This is some useful crap: toilet energy

It’s a natural reaction of just about every animal to flee the scene once digestion reaches its inevitable, fragrant conclusion.  The distance one keeps from contact with feces is something of an unspoken yardstick of development.  While India has more mobile phones than toilets (and the street center streams of sewage that comes along with no place to crap), the more genteel among the Japanese have magical robot toilet seats that squirt and air dry your nether regions while playing a jaunty ringtone. Not having to wipe yourself is the gold medal in the development Olympics.

But could our aversion to our own waste be cheating us?  Perhaps a great re-think is in order for this “brown gold”.

The U.S. military is investigating the potential of turning troops’ poops into reactor fuel, saving the expense and environmental impact of burning all those digested MREs (and Tim Hortons).  While making shit nuclear is something of a new venture (‘dude, shit just got nuclear!’), the concept of harvesting energy from sewage is older than recorded history and a technology that has been steadily improved and adapted to meet the needs of changing societies.

The simplest way would be collection, drying and burning:

After drying in the hot Plains sun for a few weeks, bois de vache was practically odorless and clean to handle. Burning with little flame, buffalo chips were ideal for cooking and heating. Much like hay, frequent stoking of the fire was necessary. However, the fuel supply was soon exhausted because buffalo were nearly driven to extinction. Buffalo chips did prove to be a lifesaving fuel source for travelers on the Oregon and Mormon Trails.

While this works great for the excrement of buffalo, cows and horses, not too many have gone down the road of turning humanure into fire logs.

There are other ways, however.  The same breakdown and decay that generates that telltale smell can be utilized in the production of biogas.  While you might not want to light up that jet of methane rich crap-air and get to roasting marshmallows, burning it in a contained environment works well enough.  Afrigadget shows you one approach to making the most of your gas here.

Taking another step and using a biogas converter, like this intrepid farmer, lets you generate electricity from the stuff.  The Daily Telegraph’s New Delhi office built their own to make use of vegetable scraps, documenting the process.

One hitch in the plan for making use of human waste as the power source of the future is the toilet users’ poor quality control:

The problem is that everything dumped down the drain, both at home and at factories, ends up in the sewage treatment system. This includes household soaps and chemicals, industrial oils and solvents, heavy metals such as mercury and cadmium, and even some mildly radioactive materials. While some fraction of these is separated out during the sewage treatment process, and other items decay or de-volatize, much of the stuff ends up in the sludge.

So if we can only manage to keep our sewer systems exclusively for our nice clean shit, we just might be able to turn that brown sludge into green energy. Good luck with that.

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