Methyl Ethyl Sulfide Synthesis via Cross-Coupling

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Solution Overview

Problem

Current methods for producing methyl ethyl sulfide result in significant mercaptan byproducts and waste products, limiting yield and efficiency.

Innovation Solution

An integrated mercaptan and sulfide manufacturing system and method that involves reacting dimethyl sulfide and diethyl sulfide in the presence of a catalyst to produce methyl ethyl sulfide, with a focus on minimizing byproducts and maximizing yield, using a fixed bed reactor with a CoMo or γ-alumina catalyst at optimized temperature and pressure conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If methyl ethyl sulfide is prepared by reacting a suitable symmetrical sulfide with a suitable mercaptan, then the product can be obtained, but significant mercaptan byproducts are produced

Engineering Contradiction:
Improveproduct obtainabilityVSAvoidmercaptan byproducts
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes the harmful mercaptan byproducts from the reaction system by using a catalyst that selectively promotes the desired cross-coupling reaction while suppressing mercaptan formation. The catalyst system (CoMo or NiMo on alumina) is designed to favor the formation of methyl ethyl sulfide over mercaptan byproducts, effectively extracting the harmful byproduct formation pathway from the reaction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the reaction parameters by introducing specific catalysts (CoMo or NiMo on alumina) and controlling reaction conditions (temperature, pressure, reactant ratios) to shift the reaction pathway. By optimizing these parameters, the reaction selectively produces methyl ethyl sulfide with minimal mercaptan byproducts, transforming the reaction outcome from a byproduct-heavy process to a high-selectivity process.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If methyl ethyl sulfide is prepared by reacting sodium methyl mercaptide and ethyl chloride, then the product can be obtained, but significant waste products are produced

Engineering Contradiction:
Improveproduct obtainabilityVSAvoidwaste products
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention changes the reaction parameters by using alternative reactants (dimethyl sulfide and diethyl sulfide) combined with specific catalysts (CoMo or NiMo on alumina). This parameter change transforms the reaction pathway to one that produces minimal waste, eliminating the need for stoichiometric amounts of sodium methyl mercaptide and avoiding the formation of significant waste products associated with the traditional method.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the potential harm of using sulfide reactants (which could lead to waste) into a benefit by using a catalyst system that achieves high selectivity. The catalyst transforms what could be a waste-generating reaction into a high-efficiency process with minimal waste, turning the potential disadvantage into an advantage through selective catalysis.

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

3Productivity

If traditional synthesis methods are used for methyl ethyl sulfide, then the product can be produced, but yield and efficiency are limited due to byproducts

Engineering Contradiction:
Improveproduction efficiencyVSAvoidmercaptan byproducts
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention implements feedback control through catalyst selection and reaction condition optimization. The CoMo or NiMo catalyst system provides a pathway that continuously favors the formation of methyl ethyl sulfide over mercaptan byproducts. By monitoring and controlling reaction parameters (temperature, pressure, reactant ratios), the system maintains high selectivity and productivity, with the catalyst acting as a feedback mechanism that directs the reaction toward the desired product.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes multiple reaction parameters simultaneously: using specific catalysts (CoMo or NiMo on alumina), optimizing temperature and pressure conditions, and controlling reactant ratios. These parameter changes work together to maximize productivity by directing the reaction toward high-yield formation of methyl ethyl sulfide while minimizing mercaptan byproduct formation, achieving both high efficiency and high selectivity.

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 achieves high conversion and yield of methyl ethyl sulfide with minimal mercaptan byproducts, suitable for use as a natural gas odorant with desirable boiling and freezing points, and low odor fade.

Implementation Method 1

reacting dimethyl sulfide and diethyl sulfide in the presence of a catalyst to produce methyl ethyl sulfide, with a focus on minimizing byproducts and maximizing yield, using a fixed bed reactor with a CoMo or γ-alumina catalyst

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP3762361B1Synthesis of methyl ethyl sulfide and related production systems
Publication Date: 2022.12.21 CHEVRON PHILLIPS CHEMICAL COMPANY LP
  • EP3762361B1 patent drawingFigure 1
  • EP3762361B1 patent drawingFigure 2
  • EP3762361B1 patent drawingFigure 3

AI summary

The present invention discloses processes for producing methyl ethyl sulfide by contacting dimethyl sulfide and diethyl sulfide in the presence of a suitable catalyst. Methyl ethyl sulfide can be used as an odorant in natural gas. Integrated mercaptan and sulfide manufacturing systems and integrated methods for making mercaptans and sulfides also are disclosed.