Production of Benzene by the Hydrodemethylation of Toluene with Carbon‐Supported Potassium Hydride
Fei Chang, Alexey Fedorov
Abstract
Abstract The hydrodemethylation (HDM) of toluene to benzene is an industrial process performed at elevated temperatures (≈500 °C and higher). Here, it was reported that heating graphite‐supported potassium hydride (KH/C) with toluene under H 2 atmosphere provided benzene already at 125–250 °C. Depending on the H 2 pressure, the reaction was either substoichiometric ( ≤11 bar) or catalytic ( ≥50 bar) with respect to KH, indicating that KH may serve as a radical chain initiator. At 250 °C, the selectivity to benzene was 98 and 63 % when using 6 and 80 bar of H 2 , respectively, owing to the competing formation of cyclohexane and methylcyclohexane at high H 2 pressure. The used KH/C material was amenable to recycling without a notable loss in the yield of benzene.