natural compressed gas
natural compressed gas
(OP)
OK GUYS, I'M NEW HERE AND AN OLD MAN, SO PLEASE BE GENTAL,LOL
WHAT I WOULD LIKE YOUR INPUT ON IS ............ IS IT FEASABLE TO HAVE A NATURAL GAS WELL AND COMPRESS THE GAS AND USE IT FOR MY CAR? WHAT DO YOU THINK? THANKS.
WHAT I WOULD LIKE YOUR INPUT ON IS ............ IS IT FEASABLE TO HAVE A NATURAL GAS WELL AND COMPRESS THE GAS AND USE IT FOR MY CAR? WHAT DO YOU THINK? THANKS.





RE: natural compressed gas
The most effective natural gas powered engines are converted diesels because you need the extra compression to get the fuel dense enough to compete with petrol. You can run a gasoline (petrol) engine on natural gas, but you pay a significant loss of power.
If you "just" want to drill a gas well out back (and you have the mineral rights and you have the expertise and you have the equipment) then mother nature will give you what she gives you. That can include H2S (poison gas), CO2 (won't burn), liquid hydrocarbons (need further processing before they're useful to you), etc. Then if you are looking to use CNG you need equipment to compress it up to over 3600 psig and vessels to hold high pressure gas. At the end of the day, a "typical" 3000 ft deep well, separation equipment, deliquification equipment, storage equipment and compression equipment should cost you about $2 million. At $4/gallon and 20 miles/gallon the payout is 10 million miles.
Good luck.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
RE: natural compressed gas
easy is really not appropriate as natural gas is a flammable gas, a gas not to be taken lightly or by the average human. the recommended course of action is to seek a responsible and competent engineer. so you know, the practice of compressing natural gas for auto usage is widespread and the equipment is available. it is a matter of being knowledgeable & capable of designing a system to meet your needs.
but before you do this, please read zdas04 response about the engine output power + other possible requirements. zdas04 is one saavy sourdough engr. you may want to change your mind.
-pmover
RE: natural compressed gas
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: natural compressed gas
RE: natural compressed gas
The EPA regulates conversion of an engine from gasoline to natural gas. Therefore all modifications must be tested to assure that the modification meets rules. Because of this, there are companies that make conversion kits that have been tested, but they only make them for very popular cars and trucks. You can google up and see that kits for Ford F150 trucks and Chevy trucks are available.
Once you have done the conversion, google up CNG compressors. They are pricey, but typically you take 8 hours to fill the compressed gas tank.
Gas quality can be an issue like what has been stated above, but even worse is the WATER in the gas. If you do not remove the water, when you let the pressure down from tank pressure to injection pressure, the line will freeze and you are at a dead stop.
RE: natural compressed gas
MAYBE WILL HAVE TO USE DRYER? THANKS FOR THE INFO.......
RE: natural compressed gas
Virtually all the field natural gas engines that I see are diesel conversions--that is you start with a diesel engine to get the compression ratios and then add a spark ignition system. There are exceptions like the Compressco and some GM and Ford industrial engines, but they are all very horsepower limited (e.g., the Compressco is half a Ford V-8 which is 300 hp as a V-8 on gasoline and 30 hp as a straight 4 on natural gas).
Natural gas conversion kits for gasoline engines pay a horrible price in terms of lost power. That is what I said above.
The built for purpose CNG engines have high compression ratios.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: natural compressed gas
RE: natural compressed gas
There may be hope that somebody doesn't find out, but I have found that it is just a matter of time that they do. The more time, the worse the final result.
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: natural compressed gas
You can by a home compressor. I think these are intended to be connected to a commercial source of clean natural gas so you would probably need to add various filters/water separators.
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: natural compressed gas
http://www.popularmechanics.com/cars/how-to/mainte...
Best regards
RE: natural compressed gas
Doug
RE: natural compressed gas
So if you go straight from a 25 psig well into a 3600 psig vehicle tank you need to do something like 104 compression ratios--heat of compression would take 80°F gas up to 1032°F if there was any way to do it in one stage (there isn't). This would be a pretty good 4 stage application, but I'd probably design it as a 5-stage to make sure that I could get into the tank when it is almost full.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
If it ain't broke, don't fix it. If it's not safe ... make it that way.
RE: natural compressed gas
RE: natural compressed gas
Best regards
Morten
RE: natural compressed gas
The block and crank are about the only simularities between a diesel cat and a nat gas cat. The difference is the BMEP, the diesel is higher because it has such a high CR.
RE: natural compressed gas
The performance we saw was awful. Pulling a 6500 lbm trailer in a 1 ton truck up a reasonably shallow, but very long hill. On CNG the truck was in first gear and was running out of power at 5 mph. We flipped the switch to gasoline and by the top of the hill we were at the speed limit in 4th gear. CNG tank pressure was over 3000 psig. These were top of the line conversion kits and everyone had a great deal of interest in making it work (the pumper with the lowest gasoline to CNG ratio at the end of each month got a bonus).
Any idea of an alternative explanation for the poor performance?
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
Without further understanding the complete fuel system it's hard to speculate on the reason for the lack of power. If I had to guess the conversion was the old style with a mixer mounted to the throttlebody. I would guess if it a good conversion with a dual ECM and NG injectors you wouldn't have seen that drop off in power. Generally on NG spark maps are radically different from gasoline.
I've been involved in late model GM NG conversions where you couldn't detect the difference between Gasoline and NG without looking at the switch.
RE: natural compressed gas
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
...but you'd make it up on the LHV difference (47.141kJ/kg methane vs. 43.448kJ/kg gasoline)
...of course, the gaseous CNG will displace a heck of a lot more air in-cylinder than the liquid gasoline will, so you'll end up getting less air in. At STP, gasoline 719.7 kg/m3 and methane is 0.7 kg/m3... when the cylinder is full at stoich, gasoline takes up 0.0001/1 of the space, and cng takes 0.0929/1 of the space.
...If you have 1l/cyl displacement, operating at stoich and considering all of the above, you get about 3.07 kJ/cycle from your CNG and about 3.56 kJ/cycle from gasoline. That gives about 14% reduction in power.
if you compare the specs on the "regular" honda to the CNG version, you'll see that the power is down significantly, and compression ratio is up significantly... a 19% reduction in power. I would assume that timing is optimal in each case. Not sure where the rest of the lost power comes from.
DX Coupe
Engine Specifications
1.8L 140 hp I4
Horsepower 140 @ 6300 RPM
Torque (lb-ft) 128 @ 4300 RPM
Fuel Type/System Gasoline/MPFI
Valves/Valve Configuration 16/SOHC
Displacement (cc) 1799
Bore X Stroke (in.) 3.19 X 3.44
Compression Ratio 10.5:1
Turbocharger No
Supercharger No
GX sedan
1.8L 113 hp I4
Horsepower 113 @ 6300 RPM
Torque (lb-ft) 109 @ 4300 RPM
Fuel Type/System Compressed Natural Gas/MPFI
Valves/Valve Configuration 16/SOHC
Displacement (cc) 1799
Bore X Stroke (in.) 3.19 X 3.44
Compression Ratio 12.5:1
Turbocharger No
Supercharger No
RE: natural compressed gas
Your explanation also helps me get my head around why the guys doing an LNG test the same time we were doing the CNG test had no noticeable power reduction.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: natural compressed gas
RE: natural compressed gas
Look up the HP difference on the plain ol 2.5 liter Subie and one that uses a turbo to artifically increase HP. Plain ol subie, 175 HP, simple turbo that is equal to a 11 to 1 compression ration, 250HP