Hydrothermal alkaline conversion of actual acrylonitrile wastewater to organic acids

• Published in: Process safety and environmental protection 2020-12, Vol.144, p.93-99
• Main Authors: Shen, Zheng, Yu, Yibiao, Wang, Ke, Yue, Chang, Miao, Jia, Xia, Meng, Gu, Minyan, Zhang, Yalei
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetonitrile; Acids; Acrylic acid; Acrylonitrile; Acrylonitrile wastewater; Alkaline hydrothermal conditions; Conversion; Cyanide; Formic acid; Industrial wastes; Industrial wastewater; Nitriles; Organic acid; Organic acids; Reaction time; Resource; Sodium hydroxide; Succinonitrile; Wastewater
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2020.07.015

[Display omitted] •17 organic components were detected in the actual acrylonitrile wastewater.•Hydrothermal reaction conditions and pathways of three nitriles were studied.•The reaction conditions of actual acrylonitrile wastewater were optimized.•A new method of acrylonitrile wastewater recycling is provided. Acrylonitrile wastewater is a kind of highly toxic industrial wastewater, but it contains a lot of valuable chemical materials. In this study, by using the most promising hydrothermal technology, we investigated the best reaction conditions and possible reaction pathways for the conversion of the three nitriles (acrylonitrile, acetonitrile, and succinonitrile) to organic acids under alkaline hydrothermal conditions. Then, the reaction conditions for the conversion of actual acrylonitrile wastewater to organic acids were further optimized. The actual wastewater of acrylonitrile was converted into 1.33 × 104 mg/L acrylic acid, 1.98 × 104 mg/L formic acid and 9.40 × 103 mg/L acetic acid at optimal reaction conditions (reaction temperature 300 °C, reaction time 90 s, and initial NaOH concentration 1.0 mol/L). It is the theoretical basis of the application of the hydrothermal alkali-catalyzed method in the acrylonitrile wastewater resource engineering.