title: Performance of polydimethylsiloxane membrane contactor process for selective hydrogen sulfide removal from biogas.
abstract: H2S in biogas affects the co-generation performance adversely by corroding some critical components within the engine and it has to be removed in order to improve the biogas quality. This work presents the use of polydimethylsiloxane (PDMS) membrane contactor for selective removal of H2S from the biogas. Experiments were carried out to evaluate the effects of different pH of absorption liquid, biogas flowrate and temperature on the absorption performances. The results revealed that at the lowest loading rate (91mg H2S/m2·h) more than 98% H2S and 59% CO2absorption efficiencies were achieved. The CH4content in the treated gas increased from 60 to 80% with nearly 5% CH4loss. Increasing the pH (7-10) and loading rate (91-355mg H2S/m2·h) enhanced the H2S absorption capacity, and the maximum H2S/CO2and H2S/CH4selectivity factors were 2.5 and 58, respectively. Temperature played a key role in the process and lower temperature was beneficial for intensifying H2S absorption performance. The highest H2S fluxes at pH 10 and 7 were 3.4g/m2·d and 1.8g/m2·d with overall mass transfer coefficients of 6.91×10-6and 4.99×10-6m/s, respectively. The results showed that moderately high H2S fluxes with low CH4loss may be achieved by using a robust and cost-effective membrane based absorption process for desulfurization of biogas. A tubular PDMS membrane contactor was tested for the first time to remove H2S from biogas under slightly alkaline conditions and the suggested process could be a promising for real scale applications.
authors.affiliation: Department of Environmental Engineering, Marmara University, 34722 Goztepe, Kadikoy, Istanbul, Turkey. Electronic address: ebroti@gmail.com.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Tilahun
authors.affiliation: Department of Environmental Engineering, Marmara University, 34722 Goztepe, Kadikoy, Istanbul, Turkey; Department of Environmental Engineering, Necmettin Erbakan University, 42140 Meram, Konya, Turkey. Electronic address: alperbayrakdar@gmail.com.
authors.forename: Alper
authors.initials: A
authors.lastname: Bayrakdar
authors.affiliation: Department of Bioengineering, Istanbul Medeniyet University, 34700 Goztepe, Istanbul, Turkey. Electronic address: erkansahinkaya@gmail.com.
authors.forename: Erkan
authors.initials: E
authors.lastname: Sahinkaya
authors.affiliation: Department of Environmental Engineering, Marmara University, 34722 Goztepe, Kadikoy, Istanbul, Turkey. Electronic address: baris.calli@marmara.edu.tr.
authors.forename: Bariş
authors.initials: B
authors.lastname: Çalli
mesh_terms: D056804:Biofuels / Q000191:economics; D002245:Carbon Dioxide / Q000737:chemistry; D003362:Cost-Benefit Analysis; D004129:Dimethylpolysiloxanes; D004867:Equipment Design; D006862:Hydrogen Sulfide / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D013696:Temperature
chemical_list: D056804:Biofuels; D004129:Dimethylpolysiloxanes; D002245:Carbon Dioxide; C013830:baysilon; D006862:Hydrogen Sulfide
keywords: Biogas cleaning; Hydrogen sulfide removal; Membrane contactor; Silicone membrane