Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Nitrogen rejection and liquifier system for liquified natural gas production

a liquifier and natural gas technology, applied in refrigeration, liquifaction, solidification, etc., can solve the problems of high energy requirements for purifying renewable methane, high capital and operating costs, and high cleanup costs of biogas/landfill gas, etc., to maximize liquefied natural gas production and minimize product flash losses

Inactive Publication Date: 2012-03-22
LINDE AG
View PDF8 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The invention is a method for recovering liquefied natural gas (LNG) from a natural gas stream. The method involves purifying the natural gas stream, expanding it, and separating it from flash gas. The flash gas is then recycled back to the purification system or combined with the raw natural gas. The end flash from the flash vessel is designed to produce some more gas inside the line, so the flash pressure should be lower than the storage pressure. The technical effects of the invention include improved LNG production and minimized product flash losses, reduced nitrogen rejection unit waste, and reduced cost and maintenance issues.

Problems solved by technology

Further, the energy that is required to purify the renewable methane is significant.
The cleanup of biogas / landfill gas is both capital and power intensive because it contains a large number of trace and bulk contaminants in fairly large concentrations.
However, these processes can be expensive in both capital and operating costs and it is important to minimize these costs to achieve an economically viable process.
LNG production is particularly challenging since all condensable contaminants including carbon dioxide must be removed to low ppm levels.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Nitrogen rejection and liquifier system for liquified natural gas production
  • Nitrogen rejection and liquifier system for liquified natural gas production
  • Nitrogen rejection and liquifier system for liquified natural gas production

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0022]Landfill gas is purified and all the water, sulfur compounds, NMOCs and carbon dioxide are removed in a pre-purification process. The purified gas contains methane, nitrogen and oxygen and has the following composition:

TABLE 1NRU Feed Gas CompositionSpeciesMole FractionCarbon Dioxide0.0100Nitrogen0.2160Methane0.7720Oxygen0.0020

[0023]The gas is further purified in an adsorption system so that the carbon dioxide level is reduced below 50 ppmv and a large portion of the nitrogen is removed. Oxygen usually does not adsorb appreciably and about 50% of the oxygen is removed in each case. FIG. 1 illustrates a typical MR liquefier stream without process integration. In this case both storage tank losses and nitrogen rejection unit waste streams are not recovered.

[0024]Turning to the figures, FIG. 1, represents a base case mixed refrigerant liquefied natural gas liquefier. Purified natural gas is fed through line 1 through main heat exchanger A where it will be warmed and fed through v...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method for recovering liquefied natural gas from a gas mixture containing natural gas and impurities by subjecting the natural gas to a series of steps beginning with feeding a natural gas stream containing impurities to a nitrogen rejection unit; feeding the purified natural gas stream to a liquefier heat exchanger; expanding the liquefied natural gas and feeding the expanded liquefied natural gas to a flash vessel; flashing the liquid natural gas and separating the liquefied natural gas from the flash gas; and feeding the liquefied natural gas to storage and the flash gas to the nitrogen rejection unit.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from U.S. provisional patent application Ser. No. 61 / 317,466, filed Mar. 25, 2010.BACKGROUND OF THE INVENTION[0002]The invention relates to the integration of a liquefied natural gas (LNG) liquefier system with a nitrogen rejection unit (NRU) so as to minimize the capital and operating costs while maintaining liquefied natural gas product purity requirements.[0003]Renewable methane can be recovered from a number of sources, such as anaerobic digestion of municipal or industrial waste streams, the degradation of biomass in landfills, the gasification of waste and biomass streams, amongst others. In many instances, this renewable methane require purification before it can be used and / or sold into higher valued markets, such as injection into the pipeline grid, as a feedstock for liquefied natural gas, as a vehicle fuel, or as a feedstock for the production of hydrogen. Further, the energy that is required to...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): F25J1/00
CPCC10L3/105F25J2290/62F25J1/0022F25J1/004F25J1/0055F25J1/0219F25J1/0258F25J1/0259F25J1/0262F25J1/0264F25J1/0291F25J2205/60F25J2210/06F25J2210/66F25J2220/62F25J2230/30F25J2245/02F25J2245/90F25J2290/32Y02E50/346F25J1/0279Y02E50/30
Inventor SETHNA, RUSTAM H.PAGES, GUILLAUME
Owner LINDE AG
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com