Modest Experiment In Methane Gas Production

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Ain't no doubt about it. . . if MOTHER's mail is any indication, an awful lot of folks want to know how to recycle home and farm wastes into high-quality fertilizer and methane gas for fuel. The only trouble is that—at this point—very few people in the United States and Canada know exactly how to go about the undertaking.

How big should a digester-generator be? What materials are best for its construction? Is the "batch" or "continuous feed" loading cycle most efficient? Can human waste be processed in a digester? Should the unit be above or below ground? Will the processor produce an odor problem? Can a house really be heated with the gas that is taken from decayed organic matter? Will the fuel power an internal combustion engine? Would it work better driving a steam powerplant? The questions pouring into our mailbox are endless.

Well, if you're a regular MOTHER reader, you know that—in an effort to pin down firm answers to such queries—we asked Ram Bux Singh (the world authority on farm and village-size methane generators) to help us build a prototype digester for MOTHER last summer. Singh's design—constructed almost entirely of recycled and scrap materials—was a marvel of low-cost, do-it-yourself engineering . . . and we had hoped to be able to pass some operational facts and figures along to you by now.

The only trouble is that the "expert" welder (no, we still won't tell you his name) who spent so much time telling us what a great job he was doing on the digester's water jacket . . . didn't do a great job at all. Matter of fact, it was an unbelievably lousy job and the whole generator is still—at this point—worthless for experimental purposes.

Come the first warm day in spring, though, we're gonna roll it out and fabricate a new water jacket for the critter . . . and, by fall, we should know a lot more than we do now about designing and building and operating a do-it-yourself methane gas station.

In the meantime, for all the folks who want to find out firsthand if decaying garbage will actually and truly and honestly and really produce burnable methane . . . here is Robert C. McMahon's modest experiment in methane gas production.

While you're waiting to build a digester large enough to process your farmstead waste into enough methane to heat the house . . . you may wish to try a simple, low (or zero) cost experiment that will familiarize you with the fuel's production and some of its characteristics.

Well, wish no more. Here's how to put together one of the simplest and least expensive methane production experiments of all. You'll need only a gallon cider jug, some sort of gas holder (I use a recycled, heavy-duty plastic bag) and—from the chemistry lab—some rubber tubing, a couple of tubing clamps, a two-hole rubber stopper, glass tubing and a glass "Y".

Your first step in constructing a mini-methane-generator will be to make a manometer. This is a U-shaped tube, partly filled with water, that will let you know when your little digester is producing gas, indicate the pressure of that gas and act as a safety valve (since excess pressure will blow the water out of the manometer). Any chemistry student should be able to show you the proper way to heat and form your glass tubing.