Making reservoirs for Biogas
Margarita was in a flurry: “We need 475 thousand pesos by Saturday to pay for the next roll of plastic!” She was going to try to raise it (about $120 US) locally from a women’s group, but I decided to try Gogetfunding to see what I could do. Thanks to my generous friends, in three days we had raised $200! Margarita, Rafa and I headed down to Paúl’s farm on November 12.
This workshop was for making simple plastic reservoir bags fitted with a half-inch PVC tube and “T” adaptor, for storing biogas. Lylian and Ricardo taught, using some videos, and then we got into teams and made four bags. Each is about 4 meters long and can be stored either horizontally or vertically — Paul plans to build a covered structure to store theirs vertically. Also present at the workshop were Somara and Sandra, who already have digesters; each of them took home a reservoir bag. Sandra really needs the reservoir because her digester is quite far from her kitchen.
Another attendee, Cecilia, was one of those farmers whose gas line had been blocked with water on our previous visit; we had fashioned a water trap for her and placed it in-line, close to the house. There were also two AfroColombian women from the Cartagena area; a young couple who had heard Lylian speak at their high school, one of whom now works in geothermal energy; a teacher at an Agropecuario (high school with emphasis on farming), and others.
Paul showed how easy it was to use his improvised system of shoveling cow manure into a large plastic barrel, adding water and mixing it well, then opening a valve to allow the slurry to flow through a 1½-inch hose downhill to the digester. Lylian spoke approvingly of how often farmers innovate. Paúl is in the process of putting together tubes to carry the effluent from the first digester into the second, smaller one. The second digester will allow a long enough retention time for pathogens to be killed by the anaerobic bacteria.
One digester we’d visited in October, belonging to an elderly couple, had a hole perhaps chewed by a mouse. Lylian and Ricardo brought a homemade device to create a patch, consisting of a small rigid plastic cutting board into which they had drilled many holes. They then cut 2 pieces of rubber from one of the motorcycle inner tubes that had been brought, and put it all together with bolts, washers and nuts. No glue needed! We didn’t have time to bring it to the old couple, but it will be ready to take over and install.
Lylian is encouraging us to form our own team, with a “kit” like what she and Ricardo carry in their car, to help repair malfunctioning digesters. She told me briefly about an exciting meeting of RedBioCol (Network of Biomass, Colombia) members in Bogota she’d attended, promoting the use of alternative fuels.
Paúl’s wife Emerita and son Alejo arrived late, having both taken part in a bicycle competition in Guane. They were proud of themselves for having ridden 27 very steep kilometers!