Dialkyl Sulfide Sulfhydrolysis After Purification to Prevent Reactor Clogging

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Solution Overview

Problem

The integration of a sulfhydrolysis unit into a mercaptan production unit leads to reactor clogging and pressure drops due to the formation of dialkyl sulfides, which are difficult to manage and costly to dispose of, and secondary reactions with sulfur-containing impurities cause safety and production issues.

Innovation Solution

A process that separates dialkyl sulfides from the reaction stream, purifies them, and then subjects them to sulfhydrolysis in a separate reactor, avoiding the accumulation of impurities that cause clogging and pressure losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sulfhydrolysis unit is integrated into a mercaptan production unit, then dialkyl sulfides are converted into useful mercaptans, but reactor clogging and pressure drops occur due to impurity accumulation

Engineering Contradiction:
Improvemercaptan production efficiencyVSAvoidreactor operation stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The process is divided into distinct stages: a first reactor for mercaptan synthesis, a separation unit for removing dialkyl disulfides, and a second reactor for sulfhydrolysis of purified dialkyl sulfides. This segmentation prevents impurity accumulation in any single reactor, maintaining operational reliability while achieving high productivity through systematic material flow management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Dialkyl sulfides are purified by removing dialkyl disulfide impurities before introducing them to the sulfhydrolysis reactor. This preliminary purification action prevents the formation of clogging substances, ensuring the sulfhydrolysis reactor operates reliably without pressure drops or blockages while maintaining high conversion efficiency.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If dialkyl sulfides are directly subjected to sulfhydrolysis without purification, then the process is simple, but secondary reactions with sulfur impurities cause safety and production issues

Engineering Contradiction:
Improveprocess simplicityVSAvoidsafety and production risks
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

Dialkyl disulfide impurities are extracted and removed from the dialkyl sulfide stream before sulfhydrolysis. This extraction eliminates the harmful sulfur-containing impurities that would otherwise cause secondary reactions, safety issues, and production problems, while the main sulfhydrolysis process remains straightforward and efficient.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The harmful dialkyl disulfide impurities are converted into a beneficial separation step. By removing these impurities, the process not only eliminates safety and production risks but also improves the overall efficiency of the sulfhydrolysis reaction, as the purified dialkyl sulfides react more effectively without side reactions.

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

3Productivity

If dialkyl sulfides are disposed of as by-products, then the mercaptan production process is straightforward, but efficiency is lost and disposal costs increase

Engineering Contradiction:
Improvemercaptan production efficiencyVSAvoiddialkyl sulfide waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

Instead of discarding dialkyl sulfides as waste by-products, the process recovers them through separation and purification, then utilizes them as feedstock for sulfhydrolysis to produce additional mercaptans. This recovery and reuse approach eliminates substance loss, reduces disposal costs, and enhances overall productivity by converting waste into valuable product.

Inventive Principle:
Principle #34Discarding and recovering

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 prevents reactor clogging and pressure drops, allowing safe and continuous operation, efficiently recycling dialkyl sulfides, and enhancing productivity by integrating the sulfhydrolysis into the mercaptan production line with minimal modifications.

Implementation Method 1

a sulfhydrolysis reaction of the dialkylsulfide(s) is carried out by H2S to obtain an outgoing flux F4 comprising the said mercaptan(s)

Methodology Applied
Scientific EffectSulfhydrolysis: Hydrolysis

Implementation Method 2

The H2S and said at least one alcohol are reacted to obtain an output stream comprising at least one mercaptan, at least one dialkyl sulfide and at least one dialkyl disulfide (DADS)

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP4359379B1Method for preparing mercaptans with sulfhydrolysis of purified dialkyl sulfides
Publication Date: 2026.04.08 ARKEMA FRANCE SA
  • EP4359379B1 patent drawingFigure 1
  • EP4359379B1 patent drawing

AI summary

The present invention relates to a method for preparing at least one mercaptan, which comprises the following steps: A) introducing H2S and at least one alcohol into a first reactor; B) reacting the H2S and said at least one alcohol in order to obtain an outgoing stream comprising at least one mercaptan, at least one dialkyl sulfide and at least one dialkyl disulfide (DADS) and optionally unreacted H2S; C) separating the following from said outgoing stream of step B): - a stream F1 comprising the mercaptan(s), - a stream F2 comprising the dialkyl sulfide(s) and the DADS(s), and - optionally a stream F3 comprising H2S; D) carrying out a step of purifying the stream F2 so as to separate: - a stream F2' comprising the dialkyl sulfide(s), and - the DADS(s); E) introducing the stream F2' with H2S into a second reactor; F) performing a sulfhydrolysis reaction of the dialkyl sulfide(s) with the H2S in order to obtain an outgoing stream F4 comprising said mercaptan(s), and optionally unreacted H2S; G) optionally, recycling the stream F4 resulting from step F) to step A).