Biogas reactors

Composting toilets suck, or at least the ones I've used. I know I've owned and used one for over a year. They also generate a lot of noxious gases and odors which are many times more harmful to the atmosphere than CO2. Methane is the primary gas we are interested in because it's also a fairly good direct substitute for natural gas.

Biogas generators are in use in India and China. They are simple brick enclosures. I will be posting more about my research into them here. The gas is often used for cooking. Biogas digested biological materials are also useful as fertilizer. There may be prohibitions against their use with human waste, but I'm thinking of personal size units which could supply a rural household with gas for heating/cooking/electricity from garden/animal waste. There would be many benefits and essentially no waste as the methane is collected and burned which turns it into CO2 and water which is a much less harmful greenhouse gas. The left over digested material could be used for fertilizer and so the carbon released by the biogas would be re-sequestered each year with the growth and harvest of crops. Incidentally biogas burners are often used in green houses to keep them warm and provide co2

Apparently you need water filtration of some kind if you want to use the gas for anything other than rudimentary heat/burning due to corrosive compounds and water in the collected product. I need to look into whether this produces an unusable water stream, if the filter water can be used for irrigation with no ill effects to food it would be ideal.