System and method for producing liquefied natural gas

Solution Overview

Problem

Current LNG production systems are inefficient and costly due to the reliance on a cold box for multiple cooling cycles, which limits the capacity and increases the size and expense of the system.

Innovation Solution

A system and method that utilize a refrigeration loop with a supersonic chiller to separate liquefied natural gas liquid from the gaseous stream before cooling it further in a cold box, reducing the size and cost of the cold box and enhancing NGL production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a cold box is used for multiple cooling cycles to liquefy natural gas, then the LNG production is achieved, but the system size and cost increase

Engineering Contradiction:

ImproveLNG production efficiencyVSAvoidcold box size

Core Design Contradiction:

ProductivityVSVolume of stationary object

Solution Approach 1:

The cooling process is divided into two distinct stages: a first cooling cycle that achieves initial cooling and partial liquefaction, and a second cooling cycle that completes the liquefaction. This segmentation allows each cycle to be optimized independently, with the first cycle handling the bulk cooling load and the second cycle handling the final liquefaction, thereby reducing the overall cold box size required for a single-cycle system while maintaining production efficiency

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first cooling cycle performs preliminary cooling and partial liquefaction of the natural gas before it enters the second cooling cycle. By pre-cooling and partially liquefying the gas in the first cycle, the second cycle only needs to handle the remaining cooling load, which significantly reduces the size requirements of the cold box for the second cycle while maintaining overall LNG production efficiency

Inventive Principle:

Principle #10Preliminary action

2Productivity

If a cold box is used for multiple cooling cycles to liquefy natural gas, then the LNG production is achieved, but the system cost increases

Engineering Contradiction:

ImproveLNG production efficiencyVSAvoidsystem cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The cooling process is divided into two distinct stages: a first cooling cycle that achieves initial cooling and partial liquefaction, and a second cooling cycle that completes the liquefaction. This segmentation allows each cycle to be optimized independently, with the first cycle handling the bulk cooling load and the second cycle handling the final liquefaction, thereby reducing the overall cold box size required for a single-cycle system while maintaining production efficiency

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first cooling cycle performs preliminary cooling and partial liquefaction of the natural gas before it enters the second cooling cycle. By pre-cooling and partially liquefying the gas in the first cycle, the second cycle only needs to handle the remaining cooling load, which significantly reduces the size requirements of the cold box for the second cycle while maintaining overall LNG production efficiency

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces the size of the cold box by up to 20% and increases NGL production while maintaining efficient LNG production, achieving better energy utilization and cost savings compared to traditional methods.

Implementation Method 1

receiving and chilling, via a supersonic chiller, a first gaseous natural gas stream to produce a liquefied natural gas liquid

Methodology Applied

Scientific EffectJoule-Thomson effect: Joule-Thomson Effect

Implementation Method 2

supersonic chiller for receiving and chilling a first gaseous natural gas stream

Methodology Applied

Scientific EffectSupersonic expansion cooling: Adiabatic Cooling

Implementation Method 3

cooling the second gaseous natural gas stream to obtain a liquefied natural gas by heat exchanging between the second gaseous natural gas stream and the cold stream of refrigerant

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3479036A1System and method for producing liquefied natural gas

Publication Date: 2019.05.08 BAKER HUGHES OILFIELD OPERATIONS LLC

AI summary

A system and a method for producing liquefied natural gas are provided. The system includes a refrigeration loop system for providing a cold stream of refrigerant, a supersonic chiller for receiving and chilling a first gaseous natural gas stream to produce a liquefied natural gas liquid and separating the liquefied natural gas liquid from the first gaseous natural gas stream to obtain a second gaseous natural gas stream, and a cold box for receiving the cold stream of refrigerant and the second gaseous natural gas stream and cooling the second gaseous natural gas stream to obtain a liquefied natural gas by heat exchanging between the second gaseous natural gas stream and the cold stream of refrigerant.