CO2 Recovery Apparatus Dehydration Startup Sequence

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Solution Overview

Problem

The corrosion of high-pressure side compressors in CO2 recovery systems is a concern when CO2 containing moisture is introduced, as it takes time for the dehydration device to start up, leading to potential corrosion issues.

Innovation Solution

A CO2 recovery apparatus and method that includes a regeneration tower for heating and regenerating CO2 absorbents, a series of compressors for compressing CO2 gas, a dehydration device to remove moisture, and preliminary operations to stabilize the system before starting the compressors, including bypassing the dehydration device and supplying air or N2 gas to pre-operate the system, along with an O2 removal device to reduce oxygen concentration in the CO2 gas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the dehydration device is started at the same time as the compressor, then the system startup is simplified, but moisture-containing CO2 enters the compressor causing corrosion

Engineering Contradiction:

Improvesystem startup procedureVSAvoidcompressor corrosion

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The dehydration device is started and operated in advance before the compressor to remove moisture from the CO2 gas. This preliminary dehydration action ensures that when the compressor subsequently starts, it receives dry CO2 gas and avoids corrosion from moisture-containing gas.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If air or N2 gas is supplied to pre-operate the dehydration device, then moisture removal is effective, but oxygen in the supplied gas may contaminate the CO2

Engineering Contradiction:

Improvemoisture removal effectivenessVSAvoidCO2 purity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Nitrogen gas is supplied to pre-operate the dehydration device instead of air. Nitrogen is used because it is inert and will not contaminate the CO2 with oxygen, while still effectively driving moisture through the dehydration device for reliable moisture removal.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

Nitrogen gas acts as an intermediary carrier gas to transport moisture through the dehydration device during pre-operation. It performs the dehydration function without introducing harmful oxygen contamination, mediating between the need for effective moisture removal and CO2 purity maintenance.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the dehydration device operates alone before the compressor, then compressor corrosion is prevented, but system startup time increases

Engineering Contradiction:

Improvecompressor corrosion protectionVSAvoidsystem startup time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The dehydration device operates continuously during the pre-startup phase to remove moisture, and this useful dehydration action is maintained without interruption. The continuous operation ensures complete moisture removal while the timing is optimized to minimize the startup time penalty.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The pre-operation of the dehydration device is performed rapidly to quickly establish dry conditions before compressor startup. The useful dehydration action is rushed through efficiently to minimize the time delay while still achieving the corrosion protection goal.

Inventive Principle:

Principle #21Skipping (Rushing through)

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 prevents corrosion of high-pressure side compressors by ensuring a stable and dry CO2 environment, improving the purity of recovered CO2 and reducing startup time for the dehydration device.

Implementation Method 1

a regeneration tower configured to apply heat to the CO2 absorbent that has absorbed CO2, configured to separate and remove CO2 from the CO2 absorbent

Methodology Applied

Scientific EffectThermal desorption: Desorption

Implementation Method 2

a dehydration device provided between the plurality of compressors and configured to remove moisture from the compressed CO2

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS8961663B2Carbon dioxide recovery apparatus and method

Publication Date: 2015.02.24 MITSUBISHI HEAVY IND LTD

AI summary

An apparatus that separates and recovers CO2 from a CO2 absorbent that has absorbed CO2 includes a regeneration tower configured to apply heat to the CO2 absorbent that has absorbed CO2, configured to separate and remove CO2 from the CO2 absorbent, configured to exhaust CO2 gas, and configured to regenerate the CO2 absorbent, a plurality of compressors configured to compress the CO2 gas exhausted from the regeneration tower, a dehydration device provided between the plurality of compressors and configured to remove moisture from the compressed CO2, and a line configured to supply air or N2 gas into the dehydration device to preliminarily operate the dehydration device until a stable state is achieved before starting the compressor.