Granular Fly Ash Adsorbent for Biogas Purification

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Solution Overview

Problem

Current methods for cleaning biogas are costly and lack an environmentally friendly solution for removing trace contaminants like siloxanes, organo-chlorine, and hydrogen sulphide, while fly ash, a by-product of incineration, is hazardous and difficult to dispose of.

Innovation Solution

Utilizing fly ash in granular form, processed through high-pressure compaction to create a medium for biogas purification, where the ash's metal active sites react with and absorb these contaminants, rendering the ash less eco-toxic and allowing for its reuse in construction materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If activated carbon and activated alumina are used to remove siloxanes from biogas, then siloxane removal efficiency is improved, but cost increases significantly

Engineering Contradiction:
Improvesiloxane removal efficiencyVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses fly ash, a cheap waste material from incineration plants, as an alternative to expensive activated carbon and alumina. Fly ash is used in a fixed bed reactor where it adsorbs siloxanes from biogas. After saturation, the spent fly ash can be disposed of or potentially regenerated, providing a cost-effective solution for siloxane removal without requiring continuous purchase of expensive adsorbents.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent converts fly ash, which is a hazardous waste product from incineration plants that requires costly disposal, into a useful adsorbent for removing siloxanes from biogas. This transforms an environmental liability into a functional resource, simultaneously solving two problems: biogas purification and fly ash disposal.

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

2Object-affected harmful factors

If fly ash is disposed of as hazardous waste, then environmental compliance is maintained, but resource utilization is reduced

Engineering Contradiction:
Improveenvironmental complianceVSAvoidresource utilization
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent transforms fly ash from a hazardous waste requiring disposal into a valuable adsorbent material for biogas purification. By utilizing fly ash's adsorptive properties to remove siloxanes from biogas, the invention converts an environmental liability into a functional resource, achieving both environmental compliance and resource utilization.

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

Solution Approach 2:

The patent allows fly ash to serve its own purpose by utilizing its inherent adsorptive properties to remove contaminants from biogas. Rather than requiring external processing or treatment to make fly ash useful, the invention directly employs the waste material's natural characteristics for purification, making the system self-sufficient and cost-effective.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If high-pressure compaction is applied to fly ash, then granular form is achieved for better flow, but energy consumption increases

Engineering Contradiction:
Improveflow characteristicsVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies high-pressure compaction to transform fly ash from a fine powder into granular form. This parameter change in physical structure improves the flow characteristics and bed stability of the adsorbent material in the fixed bed reactor, preventing channeling and improving gas-solid contact efficiency while managing the energy input required for granulation.

Inventive Principle:
Principle #35Parameter changes

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

Effectively removes siloxanes, organo-chlorine, and hydrogen sulphide from biogas, purifying the gas while reducing the leachability of metals in fly ash, making it non-hazardous and suitable for recycling into construction materials.

Implementation Method 1

the ash's metal active sites react with and absorb these contaminants

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

processed through high-pressure compaction to create a medium for biogas purification

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2457982B1Method for the treatment of biogas
Publication Date: 2015.01.21 VIRIDOR WASTE MANAGEMENT
  • EP2457982B1 patent drawingFigure 1
  • EP2457982B1 patent drawingFigure 2~3
  • EP2457982B1 patent drawingFigure 4

AI summary

The invention relates to a method for the treatment of biogas comprising the step of contacting the biogas with fly ash and a composition for the treatment of biogas comprising fly ash in a granular form. The invention further relates to a method for the treatment of fly ash, comprising the step of contacting fly ash with biogas.