Activated Carbon Supported Cobalt Catalyst for Linear Alcohol Synthesis

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Solution Overview

Problem

Existing methods for converting synthesis gas to higher aliphatic alcohols and diesel fuels are inefficient, particularly in producing substantial yields of C2 to C18 linear alcohols and middle distillates with minimal methane and CO2 production, and lack catalysts that enable direct synthesis under moderate conditions without additional separation steps.

Innovation Solution

An activated carbon supported cobalt-based catalyst, promoted with zirconium, lanthanum, or other metals, is used to directly synthesize mixed linear alpha-alcohols and naphtha distillates from synthesis gas, offering enhanced selectivity and activity for C2-C18 products and maintaining high selectivity for C10-C20 hydrocarbons under moderate conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional Fischer-Tropsch processes are used to convert synthesis gas to alcohols and hydrocarbons, then hydrocarbon production is achieved, but selectivity is poor and productivity is low

Engineering Contradiction:
ImproveselectivityVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the chemical parameters of the catalyst system by using cobalt-based catalysts with specific promoters (alumina, silica, titania, zirconia, magnesia) and optimizing the synthesis gas composition (H2/CO ratio) and reaction conditions (temperature, pressure) to achieve both high selectivity for linear alpha-alcohols and high productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite catalyst materials combining cobalt with various promoters and supports (activated carbon, alumina, silica) to create a synergistic system that simultaneously improves selectivity for C2-C18 linear alpha-alcohols and maintains high productivity through enhanced catalytic activity

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If zinc chromite catalysts are used for alcohol synthesis at high temperature and pressure, then methanol and ethanol are produced, but the products are predominantly non-linear primary and secondary alcohols

Engineering Contradiction:
Improveproduct selectivityVSAvoidreaction temperature
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The patent changes the temperature parameter from high temperature (conventional zinc chromite process) to moderate temperature (200-400°C) using cobalt-based catalysts, which enables selective production of linear alpha-alcohols while maintaining acceptable reaction rates

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses porous support materials (activated carbon, alumina, silica, titania, zirconia, magnesia) with controlled pore structures to enhance the selectivity for linear alpha-alcohols by providing appropriate adsorption sites and restricting transition states that lead to branched products

Inventive Principle:
Principle #31Porous materials

3Manufacturing precision

If molybdenum disulfide catalysts are used for CO hydrogenation, then C1 to C4 mixed alcohols are produced, but yields of higher alcohols (C6-C18) are limited

Engineering Contradiction:
Improvealcohol chain length distributionVSAvoidyield of higher alcohols
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the catalyst composition from molybdenum disulfide to cobalt-based catalysts with specific promoters, and optimizes reaction parameters (temperature, pressure, space velocity) to shift the product distribution toward higher alcohols (C6-C18) while maintaining high yields

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces local quality differences by using specific promoter materials (alumina, silica, titania, zirconia, magnesia) that create distinct active sites on the cobalt catalyst surface, each favoring different aspects of the reaction to collectively enhance higher alcohol production

Inventive Principle:
Principle #3Local quality

4Manufacturing precision

If additional separation steps are used to purify alcohol products, then product purity is improved, but process complexity and time are increased

Engineering Contradiction:
Improveproduct purityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the separation function from the main process by designing a catalyst system that produces highly selective linear alpha-alcohol products with minimal byproducts, thereby eliminating or simplifying the need for additional separation and purification steps

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The catalyst system performs self-service by inherently producing products with the desired purity and selectivity during the main reaction process, without requiring external separation interventions

Inventive Principle:
Principle #25Self-service

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 catalyst achieves high yields of clean, sulfur-free, nitrogen-free, and aromatic-free mixed linear alpha-alcohols and diesel fuels with a cetane number of at least 60, directly from synthesis gas, reducing the need for additional separation steps and enabling the use of high space velocities.

Implementation Method 1

An activated carbon supported cobalt based catalyst for directly converting of synthesis gas to mixed linear alpha-alcohols and paraffins

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The Fischer-Tropsch process is carried out by passing a mixture of CO and H2 over a catalyst for the hydrogenation of CO

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Implementation Method 3

An activated carbon supported cobalt based catalyst

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentUS7670985B2Activated carbon supported cobalt based catalyst for directly converting of synthesis gas to mixed linear alpha-alcohols and paraffins
Publication Date: 2010.03.02 CNOOC NEW ENERGY INVESTMENT

AI summary

The invention provides an activated carbon supported cobalt based catalyst for directly converting of synthesis gas to mixed linear alpha-alcohols and paraffins, comprising cobalt, an activated carbon carrier, a metal promoter which is at least one selected from the group consisting of a zirconium component, a lanthanum component, a cerium component, a chromium component, a vanadium component, a titanium component, a manganese component, a rhenium component, a potassium component, a ruthenium component, a magnesium component and a mixture thereof, wherein the cobalt and the promoter are deposited on the activated carbon carrier or substantially uniformly dispersed therein, and the metal promoter is present in the form of a metal, an oxide or a combination thereof.