Several months ago one of my neighboring volunteers was in the middle of writing a grant to make a biodigester with a local farmer close to his community. My first reaction to this was, "what the hell is a biodigester?" I had heard about biodigesters vaguely over my time both here and in college, but had no real idea of what they were or how they worked. My friend Jimmy, who has since left Paraguay for a graduate school opportunity in Germany, explained that basically it is a device that can harness methane gas through an anaerobic process which combines a set ratio of manure and water. The gas it creates can be used as cooking fuel, which minus the cost of building the thing is totally sustainable. Typical Paraguayan families who live in the countryside, have cows, pigs, and chickens. Chicken excrement is the most concentrated of the three animals and, therefore, produces higher quantities of the gas, if the appropriate amount is available. You do need a lot of chickens to create the amount of manure necessary to sustain the biodigester, but families normally don’t have the amount of waste necessary from chickens. However, they do often have plenty of pigs or cows whose manure is more commonly utilized in small scale bidigesters. It takes 3-4 pigs or cows to produce the daily amount of manure necessary to create the gas. Jimmy had all but finished the application to receive money from the Environmental Climate-Change Partnership of the Americas, EPCA, when he was accepted to a very well respected graduate program in Germany . I was at his house one day when he asked if I would be interested in taking over this project when he left. This was prior to receiving the funds for the garbage project, and before we had finished planting all of our trees, so naturally I said sure thinking to myself how hard could it be?
The short answer is I still don’t know. Next Wednesday, the 24th, along with a local farmer, Daniel Rios, and I will be putting on a biodigester workshop to present to members of his committee and the surrounding area. A big part of the application to receive funding from ECPA is to make sure the project isn’t exclusively focused on improving the livelihood of one individual. The idea is to use the money to facilitate an exchange of information using the biodigester as a mechanism to do just that. The most challenging part of the process to this point has been the coordination of everything to get us in position to conduct the workshop.
As for the rest of the materials, they comprise a wide range of things including, plastic hose, 0.5 meters of pvc, two large plastic barrels and an empty two liter bottle of any kind just to name a few. It took me most of the day and trips to five different hardware stores to find all the necessary materials. Lucky for me that hardware stores are one of the five types of businesses that operate in ubiquity in Paraguay . The other 4 include pharmacies, small grocery stores, furniture/appliance stores, and hair salons, so I was, thankfully, not without options.
A biodigester utilizes a pretty basic concept. As I mentioned earlier, the biodigester is a way to harness the gas produced by manure to burn as cooking fuel. The amount of gas that can be produced depends on the size of the bidigester. For example a biodigester that is seven meters would need roughly 5-6 cows to produce the manure necessary to make between 4-5 hours of cooking gas daily. 4-5 hours of cooking gas is a lot of gas, so what you don’t use in a day you release out into the air so as not to overflow the capacity. Biodigesters are not a new concept in the slightest. In fact, people have been experimenting with them for decades all over the world in places as far reaching as If this project is successful, it will be interesting to see whether or not it can be sustained or built upon as a viable alternative to propane powered cooking stoves or wood burning ovens. My hope is that this workshop will help me do another one next year in my community. My only concern is it is always difficult for people to make capital investments on things of this nature. If I didn’t receive a grant to do this project it is likely that it would have never happened. The cost is a lot and finding all the materials requires several trips outside of the area where we are building it. The other disadvantage is that the biodigester itself is primarily advantageous to the family I am building it with. They alone will reap the benefits of the gas and the nutrient rich by product, which can later be used on their fields or garden. I am not sure what the future will hold for this technology in my area. HeckI don’t even know if I am going to be able to get it to work in the first place, but in most ways this is like every other project I have done to this point in my service in that you don’t know until you try.
You know, I've never really understood how the gas is stored. I always just imagine that big ridiculous thing plugged right into a stove, which adds to my skepticism for the whole idea. Does it go into a canister or something?
ReplyDeleteAnd so, if someone had a lot of animals, could they sell the gas to their neighbors? I feel like that would really make the project more attractive to folks.