askme:
You're probably a young Chem E who hasn't been exposed to the Hydrocarbon industry - especially fossil fuels.
NGL is an acronym for Natural Gas Liquids - the liquid hydrocarbons normally associated with "Natural" gas, which is composed mainly of methane, ethane, and "heavies" like propane & butanes. Depending on the gas pressure, the heavies will condense and constitute the liquid or "wet" portion of the natural gas. NGLs are much more valuable as raw material for further processing than as fuel for simple combustion.
LNG is an acronym for Liquefied Natural Gas - the gaseous portion of a natural gas (mostly the methane and a little ethane) in the liquefied state (-260 oF) & 1 atm. This is an efficient way to move, transport and handle large, bulk quantities of natural gas instead of trying to store it in the gaseous state at elevated pressures.
I hope this clears up your understanding of the terms.
Art Montemayor
Spring, TX