Water Scrubbing for Removal of Hydrogen Sulfide (H₂S) Inbiogas from Hog Farms

Cheng-Chang Lien, Jeng-Lian Lin, Ching-Hua Ting

Department of Biomechatronic Engineering, National Chiayi University, Chiayi, Chinese Taipei.
Department of Mechanical and Energy Engineering, National Chiayi University, Chiayi, Chinese Taipei.

DOI: 10.4236/jacen.2014.32B001                

Abstract

Biogas from anaerobic digestion of biological wastes is a renewable energy resource. H₂S in biogas may cause corrosion or other damage to engines if it is not removed from the gas before utilization. Because the solubility of H₂S in water is higher than methane, water can be used as an adsorbent to remove H₂S from biogas. A simple water scrubbing column to reduce the H₂S content was designed in this study. The biogas purification process took place in the scrubbing column with water where the gas was continuously fed from the bottom of the column through the diffuser which could produce bubbles. The biogas bubbles and the water can accelerate the reaction inside the column. The water in the column was circulated by means of a pump. H₂S content in raw biogas was about 6000 ppm. First, the efficiencies of H₂S removal for different biogas flow rate and water level were conducted at 30 and 90 sec. Second, the efficiencies of H₂S removal with water recycling system were induced. The results showed that the concentration of H₂S in biogas decreased significantly with water level and increased with biogas flow rate through the water scrubbing. It was an effective technique for removing H₂S in a short operation time, but absorption capability of water declined rapidly with time. To maintain high absorption rate, water scrubbing after adsorption needed to be replaced or regenerated. The water scrubbing system is a simplest and cheapest method. This work is investigated the feasibility of water scrubbing system and its application to a small hog farm.

Keywords

Biogas; Hydrogen Sulphide; Water Scrubber

Conflicts of Interest

The authors declare no conflicts of interest.

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