The fate of abandoned small-scale biogas plants – case of Vietnam

Bc. Kseniia Paramonova

Master's thesis

Abstract:

Biogas production through anaerobic digestion process has been promoted in Vietnam as an appropriate technology for animal waste management and cooking activities within rural households (replacing traditionally used firewood and LPG). Despite the large quantity of small-scale biogas plants being built and promoted, there were increasingly reported cases of abandonment of biogas technology. Therefore, this study attempted to present the state of the art of small-scale biogas plants abandonment issue including reasons leading towards it. The primary data were collected in province Thua Thien Hue in Vietnam in August 2019, including semi-structured interviews with small-scale biogas plants owners who abandoned biogas technology (minimum 6 months before the survey) (n = 37) and with small-scale biogas plant owners who continually use this technology (n = 62). Using a logistic regression analysis of various cross-sectional data (with SPSS software), key forces were uncovered in order to find out the reasons behind the abandonment of biogas technology. The findings showed that households with more members working on the farm and more satisfied with the maintenance of the biogas plant are less likely to abandon it. Reported reasons for abandonment included the failure of organic waste supply (from pig keeping) as a substrate for biogas production. In majority of cases, households were not able to keep pigs due to difficulties such as reduced availability of family labour or African swine fever in the area. Furthermore, technical problems were reported as reasons too. Abandoned plants are usually not used for any other purposes but some of digesters (initially connected to the toilet) are used only for human excreta storing. In accordance with the findings of study, it can be concluded that the dis-adoption of biogas technology leads to the return of rural households to conventional energy for cooking, resulting in waste of investments to biogas technology and its possible advantages.

Keywords

Vietnam, biogas, anaerobic digestion, small-scale biogas technology, biogas plant maintenance

Language used: English

Date on which the thesis was submitted / produced: 14. 8. 2020

Thesis defence

• Supervisor: Ing. Hynek Roubík, Ph.D.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme / field:
Tropical Agriculture / Sustainable Rural Development in the Tropics and Subtropics