Beta-Mercaptocarboxylic Acid Synthesis via Atmospheric Pressure Reaction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing β-mercaptocarboxylic acid face issues such as decreased yield due to by-product formation, increased manufacturing costs, and the need for pressurized conditions, which complicate the process and increase waste production.
Innovation Solution
A process involving the reaction of hydrogen sulfide, alkali hydroxide, and unsaturated carboxylic acid under atmospheric pressure, with neutralization and the presence of sulfur, to produce β-mercaptocarboxylic acid while minimizing by-product formation and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pressurized conditions are used to react unsaturated carboxylic acid and hydrogen sulfide compound, then reaction yield is improved, but device complexity and manufacturing cost increase due to pressurization equipment requirements
Solution Approach 1:
The patent changes the pressure parameter from high pressure (3.5-20 MPaG in prior art) to atmospheric pressure conditions. By optimizing other reaction parameters (molar ratios, temperature, reaction time) under atmospheric pressure, the invention achieves comparable or improved yields without requiring pressurization equipment, thus resolving the contradiction between yield and device complexity
Solution Approach 2:
The invention uses conventional atmospheric pressure reactors instead of expensive pressure-resistant apparatus. This substitution of equipment type reduces manufacturing cost and simplifies the process while maintaining reaction effectiveness through optimized chemical conditions
2Ease of manufacture
If alkali hydrosulfide is used as raw material to prepare β-mercaptocarboxylic acid, then reaction can proceed, but dithiodicarboxylic acid by-product is largely produced decreasing reaction yield
Solution Approach 1:
The patent changes the raw material from alkali hydrosulfide to hydrogen sulfide gas, and adjusts the molar ratio parameters to suppress by-product formation. This parameter change eliminates the dithiodicarboxylic acid by-product issue while maintaining reaction feasibility, resolving the contradiction between ease of manufacture and productivity
Solution Approach 2:
The invention converts the potential harmful effect of hydrogen sulfide gas handling into a benefit by using it to generate the desired product with high selectivity. The gas phase hydrogen sulfide reacts cleanly with the unsaturated carboxylic acid under atmospheric pressure to give high yields with minimal by-products
3Productivity
If dithiodicarboxylic acid by-product is reduced to obtain β-mercaptocarboxylic acid, then product can be recovered, but used amount of reducing agent increases and manufacturing cost increases along with waste production
Solution Approach 1:
Instead of treating dithiodicarboxylic acid as a by-product requiring reduction, the invention prevents its formation in the first place by using hydrogen sulfide gas as raw material with controlled molar ratios. This eliminates the need for reducing agents and associated waste, converting a harmful by-product problem into a clean synthesis process
Solution Approach 2:
The invention extracts or removes the problematic intermediate step involving dithiodicarboxylic acid formation from the synthesis pathway. By using direct reaction conditions with hydrogen sulfide gas, the process bypasses the by-product formation entirely, eliminating the subsequent reduction step and its associated costs and waste
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
This method achieves high yield of β-mercaptocarboxylic acid under atmospheric pressure, reduces by-product formation, and simplifies the industrial process, thereby lowering costs and waste production.
Implementation Method 1
reacting hydrogen sulfide, alkali hydroxide represented by a formula: XOH (X represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) under atmospheric pressure to obtain a reaction solution including a compound represented by the following General Formula (2)
Implementation Method 2
neutralizing the reaction solution in an acid
Data Source
AI summary
There is provided a process for preparing β-mercaptocarboxylic acid represented by the following General Formula (3) comprising step of reacting hydrogen sulfide, alkali hydroxide represented by a formula: XOH (X represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) under atmospheric pressure to obtain a reaction solution including a compound represented by the following General Formula (2) and step of neutralizing the reaction solution in an acid. An amount of the alkali hydroxide is equal to or greater than total moles of the unsaturated carboxylic acid and the hydrogen sulfide.