Universal Journal of Agricultural Research Vol. 4(2), pp. 60 - 65
DOI: 10.13189/ujar.2016.040206
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Application of Low Pressure Water Scrubbing Technique for Increasing Methane Content in Biogas

Ronald Walozi ^1,*, Betty Nabuuma ², Adam Sebiti ^2
1 AETREC-Namalere, National Agricultural Research Organisation (NARO), Uganda
² Department of Mechanical Engineering, College of Engineering, Design, Art and Technology, Makerere University, Uganda

ABSTRACT

For many developing nations, biogas has traditionally been used for household cooking and lighting. Methane (CH₄) content in biogas has to be increased by removing incombustible carbon dioxide (CO₂) and potentially corrosive constituents such as hydrogen sulphide (H₂S) and moisture. This study set out to increase biogas from 55.8% CH₄, 43% CO₂, 0.85% oxygen (O₂), 75.1 ppm H₂S to >80% methane and non-traceable H₂S without enhancing raw biogas pressure. By using a single scrubber column and varying water scrubbing system operating parameters of packing material type, packing depth, water and gas flow rates, appropriate parameters for achieving the above objective were determined. The experiments were carried out at an average digester pressure of 1.0589bar. Results show that packing a column with steel-wire mesh to a depth of 0.4m increases the volumetric percentage of CH₄ in biogas to >80% for water to gas flow rate ratios 1.9 and above. Increasing the packed depth to 0.8m increases volumetric percentage of CH₄ in biogas to 80% at a lower ratio of 0.7. This increase in packed depth resulted in an improvement from 1800 litres to 700 litres of water for every m³ of raw biogas upgraded. However, to achieve >80% CH₄ in marble packed columns of similar depths, the water to gas flow rate ratio has to be raised above 2.5.

KEYWORDS
Biogas Upgrading, Methane, Packed Column, Renewable Energy, Water Scrubbing

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Ronald Walozi , Betty Nabuuma , Adam Sebiti , "Application of Low Pressure Water Scrubbing Technique for Increasing Methane Content in Biogas," Universal Journal of Agricultural Research, Vol. 4, No. 2, pp. 60 - 65, 2016. DOI: 10.13189/ujar.2016.040206.

(b). APA Format:
Ronald Walozi , Betty Nabuuma , Adam Sebiti (2016). Application of Low Pressure Water Scrubbing Technique for Increasing Methane Content in Biogas. Universal Journal of Agricultural Research, 4(2), 60 - 65. DOI: 10.13189/ujar.2016.040206.