Homogeneous Catalyst Recycles Oxygenates for C3+ Alcohol Yield

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Solution Overview

Problem

Conventional processes for converting methane to higher-value hydrocarbons face challenges such as high energy requirements, hazardous reactions, and significant by-product yields, particularly in producing C2+ and C3+ oxygenates, while also generating unwanted hydrocarbon by-products.

Innovation Solution

A homogeneous catalytic process that recycles a liquid-phase portion of ethanol and non-ethanol C2+ oxygenates, such as ethylene glycol, in the presence of carbon monoxide and molecular hydrogen using metal-containing compounds like Co, Rh, and Ru, to enhance the yield of C3+ monohydric alcohols and C2+ glycols, while reducing methanol production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional heterogeneous catalytic processes are used to convert syngas to oxygenates, then the process is simpler and more robust, but the yield of C3+ alcohol is low and methane selectivity is high

Engineering Contradiction:
ImproveC3+ alcohol yieldVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the catalytic system from heterogeneous to homogeneous catalysts (specifically using metal complexes with ligands such as carbonyl, phosphine, or nitrogen-based ligands), which fundamentally alters the reaction mechanism and selectivity. This parameter change enables higher C3+ alcohol yields while maintaining manageable process complexity through controlled reaction conditions (temperature, pressure, catalyst concentration).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs composite catalytic systems combining metal centers with specific ligands to create homogeneous catalysts that achieve superior selectivity for C3+ alcohols. The composite nature of these catalysts (metal+ligand framework) allows precise control over reaction pathways, increasing productivity without proportionally increasing overall process complexity.

Inventive Principle:
Principle #40Composite materials

2Productivity

If conventional homogeneous catalytic processes are used, then the selectivity for oxygenated products is increased, but the yield of methanol is high and C3+ alcohol yield is limited

Engineering Contradiction:
ImproveC3+ alcohol yieldVSAvoidmethanol yield
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by designing catalysts with specific ligand environments around metal centers that create localized electronic and steric properties favorable for C3+ alcohol formation. The ligands are specifically chosen (carbonyl, phosphine, nitrogen-based) to modify the catalyst's local chemistry, thereby directing selectivity toward desired C3+ products while suppressing methanol formation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention modifies catalytic parameters by using specific metal complexes with controlled ligand fields, operating at optimized temperatures (typically 50-200°C) and pressures (1-50 atm). These parameter changes shift the reaction distribution away from methanol toward higher C3+ alcohols, resolving the contradiction between oxygenate selectivity and methanol yield.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high temperatures are used for non-oxidative methane conversion, then the conversion rate increases, but the energy consumption increases and equilibrium limitation is reached

Engineering Contradiction:
Improvemethane conversion rateVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent replaces high-temperature thermal energy input with catalytic activation. By using homogeneous metal complexes with specific ligands, the system lowers the energy barrier for methane activation and C-C bond formation. This substitution of thermal mechanics with catalytic chemistry enables high conversion rates at much lower temperatures, dramatically reducing energy consumption while avoiding equilibrium limitations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Speed

If oxidative coupling methods are used for methane conversion, then the reaction is highly exothermic and fast, but hazardous reactions occur and carbon oxides are produced

Engineering Contradiction:
Improvereaction rateVSAvoidhazardous reactions and carbon oxide production
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful high-energy exothermic oxidative coupling into a controlled, selective homogeneous catalytic process. By using metal complexes with specific ligands, the system channels the reaction energy productively into C-C bond formation at lower temperatures, eliminating hazardous runaway reactions and carbon oxide by-products while maintaining high reaction rates through catalytic acceleration.

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

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 increases the yield of C3+ monohydric alcohols and C2+ glycols, decreases methanol yield, and maintains intermediates in the liquid phase, preventing precipitation and improving the efficiency of oxygenate homologation reactions.

Implementation Method 1

A homogeneous catalytic process that recycles a liquid-phase portion of ethanol and non-ethanol C2+ oxygenates, such as ethylene glycol, in the presence of carbon monoxide and molecular hydrogen using metal-containing compounds like Co, Rh, and Ru

Methodology Applied
Scientific EffectHomogeneous catalysis: Catalysis

Implementation Method 2

reacting at least a portion of the feed mixture's CO and at least a portion of the feed mixture's molecular hydrogen in the presence of the process fluid under oxygenate formation conditions

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS20170342005A1Oxygenate Synthesis and Homologation
Publication Date: 2017.11.30 EXXONMOBIL CHEMICAL PATENTS INC

AI summary

The invention relates to processes for oxygenate synthesis and homologation, to equipment and materials useful in such processes, and to the use of such oxygenate for producing olefin and polyolefin.