Carbon dioxide capture apparatus and process combined with biogas upgrading

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Solution Overview

Problem

Existing biogas upgrading processes struggle to efficiently separate and recover high purity methane and carbon dioxide, leading to low energy efficiency and environmental issues from carbon dioxide emissions.

Innovation Solution

A carbon dioxide capture apparatus and process utilizing multiple separation membranes and a liquefaction heat exchanger to separate and recover high purity methane and carbon dioxide, incorporating a heat exchanger network to optimize temperature and reduce energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional biogas upgrading processes are used, then methane can be separated, but carbon dioxide recovery efficiency is low and energy consumption is high

Engineering Contradiction:

Improvecarbon dioxide recovery efficiencyVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The biogas stream is divided into multiple stages of separation membranes with different selectivities. The first separation membrane performs initial CO2 removal, while subsequent membranes further purify the methane stream. This segmented approach achieves high CO2 recovery efficiency (90% or more) while optimizing energy consumption by processing gas at progressively lower pressures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system utilizes pressure changes across multiple membrane stages to optimize separation efficiency. The first compressor increases pressure for the first membrane stage, then the second compressor further pressurizes the permeate stream for the second membrane stage. This parameter change strategy enables efficient CO2 recovery at each stage while managing overall energy consumption.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If multiple separation membranes are used to improve separation efficiency, then device complexity increases

Engineering Contradiction:

Improveseparation efficiencyVSAvoidapparatus complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple separation membrane units are merged into a integrated system where the permeate stream from one membrane becomes the feed for the next membrane. This combining approach achieves high separation efficiency (95% or more methane purity) while reducing overall device complexity compared to separate processing units. The system merges compression, separation, and CO2 recovery functions into a unified flow path.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The separation membrane system performs multiple functions simultaneously: CO2 removal, methane purification, and CO2 recovery. The same membrane units that separate methane from CO2 also concentrate CO2 for recovery, eliminating the need for separate recovery equipment. This multi-functionality reduces device complexity while maintaining high separation efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If carbon dioxide is discharged to atmosphere, then disposal is simple, but environmental harm increases

Engineering Contradiction:

Improvedisposal simplicityVSAvoidenvironmental harm

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The system converts the harmful CO2 byproduct into a valuable recovered resource. Instead of discharging CO2 to the atmosphere, the multi-stage membrane separation concentrates and recovers CO2 in high purity (90% or more). This converted CO2 can be utilized for enhanced oil recovery, carbonation processes, or other industrial applications, transforming an environmental harm into a beneficial resource while maintaining operational simplicity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

Simultaneously achieves high purity methane and carbon dioxide recovery with improved separation efficiency and reduced energy consumption by leveraging gas streams post-liquefaction and recovering cold heat in low temperature streams.

Implementation Method 1

gas separation using the separation membrane is based on solution and diffusion

Methodology Applied

Scientific EffectSolution and diffusion: Diffusion

Implementation Method 2

a liquefaction heat exchanger configured to cool down the gas compressed by the second compressor

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS12569801B2Carbon dioxide capture apparatus and process combined with biogas upgrading

Publication Date: 2026.03.10 AIRRANE CO LTD

AI summary

The present disclosure relates to a carbon dioxide capture apparatus and process combined with biogas upgrading, and there is provided the carbon dioxide capture apparatus combined with biogas upgrading for simultaneously obtaining high purity methane and carbon dioxide, and improving separation efficiency without an additional process by making use of gas streams after a liquefaction process, and recovering cold heat in the process.