Metal Sulfide Alkene Generation via Segmented Reactor Design

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Solution Overview

Problem

Catalytic oxidative dehydrogenation (ODH) systems for alkene generation face challenges such as carbon deposition, catalyst deactivation, and reduced selectivity due to the co-feeding of oxidant and alkane streams, leading to the formation of undesired side products and requiring complex regeneration steps.

Innovation Solution

A method involving a two-reactor system where a metal sulfide particle reacts with an alkane to generate an alkene and hydrogen sulfide, with the reduced metal sulfide then being regenerated in a separate reactor using a sulfur stream, allowing for independent operation and improved alkane conversion without the need for co-feeding oxidants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If molecular oxygen is used as oxidant in oxidative dehydrogenation, then alkane conversion is improved, but selectivity deteriorates due to formation of CO and CO2

Engineering Contradiction:

Improvealkane conversionVSAvoidselectivity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the chemical nature of the oxidant from molecular oxygen (strong oxidant) to metal sulfide (softer oxidant). This parameter change in oxidant strength allows achieving high alkane conversion while maintaining high selectivity to desired alkene products, avoiding over-oxidation to CO and CO2

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces metal sulfide as an intermediary substance that mediates the oxidation process. Instead of direct oxygen-alkane interaction, the metal sulfide acts as an intermediate carrier that transfers sulfur to the alkane, enabling controlled oxidation with improved selectivity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If co-feeding oxidant and alkane streams is performed, then alkane conversion is improved, but harmful factors increase due to side product formation

Engineering Contradiction:

Improvealkane conversionVSAvoidside product formation

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the oxidation process into two separate steps: (1) sulfur transfer from metal sulfide to alkane to form alkene and metal, and (2) regeneration of metal sulfide from metal using sulfur source. This segmentation eliminates the need for co-feeding oxidant and alkane, preventing side product formation while maintaining high conversion

Inventive Principle:

Principle #1Segmentation

3Productivity

If sulfur is lost as H2S during catalyst reaction, then alkene production is improved, but catalyst activity deteriorates

Engineering Contradiction:

Improvealkene productionVSAvoidcatalyst activity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements a regeneration cycle where the metal catalyst (after losing sulfur as H2S during alkene production) is recovered and re-sulfurized using a sulfur source to regenerate the active metal sulfide catalyst. This closed-loop approach maintains continuous catalyst activity while enabling sustained alkene production

Inventive Principle:

Principle #34Discarding and recovering

4Productivity

If high temperature is used to achieve higher propane conversion, then productivity is improved, but selectivity deteriorates due to C-C bond activation

Engineering Contradiction:

Improvepropane conversionVSAvoidselectivity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the reaction mechanism by using metal sulfide as catalyst, which enables high propane conversion at lower temperatures through sulfur transfer mechanism. This parameter change in reaction pathway avoids the need for high temperature, thereby preventing C-C bond activation and maintaining high selectivity to propylene

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

This approach enhances alkene selectivity and stability by decoupling the oxidant and alkane streams, reducing side product formation, and eliminating the need for extreme regeneration steps, thereby improving the efficiency and longevity of the catalyst.

Implementation Method 1

the metal sulfide (MSx) particle reacts with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and a sulfur containing compound

Methodology Applied

Scientific EffectChemical reaction: Reaction (physics)

Implementation Method 2

the reduced metal sulfide (MSx-1) particle reacts with sulfur in the sulfur stream to generate the metal sulfide (MSx) particle and hydrogen (H2)

Methodology Applied

Scientific EffectChemical reaction: Reaction (physics)

Data Source

PatentUS11767275B2Alkene generation using metal sulfide particles

Publication Date: 2023.09.26 OHIO STATE INNOVATION FOUND

AI summary

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx−1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx−1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).