Tuning alkylation reactions with temperature in near-critical water

✍ Scribed by Karen Chandler; Charles L. Liotta; Charles A. Eckert; David Schiraldi

• Publisher: American Institute of Chemical Engineers
• Year: 1998
• Tongue: English
• Weight: 754 KB
• Volume: 44
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690440915

✦ Synopsis

Quantitative kinetics for the alkylation reactions of phenol and p-cresol with tert-butyl alcohol in near-critical water as a function of temperature are reported. The reaction products of the alkylation reactions were ortho-and para-substituted phenols, which are used extensively as antioxidants in numerous polymer systems. A new experimental reaction apparatus was designed, constructed, and successfilly operated to allow pressure control and sampling of the reaction .lystems, which provided rate constants in the temperature range 250 -300°C. Additionally, activation energies and heats of formation were calculated fvom the temperature dependence of the rate constants, and orthosubstitution was found to be exothermic whereas para-substitution was found to be endothermic. These results demonstrate that product distribution of the alkylation reactions could be tuned with temperature to produce specific products.