Cryogenic Oxogas Production with Dual-Stream Temperature Control

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Solution Overview

Problem

Existing methods for producing a gaseous mixture of carbon monoxide and hydrogen struggle to maintain a consistent low temperature for the oxogas, leading to fluctuations in volume flow rate and potential compressor stoppages due to temperature variations, which increases investment and electrical consumption in compression processes.

Innovation Solution

The method involves compressing a gas with at least 50% carbon monoxide and mixing it with a gas containing at least 50% hydrogen from a cryogenic distillation separation unit, where the gases are cooled and heated in a heat exchanger to achieve a stable intermediate temperature for mixing, allowing precise control of the oxogas temperature, often below 20°C, without the need for additional refrigeration units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the oxogas temperature is reduced below the cooling water circuit temperature to reduce compressor volume flow rate, then compressor investment and electrical consumption are reduced, but temperature stability becomes difficult to maintain and fluctuations occur

Engineering Contradiction:
Improvecompressor electrical consumptionVSAvoidoxogas temperature stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The hydrogen-rich fraction is divided into two separate streams: one stream is cooled to a lower temperature (e.g., 0°C to 10°C) and the other stream is cooled to a higher temperature (e.g., 15°C to 25°C). These two streams are then mixed to produce oxogas at a stable intermediate temperature. This segmentation allows independent temperature control of each stream while achieving stable overall temperature through mixing ratios.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the temperature parameter of the hydrogen-rich fraction by creating two distinct temperature levels within the cryogenic separation unit. By controlling the cooling degree of different portions of the hydrogen-rich fraction, the system can adjust the mixing ratio to maintain stable oxogas temperature at the desired set point, preventing temperature fluctuations that would otherwise occur.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If additional refrigeration units are added to maintain low oxogas temperature, then temperature stability is improved, but device complexity and investment cost increase

Engineering Contradiction:
Improveoxogas temperature stabilityVSAvoidrefrigeration system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cryogenic distillation separation unit performs multiple functions: it separates hydrogen, carbon monoxide, and other gases, and simultaneously provides two different temperature streams for oxogas production. The system uses the existing cooling capacity of the cryogenic unit to generate both cold streams without requiring additional dedicated refrigeration equipment, thus achieving multi-functionality with existing infrastructure.

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

Solution Approach 2:

The cryogenic distillation separation unit serves itself by providing the cooling capacity needed for oxogas temperature control through its own operation. The cold streams required for stable oxogas production are generated as a byproduct of the separation process, eliminating the need for external refrigeration units and reducing system complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If the oxogas temperature fluctuates, then compressor intake conditions become unstable, but maintaining constant temperature requires complex control systems

Engineering Contradiction:
Improvecompressor operation reliabilityVSAvoidtemperature control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention implements dynamic temperature control by continuously adjusting the mixing ratio of the two hydrogen-rich fraction streams with different temperatures. This dynamic adjustment responds to changing process conditions to maintain stable oxogas temperature, ensuring reliable compressor operation without requiring complex external control systems.

Inventive Principle:
Principle #15Dynamics

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 stabilizes the oxogas temperature, reducing compressor stress and energy consumption by maintaining a consistent low temperature, thereby enhancing process efficiency and reliability.

Implementation Method 1

cooled in a heat exchanger with cooling water from the main cooling water circuit of the separation process

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

one part is heated in the exchanger to form impure hydrogen at approximately 37°C

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a cryogenic separation unit, also known as a cold box, for the production of CO or an H2/CO mixture

Methodology Applied
Scientific EffectCryogenic separation: Cryogenics

Implementation Method 4

a cryogenic distillation apparatus comprising a methane scrubbing column and a carbon monoxide and hydrogen separation column

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 5

compressing the carbon monoxide in a compressor

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3350119B1Method and apparatus for producing a mixture of carbon monoxide and hydrogen
Publication Date: 2019.06.19 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3350119B1 patent drawingFigure 1
  • EP3350119B1 patent drawingFigure 2
  • EP3350119B1 patent drawingFigure 3

AI summary

In a method for producing a gaseous mixture (27) of carbon monoxide and hydrogen, a first gas (21) comprising at least 50% carbon monoxide is compressed in a first compressor (C1) to form a first compressed gas cooled to a first temperature and mixes with a second gas (5) comprising at least 50% hydrogen in order to form the gaseous mixture, at least one of the first and second gases originating from a cryogenic distillation separation unit in which a feed gas containing hydrogen and carbon monoxide cools in a first heat exchanger (E1) and is separated in at least one distillation column (K1, K2, K3) and at least one part of the second gas (5A) heats in the separation unit to a third temperature lower than the first temperature and is then sent to mix with the first gas.