Biogas in Urban Areas




What do you usually do with food waste? We know - you throw it out (hopefully in the trash can). Let me tell you what happens next.

This waste is then taken to massive wastelands and gets dumped there. You may think that it isn’t that bad - such food waste will just decompose, it is not plastic - it won’t take hundreds of years to decompose, right? Yes, indeed.

But while it decomposes in these valleys of darkness, full of household waste, it produces something called landfill gas (basically a mix of methane and CO2). If concentrated, it gets highly flammable (with explosions following the concentration). Methane is 21-28 times more harmful than carbon dioxide (CO2) in terms of greenhouse effect. And it stays in the atmosphere for 12 years. That is too much! If you were stuck in a room full of cow farts for 12 years, you would do something about it right? We hope so! (You may ask “why cow farts?”. Keep on reading).


One of the best short-term methods of curbing the global warming is the capture of methane. This brings us to biogas.


It is a renewable energy resource, that helps prevent the ejection of methane into the atmosphere. It is possible to produce it by recycling manure, and house hold waste - food leftovers, used cooking oil, vegetable and fruit peel and so on.


A simple analogy for you. Imagine a cow eating grass. Got it? Splendid. Now try to imagine what happens inside its stomach (I know you haven’t seen it, but try). The food is digesting without any oxygen around it and is then producing two things - biogas (mostly methane) and manure. Now what do we do with this information? How does cow farts and poo help us?



Let’s start with cow farts. Did you know that cows contribute greatly to global warming? One cow can release 200 kg of methane into the atmosphere in a year. And since, we, the people, eat so much beef, the amount of cows on our planet is insane. (It is actually the burps that are worse, by the way). If we could use that gas for something productive instead…


The only thing we can do is to recreate such a process in special anaerobic digesters to produce biogas to support your household, farm or industry (depends on what you have).

Cow poo is used for fertilising the soil. We know it as manure, since it is, apparently, childish to call it cow poo. It makes gardens blossom, but sometimes not fast and good enough so farmers sometimes have to use chemicals and pesticides. The good thing is that with such a biogas that we described earlier, we can recycle the manure as well. Will it also produce some biogas? Of course! And, as a bonus, what didn’t turn into biogas will come out as a liquid biofertilizer, that is so efficient, that you wouldn’t need any pesticides for your garden and farm (if you have one).


Once again we stumbled upon someone who is working with biogas, now in Senegal. Last time (www.themeridianexpedition.com/post/biogas-solutions) we learned about the use of biogas for farmers, and now we are going to learn how it can be beneficial for an ordinary person in an urban area.


We visited Dr. Lamine Ndyae, who has a biogas installation at his home in Dakar (he uses HomeBiogas). He explained to us how it works and it turned out to be pretty simple. He takes all foodwaste, manure, cooking oil and so one (all the organic waste) and puts it inside the digester, which works the same way as a cows belly - produces gas and a fertilizer.


Take a look at the garden on the roof. He grows his own plants naturally, and is all effortless. When asked, whether he sticks to biogas because it is cheaper, he simply replies: “No, it is not cheaper. But I do it because I care about the environment. I want to set an example to others. Because it is a solution to the problem of waste management”.


And he does. It is not a huge step, but it plays a part in the global awareness of the opportunities that lie within this sustainable way of living. We sincerely hope that more people in the world follow the example that he sets.

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