Desulfurization Slurry Stabilizer for Flue Gas

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Solution Overview

Problem

Wet limestone-gypsum flue gas desulfurization systems face challenges with fluctuating sulfur content in coal, leading to overloaded operations, slurry foaming, decreased pH, and reduced desulfurization rates, as well as corrosion from sulfuric acid mist due to the inability to remove oxidized sulfur compounds.

Innovation Solution

A desulfurization slurry stabilizer composed of lime, sodium formate, and an antifoaming silicone-polyether solid complex, with specific mass percentages, is used to stabilize pH, inhibit foam generation, and enhance mass transfer in the desulfurization process, reducing sulfuric acid mist emission and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wet limestone-gypsum flue gas desulfurization technology is used to achieve high desulfurization rate, then desulfurization efficiency is improved, but slurry foaming and pH decrease occur leading to reduced desulfurization rate

Engineering Contradiction:
Improvedesulfurization rateVSAvoidslurry stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces a slurry stabilizer as an intermediary substance containing lime, sodium formate, and antifoaming agent. This stabilizer mediates between the flue gas and slurry by neutralizing acid, suppressing foam, and maintaining pH stability, thereby resolving the contradiction between high desulfurization rate and slurry stability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical composition parameters of the slurry by adding specific substances (lime for pH control, sodium formate for foam suppression, antifoaming agent for stability). These parameter changes maintain optimal slurry conditions for high desulfurization efficiency while preventing foaming and pH degradation

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If SCR technology is used to control nitric oxides emission, then NOx control is improved, but sulfuric acid mist corrosion occurs due to inability to remove oxidized sulfur compounds

Engineering Contradiction:
ImproveNOx emission controlVSAvoidsulfuric acid mist
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful sulfuric acid mist into a beneficial effect by using lime in the slurry stabilizer to neutralize the acid. The harmful SO3 that forms sulfuric acid mist is transformed into beneficial calcium sulfate through neutralization reactions, protecting downstream equipment while maintaining NOx control benefits

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

3Adaptability or versatility

If fire coal with varying sulfur content is used to adapt to market changes, then fuel flexibility is improved, but desulfurization system overload and foaming occur

Engineering Contradiction:
Improvefuel flexibilityVSAvoiddesulfurization efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent introduces a dynamic adjustment mechanism through the slurry stabilizer that adapts to varying coal sulfur content. The stabilizer dynamically compensates for fluctuations in SO2 emission by maintaining stable slurry pH and properties, enabling the system to handle diverse fuels without overload or foaming while maintaining high desulfurization efficiency

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

The stabilizer effectively maintains slurry pH, prevents foaming, reduces sulfuric acid mist, and enhances desulfurization efficiency by neutralizing excess H+, inhibiting foam, and improving mass transfer in the desulfurization reaction, resulting in improved desulfurization rates and reduced emissions.

Implementation Method 1

The Ca(OH)2 contained in the desulfurization slurry stabilizer of the present application can neutralize excessive H+ to stabilize the pH value of desulfurization slurry

Methodology Applied
Scientific EffectNeutralization reaction: Chemical Bonding

Implementation Method 2

The silicone-polyether solid complex compounded by high hydrophilic polyether capable of inhibiting foam for a long time and high hydrophobic organic silicon capable of breaking foam quickly is capable of preventing the generation of desulfurization slurry foam

Methodology Applied
Scientific EffectAntifoaming action: Antifoam

Implementation Method 3

The Ca(OH)2 in the desulfurization slurry stabilizer which enters into the solid-liquid-gas three-phase reaction absorption area of an absorption tower after passing the slurry circulating pump and a slurry atomizing and spraying device reacts with sulfuric acid mist, thus reducing the emission of sulfuric acid mist

Methodology Applied
Scientific EffectChemical absorption: Absorption (physical)

Implementation Method 4

the sodium formate in the desulfurization slurry stabilizer is capable of improving the mass transfer process of a desulfurization mechanical reaction, improving reaction activity

Methodology Applied
Scientific EffectMass transfer enhancement: Diffusion

Data Source

PatentUS9399191B2Wet limestone flue gas desulfurization slurry stabilizer and method for using the same
Publication Date: 2016.07.26 STATE GRID CORPORATION OF CHINA

AI summary

A wet limestone flue gas desulfurization slurry stabilizer and a method for using the same are disclosed. The stabilizer consists of lime, sodium formate and an antifoaming agent, the components and mass percentages thereof are as follows: lime, 30% to 70%, sodium formate, 15% to 40%, the antifoaming agent, 15% to 40%. The method for using the desulfurization slurry stabilizer comprises: preparing the slurry stabilizer into a homogeneous liquid having a mass concentration of 10% to 30% with water or desulfurization slurry outside a desulfurization tower, and spraying the homogeneous liquid into the absorption area and the reaction area of the desulfurization tower using a pump and a slurry atomizing and spraying device.