Fuel from Garbage?

In posting this I am expecting four things:

There is a fifth, GARBAGE!!!

You are describing power generation using biogas from decomposing organic matter, and it is quite common.

Google "landfill methane or biogas generation", or have a look on CR4 for previous posts and threads by myself and others on the subject.

http://cr4.globalspec.com/thread/35238/Trash-Burning-Power-Plants

http://en.wikipedia.org/wiki/Biogas

I was involved in designing and comissioning one of these multi MW generation plants on a landfill site generating power 24/7 and it works quite well. Due to landfil capacity even if the landfill is closed to new dumping it will still be producing power 10-20 years from now too.

Hey Jack,

Thanks for the post and the links, very informative. I'm in the state of Florida, about 50 miles south of the Port St. Lucie and Ft. Pierce plants mentioned in the links. Maybe that will help with the "artificial mountain" landfill In ST. Lucie County. i think the highest points in South Florida are the landfills. In Palm Beach County where I live , they have a trash-fueled powerplant, I believe that the trash undergoes some kind of segregation before burning. There was an incident a few years back that resulted in a death at this plant. What happened, according to the investigation , a crate of dynamite was in a load of trash , during processing it detonated. The doors were blown off the access to this area,( a designed in weak point to prevent greater damage to the plant) and unfortunately, were propelled a distance down a corridor, striking and killing a worker. They added some new systems and safeguards to prevent a re-occurrence .

I notice the landfill has a system of pipes to collect the methane produced, but it is just burned off in a flare pipe.

Packdrill

I notice the landfill has a system of pipes to collect the methane produced, but it is just burned off in a flare pipe.

The pipes and flare stack are necessary to burn off the continuously generated methane gas at tip sites containing at least part organic waste (which cannot be stopped). Without the gas constantly being burned off the site would fill with dangerous gas and an explosion could occur (it has happened before).

The equipment and on-going maintenance costs for the Methane gas turbines (converting the stream of impure methane to energy) are rather high so energy generation on some tip sites may not be economically viable. Note that all sites still need a flare stack (in fact the site I worked on produced so much gas that even with the Methane generators running excess gas was being burnt off in the flare stack.

Before methane gas to energy generation tip sites also employed other methods to use this methane gas like on site methane powered ovens (I think they were for special waste incineration) and compressing and filling gas bottles with methane. All options have their problems however due to the fact the methane gas is very impure and contains lots of nasty and corrosive substances like sulfur (which combines nicely with the moisture to create sulfuric acid), carbon monoxide, etc (this results in large equipment maintenance and monitoring costs). What's interesting is that the gas mixture has to constantly be monitored as it changes during the day due to such things as sun heating the tip. Fascinating stuff.

What happened, according to the investigation , a crate of dynamite was in a load of trash , during processing it detonated...... They added some new systems and safeguards to prevent a re-occurrence .

One would think that since dynamite is considered "dangerous goods" it would be clearly covered by special disposal requirements (oh wait, it is). There's always some idiot, its a shame an innocent bystander was killed in this case.

Hey Jack,

Right about the dynamite, either someone did it intentionally hoping that something like this would happen or they were just not very bright. Either way a poor, working stiff bought it

Packdrill

You probably can't bore a very deep hole in Florida before hitting water

Yeahhhhh, it's about 10' above sea level here. So , unlike most places where one has placed their ultra-deep borehole and the overriding concern is a surprise attack by the mole people, here we have to worry about an invasion by an alliance of the manatee men and the stinging Portugese man-o-shevitz. TO THE RAMPARTS, THE ENEMY DOTH APPROACH.

Off-Topic? Your kidding, right?

Nope,

Keep them in their place by leaving a couch, fridge and washing machine parked on top of the hatch.

DMS-IV Poster boy ----------out

. . . . check this out . . . .

http://crazynest.multiply.com/photos/album/15/Montalban_Methane_Power_Plant

http://www.alternat1ve.com/company-list/

http://www.chpcenterma.org/docs/Project%20profiles/BRESCO%20CHP%20Project%20Profile_final.pdf

CR4 Admin: Removed broken link

The nation's largest land fill site is located in south-central Washington state on the Columbia River. Much of CA garbage is brought there by rail. They have 4 methane burning generators that put out LOTS of electricity, I don't know how much but you could Google "Rabanco" the owner operator and find out. They are headquartered in the Puget Sound area so you'd need to go to the listing of their dump sites and find this one. The methane fired turbines are quite large. They also have a flare-off system for the reasons posted above.

In India small plants that can cater to individual homes have been developed.

http://www.dae.gov.in/ni/ninov02/biogas.htm

http://www.arti-india.org/content/view/45/52/

http://www.ias.ac.in/currsci/jul10/articles13.htm

http://www.google.co.in/search?q=biogas&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a

Very good links

It would seem to be a good idea to have community based processing facilities to convert organic waste into energy. Even if the biogas was used for simple things like street lights

If I remember correctly, the BMW automobile plant in Greer, South Carolina USA is using methane extracted from a landfill for a significent amount of its energy requirements.

Corradini, thanks for the post, very informative ,I will check out the links and do further research. I have a spotty grasp of chemistry but I am very curious, I mean people do find me curious and odd, but I should say I have eclectic interests. You seem to know what you're talking about, so while I have you on the line I hope you don't mind if I ask you a few questions.

My initial musings on the garbage to fuel subject were in the direction of having a somewhat passive system, with the pay-off of harvesting anything useful out of it possibly occurring many generations down the road. So I was wondering how deep of a hole would be necessary for the weight (mass) of the material placed in the hole to provide sufficient pressure to sustain the process?

I was envisioning a continuous process where the garbage is dropped in the top and a useful product is drawn off at the bottom. By useful product it could be the precursor for further processing to produce plastics, fertilizers, fuels or Vega-mite.

The other thing is a few years ago, I caught the tail-end of an interview on NPR, don't remember the interviewee's name or what discipline he was credentialed in, but he was talking about how geologists ( oil exploration dudes, not sure what one calls them), were wrong about there concept regarding the formation of fossil fuels. He was saying , if I remember correctly, that the actual process required limestone, iron oxide and now as I'm writing this can't remember third component, might be salt water. So this stuff , not ancient marine life , is what crude oil is made of. Familiar with this guy or any thoughts on his view?

Any input would be greatly appreciated.

Pack drill

The pressure required by thermal depolymerization (read that link - good one) is on the order of 4GPa or about 600 psi. It also needs to be at a temp of about 250°C - at least, that's what CWT did. (Of course, that did the conversion of, say, turkey guts and steam into syn-petrol in about 15 minutes, and it's flash evaporated and heated to 500°C, as well.)

So - as far as "how deep the hole" - I dunno the average density of garbage, but one foot of water-head is 0.433 psi. So, if your feedstock had about the density of water, you'd need about 1,400 feet of shaft to get 600psi at the bottom. I haven't even thought about the pressure -> heat issue; presumably at 600psi you'll get some heating. ;-)

BUT - you now have an energy cost of lifting both the 'fuel' -- and the 'slag' back to the surface, to subtract from the heat value of the fuel.

Basically - gravity ain't a free source of compression, unless you're burning fuel at the bottom of a mine shaft, AND have massive cavities down deep into which to put your waste matter. It's possible to cheat - well, at least find loopholes - with heat; compression seems to be a lot harder.

Petroleum energy is derived from solar (something grew the ferns/dead dinosaurs) and from geologic-scale energy (compression and heat). Just digging a deep hole costs energy in the digging, and in the pumping back to the surface. (Yeah, you have to pump oil out of the ground, too, but the compression was 'discounted' by geologic-scale movements.)

Hey corradini,

Good answer . This was what I was curious about when I posted my original question. I am going to check out the thermal depolymerization link and report back.

Packdrill

First you should want suitable rock, not soil.

Second, hold the clay (kitty stuff).

Third, how do you plan to retrieve the boring machine?

Fourth, please explain how Mother Nature moved all that organic trash deep enough to provide the pressure (from the mass?). From that, I will understand the heat, and the product.

Fifth, what's your expected delay to profitability?

Sixth, what's to keep Gaia from interfering during the wait?

Hi semtex,

Thanks for responding.

1. rock, okay, makes sense.

2.hold the clay, worried that it will cause problems with impermeability?

3. not necessary to retrieve machine, similar to Chunnel boring machine solution, bore it a distance off shaft axis and abandon it. Or trade it to the Mole people for manganese nodules.

4.I don't have my original question in front of me and I'm too lazy to look for it , but I think the reference is to organic material covered with sediments and then subjected to metamorphic geologic action.

5. Forever, never, indefinite, this was proposed mainly as a thought experiment, so persons could weigh in with their thoughts, views, ideas and observations on my mental condition. If this is not economically viable over the long haul, then by all means I would like someone to make a well- supported post as to why. Barring that a half-baked observation on my ancestry or comparisons between my reasoning ability and that of a box of rocks will be cheerfully accepted, if it makes a t least one person chuckle.

6. I would think that , Gamarah, the giant flying, flaming turtle can deal with anything your puny Gaia can dish out.

7. basically, the question could be: how deep does the hole have to be to create enough pressure?

I would think rock would be problematic, how many suitable formations that are several thousand feet deep [guessing the magnitude of hole needed] with out significant cracks or porosity are there?

Hey Garthh,

I would guess, not many. We're going to have to line this baby to keep the good stuff from leaking out. Since were lining it now, we can go back to the area with soil.

Packdrill

Attention all, i'm going off the grid for about a week, don't fret i'll be back, no it's not jail this week.

Packrat----out

Along similar lines, and a smaller scale are biogas digesters. They can be made fairly cheaply and can be as small or as large as needed. It all depends on the amount of organic waste and how much methane you need. I've built one for a pig farm to cook with, but the idea can really be scaled to work for many scenarios. I'm working on a 55 gallon drum design for smaller scale needs. The methane produced has many uses and the digested material makes great compost.

-BOG

Sounds promising . care to elaborate

Well, its similar or the same as the idea posted in the links by bioramani. The basic idea is you have a sealed container that you put a slurry of water and poop or other material (any kind of poop or any kind of plant material) The micro organisms that are already present in the slurry break down the material, methane is produced and pressure builds in the container and the methane is piped to another chamber that filters the gas through some water and functions as one way valve. From this chamber the gas is piped to whatever you need to use it for. Stove, heater, lantern, generator. Back in the first container once any material has been digested it sinks where you then have another outlet to empty it and use that digested material as compost. Might be a bit difficult to understand in writing, and the concept is simple but it can get complicated. Its a living system, if something gets in that inhibits digestion or kills the bacteria the system needs to be cleaned out and restarted. I've always thoughts its pretty cool to be able to cook with poop.

-BOG

Take a look at the following pdf from NETL:

http://www.netl.doe.gov/technologies/coalpower/advresearch/pubs/ARSS-011_4P.pdf

Cons:

Your initial premise that such aplace can be found: "Start in a venue with suitable soil for excavating deep, relatively impermeable vertical pits."

No such place can be found near any habitations producing said garbage. The humans who live there will insist that such a venue be located "Not in my backyard"

And if you placed it without regard to their opinion because say, they were poor and oppressed and lacked power, some attorney or NGO would turn this into a cause celebre' and tie you up in court until all you cash was gone and you had to cancel your order for the boring machine. The company making it wouldclose, and... you can figure the rest of the story.

milo

It is really sad that we all think about how much money can be made, or how much it will cost us, instead of thinking how can we survive as a race on this rock.