COMPRESSED NATURAL GAS; QUESTIONS

[ZAMMY1]

locally, there's a lot of discussions and little info about the control and feedback systems for cars' fuel mixture.
i'm familiar with the old 'mixing valve' stuff we used on fork trucks, etc. (propane, et al) but i suspect the new cars designed for CNG use have a full feedback system for mixture control.
question: can these systems as presently designed use CNG of varying BTU per MCF?
or are they locked into using the standard (1000 BTU/mcf ?) cooking gas?
i'm hearing that some gas as pumped from the well is running substantially higher BTUs and must be cut down by fractioning off the offending gases.
it seems that if the mixture systems in use can cope with the varying BTU content, it would be prudent to use the highest BTU stuff available.
people are getting serious about compressing their own gas and using it in their vehicles and fleets, at least around here.
i'll bet someone in this group is familiar with this stuff.
sam

[qball]

The only kind of compressed natural gas I am familiar with is the kind that I release when I wake up in the morning...

[Bruce]

Originally Posted by ZAMMY1

locally, there's a lot of discussions and little info about the control and feedback systems for cars' fuel mixture.
i'm familiar with the old 'mixing valve' stuff we used on fork trucks, etc. (propane, et al) but i suspect the new cars designed for CNG use have a full feedback system for mixture control.
question: can these systems as presently designed use CNG of varying BTU per MCF?
or are they locked into using the standard (1000 BTU/mcf ?) cooking gas?
i'm hearing that some gas as pumped from the well is running substantially higher BTUs and must be cut down by fractioning off the offending gases.
it seems that if the mixture systems in use can cope with the varying BTU content, it would be prudent to use the highest BTU stuff available.
people are getting serious about compressing their own gas and using it in their vehicles and fleets, at least around here.
i'll bet someone in this group is familiar with this stuff.
sam

Rich gas is processed for 2 reasons. 1) The heavy hydrocarbons are removed so that you don't get liquid hydrocarbons condensing when you take pressure drops and cooling occurs (Joule-Thompson effect) and 2) The BTU's are worth more as liquids than gas.