Let's share info and experience about how to fuel up your car/truck at your home with CNG. After searching the web for a while I decided to start this new thread. Here is what we have:
1. Only few commercial pumps are available for home use. They are all super expensive to buy(5k-7k) and every few thousand hours you have to pay 2k to rebuild it.
2. What kind of equipment is used to pump CNG? In most cases it is 3-4 stage reciprocating piston compressor. The same technology is used for high pressure compressing air, nitrogen and other gases.
3. I found some info about one pump that uses hydraulics to compress CNG. Very good idea but.... It costs 6.5k and I can't find even one real review from somebody who used it....
4. I found some info :
He used Bauer high pressure air compressor modified to pump CNG. I have no details but it seems to me he vented crank case to intake and vented safety pressure relief valves (they are after each stage to protect from over-pressure)
5. I found some info about using low pressure CNG and active carbon (adsorption method):
http://web.anl.gov/PCS/acsfuel/prepr...03-96_0246.pdf
This is very cool but I don't have enough equipment to test it.... Also Carbon will add extra weight to already heavy tanks and it is not cheap