Reactive Distillation for Synthesizing Ethyl tert-Butyl Ether from Low-Grade Alcohol Catalyzed by Potassium Hydrogen Sulfate

Synthesis of ethyl tert -butyl ether (ETBE) from the reaction between ethanol (EtOH) and tert -butyl alcohol (TBA) in the presence of different acid catalysts (KHSO 4, NaHSO 4, H 2 SO 4, and Amberlyst 15) was investigated at low alcohol grade (mixture of 80 mol % water). Potassium hydrogen sulfate (KHSO 4 ) showed the highest selectivity among the tested catalysts. Other catalysts caused the dehydration of TBA into water (H 2 O) and isobutene (IB). In the top of the reactive distillation column with total reflux, the condensate was split into two layers. The upper layer contained ETBE with a more than 60 mole fraction.