LiFSI Production Gas Treatment via Alkaline Absorption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current processes for producing lithium bis(fluorosulfonyl)imide salt, such as LiFSI, involve chlorination stages that result in the release of toxic products like HCl and SO2, posing environmental and economic concerns.

Innovation Solution

A process involving the chlorination of sulfamic acid with a chlorinating agent and a sulfur-containing agent, followed by treatment of the gas stream containing HCl and SO2 with an alkaline aqueous solution or hydrogen peroxide, allowing for the recovery and absorption of these gases, thereby preventing their discharge into the atmosphere and enabling the production of lithium bis(fluorosulfonyl)imide salt in a more environmentally friendly and economically viable manner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional chlorination processes are used to prepare lithium bis(fluorosulfonyl)imide salt, then the salt can be produced, but toxic products (HCl and SO2) are released into the atmosphere causing environmental harm

Engineering Contradiction:

Improveproduction of lithium bis(fluorosulfonyl)imide saltVSAvoidrelease of toxic products (HCl and SO2)

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies this principle by capturing the harmful HCl and SO2 gases produced during chlorination and converting them into valuable chemical products through reaction with alkaline solutions or hydrogen peroxide, thereby transforming environmental pollutants into useful chemicals while maintaining the production process

Inventive Principle:

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

Solution Approach 2:

The patent introduces alkaline solutions or hydrogen peroxide as intermediary substances that mediate between the harmful chlorination byproducts and the environment, capturing the toxic gases and converting them into harmless or useful products, thus resolving the contradiction between production and environmental protection

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If chlorination stages are performed to produce lithium bis(fluorosulfonyl)imide salt, then the salt is obtained, but environmental protection is compromised due to toxic emissions

Engineering Contradiction:

Improveproduction of lithium bis(fluorosulfonyl)imide saltVSAvoidenvironmental impact from HCl and SO2 discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The harmful emissions are converted into beneficial chemical products through controlled reactions with alkaline solutions or hydrogen peroxide, maintaining productivity while eliminating environmental harm

Inventive Principle:

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

Solution Approach 2:

Instead of discarding the harmful HCl and SO2 gases, the patent recovers them by capturing and reacting these gases to produce useful chemical products, thereby maintaining production efficiency while protecting the environment

Inventive Principle:

Principle #34Discarding and recovering

3Device complexity

If toxic products are discharged to the atmosphere during salt preparation, then the production process is simple, but economic profitability is reduced due to environmental costs

Engineering Contradiction:

Improvesimplicity of production processVSAvoidtoxic emissions affecting economic profitability

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The additional processing steps convert harmful emissions into valuable chemical products, transforming what would be environmental liabilities into economic assets, thereby improving profitability while maintaining process feasibility

Inventive Principle:

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

Solution Approach 2:

The patent changes the chemical parameters of the waste gases by reacting them with alkaline solutions or hydrogen peroxide, transforming toxic HCl and SO2 into useful chemical products, thus converting environmental costs into economic benefits

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

The process effectively captures and recycles HCl and SO2, reducing environmental impact and providing economic value to secondary streams, thus offering a more sustainable and profitable method for producing lithium bis(fluorosulfonyl)imide salt.

Implementation Method 1

a stage of bringing said stream F2 into contact with an alkaline aqueous solution, and/or a stage of absorption of HCl contained in said gas stream F2 in an aqueous solution

Methodology Applied

Scientific EffectChemical absorption: Absorption (physical)

Implementation Method 2

a stage of bringing said stream F2 into contact with a hydrogen peroxide solution

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 3

a stage of absorption of SO2 contained in said gas stream F2 in a concentrated sulfuric acid solution

Methodology Applied

Scientific EffectPhysical absorption: Absorption (physical)

Data Source

PatentUS11261087B2Method for preparing lithium bis(fluorosulphonyl)imide salt

Publication Date: 2022.03.01 ARKEMA FRANCE SA

AI summary

A method for preparing Cl—SO2NHSO2Cl including a step of chlorinating sulphamic acid with at least one chlorinating agent and at least one sulphur-containing agent, the method resulting in a flow F1, preferably liquid, including Cl—SO2NHSO2Cl and a gas stream F2 including HCl and SO2, the method including a step a) of treating the gas stream F2. Also, a method for preparing LiFSl including the abovementioned method for preparing Cl—SO2NHSO2Cl.