Abstract
Catalytic activity of various solid acid catalysts is evaluated for the continuous hydroxyalkylation of p-cresol to [2,2′-methylenebis(4-methylphenol)] (DAM) in a fixed bed reactor. This is an industrially important process generally carried out in the presence of mineral acids. In the present study, we show that solid acids can be successfully used for this important process. The characterization of these solid acids is done using ammonia TPD measurement based on which the observed activity results can be explained. The performance of both batch and continuous operation has been studied for the hydroxyalkylation of p-cresol using the montmorillonite KSF/0 catalyst. The effect of reaction parameters such as mole ratio, temperature and catalyst concentration on the conversion of p-cresol and DAM selectivity have also been studied in both batch and fixed bed reactors. Significant difference is observed on the conversion of p-cresol and DAM selectivity with changing flow rate of reaction mixture in continuous operation.
