| Author | Dissanayake, Malwila Gamini |
| Call Number | AIT Thesis no. 1093 |
| Subject(s) | Manure gases
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand |
| Publisher | Asian Institute of Technology |
| Abstract | The purpose of this study was to establish the feasibility of biogas production at village level. On a pilot plant designed to suit the
village conditions, cow dung, chicken manure, fruit and paper and grass clippings & chicken manure, were tested. In the experiment, energy potential of the four wastes, effluent nutrient values, degradation pattern of the organic loading and the impact of certain meteorological and topographical conditions on the efficiency of digestion process, were investigated. The final aim was to correlate all the above factors in order to optimize the use of bio-gas reactors.
The retention time was 30 days for all the mixtures and batch feeding was adopted. The four mixtures yielded the following amounts of bio-gas per kg of dry matter fed in.
Dilution Used Gas per kg
of dry matter
Cow dung 2.0 1.188
Chicken manure2.5 3.344
Fruit and paper 4.0 1.100 Grass & chicken maure 8.0 3.124
Variations in ambient temperature affected the digestion process significantly, but the pH value of the mixtures remained within 6-7.2. The natural variation of pH within the above range did not have any significant effect on the digestion process. The degradation of nitrogen
and phosphates was studied both for the sludge and the solution. The results revealed that only less than 50% of the influent nitrogens and
phosphates get degraded and the remainder to be present in the final stages of the sludge. Hence, the effluent is much suited for farm use as a fertilizer or a soil conditioner. The real value of the bio-gas stems from the use of digested effluent in the fields. Cow dung was tested in laboratory scale plants in order to establish the correlation of dilution. According to the results 1:1.5 mixture gave the highest amount of gas.
At village level small scale gas plants are proved to be quite profitable and they can provide the villagers with their domestic energy requirements. Most important of all is that they can use the effluent in their farms as a renewable fertilizer source. With domestic and farm
wastes, small-scale bio-gas reactors can fulfill the energy and fertilizer requirements of the villagers |
| Year | 1977 |
| Type | Thesis |
| School | Student Research Before 1979 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Nguyen, Cong Thanh |
| Examination Committee(s) | Ouano, E.A.R. ;Edwards, Peter
|
| Scholarship Donor(s) | Government of the United Kingdom |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1977 |