[ohanian]

I have a question.

If Cow Dung can be turn into methane gas and then into energy


So why can't we do the same with Human Dung?


http://www.itdg.org/?id=biogas


I hate to see millions of tonnes of human dung go to waste in waste treatment plants around the world.

[WisJim]

Some sewage treatment plants used to use the methane produce in the plants to run engines to produce power to run the plant and other loads. I don't think that as many treatment plants do this as in years past, but it is entirely possible to do.

[Ludi]

Yep, all human waste could be used to produce methane to power the waste treatment plants or nearby facilities, and the product at the end of methane digestion could be composted and used to grow plant products for other uses (such as more methane production,or ethanol production, wood products, etc). Most "waste" products have several uses and no "waste" product should just be disposed of without serving a useful purpose. In my opinion.

[oilfreeandhappy]

As an Engineer, I had the opportunity to tour a Wastewater Treatment plant. At this facility, they were burning off the methane into the atmosphere. The flame was continuous, and about 2 feet high.

We asked the Engineers about using this gas, and they mentioned that it was more cost effective to burn it off, than to try to sterilize it, and deal with the potential legal ramifications and bureacracy. This was about 10 years ago, but I doubt much has changed.

[azreal60]

I'm curious about a statement previous. You said it was more cost effective to burn it off rather than sterilize it. I thought we where talking about using it for power generation in which case burning it off is exactly what would be happening. I guess that statement didn't seem to make sense to me. Isn't burning it off exactly what was being proposed?

[MonteQuest]

$this->bbcode_second_pass_quote('pstarr', 'T')his just goes to show how little energy these natural systems (inlcuding oil crops and other biofuels) have in comparison to petroleum. There will never be another party like this one. whoopee

[Ludi]

Do you know how many of those plants are still in service, Monte? I recall someone posted that many are not still in service because the people found them difficult to use, requiring collection of dung. They were not convenient to use because the waste was not in a central location as it is at our sewage plants and animal feedlots here in North America.

[thor]

$this->bbcode_second_pass_quote('ohanian', 'I') have a question.

If Cow Dung can be turn into methane gas and then into energy


So why can't we do the same with Human Dung?


http://www.itdg.org/?id=biogas


I hate to see millions of tonnes of human dung go to waste in waste treatment plants around the world.

[nocar]

The vast sewage treatment plant in Stockholm collects sewage from about a million people. It produces biogas to fuel a few buses i central town. At most about a thousand people can travel 5 km daily on that. By bus.

So it is possible. But a lot of people need to produce in order for a few to travel on it. And there is necessary to a huge infrastructure in place.

nocar

[thor]

$this->bbcode_second_pass_quote('nocar', 'T')he vast sewage treatment plant in Stockholm collects sewage from about a million people. It produces biogas to fuel a few buses i central town. At most about a thousand people can travel 5 km daily on that. By bus.

So it is possible. But a lot of people need to produce in order for a few to travel on it. And there is necessary to a huge infrastructure in place.

nocar

[gigacannon]

Humans aren't ruminants. You can't use human faeces as a fuel source like you can with cow dung for pretty much the same reason you can't smear human faeces over fields to grow crops.

[grabby]

Human dung is infectious to humans.
and estimated 4% of people in a city have hepatitis C (and B)
some have aieds, 10% have gastroenteritis and viruses.

in a group of 100 people this would guarantee that all these viruses are present.
These viruses do not dissipate or become destroyed there is also staph and MRSA in the community now

Putting human waste on a garden is a very foolish behaviour.

in n contrast, cow dung has NONE of these things and is safe.
Pig dung is not safe, they carry many of the things we can catch, the people thousands of years ago knew this and classed them as contagious animals.
Cow and ruminants are safe we rarely catch anything from them.

now the energy left in our stoooll is very little, there is more energy in grass clippings.

to make enough grass clippings to supply our power needs we need about 4 billion bushels which would stretch across the world 22 times DAILY forgetaboudit.

[Ludi]

Human waste makes a perfectly fine fertilizer for some crops, and can be solar pasteurized to kill most pathogens.

See the book "Solviva" (or the website linked below) for discussion of human waste treatment using composting.

The Chinese used human waste as fertilizer for approx 4000 years and had one of the most productive farming methods ever developed, which is one reason why their population was always so enormous.

[Ludi]

Yet there are other facilities which do use methane power, so why is one failure (or even a bunch of failures) reason to think it "wouldn't work anywhere"? Certainly these sorts of technologies will tend to appear to be "too much trouble" while cheap petroleum is available. Most "sustainable" or "earth friendly" or "appropriate technolgies" (whatever term you want to use) are seen as "too much trouble" because they are outside of the typical way of doing things currently. This may change as petroleum becomes more expensive (or it may not).

I don't know if you've read the book "Solviva" pstarr. I know I'm hyping it a lot recently I've found it very encouraging in some ways, extremely discouraging in others. The author, Anna Edey, was stymied in her efforts to promote more sustainable management of human waste not because her technologies didn't work, but because of bureaucratic nonsense having nothing to do with the actual results of her processes, which resulted in far less damaging effluent than typical septic systems or sewage processing plants.

[MonteQuest]

$this->bbcode_second_pass_quote('gigacannon', 'H')umans aren't ruminants. You can't use human faeces as a fuel source like you can with cow dung for pretty much the same reason you can't smear human faeces over fields to grow crops.

[MonteQuest]

$this->bbcode_second_pass_quote('Ludi', 'D')o you know how many of those plants are still in service, Monte? I recall someone posted that many are not still in service because the people found them difficult to use, requiring collection of dung. They were not convenient to use because the waste was not in a central location as it is at our sewage plants and animal feedlots here in North America.

[Ludi]

Monte, I'm not the one claiming they are inconvenient to use, someone else posted that, months ago, I don't remember which thread.

I know they collected the dung before, to use as fuel.

*sigh*