Browsing by Author "Dai, Le"

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A mutant strain of microalga Chlorella sp for the carbon dioxide capture from biogas
(2012-01-01)
Kao, Chien-Ya
;
Chiu, Sheng-Yi
;
Huang, Tzu-Ting
;
Dai, Le
;
Wang, Guan-Hua
To upgrade biogas produced from the anaerobic digestion of swine wastewater, an outdoor photobioreactor was established in this study. A mutant strain of microalga Chlorella sp. MM-2 was firstly isolated by ethyl methane sulfonate-induced random mutagenesis. The Chlorella sp. MM-2 grew in the presence of gas containing H2S < 100 ppm, and the growth capacity of the microalgal culture aerated with 80% CH, was similar to 70% that of the control culture (0% CH4). In the field study, CO2 capture efficiency of the Chlorella cultures, at a biomass concentration of 1.2 g L-1, from the desulfurized biogas (-20% CO2, 70% CH4 and H2S < 100 ppm) was approximate 70% on cloudy days and 80% on sunny days. CH4 concentration in the effluent biogas from the Chlorella cultures was increased to approximate 84% on cloudy days and 87% on sunny days from its original 70%. The established outdoor photobioreactor system using a gas cycle-switching operation could be used as a CO2 capture model for biogas upgrading. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
Ability of a mutant strain of the microalga Chlorella sp to capture carbon dioxide for biogas upgrading
(2012-05-01)
Kao, Chien-Ya
;
Chiu, Sheng-Yi
;
Huang, Tzu-Ting
;
Dai, Le
;
Hsu, Ling-Kang
In this study, a culture system with outdoor microalgae-incorporating photobioreactors was utilized to upgrade biogas produced from the anaerobic digestion of swine wastewater. Using ethyl methane sulfonate (EMS) random mutagenesis, we isolated a mutant strain of microalga, Chlorella sp. MB-9, which was tolerant to high CH4 and CO2. In the field study of outdoor operation, the maximum growth rates of Chlorella sp. MB-9 aerated with desulfurized biogas at 0.05, 0.1, 0.2 and 0.3 vvm were 0.32, 0.311, 0.275 and 0.251 g L-1 d(-1). In addition. similar to 70% of the CO2 in desulfurized biogas (similar to 20% CO2. similar to 70% CH4, and H2S < 50 ppm) could be captured by the Chlorella sp. MB-9 cultures. The CH4 concentration in the effluent biogas from the Chlorella cultures increased from its original 70% up to 85-90%. The established outdoor microalgae-incorporating culture system with a gas cycle-switching operation could be efficiently used as a CO2 capture model for biogas upgrading. (C) 2012 Elsevier Ltd. All rights reserved.