Informatics Publishing Limited

Antonio-Abdu Sami M. Magomnang ¹, Amado L. Maglinao Jr. ², Sergio C. Capareda ², Eliseo P. Villanueva ³

Affiliations
1 Mechanical Engineering Department, University of Science and Technology of Southern Philippines – CDO Campus, Lapasan, Cagayan de Oro City - 9000, PH
2 Bio-Energy Testing and Analysis Laboratory, Biological and Agricultural Engineering Department, Texas A & M University, College Station, Texas - 77843, United States of America
3 Mechanical Engineering Department, Mindanao State University – Iligan Institute of Technology, Tibanga, Iligan City - 9200, PH

Abstract

Objectives: This study aims to assess the performance of a Pressure Swing Adsorption (PSA) unit in removing the carbon dioxide from biogas by evaluating the breakthrough and adsorption capacity of the adsorption process as well as determining the effects of cyclic regeneration of the adsorbent. Methods: The PSA system was developed in order to establish the behavior of different gas separation experiments. It can be operated up to 10 bars pressure at ambient temperatures and gas flow rate from 0 to 15 L min-1. It is composed only of one main vessel made up of 316 stainless steel components. Use of physical adsorbent (Zeolite 13X) in a Pressure Swing Adsorption (PSA) system will consume the gaseous impurities such as CO2. Product gas was collected into 1 L Tedlar bags and analyzed using SRI gas chromatograph with TCD and HID detector to validate the CO2 and CH4 composition. Findings: The results of the Pressure Swing Adsorption (PSA) experiments showed an average increase of 160% in the net heating value over that of a certified gas standard. The amount of methane was also significantly higher although the amount of the other gasses (i.e. nitrogen) remained comparatively the same. The number of other gases was significantly lower and no trace of carbon dioxide was observed in the PSA product gas indicating that carbon dioxide had been completely absorbed by the system. Application: This study helps to reduce CO2 emitted to the atmosphere from the anaerobic co-digestion of biogas to produce high energy content bio-methane fuel.

Keywords

Adsorption, Biogas, Carbon Dioxide, Methane Gas, Pressure Swing Adsorption, Zeolite 13X

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Antonio-Abdu Sami M. Magomnang ¹, Sergio C. Capareda ²

Affiliations
1 Department of Mechanical Engineering, University of Science and Technology of Southern Philippines – Cagayan de Oro Campus, CM Recto Avenue, Lapasan, Cagayan de Oro City, PH
2 Biological and Agricultural Engineering Department, Texas A&M University, College Station, Texas, USA

Abstract

Objectives: This study aims to determine the effects of various pretreatment methods on the biomass properties and biogas yield in the anaerobic co-digestion of agricultural biomass waste co-digested with different biomass feedstocks for power generation applications. Methods: This study was carried out in order to determine the effects of the methane production on the two pre-treatments (3% and 4% w/v NaOH) subjected to sequential NaOH-ultrasonication and Liquid Hot Water treatment for the rice straw and coconut shell feedstocks, which can be used as substrates for the anaerobic co-digestion experiments; using cow manure, digested manures and sewage sludge as inoculant. Findings: Results showed that the methane production increased by 140% and 290% from the pre-treatment of rice straw and coconut shells, respectively. With these, the pre-treated coconut shell subjected to ultrasonication with 3% NaOH and Liquid Hot Water has the best effect among the pre-treatment of biomass feedstocks of rice straw and coconut shell at various NaOH concentrations. Applications: The results of this experiment would give a viable estimate on the possible methane production from co-digestion of these resources. The enhancement of the biogas yield was attributed to the improvement of biodegradability of rice straw and coconut shell through the pre-treatments. The changes of chemical compositions, chemical structures, and physical characteristics made rice straw and coconut shell feedstocks become more available and biodegradable and thus were responsible for the enhancement of the biogas yield. These results are contributing to develop a feasible biogas production from rice straw and coconut shell.

Keywords

Anaerobic Digestion, Biogas, Cattle Manure, Coconut Shell, Rice Straw, Sewage Sludge

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