normally we liquefy gas by compression or cooling, yet the critical temperature for most of the gases is
much lower than ambient temperature. those gases cannot be liquefied through compression solely, thus
cryogenic technology can be applied to cool the gas below its dew point temperature to create the liquid
product. liquefied gas can be transported and stored easily. Some of the liquefied gases like liquid helium
and liquid hydrogen have special applications and require experience and expertise.