improve the equilibrium yield of olefins. When the molar ratio of methanol to n-heptane is 1:1, the equilibrium yield of propylene is increased by about 15 percentage points. Compared with alkane products, the changes of temperature and pressure have a greater effect on the equilibrium composition of olefin products. The equilibrium yield of propylene has a maximum value with temperature changes, and low pressure is conducive to the formation of propylene.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">methanol, n-heptane, catalytic pyrolysis, Gibbs free energy, equilibrium constant, reaction conversion, olefin products, equilibrium yield