@article{Mbugua_Mwaniki_Nduta_Mwaura_2021, title={Upgrading biogas using Eburru zeolitic rocks and other adsorbent materials to remove carbon dioxide and hydrogen sulphide}, volume={47}, url={https://tjs.udsm.ac.tz/index.php/tjs/article/view/636}, DOI={10.4314/tjs.v47i2.2}, abstractNote={<p>The trace amounts of carbon dioxide and hydrogen sulfide in raw biogas lower its calorific value,<br />cause corrosion and make it hard to compress biogas into the cylinder. Raw biogas was obtained<br />from anaerobic digestion of cow dung and market wastes. The gas was stored in tubes or urine bag<br />before upgrading. Natural zeolite rocks, maize cobs, steel wire, desulphurizer, and worn-out tyres<br />were used as the upgrade materials. The composition of biogas was recorded before and after<br />upgrading using a GP180 portable biogas analyzer from Henan, China. The measured level of raw<br />biogas was 0.0227% H<sub>2</sub>S, >20% CO<sub>2</sub> and 52-56% CH<sub>4</sub>. The most efficient upgrade materials were<br />zeolite rocks with upgrade levels of 89–93% methane. The total removal using zeolite was<br />observed to be 75% CO<sub>2</sub> and 95.34% H2S. The morphological structures of zeolitic rocks account<br />for its higher upgrading properties compared to other materials. In addition, the porosity in these<br />rocks mean that CO<sub>2</sub> and H<sub>2</sub>S were adsorbed resulting in high CH<sub>4</sub> levels in the upgraded biogas.<br />Other adsorbents showed upgrading properties with removal rates above 70% for both H<sub>2</sub>S and<br />CO<sub>2</sub>.</p> <p><strong>Keywords</strong>: Biogas, Upgrading, Natural zeolite, Bio-methane</p>}, number={2}, journal={Tanzania Journal of Science}, author={Mbugua, James K and Mwaniki, Joseph M and Nduta, Damaris M and Mwaura, Francis B}, year={2021}, month={May}, pages={421–431} }