Dry Sorbent Injection With Sodium Hydroxide Recirculation

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Solution Overview

Problem

Existing dry sorbent injection systems for removing sulfur oxides from flue gas are inefficient and produce excess waste or by-products, lacking effective recovery and recirculation options.

Innovation Solution

A process involving dry sorbent material treatment of flue gas to produce sodium sulfate particulates, followed by dissolution in water and reaction with calcium hydroxide slurry to form calcium sulfate precipitate and sodium hydroxide solution, allowing for the recovery and recirculation of gypsum and sodium hydroxide for further use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional dry sorbent injection is used to remove sulfur oxides from flue gas, then sulfur oxide removal is achieved, but efficiency is low and excess waste by-products are produced

Engineering Contradiction:

Improvesulfur oxide removal efficiencyVSAvoidwaste by-product generation

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent recovers sodium sulfate produced during sulfur oxide removal and converts it to valuable gypsum product through reaction with calcium hydroxide. The sodium hydroxide solution is also recovered and recirculated back to the dry sorbent injection system, transforming waste by-products into useful products and eliminating disposal costs.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The patent converts the harmful sodium sulfate by-product into beneficial gypsum product (calcium sulfate) that can be sold or used in construction applications. The sodium hydroxide solution, initially a waste stream, is converted into a valuable recirculating reagent that enhances system efficiency.

Inventive Principle:

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

2Productivity

If traditional dry sorbent injection systems operate without recirculation, then simple operation is maintained, but system efficiency is limited

Engineering Contradiction:

Improvesystem efficiencyVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a feedback loop where sodium hydroxide solution produced in the reaction tank is recirculated back to the dry sorbent injection system. This feedback mechanism allows the system to reuse valuable reagents, improve sulfur oxide removal efficiency, and maintain optimal operating conditions through continuous circulation of active chemicals.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The sodium hydroxide solution serves multiple functions: it reacts with sulfur oxides in the flue gas during dry sorbent injection, and the resulting solution is then used to convert sodium sulfate to gypsum. This multi-functional use of the same material increases system efficiency without proportionally increasing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enhances sulfur oxide removal efficiency while producing high-purity calcium sulfate for sale and recirculating sodium hydroxide for flue gas pre-treatment, reducing waste and improving system efficiency.

Implementation Method 1

treating the flue gas with a dry sorbent material that reacts with at least a portion of the sulfur oxides to produce sodium sulfate particulates

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

dissolving the sodium sulfate particulates in the water to form a sodium sulfate solution

Methodology Applied

Scientific EffectDissolution: Solvation

Implementation Method 3

reacting at least a portion of the sodium sulfate solution with at least a portion of the calcium hydroxide slurry to produce a reaction mixture comprising a calcium sulfate precipitate and a sodium hydroxide solution

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 4

reacting at least a portion of the sodium sulfate solution with at least a portion of the calcium hydroxide slurry to produce a reaction mixture comprising a calcium sulfate precipitate

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Data Source

PatentUS12447439B2Dry sorbent injection with recirculation

Publication Date: 2025.10.21 IND ACCESSORIES CO

AI summary

Described herein is a dry sorbent injection system and process for removing sulfur oxides from a flue gas. The process generally comprises treating the flue gas with a dry sorbent material to convert the sulfur oxides to sodium sulfate particulates. The sodium sulfate particulates may then be introduced into a mix tank with water to form sodium sulfate solution. The sodium sulfate solution may then be reacted with a calcium hydroxide slurry to produce a reaction mixture comprising calcium sulfate precipitate and a sodium hydroxide solution. The calcium sulfate (gypsum) may be recovered, and the sodium hydroxide solution may be recirculated to pre-treat the flue gas by removing at least a portion of the sulfur dioxide and/or cooling the flue gas stream.