ALKYLATION OF ISOBUTANE BY ETHYLENE - A THERMODYNAMIC STUDY

Alkylation of isobutane by ethylene produces mainly hexanes, but a var iety of other compounds, alkanes or alkenes, may be formed by secondar y reactions such as successive alkylations, isomerization, and ethylen e polymerization. The equilibrium distribution of products is evaluate d in the temperature range 280-680 K and at various initial compositio ns and pressures. Isomer groups are treated using Alberty's formulatio n. Calculations show that alkenes are thermodynamically unstable under usual reaction conditions. The equilibrium amounts of alkanes are suc h that C6 much greater than C-8 much greater than C-10 and heavy alkan es also appear unstable. The selective formation of particular isomers (dimethylbutanes, trimethylpentanes) is also integrated in the equili brium equations. The calculated compositions (C6:C-8:C-10) are compare d with experimental data.