I’m just starting to check into the whole CNG vehicle thing but I’ve noticed a few things:
1: CNG fueling pressures vary. A good fill is 3,000 to 3,400 psi. Many of the current CNG pumps don’t deliver a consistent psi fill rate.
2. CNG fuel has a higher octane than regular gas but you get 12% to 15% less mileage from an equivalent amount of fuel. (However, I’ve seen E85 mileage rates as being 30% to 35% less than gas = Advantage CNG)
3. CNG is only attractive if the price spread between gas and CNG makes it a “good” deal. It will only take the states so long until they tax CNG at gasoline levels thus eliminating the spread. Then we are back at square one again.
My local welding supply has several photos of what an exploding oxygen tank can do to a car. They are typically at 2,000psi. The entire rear of the car was gone and oxygen is not explosive. A tank strong enough to be safe and big enough to be practical would weigh 500lbs.
“1: CNG fueling pressures vary. A good fill is 3,000 to 3,400 psi. Many of the current CNG pumps don’t deliver a consistent psi fill rate.”
Are you sure about that? That doesn’t sound right. I was under the impression that methane/propane, the primary components of NG would liquefy at MUCH lower pressures than that, talking low hundreds of pounds. Once a liquid, no further compression is possible. You buy a new propane cylinder for a hand-held torch, you can hear liquid propane sloshing around. That type of stamped sheet-metal cylinder is no kind of 3000 lb affair, that’s for certain. Maybe methane has a higher vapor pressure but I doubt either of them (methane/propane) are in the thousands of lbs. I will check.