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What Is a Biogas Generator?
A biogas generator is a reactor or chemical processing system designed to organically break down biological source materials into gasses such as methane and hydrogen that can then be combined with oxygen for use as a source of fuel. Many types of waste matter can be used to generate biogas, including municipal waste and manure, plant waste from crop fields, residential lawns, parks, and more. Simple biogas generation systems are not hard to build, and are often the subject of high school science projects.
Building a biogas system can be done in less than an hour by following online videos on popular social websites. A biogas generator in this case is a sealed container with organic waste infused with anaerobic bacteria. The bacteria break down the waste in the absence of oxygen into a gas mixture of about 60% methane and 40% carbon dioxide, which is then siphoned off into another container.
Industrial level systems are simply larger scale versions of the same process. They have an elevated waste feeding chamber that channels the material into a reactor chamber filled with a digesting slurry. The biogas generator pipes the gas out of the top of the chamber and treated sewage known as effluent out the side.
Methane from a biogas generator is the main component in natural gas, which is used to heat many homes and for other uses such as cooking and hot water production. Using large-scale applications of biogas technology has made it a form of renewable energy that is a valuable commodity in the electricity market. In the UK and Germany, sewage treatment plants for municipalities turn this waste into biogas that is then used as a fuel to power electric power plants. Small, home-sized biogas generator systems are widespread throughout Nepal, China, and India. A home biogas generator can process food waste and meet 25% to 50% of cooking fuel demands for rural families.
Biogas production worldwide is an alternative fuels industry that has become a big business. As of 2011, over 700 companies are involved in producing biogas throughout the world, and projections are that, by 2030, it will be a $50,000,000,000 US Dollars (USD) industry. In nations such as India, biogas production meets 57% of its energy demands, with most of the source waste material coming from agriculture and the 300,000,000 cattle there. Two positive side effects of producing biogas from cattle feces is that a byproduct of the process is a valuable fertilizer for crops, and it reduces India's levels of deforestation, since wood is the other primary heating fuel.
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![In India, biogas production meets 57% of its energy demands.]()
By: polesnoyIn India, biogas production meets 57% of its energy demands. -
![A biogas generator can convert cow manure into fuel.]()
By: branexA biogas generator can convert cow manure into fuel. -
![Anaerobic digestion produces methane gas as a byproduct of wastewater treatment.]()
By: chartcameramanAnaerobic digestion produces methane gas as a byproduct of wastewater treatment.
Discussion Comments
This sounds like a fantastic project to do with schools, particularly those schools who are focusing on project based learning and need to give their students a new project to focus on.
Although I do wonder if a useful biogas electric generator is as easy to make as a generator that would just demonstrate the abstract uses of biogas.
I know a school that recently led its students in an investigation of water tanks and filters and they managed to get the whole school onto rainwater. I think they might be ready to look at different possibilities for powering their school and this might be one of the things that they look at.
@pleonasm - Well, yes and no. It's true that biogas isn't a perfect solution when you take climate change into account. Another thing that you missed was the fact that biogas often isn't as stable as other kinds of fuels and it can be difficult to process it in the same way.
But, in a lot of cases, it's collected from waste that was going to end up releasing these gases anyway. If anything, using biogas as a fuel may mitigate some of the damage that could be done with these waste products.
I don't know a lot about it though and I don't know all the pros and cons or how they weigh against each other when you lay them all out.
The problem with biogas is that it's still using combustion to create energy and that leads to carbon being released into the atmosphere.
It's great that it can be sourced from almost anywhere (unlike coal and oil) and it's great that it can be very cheap to make, but I don't think it solves the larger problem of pollution and climate change.
Another problem is that methane is actually much worse for the atmosphere than your average greenhouse gas, which is one of the reasons climate change scientists advise that huge cattle farms are unsustainable.
A solar generator or a wind generator is just a much better idea.
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