compresing natural gas in home compressor

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From a purely theoretical standpoint, I honestly have no idea about the issues involved in this project.

From a practical perspective, I hope you don't live anywhere near peekskill, ny.

Jim

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I'm guessing you want to use natural gas for a cutting/welding torch. I saw a commercially built compressor to do just that. IIRC, it wasn't cheap enough for home use, but made sense for a shop.

-Carl

What about the NG leaking past the rings? You will have NG coming out of the crank case breather.

Richard W.

You might find out:-) CNG is used to power some fleets and the filling stations employ compressors. Maybe you can get some info by searching the topic.

Let us know your address and when you plan to try it. You could probably make enough money selling tickets to buy an honest-to-goodness NG compressor.

How about using the compressor off of an HVAC? Would solve the crankcase blowby issue. You wouldn't think they have any internal electrical contacts, though I haven't looked at how the starting windings are engaged. I have an old Carrier reciprication three phase compressor that I have been looking for a project for. I figured I would use it for a self contained air hammer. Maybe a Three phase unit would be better for Don's project.

Charles

Richard W. wrote:

Why don't you look up the compressor that blew up while refueling the MTA bus fleet in NYC? I think at least one person was severely burned at the Keyspan depot.

Normally, both windings are brought to terminals that come through the compressor wall. Start/run switching is done by an external relay that senses voltage or current. So, no switches inside the crankcase.

Dave

I was thinking he should pair up with the guy with the anhydrous ammonia cylinder. We could tell the Texas A&M joke again.

I know one guy who used a York compressor out of a car to compress natural gas with. The only gotcha with this is you need a separator for the oil that gets out of the compressor so it can be put back in. He's on a owned well and is allowed to get free gas from it. But the gas company put a vacuum pump on the well for a while and thus he had to have a compressor to for him to use it (he couldn't hook up on the pressure side of the compressor without paying for it).

I also know of at least one man who used a standard air compressor for this same job. I questioned it when he brought it in for some threads to be chased but apparently he's been running one for years that way. Personally I don't like the idea since the crank case on a air compressor isn't sealed in any way. Even if you pipe the crankcase back to the suction line the shaft doesn't have the proper sealing to prevent either suction of air into the system or leaking of gas out.

Natural gas is compressed all the time to moderate pressures for piping. It's also very common to pull a vacuum on a well to increase productivity. In fact I just got through dismantling a lobe type vacuum pump (think roots blower) that's used for just that. I have to rebuild these from time to time. In the old days a piston compressor was fairly common. Now days they tend to use more modern methods like turbines, etc. However many of them are still piston type (many are rather large like in 36" pistons). I chased the threads on a cross head bolt for one of those a few days ago.

Wayne Cook Shamrock, TX

Really I was thinking that. But that is a once-a-year-per-newsgroup joke and if you use it too much folks start mailing you old dead possums etc.

Jim

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Some of the energy co.'s were pushing natural gas conversions for cars a while back. To get around the lack of NG fuel stations, they were leasing out a compressor that would get plumbed into your home delivery gas line and would refill your vehicle while it was parked. Somwhere out there, there are a pile of those pump units. It has been done.

I have a tank from a CNG fuelled truck (GM SUV take-off, from a dual fuel conversion). It was one of four that were in the truck. It is about the same size as a 100 pound propane tank, and is rated at 3000 psi. It's heavy. Four of them take up most of the luggage space. I doubt very much that I will ever have any problems with it as an air receiver for a compressor. Or it may become a lawn roller. :-)

Cheers Trevor Jones

How much pressure do you want? If you want to use natural gas for a torch you could use a diaphram pump. If you want to use it for a portable tank say for a steam powered boat, you would need a lot more pressure. Some boat marinas sell Compressed natural gas ( CNG ) for use on boats for cooking ( no problem with fumes accumulating in the bilge ) and CNG is also available for cars and trucks. But the pressures are a couple thousand lbs / sq inch for CNG.

Dan

Finally, somebody that has it right! For vehicle fueling, CNG is in the very-high pressure arena, no way a refrigerator compressor is going to do the job. Now, if the OP just wants a higher pressure for his forge or heat-treat furnace burners, contact the gas utility, they do have regulators that put out much higher pressures, you have to pay for the service, of course. It would be much safer than trying to compress natural gas with something not designed for the job.

I've always wondered how much energy would be consumed just compressing natural gas(or hydrogen) for car fuel if a significant portion of cars were converted over.

Stan

Not sure I've heard it. Is the year yet :^)?

John

Please note that my return address is wrong due to the amount of junk email I get. So please respond to this message through the newsgroup.

Aggie desides he wants to parachute jump. He rents a chute, hires a plane, goes up and jumps out. He pulls the cord and nothing happens. He starts to worry but then sees another Aggie flying up towards him. As they pass he yells "Do you know anything about parachutes?". The other Aggie flys past him and yells "No, do you know anything about welding propane tanks?"

The orignal was "No, do you know anything about soldering gas tanks!?" But the joke permutated a bit because it was applied to a popular thread here on rcm.

Jim

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And as the Aggie continued his descent, he passed a fellow Aggie who had jumped moments earlier was under chute in a normal descent. As he rocketed past, that Aggie did a double take, said "Oh, you wanna race, huh?" and smacked his quick release, shrugged his harness off, and took off after his buddy.

As it happened, the chuteless Aggies hit the ground in drive in movie theater that was, thankfully, not occupied because it was daytime.

But the police and emergency crews responding to the scene found an dusty Olds Vista Cruiser setting in the drive in that contained the desiccated remains of a family of seven. The car had an Aggie sticker on it and it was later determined that the family perished while waiting for "Closed For The Season" to start.

A company about thirty miles up the valley from me in BC (Canada) manufactures natural gas compressors. They are cross head piston units. Some are two stage and others are three stage. The pistons have special rings... some sort of teflon plastic. Between stages there is some serious cooling going on. These units are being marketed outside North America for fleet vehicles where natural gas is plentiful. The North American market for such compressors is dead. Needless to say all kinds of saftey devices are on the setups. Hereyago, Fill yur boots!