Biochars derived from by-products of microalgae pyrolysis for sorption of gaseous H2S. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Ma, Chi; Zhao, Yue; Chen, Hui; Liu, Yangxian; Huang, Renkun; Pan, Jianfeng
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: H2S adsorption -- KOH modification -- Microalgae biochar -- Hg0 removal; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107370
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: KOH-modified biochars derived from by-products of microalgae pyrolysis were prepared to adsorb gaseous H2 S. Influences of various parameters (e.g., mass ratio between KOH and biochars, and adsorption temperature) on desulfurization performance were investigated. Kinetics/mechanisms of H2 S adsorption, and reutilization of spent adsorbents for capturing gaseous Hg 0 were also explored. Results exhibited that KOH modification greatly improved the desulfurization performance of biochars via improving the pore structures of biochar and increasing the surfaces oxygen-containing group. The modified biochars (CK2 and SK2) achieve optimal desulfurization performance, with an adsorption capacity of 59.10 mg/g for CK2 and 42.30 mg/g for SK2, respectively. Adsorption temperature showed a double effect on desulfurization. S 0 and sulfate were successfully detected on biochar surface after adsorption via XPS and XRD analysis, indicating that chemical adsorption occurred in the H2 S adsorption. Kinetic study showed that physical adsorption governed the H2 S adsorption process, and mass transfer was the main control step of the desulfurization process. The spent adsorbents (i.e., spent containing-sulfur biochars) could capture efficiently Hg 0 in gas and shown good competitiveness as compared with commercial activated carbon. Graphical Abstract: ga1 Highlights: Porous carbons derived from by-products of microalgae pyrolysis were used to adsorb H2 S. The prepared porous carbons exhibit good H2 S adsorption performance. Spent adsorbent is containing-sulfur porous carbon, which can efficiently capture Hg 0 . Spent adsorbent shows better competitiveness for capturing Hg 0 than activated carbon. This technology achieves pyrolysis waste utilization and separation of H2 S and Hg 0 .