Alkaline Earth Carbonate Sorbent Thermal Activation

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Solution Overview

Problem

Current dry flue gas cleaning methods using alkaline earth metal carbonate and hydroxide sorbents are inefficient due to high sorbent consumption and incomplete reaction, leading to reduced absorption capacity and increased costs.

Innovation Solution

Thermal activation of materials containing alkaline earth metal carbonate and hydroxide by heating between 200°C and 850°C, particularly between 250°C and 750°C, to enhance their absorption capacity for sulfur oxides and other pollutants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If dry exhaust gas cleaning is used with alkaline earth metal carbonate and hydroxide sorbents, then exhaust gases can be cleaned, but sorbent consumption is very high

Engineering Contradiction:
Improvepollutant removalVSAvoidsorbent consumption
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The sorbent is pre-heated to temperatures between 200-850°C before use in the bulk layer filter. This preliminary thermal activation removes surface moisture and activates the sorbent material, enabling it to react more completely with acidic pollutants and thereby reducing overall sorbent consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the sorbent from ambient to elevated temperatures (200-850°C) through pre-heating. This parameter change activates the sorbent material, significantly improving its reaction efficiency with sulfur oxides and other acidic components, thus reducing the amount of sorbent needed.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If sorbent is used in bulk layer filter, then acidic pollutants can be separated, but reaction products form a layer that closes the reactive surface

Engineering Contradiction:
Improveacidic pollutant separationVSAvoidreactive surface availability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The sorbent undergoes preliminary thermal activation before being placed in the filter. This pre-treatment creates a more reactive surface that can accommodate reaction products without quickly becoming passivated, maintaining reactive surface availability throughout the sorbent's service life.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By changing the temperature parameter through pre-heating, the sorbent's surface properties are modified to prevent rapid formation of passivating layers. The thermal activation alters the surface chemistry, allowing sustained reactivity even as reaction products accumulate.

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If sorbent consumption is reduced by mechanical reprocessing, then unreacted sorbent can be reused, but the method is insufficient in increasing absorption capacity

Engineering Contradiction:
Improvesorbent consumptionVSAvoidabsorption capacity
Core Design Contradiction:
Loss of substanceVSProductivity

Solution Approach 1:

Instead of reprocessing after use, the invention applies preliminary thermal activation before the sorbent is put into service. This pre-treatment fundamentally enhances the sorbent's absorption capacity from the outset, making mechanical reprocessing unnecessary for achieving high absorption performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention permanently changes the sorbent's physical and chemical parameters through thermal activation at 200-850°C. This parameter change increases the specific surface area and reactivity of the sorbent particles, dramatically improving absorption capacity without requiring mechanical reprocessing cycles.

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

Significantly increases the sorbent's absorption capacity, reducing the need for sorbent material and improving pollutant separation efficiency in dry flue gas cleaning processes.

Implementation Method 1

The invention is based on the finding that the absorption capacity of materials (sorbents) containing alkaline earth metal carbonate and/or alkaline earth metal hydroxide can be significantly increased by a single heating to temperatures between approximately 200° C. and approximately 850° C.

Methodology Applied
Scientific EffectThermal activation: Heating

Implementation Method 2

Sorbents based on limestone (CaCO 3 ), in particular granulated or pelleted products based on limestone (CaCO 3 ) and/or hydrated lime (Ca(OH) 2 ) and/or the corresponding dolomitic products, are used here. In these filters, the exhaust gas to be cleaned flows through a granular bulk layer of material containing alkaline earth metal carbonate and/or alkaline earth metal hydroxide. Here, the acidic exhaust gas components are separated on the material (sorbent) containing alkaline earth metal carbonate and/or alkaline earth metal hydroxide.

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2644267B2Activation of an alkaline earth calcium carbonate and/or materials containing alkaline earth calcium carbonate for dry cleaning of waste gas
Publication Date: 2021.01.20 RHEINKALK GMBH
  • EP2644267B2 patent drawingFigure 1~2

AI summary

A method for increasing the absorption capacity of a material containing alkaline earth carbonate and/or alkaline earth hydroxide towards sulfur oxides and/or other pollutants, particularly in flue gas, characterized in that the material containing alkaline earth carbonate and/or alkaline earth hydroxide is activated by heating to approximately 200°C to approximately 850°C.