Treatment of wastewater from biomass pyrolysis and recovery of its organic compounds with char-assisted drying

Mofrad, A.Z., Gao, X.ORCID: 0000-0003-2491-8169, Oluwoye, I.ORCID: 0000-0002-0221-020X, Hayashi, J-I, Altarawneh, M.ORCID: 0000-0002-2832-3886 and Wu, H. (2022) Treatment of wastewater from biomass pyrolysis and recovery of its organic compounds with char-assisted drying. Fuel, 312 . Art. 122825.

Abstract

This study proposes a new process that treats pyrolytic wastewater (PWW) from biomass pyrolysis with char-assisted drying. It can be operated at two modes: (I) one-stage drying for PWW treatment; and (II) two-stage drying and condensation for both treating PWW and recovering valuable chemicals (e.g., acetic acid). The process is proved via drying the mixture of a char and a synthetic PWW solution containing acetic acid, acetol, furfural, and phenol at different temperatures (60, 80, and 105 °C) and char-to-PWW mass ratios (1.0, 1.5, and 2.0). The results, supported by density functional theory (DFT) calculations, demonstrate that under Mode I, the char captures over 97.1% of the organic compounds in the PWW at 60 °C and a char-to-PWW ratio of 2.0, while evaporating almost all the water. The evaporated stream can be potentially discharged into the atmosphere without condensation or condensed into wastewater with a significantly reduced content of total organic carbon. Under Mode II, the char-PWW mixture is sequentially dried at 60 and 105 °C, with the exhaust gases being separately condensed. This yields a stream of purified acetic acid solution (concentration: ∼76 wt%) concentrated by a factor of ∼6.3 (compared with the PWW), with a recovery rate of ∼29%.

Item Type:	Journal Article
Murdoch Affiliation(s):	Mathematics, Statistics, Chemistry and Physics Centre for Water, Energy and Waste Harry Butler Institute
Publisher:	Elsevier BV
Copyright:	© 2021 Elsevier Ltd.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/63476

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