Polyester conversion by homogeneous catalysis for separating and recycling ammonia from biogas

• Published in: The Science of the total environment 2024-01, Vol.907, p.168138-168138, Article 168138
• Main Authors: Han, Zhangliang, Yan, Yubo, Pang, Xiaobing, Zhang, Aoran, Hu, Zhong-Ting, Wenren, Gutian, Lan, Senchen, Sun, Dezhi
• Format: Article
• Language: English
• Subjects: Ammonia adsorbent; Ammonia recovery; Biogas purification; Plastic circulation; Polyester
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.168138

Biogas is being promoted as a renewable and clean energy source. However, NH3 is a precursor of NOx and PM2.5 within the biogas, threatening ecological and human health. Therein, recycling waste NH3 from the biogas as a raw material of nitrogen fertilizer was tested by optimizing polyester as a sorbent material. After homogeneous catalysis, the converted polyester significantly increased the NH3 adsorption sites within polyester nanopores; correspondingly, the NH3 adsorption capacity increased from 0.56 mg·g−1 to 84.07 mg·g−1. Based on the structural characterization of polyesters, functional groups analysis before and after adsorption, and kinetic analysis during adsorption, chemical adsorption was identified as the dominant mechanism for NH3 adsorption. Moreover, selective adsorption and the regeneration experiments to optimize polyester indicated that NH3 could be efficiently separated from biogas with good regeneration performance. The results demonstrate the efficacy of recycling waste polyester and NH3 from the biogas. [Display omitted] •Polyester was converted into NH3 adsorbent by a homogeneous catalysis strategy.•An adsorption mechanism was identified between the optimized polyester and NH3.•Waste NH3 in biogas was recovered as the raw material for nitrogen fertilizer.•Purification of NH3 in biogas can mitigate atmospheric pollution.