Reactivation of an industrial spent catalyst as an environmental waste by ultrasound assisted technique for using in styrene production

摘要

In this study, the regeneration of a commercial spent catalyst for the ethylbenzene (EB) dehydrogenation was investigated and successfully utilized for styrene monomer (SM) production as a powerful catalyst. The spent catalyst as an environmental waste was regenerated in three steps: decoking of the spent catalyst, phase changing of the decoked catalyst and potassium injection to the phase changed catalyst. The spent catalyst was decoked by oxygen-nitrogen mixtures and crystalline phase change was achieved by water treatment. The potassium deficiency of the spent catalyst was compensated in an aqueous solution of 10 wt.% K2CO3 (99%, Merck) by ultrasound energy assisted technique for the first time. Evaluation of the catalyst activity showed that the styrene yield of the regenerated catalyst assisted by ultrasound energy was increased about 3.1% compared to that of fresh ones. The results also revealed that the spent catalyst could be rejuvenated to some extent of activity which can reproduce comparable performance and stability of fresh catalyst that is environmentally and economically beneficial. (C) 2016 Elsevier B.V. All rights reserved.