Removal of Hydrogen Sulfide from Biogas Using a Bubbling Tank Fed with Aerated Wastewater

Hsiu-Wen Ou ； Ming-Shean Chou ； Hsiao-Yu Chang

《Aerosol and Air Quality Research》 20卷3期 (2020/03) Pp. 643-653

https://doi.org/10.4209/aaqr.2019.12.0647

摘要

The work develops a simple bubbling tank scrubber that is fed with aerating wastewater for the removal of hydrogen sulfide (H_2S) in biogas. A 2,000 L plastic tank, in which fixed liquid levels 0.80 and 1.0 m and volumes of 1.1 and 1.4 m^3 was kept, was used for the scrubbing tests. A polyvinyl chloride (PVC) pipe with holes of 1 mm diameter was used to sparge the biogas into the tank liquid. Results indicate that with an influent liquid of pH 7.5-7.7, a flow rate of 23-25 L min^(-1), influent biogas flow rates of 0.050-0.200 m^3 min(-1), and a H_2S concentration of 907 ± 212 ppm, the pH of the effluent liquid stabilized at 6.6-6.9. With gas/liquid rate ratio of 2-8 m^3 m^(-3) liquid and volumetric gassing intensities of 0.04-0.20 m^3 m^(-3) liquid min^(-1), average H_2S removals of 86-71% were obtained. Absorption of CO_2 in the tested digester gas into the scrubbing liquid caused a decrease in the pH, thus decreasing the H_2S removal efficiency. Increasing pH of the scrubbing liquid to 8.0 improved the H_2S removal efficiency to as high as 99%.

關鍵字

Hydrogen sulfide ； Bubbling scrubbing ； Digester gas ； Air pollution control