Pre-hydrocarbon Pooling Catalyst Treatment for MTO Reactor Hot Spots

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Solution Overview

Problem

Existing MTO processes face challenges in achieving high selectivity and yield of low-carbon olefins due to uneven distribution of 'hydrocarbon pool' active species and coke deposition in catalyst beds, leading to local overheating and reduced catalytic activity.

Innovation Solution

A pre-hydrocarbon pooling method and device are introduced to treat the regenerated catalyst, forming 'hydrocarbon pool' active species and carbon deposition before entering the conversion reactor, thereby improving the distribution of these species and reducing temperature gradients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If regenerated catalyst is directly introduced into the conversion reactor, then the catalyst is quickly available for reaction, but the distribution of 'hydrocarbon pool' active species and coke deposition becomes uneven, leading to local overheating and reduced selectivity

Engineering Contradiction:

Improvecatalyst availability speedVSAvoiduniformity of active species distribution

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by introducing a pre-hydrocarbon pooling step before the conversion reaction. Regenerated catalyst is first treated in a pooling reactor where hydrocarbon pool species are formed in advance under controlled conditions. This preliminary treatment ensures uniform distribution of active species and coke deposition before the catalyst enters the main conversion reactor, eliminating local overheating issues while maintaining rapid catalytic activity.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If coke deposition amount is increased to improve low-carbon olefin yield, then selectivity improves, but temperature control becomes difficult and hot spots increase

Engineering Contradiction:

Improveyield of low-carbon olefinsVSAvoidtemperature uniformity in reactor

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent segments the reaction process into two distinct stages: a pre-hydrocarbon pooling stage in a separate reactor, and a conversion stage in the main reactor. By segmenting the process, coke deposition and hydrocarbon pool formation occur uniformly in the pooling reactor under controlled conditions, while the conversion reactor operates with uniformly distributed catalyst, preventing temperature hot spots even at high olefin yields.

Inventive Principle:

Principle #1Segmentation

3Productivity

If catalyst circulation rate is increased to maintain continuous reaction, then productivity improves, but uneven distribution of active species worsens

Engineering Contradiction:

Improvecontinuous reaction efficiencyVSAvoidconsistency of catalyst composition

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent introduces a pre-hydrocarbon pooling reactor as an intermediary between the regenerator and the conversion reactor. This intermediary device acts as a buffer zone where catalyst composition is standardized and uniform active species distribution is established before catalyst enters the conversion reactor. This allows high circulation rates for continuous production while maintaining consistent catalyst composition throughout the system.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method enhances the activity and selectivity of the catalyst for converting oxygenates to low-carbon olefins, improves the yield of ethylene and propylene, and reduces coking rates by ensuring uniform distribution of active species and optimizing temperature distribution in the reactor.

Implementation Method 1

the regenerated catalyst contacts with an activation medium to undergo reactions such as a pre-hydrocarbon pooling reaction to form 'hydrocarbon pool' active species and a certain amount of carbon deposition

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

improves the distribution of these species and reducing temperature gradients

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS12311348B2Catalyst pre-hydrocarbon pooling method and device therefor

Publication Date: 2025.05.27 LUOYANG WEIDA PETROCHEMICAL ENG CO LTD

AI summary

Disclosed are a catalyst pre-hydrocarbon-pooling method and a pre-hydrocarbon-pooling device, relating to the technical field of preparation of low carbon olefins. A regenerated catalyst enters a pre-hydrocarbon-pooling reactor, and a pre-hydrocarbon-pooling reaction occurs between the regenerated catalyst and an activation medium to form “hydrocarbon pool” active species. “Pre-hydrocarbon-pooling” treatment is performed on the regenerated catalyst by providing a pre-hydrocarbon-pooling device, so that the regenerated catalyst forms the “hydrocarbon pooled” active species and carbon deposition before entering into an oxygenate conversion reactor, by way of which “hydrocarbon pool” active species distribution and coke distribution of the catalyst in the conversion reactor are improved. This shortens or eliminates a reaction “induction period” and improves the catalytic activity and selectivity of the regenerated catalyst for a reaction of an oxygenate to low-carbon olefins.