Producing Methane for a generator

Post by **Bob** » Fri Feb 02, 2001 2:06 pm

Probably not feasible unless you have farm animals or some other substantial waste source, Charless. At best, with human wastes generated by a single family plus garbage, you could maybe make enough methane to heat your daily hot water needs.

Post by **Bob** » Sat Feb 10, 2001 6:35 am

For rough estimating purposes, (assuming appropriate waste feedstock & optimum conditions) figure that you can get about 2 - 2.5 volumes/volume of biogas per day. That is, if you have a 1 m3 tank, you can get 2 - 2.5 m3 of gas per day from it. Assume that the gas will contain about 65% methane, with a heat value of 1,000 Btu/cu ft.

To estimate the size of tank you would need, figure about 5 kg (~12 lbs) of volatile solids per m3 (~35 cu ft) per day.

Have you tried using our online digester sizing tool? A description of how it works, and instructions for downloading the Netscape plugin are at: http://biorealis.com/digester/excelsample.html

If you can use that, you should be able to answer your questions easily. If not, give me an estimate of how many animals of what kind you may be considering (e.g. 100 chickens, 1 cow, 2 horses, 4 people, 4 dogs, 1 lb/day of kitchen scraps, etc...) and I can plug them in for you...