Partial Methanol-to-Olefin Catalyst Regeneration via Steam Gasification

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Solution Overview

Problem

The existing regeneration methods for methanol to olefin catalysts using nitrogen and air or steam produce greenhouse gas CO2 and fail to maximize selectivity to light olefins, as they either completely regenerate the catalyst or lead to 'temperature runaway' and 'tail burning', reducing carbon atom utilization and catalyst performance.

Innovation Solution

A method for partial regeneration of methanol to olefin catalysts using steam to gasify coke deposition, maintaining a coke amount of 1% to 6% on the catalyst, which improves selectivity to light olefins by controlling the regeneration reaction temperature and time under an inert atmosphere, thereby enhancing catalytic activity and carbon atom utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If air or oxygen is used for catalyst regeneration, then coke is removed effectively, but temperature runaway and tail burning occur, reducing catalyst performance

Engineering Contradiction:

Improvecoke removal efficiencyVSAvoidcatalyst performance stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent uses nitrogen as an inert atmosphere carrier gas during catalyst regeneration, creating a controlled environment that prevents uncontrolled combustion. The nitrogen atmosphere allows for gradual and uniform coke oxidation while avoiding the temperature runaway and tail burning phenomena associated with air or oxygen-based regeneration methods, thus maintaining catalyst performance stability.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Reliability

If complete regeneration is performed to remove all coke, then catalyst activity is restored, but selectivity to light olefins decreases

Engineering Contradiction:

Improvecatalyst activityVSAvoidselectivity to light olefins

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies partial action by intentionally retaining a small amount of coke (0.1-5 wt%) on the catalyst after regeneration, rather than removing all coke. This partial regeneration approach maintains sufficient catalyst activity while preserving the selectivity to light olefins, as complete coke removal actually reduces selectivity. The controlled retention of minimal coke achieves optimal balance between activity and selectivity.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If air is used for regeneration, then regeneration speed is fast, but large amount of CO2 is produced, reducing carbon atom utilization

Engineering Contradiction:

Improveregeneration speedVSAvoidcarbon atom utilization

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent uses nitrogen instead of air as the regeneration atmosphere, which fundamentally changes the oxidation pathway. In the nitrogen atmosphere, coke is converted primarily to CO and H2 through controlled gasification rather than complete oxidation to CO2. This approach maintains fast regeneration speed while significantly improving carbon atom utilization by producing syngas that can be recycled or utilized, rather than losing carbon as waste CO2.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

4Loss of substance

If steam is used for regeneration, then CO2 production is reduced, but temperature control becomes difficult

Engineering Contradiction:

ImproveCO2 productionVSAvoidtemperature control

Core Design Contradiction:

Loss of substanceVSTemperature

Solution Approach 1:

The patent uses nitrogen as the primary atmosphere carrier, which provides superior temperature control compared to steam. The nitrogen atmosphere allows for uniform heat distribution and controlled exothermic reactions during coke removal, preventing hot spots and temperature runaway. While steam does reduce CO2 production, the nitrogen-based system achieves both low CO2 emissions (through controlled gasification to CO) and excellent temperature control through the inert atmosphere's thermal properties.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

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 method achieves high selectivity to light olefins, with selectivity ranging from 63% to 83%, and nearly complete methanol conversion, while minimizing CO2 production and maintaining catalyst performance comparable to fresh catalysts.

Implementation Method 1

gasifying partial coke deposited on the deactivated catalyst with steam

Methodology Applied

Scientific EffectGasification: Chemical Transport Reactions

Implementation Method 2

catalyst partially regenerated by gasifying partial coke deposited on the deactivated catalyst with steam

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS11504703B2Method for partially regenerating methanol to olefin catalyst and methanol to olefin process

Publication Date: 2022.11.22 DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES

AI summary

The present application discloses a method for partially regenerating a methanol to olefin catalyst, comprising: placing a deactivated methanol to olefin catalyst in a regenerator to carry out a partial regeneration reaction to obtain a regenerated catalyst; at least a portion of the regenerated catalyst has a coke amount of more than 1%. The present application discloses a methanol to olefin process, the methanol to olefin reaction is carried out in a fluidized bed with the use of a methanol to olefin catalyst, wherein at least a portion of the regenerated catalyst has a coke amount of more than 1%.