Methanotrophic biofilter using inorganic media : optimization of loading rate and inlet gas humidity | |
| Author | Abeynayaka, H. D. L. |
| Call Number | AIT Thesis no.EV-11-03 |
| Subject(s) | Methane Filters and filtration |
| Note | A thesis submitted in paitial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-11-03 |
| Abstract | Methane (CH4) is one of leading green house gas (GHG), having over 20 times higher global warming potential (GWP) than that of carbon dioxide (C02). Waste management sector have been recognized as the second largest source of anthropogenic CH4 emissions. The CH4 emission from waste sector contributes 5% of global GHG emissions. Biofiltration (BFn) is an economical and attractive treatment method for mitigation of CH4 emissions from waste management sector. In this method Methanotrophic bacteria are able to consume CH4 while generating less harmful biological byproducts. Plenty of researches have been undertaken so far to improve BFn technology to treat CH4 emissions, with different filter media and different operation conditions. Based on this background, the objective of this study was to select optimal volumetric loading rate and optimal inlet gas humidity for CH4 biofilter with coarse sand filter media. Four different volumetric loading rates (25, 35, 45 and 55 g/m3.h) were tested under excess inlet gas humidity concentrations to optimize the loading rates. Three different humidity levels, which cause different bed moisture contents, were tested with the optimized loading conditions (35 g/m3 .h) and highest loading rate conditions (55 g/m3 .h). Removal efficiency and elimination capacity were taken as the main evaluation parameters. Biofilters could achieve complete CH4 removal up to 35 g/m3.h volumetric loading rate (VLR). However, the loading rates tested above that range could not achieve the complete CH4 removal. The highest elimination capacity achieved was 35 g/m3.h. That was observed during 3 5 g/m3 .h and 45 g/m3 .h VLRs. However, further increment of VLR reduced the EC from 35 g/m3.h to 28 g/m3.h. Empty bed residence time (EBRT) reduction due to VLR increment was identified as the reason for EC reduction from 3 5 g/m3 .h to 28 g/m3 .h under VLR increment. The study reveals that the optimal volumetric loading rate is 35g/m3.h among the operated loading rates. When the filter bed achieved that optimal condition the optimal humidity requirement is more than 60% by volume, and the bed moisture content is between 10% and 15%. It have been found that total inlet flow rate also influences the filter bed moisture content, the evidence is the reduce of the bed moisture content with higher inlet flow rate with respect to the higher volumetric loading rate of 55 g/m3.h. Reduction of inlet gas humidity affects the bed moisture content significantly. Inlet gas humidity has a significant impact on the removal efficiencies of CH4. When the loading rate increases (while the concentration of CH4 remains same), the inlet gas humidity plays an important role than the inlet gas humidity at low loading rates. |
| Year | 2011 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-11-03 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Atmachhtre, Ajit P.; |
| Examination Committee(s) | Nguyen Thi Kim Oanh;Shipin, Oleg; |
| Scholarship Donor(s) | Thailand (HM Queen); |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2011 |