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

•Wastewater from biomass pyrolysis is treated via char-assisted drying with two modes.•Mode I is one-stage drying for wastewater treatment.•Char captures ∼97.1% of organics in wastewater at 60 °C, while water is evaporated.•Mode II is two-stage drying and condensation for recovering valuable chemicals.•Under Mode II, a purified and concentrated acetic acid solution is obtained.