Biogas upgrading with various single and blended amines solutions: Capacities and kinetics. (15th August 2022)

• Record Type: Journal Article
• Authors: Han, Siyu; Meng, Yuan; Aihemaiti, Aikelaimu; Gao, Yuchen; Ju, Tongyao; Xiang, Honglin; Jiang, Jianguo
• Is Part Of: Energy. Volume 253(2022)
• Publication Date: 2022-08-15
• Subjects: Amines solutions -- Biogas upgrading -- CO2 absorption capacity -- Kinetic model -- FT-IR analysis; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2022.124195
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Biogas is an important renewable energy and biogas upgrading which separate CH4 /CO2 to increase the heating value of biogas is necessary for its utilization. Amine scrubbing is a promising biogas upgrading technology. In this study, we applied various single and blended amines solutions for biogas upgrading and reconsidered the evaluation method by comparing the equilibrium CO2 absorption capacity ( q e ) and optimal CO2 absorption capacity under 90 vol% or 95 vol% pure CH4 requirement ( q 90 % C H 4, q 95 % C H 4 ). Three apparent kinetic models and Fourier-transform infrared spectroscopy (FT-IR) were applied to study the kinetics. The results showed that, compared with the q e, the new indicator q 90 % C H 4 and q 95 % C H 4 could better reveal the difference and improvements between various amines solutions and be more accordance with the real situation of biogas upgrading. The q 90 % C H 4 increased from 0.15 to 0.82–1.70 mol/kg after adding other amines with methyldiethanolamine (MDEA), but q e was almost the same. For kinetics, the fitting results of Avrami model are the best among the three models. FT-IR analysis before and after absorption showed CO2 formed different groups with different amine molecules. This study provided a new perspective and method on evaluation of amine scrubbing for biogas upgrading, contributing to future research and industrial application. Highlights: Various single and blended amines solutions were applied to biogas upgrading. The capacities of amines were evaluated by considering the methane purity. Capacity under CH4 purity requirement is a more suitable and objective indicator. Avrami model is most suitable for fitting the kinetic of biogas upgrading by amines. The mechanism of biogas upgrading using amines was investigated.