Renewable Revolution

Quote from: RE on May 26, 2016, 06:11:48 pm

Quote from: K-Dog on May 26, 2016, 04:31:46 pm

I know of a county in Wisconsin that is getting most of its natural gas from cow manure.

If you use cow or pig manure for methane production, then it is no longer useful as fertilizer. You've burned out the energy content.  You can't have your **** and eat it too.  :icon_mrgreen:

RE

I took a tour of one of our three poo-poo treatment plants a couple of years ago.  Settled out product was conveyed to one of five methane digesters which are huge concrete tanks several stories tall.  Methane is produced for a few weeks and then the residue is trucked to eastern Washington for use as fertilizer.  It makes wheat grow very well.

On any given day the methane is sold to the gas company or it is burned to generate electricity and sold to the electric company to offset the plant electric bill.  The methane extracted is only enough to provide one fifth of the power the plant actually uses.

This plant receives its raw material from a mixed flow of storm drain and sewage waters.  The area served does not have a separate storm drain system though there are some street drains with fish painted next to them that claim to drain directly into Lake Washington.  The relevant fact is that product to produce methane arrives quite dilute.  This may explain some of the poor efficiency.

I am going to look into how much methane is produced by a single pig's poop on an annual basis but don't let that stop anyone from posting what they know about the process first.

I do know an elephant produces enough methane to keep a range burner on because they process their fodder very inefficiently.  They are not ruminants.  Elephant poop is apparently important to distribute nutrients in their local environment and because they don't get all the energy they could from their feed elephants are consequently always full of ****.  The Republican mascot is well chosen.

My point is that like the blood of patriots the waste product of methane digestion is useful as fertilizer.

But how many therms can a pig toot?

The problem here is the generally accepted notion of "carrying capacity" that is riddled with false assumptions on the nature of energy transfer mechanisms in autotrophs (photosynthetic sunlight eaters).

From the simplistic application of Hess's Law to the cherry picking of the fossil fuel funded Charles Halls of this world, we get an amazing array of studious peer reviewed bullshit about "carrying capacity", caloric intake requirements and required nutrients.

The fact is, K-Dog, that nitrogen fixation and other plant health and growth (NOT the same thing!) processes are complex. The thermodynamics of soil microbes is not well understood because off their enzyme mediated energy transfer systems.

The reductionist and moronic 20th century Big Ag assumptions that all you needed to grow a healthy crop are phosphates, potassium and nitrogen are based on FALSE assumptions about autotroph energy (AND HEALTH) requirements.

NOBODY has quantified ERoEI in soil microbes, of which there are several MILLION per cubic INCH (including thousands of DIFFERENT SPECIES). When they do, we can begin to understand carrying capacity. Until then, assumptions about energy from fertilizer are not based on the important, and sine qua non, thermodynamic mechanisms of the soil microbes.