A Novel Simple Dipping-Nebulizing Water Absorption for Biogas Purification

Abstract

Biogas impurities CO2 and H2S decrease the quality of biogas, which leads to a reduced caloric value and corrosive behavior, respectively. A vertical/columnar wet scrubber has been widely employed for biogas purification in which the absorption of impurities strongly depends on the contact time and surface area between the biogas and water. The drawback of this method lies in the stability of CH4 production due to the influence of the bioreactor conditions and the fluctuating condition of the surrounding environment. In this work, we present a novel design of simple water absorption columns embedded with an ultrasonic nebulizer for biogas purification. In this designed system, CO2 and H2S become dissolved in the water, as the CH4 characterized by water low solubility is released on the surface of the water by using an ultrasonic diffuser/nebulizer. We optimized the water absorption performance by varying the water pH in the range 6.0-7.3. The results indicate that water pH affects biogas purification in the designed system. The optimum pH condition was 6.78, which yielded CH4 enrichment of 11%, O2 increase of 29%, CO2 reduction of 32%, and H2S reduction of 99.8%. To evaluate the biogas purification process in the upscaled system, a model and SIMULINK-based simulation were developed to predict the biogas purification process.

Pemurnian Biogas dari Co-Digestion Limbah Cair Industri Tahu dengan Kotoran Sapi Menggunakan Absorben MEA Pada Kolom Isian

“…Untuk dapat memanfaatkan biogas secara optimal, biogas yang dihasilkan dari biodigester harus dilakukan pemurnian terlebih dahulu dengan menurunkan kandungan CO2 dan H2S pada biogas. Hal tersebut karena CO2 dan H2S yang menurunkan nilai kalor, korosif, dan beracun [18][19]. Salah satu metode yang dapat digunakan untuk pemurnian biogas adalah melalui proses absorpsi.…”

Digital monitoring system for anaerobic bioreactor conditions based on information on biogas volume, biogas pressure and methane gas content

“…Biogas has the main content of methane gas (CH4) of 55% -75% and carbon dioxide gas (CO2) of about 25-45% as well as other impurity gases such as H2S gas which is corrosive [6][7][8]. Pure methane gas has a heating value of 8900 kcal/m 3 , while biogas itself has a heating value of 4800-6200 kcal/m 3 [9,10]. Biogas has various advantages compared to other fuels, including being more environmentally friendly because it is less damaging to the ozone layer, thereby reducing the greenhouse effect.…”