Dual Fluidized Bed Hydrocarbon Decomposition for Catalyst Regeneration

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Solution Overview

Problem

Current catalytic thermal decomposition technologies face challenges such as rapid catalyst deactivation, carbon encapsulation, and high carbon dioxide emissions due to the need for combustion-based heat generation, which limits their commercial deployment and efficiency in producing hydrogen and filamentous carbon from hydrocarbons.

Innovation Solution

A dual fluidized bed reaction system using supported transition metal catalysts on non-porous substrates with controlled particle sizes and gas distributor designs to minimize carbon encapsulation and maximize carbon recovery, along with a low oxygen regeneration environment to maintain catalyst activity and reduce emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If porous catalyst supports are used to provide high surface area and active metal sites, then initial hydrocarbon conversion is high, but carbon encapsulation occurs within pores and prevents catalyst regeneration

Engineering Contradiction:

Improvehydrocarbon conversionVSAvoidcatalyst activity maintenance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent uses porous catalyst supports (alumina or silica) to provide high surface area for active metal sites, achieving high initial hydrocarbon conversion. The porous structure allows carbon to be deposited within pores where it can be subsequently removed through oxidation during regeneration cycles, resolving the contradiction between maintaining high conversion and preventing permanent encapsulation.

Inventive Principle:

Principle #31Porous materials

2Use of energy by moving object

If combustion is used to generate heat for endothermic decomposition reactions, then energy requirements are met, but significant carbon dioxide emissions are produced

Engineering Contradiction:

Improveheat generation for decompositionVSAvoidcarbon dioxide emissions

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent implements a self-sustaining thermal system where carbon deposited on the catalyst during decomposition is combusted during regeneration to generate the heat required for the endothermic decomposition reaction. This internal heat generation eliminates or minimizes the need for external combustion-based heating, thereby dramatically reducing carbon dioxide emissions while maintaining energy balance.

Inventive Principle:

Principle #25Self-service

3Reliability

If catalyst regeneration is performed to remove encapsulating carbon, then catalyst activity is restored, but carbon dioxide emissions increase and catalyst deactivation may occur over extended periods

Engineering Contradiction:

Improvecatalyst activity restorationVSAvoidcarbon dioxide emissions during regeneration

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of carbon deposition (which causes deactivation) into a beneficial heat source. The carbon that would normally need to be burned off requiring external energy input is instead used as fuel to generate the heat needed for decomposition reactions. The regeneration process removes carbon through controlled oxidation, restoring catalyst activity while the heat from carbon combustion sustains the decomposition process, minimizing additional emissions.

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 achieves high hydrocarbon conversion with minimal carbon oxide production, maintaining catalyst activity over extended periods and producing high-quality filamentous carbon while avoiding combustion-based heat generation.

Implementation Method 1

Catalytic thermal decomposition processes require significantly lower operating temperatures and hence are significantly more energetically efficient and produce more valuable carbon products including filamentous carbon products such as carbon nanotubes (CNTs)

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

a new process for the decomposition of hydrocarbon feed stream(s) that achieves the conversion of a hydrocarbon feed stream to hydrogen and filamentous carbon... by the use of dual fluidized bed reaction zones

Methodology Applied

Scientific EffectFluidisation: Fluidisation

Implementation Method 3

it is desirable to regenerate the catalyst and provide the necessary heat required for the endothermic decomposition reaction(s) without the generation of significant additional carbon dioxide emissions

Methodology Applied

Scientific EffectEndothermic reaction: Endothermic Reaction

Data Source

PatentUS11685651B2Catalytic decomposition of hydrocarbons for the production of hydrogen and carbon

Publication Date: 2023.06.27 ROBERTSON MARK KEVIN

AI summary

A new process for the decomposition of hydrocarbon feed stream(s) that achieves the conversion of a hydrocarbon feed stream to hydrogen and filamentous carbon, with minimal resulting production of carbon oxides is described herein. In this invention it is proposed to achieve the hydrocarbon conversion by the use of dual fluidized bed reaction zones, fluidly connected, for (i). hydrocarbon reaction (the reactor) and (ii). catalyst regeneration and heating (the regenerator) and to use a transition metal supported catalyst to achieve high hydrocarbon conversion and to produce high quality filamentous carbon.