Location: Cool and Cold Water Aquaculture ResearchTitle: Biochar addition with Fe impregnation to reduce H2S production from anaerobic digestion
|CHOUDHURY, ABHINAV - Freshwater Institute
|LANSING, STEPHANIE - University Of Maryland
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/29/2020
Publication Date: 3/3/2020
Citation: Choudhury, A., Lansing, S. 2020. Biochar addition with Fe impregnation to reduce H2S production from anaerobic digestion. Bioresource Technology. 306:123121. https://doi.org/10.1016/j.biortech.2020.123121.
Interpretive Summary: Anaerobic digestion of organic matter from agricultural animal waste is used to produce biogas, which contains 50 - 70% methane, as a renewable energy source to generate electricity. The biogas can contain hydrogen sulfide, which is corrosive to components of the biogas combustion and electrical generation systems. Experiments were conducted to evaluate the addition of biochar from corn stover and maple as an adsorbent to reduce hydrogen sulfide levels in biogas produced from anaerobic digestion of dairy manure. This study demonstrates that biochar from both sources can substantially reduce hydrogen sulfide levels in biogas, and that addition of biochar does not affect the amount of methane produced. Furthermore, this study demonstrated that biochar impregnated with iron can completely eliminate hydrogen sulfide in biogas.
Technical Abstract: Corn stover biochar (CSB) and maple biochar (MB) were added into anaerobic digesters and evaluated for hydrogen sulfide (H2S) reductions. This was the first study to show Fe-impregnated biochar can eliminate H2S production. The novel study evaluated biochar addition on H2S reduction and nutrient concentrations using three experiments to test the effect of: 1) biochar concentration, 2) biochar particle size, and 3) Fe-impregnated biochar using triplicate lab-scale reactors. At the highest biochar dose (1.82 g biochar/g manure TS), H2S production was 90.5% less than the control treatment (351 mL H2S/kg VS). Biochar particle size did not significantly affect H2S concentration. The Fe-impregnated biochar (0.5 g biochar/g manure TS) reactors had no H2S detected in the CSB-Fe system. Methane (CH4) in the biochar and control treatments were not significantly different in all three experiments. The results show that biochar added to digesters can significantly reduce H2S production without affecting CH4 production.