Cooperative physical separation of oil and suspended solids from methanol-to-olefin wastewater: A pilot study

Bing Liu; Qi Wei; Hongpeng Ma; Liang Chen; Yulong Chang; Jianqi Chen; Li Dai; Yuxiao Sun; Hao Lu; Hualin Wang; Wenjie Lv

doi:10.1016/j.jenvman.2022.114841

Cooperative physical separation of oil and suspended solids from methanol-to-olefin wastewater: A pilot study

J Environ Manage. 2022 Mar 10:311:114841. doi: 10.1016/j.jenvman.2022.114841. Online ahead of print.

Authors

Bing Liu¹, Qi Wei², Hongpeng Ma¹, Liang Chen³, Yulong Chang⁴, Jianqi Chen², Li Dai², Yuxiao Sun², Hao Lu², Hualin Wang¹, Wenjie Lv⁵

Affiliations

¹ National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai, 200237, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, China.
² National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai, 200237, China.
³ Shaanxi Yanchang Petroleum Yan'an Energy & Chemical Co.,Ltd., Yanan, 727500, China.
⁴ College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
⁵ National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai, 200237, China. Electronic address: lvwj@ecust.edu.cn.

PMID: 35278919
DOI: 10.1016/j.jenvman.2022.114841

Abstract

Methanol-to-olefin (MTO) is an important non-petroleum chemical process for the preparation of light olefins. However, the MTO process consumes copious amounts of water and produces large amounts of untreated effluent. Therefore, the realization of efficient wastewater treatment and recycling is key to the green low-carbon development of MTO. Here, a cooperative process combining swirl regenerating micro-channel separation (SRMS) and combined fibrous coalescence (CFC) technologies was proposed to separate high contents of oil and suspended matter in MTO wastewater. Using a pilot device with a treatment capacity of 1 m³/h, the average oil content in MTO wastewater decreased from 750 mg/L to <30 mg/L, while the average content of suspended matter decreased from 108 mg/L to <15 mg/L. Compared with a commercial MTO wastewater treatment process (olefin production capacity of 0.6 million tons per annum), the proposed method could reduce wastewater discharges and costs by 57% and US$ 0.23 million per annum respectively. Equipment costs and operational energy consumption were also reduced by 30% and >95% respectively. The combined process may provide the basis for the green and sustainable treatment of MTO wastewater and its recycling.

Keywords: Combined fibrous coalescer; Methanol-to-olefin; Oily wastewater; Suspended solids; Swirl regenerating micro-channel separator.