Warm Distillation of CO2 Streams for Helium Separation

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Solution Overview

Problem

Current methods for separating light gas fractions, such as helium, from carbon dioxide streams are economically inefficient due to high capital and operating costs associated with cryogenic processes.

Innovation Solution

A process employing a warm distillation and condensation step as the primary separation method, reducing capital equipment requirements and energy costs by separating light gas components from carbon dioxide streams at elevated pressures without the need for cryogenic temperatures, followed by additional separation steps on smaller gas volumes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If cryogenic fractionation is used to separate light gas fractions from carbon dioxide streams, then separation effectiveness is improved, but capital equipment costs and operating energy costs increase significantly

Engineering Contradiction:
Improveseparation effectivenessVSAvoidcapital equipment requirements
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the temperature parameter from cryogenic conditions to warm conditions (above -6.7°C), fundamentally altering the separation mechanism from cryogenic condensation to warm distillation. This parameter change reduces capital equipment requirements while maintaining separation effectiveness through the specific distillation configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The separation process is segmented into distinct stages: a first warm distillation column for bulk separation and a second stage for fine separation. This segmentation allows each stage to be optimized independently, reducing overall capital requirements compared to a single cryogenic system while achieving the same separation effectiveness

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If cryogenic fractionation is used to separate light gas fractions from carbon dioxide streams, then separation effectiveness is improved, but operating energy costs increase

Engineering Contradiction:
Improveseparation effectivenessVSAvoidoperating energy costs
Core Design Contradiction:
Manufacturing precisionVSUse of energy by stationary object

Solution Approach 1:

The patent changes the temperature parameter from cryogenic conditions to warm conditions (above -6.7°C), fundamentally altering the separation mechanism from cryogenic condensation to warm distillation. This parameter change reduces capital equipment requirements while maintaining separation effectiveness through the specific distillation configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The process maintains continuous operation with the liquid stream from the first column continuously fed to the second column, and the refrigeration system operating continuously to provide cooling. This continuous operation improves energy efficiency compared to batch cryogenic processes by eliminating start-stop energy losses

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If traditional solvent or adsorption methods are used to remove light fractions, then equipment cost is reduced, but separation effectiveness and recovery efficiency decrease

Engineering Contradiction:
Improveequipment costVSAvoidseparation effectiveness
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent utilizes phase transitions (vapor-liquid equilibrium) in the warm distillation columns to achieve separation. The light gas fractions preferentially vaporize while carbon dioxide remains in the liquid phase, providing effective separation without the high equipment costs of cryogenic methods

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The warm distillation system serves multiple functions: it separates light gas fractions, purifies carbon dioxide to high grade, and can operate with various feed compositions. This multi-functionality replaces the need for multiple specialized units required by traditional methods

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively recovers high-grade carbon dioxide and light gas fractions like helium, enhancing the economics of carbon dioxide production and recovery, particularly for enhanced oil recovery and other applications, by minimizing capital and operating expenses.

Implementation Method 1

a first cooling and condensation step using a warm distillation process

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

The first vapor stream is warmed in a heat exchanger

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The combined stream then is compressed and is sent to a heat exchanger to be cooled

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

a refrigeration system, condenser and phase separator

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3067315B1Light gas separation process and system
Publication Date: 2019.03.06 PRAXAIR TECH INC
  • EP3067315B1 patent drawingFigure 1

AI summary

The present invention relates in one respect to a process for separating light gas components, preferably helium, from a stream containing predominantly carbon dioxide, and in another respect is directed to a process for purifying a feed stream containing predominantly carbon dioxide into a high grade carbon dioxide product stream using a waim distillation process as the primary carbon dioxide separation step.