Evaluation of the Availability of Raw Materials for Biogas Production in Medellín, Colombia

Abstract: This master thesis investigated the availability of raw materials for biogas production in the city of Medellín, Colombia. By first studying the development of biogas and its use as a vehicle fuel in the city of Linköping, Sweden, a comparison was made in order to focus on high-yield substrates. The objective was to calculate potential production given the amounts and types of substrates found locally and comparing it with the estimated demand of a local bus fleet that is planned to run on natural gas. The assessment of the raw materials was made in situ. The planned sources were visited in order to get information that would be later on analyzed for estimating its production potential. These sources were originally a municipal wastewater treatment plant, two slaughterhouses and two biodiesel plants. The wastewater treatment plant is already producing biogas, resulting from the treatment of sludge in anaerobic digesters. Nevertheless, calculations showed that current production is around 54% that of theoretical potential. Regarding the slaughterhouse, several important flows were detected, although some of them would not be currently available for biogas production, as they already have a defined use. The case for biodiesel production in the city was not very successful, as the two plants that were planned to be analyzed, have not started operations yet. However, some assumptions were made and some figures were calculated for further conclusions and analyses. During the visit, some other interesting sources were detected and were included in this report, such as another wastewater treatment plant, two fruits and vegetables markets, two landfills and biodiesel production in other areas. Several interesting points were discussed and analyzed through a comparison of the two cities. Drivers, barriers, actors, raw materials and production capacity were summarized and compared, resulting on reflections and conclusions. The results were also interesting, showing that the biogas potential at the two wastewater treatment plants would be enough to fuel the system and that if the other sources were to be used, excess biogas would be available for other uses, e.g. private cars or injection into the natural gas grid.