Methane Gas from Sewer Lines

joelcolorado · Intermediate Crude Joined: May 25, 2008 Posts: 651

I need technical help in processing methane gas from the sanitary sewer that connects to my house. My dad designed a sewer plant to run off the methane in the lines so I know it works.

Can anyone on here tell me how to do it? I know you have to compress it and also sort out the other gases. But it should run a car or truck for free with a propane setup.

NOW HERE is finally a solution for lots of ppl. Not hard to do I dont think.

Homesteader · Posted: Fri Jul 18, 2008 10:46 am Post subject: Re: Methane Gas from Sewer Lines

That is a an idea that is interesting from a lot of angles. Big oil will hate it though.
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"The era of procrastination, of half-measures, of soothing and baffling expedients, of delays, is coming to a close. In its place we are entering a period of consequences…"
Sir Winston Churchill

joelcolorado · Intermediate Crude Joined: May 25, 2008 Posts: 651

I saw it work so know its possible. Need technical help. Compressor that will work will prob be about $1,200. Can use scuba tanks or propane tank like in cars and trucks currently. That conversion usually about $800.

At least some ppl could have free fuel for cooking or cars or generators.

Kingcoal · Posted: Fri Jul 18, 2008 10:59 am Post subject: Re: Methane Gas from Sewer Lines

Well I guess your neighbors will know when you get it working - you'll have the smelliest car and house on the block!
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Gerben · Posted: Fri Jul 18, 2008 11:25 am Post subject: Re: Methane Gas from Sewer Lines

This is not easy, nor cheap.

There are a couple of options.
First of all I need to know what you mean by "a propane setup".
Since you say "car or truck" I asume that means you don't have the car or truck converted yet.
You should not convert it for running on propane, but for running on CNG (since that's methane, only higher grade methane).
This should be done by a specialised company. CNG is stored at 200 bar. Propane tanks cannot sustain such pressures, meaning you cannot take a significant amount of fuel with you.
200 bar is a very high pressure and you should not experiment with that unless you know what you are doing.
Only qualified people should touch that. (Yes, that costs money.)
Your local garage should not touch the fuel system either.

To get the gas into your car you will require a compressor.
FuelMaker (www.fuelmaker.com) has complete consumer products for natural gas compression, but they are not intended for biogas, so do not count on any warantees.

Next you will need to upgrade the gas. There are a couple of things you need:
- lower the CO2 content
- dry the gas
- filter the gas

The first thing is CO2. This is corrosive and can form solids inside your fuel tank at cold temperatures.
The usual solution is to remove CO2. But the technology to do this is expensive. And making it yourself is not easy unless you know what you are doing.
I'm not even going into that.

This leaves two other options:
1. Find someone who's good at car engines and make your car run on a petrol/biogas mixture.
Note that he should only touch the part of the car behind the pressure reducer, unless he's familiar with high pressure technology.
Running on mixtures (dual fuel) is done occasionally with diesel/natural gas mixtures and it should work just as well with a petrol/biogas mixture.
As far as I know it would be unique in the world.

2. mix the biogas with 50% natural gas to lower the CO2 content (depends on the quality of the gas, a measurement is advised)
(70% at cold weather)
(this is the easy solution)

Drying
This gas is completely soaked with water, unlike piped natural gas. So you will need multiple dryers.
First you need a low pressure condens dryer. Second I'd recommend a low pressure absorbent dryer in front of the compressor.
Finally I'd add another dryer (high pressure absorbent dryer). This might seem like overkill, but it's necessary.
CO2 plus even a tiny bit of water will kill your compressor and your car.
If you mix in natural gas, then add the gas after the condens dryer, before the low pressure absorbent dryer.

Filtering
You can use a carbon filter with a particle filter for that.
I'm not sure where to place the carbon filter in the system. Ask your supplier for advice. It should be in front of the compressor.
Probably even before the first dryer.

If you are still interested after all of this, then please let me know. I'd be willing to give you free advise, if you keep me updated on all the problems you encounter and the solutions you find.

joelcolorado · Intermediate Crude Joined: May 25, 2008 Posts: 651

http://www.truehealth.org/methane2.html

http://www.truehealth.org/methane.html

Homesteader · Posted: Fri Jul 18, 2008 2:44 pm Post subject: Re: Methane Gas from Sewer Lines

Joel, great links, thanks.

Here is the plan I was going to try until we decided to move.

http://www.ruralcostarica.com/digester-video.html
_________________
"The era of procrastination, of half-measures, of soothing and baffling expedients, of delays, is coming to a close. In its place we are entering a period of consequences…"
Sir Winston Churchill

Gerben · Posted: Sun Jul 20, 2008 2:44 pm Post subject: Re: Methane Gas from Sewer Lines