Removal of CO2 from biogas plant using chemical absorption column

• Main Authors: Mel, Maizirwan, Sharuzaman, Muhammad Amirul Hussin, Setyobud, Roy Hendroko
• Format: Conference or Workshop Item
• Language: English; English
• Published: American Institute of Physics Inc. 2015
• Subjects: TP Chemical technology; TP248.13 Biotechnology; TP751 Gas industry
• Online Access: http://irep.iium.edu.my/55316/7/55316_Removal%20of%20CO2_SCOPUS.pdf; http://irep.iium.edu.my/55316/13/55316_Removal%20of%20CO2%20from%20biogas%20plant.pdf; http://irep.iium.edu.my/55316/; http://aip.scitation.org/doi/pdf/10.1063/1.4958488

Biogas typically refers to a mixture of gasses produced during the breakdown of biodegradable organic matter in the absence of oxygen. It is primarily comprises 45-75% (v/v) of methane (CH4), 25-55% (v/v) of carbon dioxide (CO2), 2000 ppm of trace element hydrogen sulfide (H2S), and ammonia (NH3). The presence of CO2 and H2S may affect the performance of biogas. Hence, its removal before its use is crucial to improving the quality of biogas. In this work, a method to purify both gasses, CO2 and H2S were employed by using a sodium hydroxide solutions (NaOH). CH4 composition after treatment was also studied as removal of impurities is interrelated to CH4 enhancement. The concentrations of sodium hydroxide were varied as well as the biogas flow rate. Experiments that revealed the highest removal efficiency had been achieved at 14% concentration of sodium hydroxide solution used and the maximum absorption capacity was achieved when CH4 increment is about 54.9% from its original value. In the continuous flow, the composition of CH4 increased up to 26% of H2S removal, however, was unable to achieve the target due to its low concentration (ppm) in biogas mixtures. Hence, there are no significant changes in its concentration that are worth to be analyzed.