Planning on making a methane digester to run my '73 Dodge Monaco big-block V8 on methane.

Eventually, Godzilla (it's green) is going to have a turbo system to optimize the calorific content of methane and it's high octane.

I have one question though, in looking over Bate's notes, I noticed he was compressing the methane from the digester to 1100 psi to liquify it. What kind of pump do I need to use to get this gas compressed into the fuel bottles? They mention something along the lines of a scuba tank compressor, but I wouldn't think that sometime like that would be rated for a flammable gas such as methane?

Also can I just use propane parts like the carb, regulator, fuel bottle etc?

Might check out Paintball Compressors. Scuba compressors are mucho $$$$$. Check ebay.

Looked at a couple of them on fleaBay and they seem to be a 3 stage compressor. One of them compresses up to 2000 psi.

One question again, would I have make sure the methane coming off the digester was free of Hydrogen Sulfide before compressing? Seems the prudent thing to do, I know that bubbling raw methane gas through water will remove most of the sulfide.

Put ground up Lime in that water before you bubble it through. Make a paddle type rig, so you can stir the Lime occasionally.

So, should I just have a sealed drum with water and an amount of lime in the water with an agitator to treat the biogas?

Yup, that'll do it.

I found out from a friend today about a source for 70 pound scuba tanks that nobody uses anymore.

As far as he knows, they've all been hydro'd for safety and they should be able to handle liquid methane at 1100 psi.

I believe 70's are Steel. They are air filled to 2200-2250 PSI.

Do a LOT of research on compressing methane into a liquid before trying it. I think it will take more than a simple high pressure compressor. There should be no problem compressing it to a few hundred pounds as a gas but you will need some BIG tanks to even drive out of town.

There is a huge commercial natural gas compressor and storage station about 4 miles from where I live (supposidly a 2-week standby supply for Chicago's natural gas needs), a couple of my neighbors work there. There are two huge steel double-walled thermos-type cryogenic tanks to store the liquid natural gas, a million gallons each. The compressors used have huge multi-hundred horsepower electric motors driving 3-piston pumps no bigger than a washing machine. They not only compress the gas but also cool it while compressing, a portion of the already liquified methane is circulated around the pump cylinders and allowed to boil back into a gas, this cools the cylinders and there internal gas down to something VERY cold, don't know the boiling temp of liquid methane right off hand. These compressors are housed inside concrete bunkers now as the compressor cylinders have a tendancy to crystalize there mounting bolts due to the vibrations, pressures, and cryogenic temps. Prior to placing thes pumps in the bunkers they had a couple accidents where a compressor cylinder went clear through 3 buildings and ended up several hundred yards out in a corn field. Some seriously dangerous $hit .

I will have to look up the pressure/temperature graph for methane to figure out what is going on when methane is compressed to 1100psi to liquify it.

I read that Harold Bate in England was using a scuba-type compressor to liquify his homemade methane into small compressed gas bottles.

70 pound scuba tanks sound like the perfect container for this project.

Question:

Can glycerin from biodiesel production be used as a feedstock in a methane digester and if so, does the methanol need to be recovered from said glycerin prior to digester input?

hi I'm a student, forgive me if this sounds dumb, but what exactly are you making the methane gas out of?

thanks
Fishfool @ The Reef Tank

Methane is made by anaerobically "digesting" organic matter into several compounds, one of which is methane.
The are called digesters, because they work very much like a cow's stomachs and intestines.

Spencnaz: yes, you can.
I don't know too much about the stuff, but in the middle phase alcohol is in fact produced from the sugars produced in the first phase.
However be careful with the amounts and when in the process you add the glyc. + methanol.
If you use a plug processor, you can just add the glyc. + methanol as part of the measured dose at the start of the process.

I got a question for you ?
What you gone a do to scrubb your methane fot
c02 and h2s?

Just curious see what you use cause i want to do same thing here?

Bubbling the raw methane gas through water that has lime dissolved in it will remove the co2 and hydrigen sulfide, it will precipitate out of the water as limestone.

Can you compress the methane into propane cylinder ? how much methane you need to compress like a 30 pound cylinder? Can you run methane into propane equipement ? I am curious to know i will do that kind of project this summer ... Some people have personal picture showing there digester ? i see few video on youtube and see few document on net ... I want know if someone here try to be self efficient to doing that ? I am new here but i read alot of document and want to be self efficient .. I want to do that next summer and a other project with algea biodiesel ... thank to answer to me everyone and sorry for my bad english cause i am a french canadian !

Tin28 we are working on a digester based on the type Jean Pain used. Rather than requiring heat, it provides it and the methane is much easier to handle.

Compressing the gas helps, but to liquefy it takes more equipment than a noncommercial entity can probably afford. The size cylinder you are thinking of would be about 4 gallons of gasoline or less at 200psi. For stationary power it will work well, but travel distance would be limited.

All of the projects we are working on are geared toward self sufficiency and sustainability, methane plays a big part of it here even though I plan to use ethanol for travel. I havent found a reason why anything that burns propane cannot burn methane, provided the fuel isnt contaminated.

You can get a copy of Pains work, and since you speak French you dont need a translation. Ours should be operating within a month if I can find a couple more pieces I need to build it.

I just figure out around how many cubic meter i will need to heat my house ...that will be around 2500 cubic meter to heat my 2400 square feet house so how big the disgeter i will need ? somebody have one and know how much you produce with?

Why couldn't you use a AC compressor to get the methane to around 200 psi and store it in large LPG tanks for stationary use?