APPARATUS AND PROCESS FOR LIQUEFYING NATURAL GAS AND NATURAL GAS STATION INCLUDING THE APPARATUS FOR LIQUEFYING NATURAL GAS

摘要

The present invention relates to an apparatus and a method for liquefying natural gas and a natural gas filling station including a natural gas liquefaction apparatus. According to the present invention, the natural gas liquefaction apparatus includes: a gas compressor which compresses natural gas; a heat exchange unit which cools compressed natural gas compressed in the gas compressor; a gas expansion valve which insulates and expands the natural gas cooled in the heat exchange unit; a hold-up drum which separates gas and liquid from a gas-liquid mixture generated when the natural gas passes through the gas expansion valve; an LNG storage tank which stores liquefied natural gas (LNG) in a liquid state, in which gas and liquid are separated in the hole-up drum, and supplies the stored LNG to an LNG demanding place; a pretreatment cooler which liquefies heavy hydrocarbon included in natural gas supplied to the gas compressor by slipping a part of the LNG and using the same as a refrigerant; and a heavy hydrocarbon separator which separates gas and liquid from a natural gas stream transferred from the pretreatment cooler and supplies natural gas of a gas state, from which heavy hydrocarbon of a liquid state is separated, to the gas compressor. The present invention is able to liquefy natural gas efficiently.