Optimization of regeneration protocol for Pd/Ag/α-Al2O3 catalyst of the acetylene hydrogenation process using response surface methodology

Abstract

The regeneration protocol of deactivated industrial Pd/Ag/α-Al2O3 catalysts, used during acetylene hydrogenation, was studied. A three-level, four-parameter Box–Behnken design (BBD) was applied in order to investigate and optimize the regeneration parameters for the regeneration of deactivated catalysts. The effect of O2 injection temperature (165–400 °C), steam injection rate 1.2–5 (ml h−1), maximum regeneration temperature (400–500 °C) and the time of section (III) (2–6 h) was investigated in regeneration performance. The catalyst regeneration performance was determined using a TGA apparatus to evaluate the remained coke and hydrocarbons. Based experimental results, regeneration at lower regeneration temperatures could significantly prevent the sintering and reduction in the catalyst surface area. The optimization of regeneration protocol improves the catalyst regeneration performance compared with conventional industrial protocol. Some deactivated and regenerated catalysts were characterized by means of field emission scanning electron microscopy (FESEM) and Brunauer–Emmett–Teller (BET), inductive coupling plasma (ICP) spectroscopy, energy dispersive X-ray spectroscopy (EDX) techniques in addition to thermogravimetric analysis (TGA).