Natural Gas storage?

[MDM]

Here is the situation. My dad has a natural gas well on his farm and heats his house with it. We are trying to devise a way of bottling the gas in say a 100lb propane cylinder. The plan is for me to install a vent free natural gas heater in my basement - one of those 30,000 BTU wall mount units and heat my basement out of a few of those 100lb propane tanks with the natural gas. Anyone know if this is possible?

Dad says one of his buddies can T into the gas line in the house and use some sort of compressor to fill the tanks. One 100lb tank may only last a week or two, but it would save me alot in heating bills. I figured I would get 2-3 tanks, that way when one runs out, I could just go get it filled and have one in reserve. Probably not the most legal thing, but he is allowed 200,000 cubic feet per year and will never ever come close to using that amount. He wants to use as much of it as he can and I'm not going to complain. I'm not asking if this is ethical, just want to know if is physically possible.

 

[tallyho8]

With all that free natural gas available, I think I would be figuring out how to convert my truck over to natural gas too.

 

[charlz]

Very interesting... I did some poking around and found this:

index

A 'home cng filling station' says it cannot be used with well gas though. Might be able to call them and find out who might make one compatibles with well gas. Also might be able to figure out what to do to the well gas to make it compatible with their system. I was watching something on TV one time that said NG well gas has a very high water content.

Charles

 

[kenmac]

I think you would hve a cng compressor to compress at a high pressure for storage or compress at such a high pressure it turns to a liquid state. very expensive

 

[tommu56]

Here is another thread on similuar idea

http://www.tractorbynet.com/forums/oil-fuel-lubricants/110419-gas-well-farm-can-one.html?highlight=gas+farm

tom

 

[Egon]

Are you talking about non processed gas straight from the wellhead?

 

[MDM]

Yep, it comes straight from the well to the house.

 

[charlz]

I think you would hve a cng compressor to compress at a high pressure for storage or compress at such a high pressure it turns to a liquid state. very expensive

Well CNG is compressed and LNG is when it goes to the liquid state. Two similar but different processes I would imagine.

 

[charlz]

I was thinking about this last night and re-read the original post.. you are talking about using propane cylinders. I believe CNG is somewhere around 3500 psi so I don't think propane cylinders are safe for that... more like welding cylinders.

Trick is how far away are you and how often would you want to go to get more gas.

Do you live in a neighborhood? Neighbors might not take too kindly to having a potential bomb in the neighborhood

I would say most consumer NG appliances are not designed for well gas, particularly 'vent free' so:

1)find a way to clean it up similar to 'line gas'
2)find a way to compress it
3)find some cylinders that can contain it
4)find a way to transport the cylinders (small pickup with them mounted in the bed?)

Going to need to figure out what state laws might apply to transporting it. I am think unless you want to go back every couple days you are going to need a couple of cylinders.

Just found this:

http://www.harscogasserv.com/lng_pdf_files/CNG & Hydrogen Cylinders.pdf

Their largest tank at 21 inches by 7 feet holds 3494 SCF (cubic feet?) of gas at 3600 psi.... hmm someone on that other thread said they used 227 cu ft in one month (January) to heat their whole house... so maybe it wouldn't be too bad with the right size cylinder.

I am thinking this would take a lot of up front cash to get going.... would have to do your math to see how long it would take for the investment to pay off.

Sorry for the long post!

Charles

 

[shaley]

I'd buy a small cumbustion turbine and make electricty. Sell it to the neighbors and buy my gasoline.

 

[MDM]

Just thinking out loud. Why would I have to compress it to 3500 psi. If I remember right, the line to the house is about 2-3 psi then it goes down to 2-3oz. at the heater. I don't think I would have to clean up the gas because it runs my dad's vent free heater just fine, and everyone else that is one the gas line up the road for that matter. There are several wells within a few miles and every farm uses it straight from the well in their gas furnaces and vent free heaters.

I live in the country with no visible neighbors, so that wouldn't be a problem. How many cubic feet of propane will one of those 20lb propane tanks that are used for gas grills hold?

It sounds as thought this may not be as easy as we thought, but according to my dad's buddy he has done it before using standard propane cylinders. I'm sure it is not compressed to 3500 psi though.

 

[charlz]

Just thinking out loud. Why would I have to compress it to 3500 psi. If I remember right, the line to the house is about 2-3 psi then it goes down to 2-3oz. at the heater. I don't think I would have to clean up the gas because it runs my dad's vent free heater just fine, and everyone else that is one the gas line up the road for that matter. There are several wells within a few miles and every farm uses it straight from the well in their gas furnaces and vent free heaters.

I live in the country with no visible neighbors, so that wouldn't be a problem. How many cubic feet of propane will one of those 20lb propane tanks that are used for gas grills hold?

It sounds as thought this may not be as easy as we thought, but according to my dad's buddy he has done it before using standard propane cylinders. I'm sure it is not compressed to 3500 psi though.

Obviously the higher the PSI the more gas you have and the less trips/tanks you will need to make/have. I was thinking of what equipment you would get to compress the gas.... something made for CNG would probably be built to go to those pressures.

Hopefully someone will check my math on this:

A 20lb propane tank is about 5 gallons. 1 cubic foot is 7.48 gallons (according to google) so that tank is .67 cubic feet at atmosphere (14.7 psi) I found a reference that said the relief valve on a propane tank with start leaking at 375 psi and another reference that the service pressure is 240 psi.

so 240/14.7 is 16.3 cubic feet at 240 psi? sound about right? Since the tank will come down to atmosphere you probably lose .67 cu ft?

You would probably do all right with a couple tanks to swap in and out.


My concern with well gas is it typically has a high moisture content from what I have seen/read. With ventless heaters all the moisture stays in your house. Mold and mildew are already potential issues with using line gas and a ventless heater. Since others are already using it with no apparent issues you might be OK, something to be aware of though. Maybe you can use some type of dryer like they use for compressed air in whatever setup you use to fill tanks.

With the price of energy only going up I would be look hard at this.... probably for more than just heating your basement.


Charles

 

[MDM]

Charlz, thanks for your time. I thinking along the lines of a couple 100lb propane cylinders a Tractor supply which are 23 gallon tanks. If I remember right, my dad said the guys somehow used and air compressor to do it, so I won't be looking at 240 psi, probably closer to 80-100psi. According to your math, how many cubic ft would a 23 gallon tank at 80psi yield? I'm thinking ballpark around 23 cubic feet? I'm just wondering if our math is correct.

I have a heat pump/electric furnace. I have found that if I heat my basement, it is much easier to heat my upstairs portion. In fact, I have a 20,000 btu kerosene heater that I run in my basement periodically, and if I leave it on low for 8 hours in the basement, it will heat the upstair completely. My basement is almost entirely underground, so it is not that hard to heat, and we all know heat rises. I'm just figuring I could save a bundle in heating bills. My electric bill has been as high as $300 in cold months.

 

[MDM]

I just check my air compressor and it goes up to 200psi, but I have the relief set at 160psi. If this guy has devised a method to use an air compressor motor, we might be able to go up to 150 or so, depending on what the compressor is rated for. I usually go up to the farm every couple of weeks, so I would think 2 100 lb. tanks would be plenty.

 

[shaley]

LPG and NG are two different Gases. LP will become liguid at about 200 psi. The 20 LB grill bottle will hold a lot more liquid vs. vapor. NG liquifies at a much higher pressure and it is stored in a cryogenic type tank.

 

[MDM]

So does natural gas have to be compessed to it's liquid state to be useable?

If I can compress air in my 33 gallon air compressor tank to 160psi, why couldn't I compress the the NG from the gas line into a 23 gallon tank and use it that way? My brain is starting to cook. I'm not lookin to store massive amounts of cubic feet, just 20-30 cubic feet of useable NG.

Would the NG in the gas line be heavier than air?

I guess my dad's buddy has done it before with his NG gas line in his house, so I guess it must work.

 

[kenmac]

NO for your 1 st question ,but you would would have to have a special compressor to be able to compress enough to be able to use. some of The compressors used for cng vehicles are able to compress to around 3500 psi.Ng is lighter than air. If you don't compress alot it will be gone in no time !!

 

[BobRip]

If you use an air compressor, I would be concerned with leakage around the rings getting into your house. I don't know that this would be a problem because the oil chamber is usually sealed. I would make sure that the compressing is done in an area that is well ventilated. Also the compressor motors usually have a starting switch which sparks when starting. Again do this compressing well away from any structures that you care about. I hope someone will comment who knows more about this.

 

[charlz]

Yeah, I don't know about using a 'regular' compressor... I think you would want something that is 'explosion proof' rated or whatever they call it.

That is why I found that 'Phill' station I linked interesting... the more you can stay with purpose built items the better (read safer). I would contact them and find out why it can't be used with well gas. Maybe you just need some type of dryer.... or maybe they just say that for liability reasons (well gas being 'unscented')

BTW what is the pressure on his line/at the well? Anyway to tap something this is already at a decent pressure?

If you had a fill station like that and one tank out of an cng fueled vehicle you'd pretty much be set.

I still kinda like the idea of taking an old datsun pickup or something, put a couple of big cylinders in the back and then you just have to drive it over once a year to get your heating for the winter

OK, did some more poking around:

NaturalGas.org

talks about 'refining' well gas into line gas. Lots of potential stuff in there which is why the 'Phill' probably is not rated for well gas.

Gotta wonder about using it with a ventless heater and what happens to all that stuff when it burns... or doesn't burn.



Charles

 

[MDM]

We can't tap it at the well head. The gas company probably wouldn't like that. I know the main line has more pressure than the line that runs from the meter to the house. I guess I will just have to wait and see what comes of it. I will keep you posted. It might be a few weeks. The guy used to install gas furnaces and gas plumbing in houses, so maybe he has the proper compressor for the task. I think he was going to let my dad have it, whatever it was.