Disclosed is industrial arts for dehydrogenation, denitrogen and de-
carbon monoxide from high
methane gas and
liquefied natural gas production. The industrial arts comprise two parts which are low temperature
liquefaction and rectification separation. The low temperature
liquefaction part is finished in a cold box through cooling provided by a mixed cryogen. A single
tower procedure or a double
tower procedure is adopted by the rectification separation part to remove
hydrogen,
nitrogen and
carbon monoxide.
Methane component in high
methane mixed gas with the
hydrogen and the
nitrogen is liquefied sequentially through the cold box, rectifying
tower bottom
reboiler and the cold box, and the high
methane mixed gas with the
hydrogen and the
nitrogen enters into a rectification
separation system, and then the hydrogen, the nitrogen and the
carbon monoxide are removed.
Hydrogen content in obtained
liquefied natural gas (LNG) products is less than or equal to 2000 ppm, nitrogen content is less than or equal to 4%, and carbon
monoxide content is less than or equal to 6%. The invention further provides a
natural gas liquefaction art of the high
methane gas with the hydrogen, the nitrogen and the carbon
monoxide. The hydrogen, the nitrogen and the carbon
monoxide are removed, and meanwhile the LNG with a better separating effect compared with a traditional industrial art is obtained, and process
route is advanced. Compared with the traditional industrial art,
power consumption of the
system can be reduced by 20%.