Patent · US Expired

Process for producing a pressurized liquefied gas product by cooling and expansion of a gas stream in the supercritical state

US6751985B2 · kind B2 · utility

40Cited by
14References
40Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 19, 2003
Grant dateJun 22, 2004
Priority date
Expiry dateJul 11, 2023

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF25J2290/62
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

This invention is a method and apparatus for production of pressurized liquefied gas. First, a gas stream is cooled and expanded to liquefy the gas stream. The liquefied gas stream is then withdrawn as pressurized gas product and a portion is recycled through the heat exchanger to provide at least part of the cooling and is returned to the stream. Recycling the pressurized liquefied gas product helps keep the cooling and compression of the gas stream in the supercritcal region of the phase diagram. J-T valves in parallel with the expander permits running the system until the stream is in the supercritical region of its phase diagram and the hydraulic expander can operate. This process is suitable for natural gas streams containing methane to form a pressurized liquefied natural gas (PLNG) product.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.