Over-flocculated Molecular Sieve Catalyst Attrition Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current molecular sieve catalyst compositions face challenges with high attrition rates and increased slurry viscosity, which affect their durability and efficiency in hydrocarbon conversion processes, particularly in the production of light olefins from oxygenates.

Innovation Solution

A molecular sieve catalyst composition is formulated by combining an over-flocculated molecular sieve with a phosphorous compound, such as phosphoric acid, and optionally a non-over flocculated molecular sieve, to enhance attrition resistance and reduce slurry viscosity, thereby improving process operability and reducing catalyst requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If molecular sieve catalyst compositions are used in conversion processes, then conversion efficiency of oxygenates to light olefins is improved, but attrition rates increase causing particle breakdown

Engineering Contradiction:
Improveconversion efficiencyVSAvoidattrition resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent combines molecular sieve particles with a matrix material (such as alumina, silica, or other porous materials) to form a composite catalyst composition. The matrix material provides structural support and reduces particle breakdown, while the molecular sieve maintains its catalytic activity for converting oxygenates to light olefins. This composite structure resolves the contradiction by preserving conversion efficiency while improving attrition resistance.

Inventive Principle:
Principle #40Composite materials

2Productivity

If molecular sieve particles are used in catalytic conversion, then conversion performance is improved, but slurry viscosity increases affecting process operability

Engineering Contradiction:
Improveconversion performanceVSAvoidslurry viscosity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent modifies the local properties of the catalyst composition by incorporating a matrix material with specific physical characteristics (porosity, particle size, surface area) that are optimized to reduce slurry viscosity. The matrix material creates a more open structure that allows better fluid flow, thereby improving ease of operation while maintaining the molecular sieve's conversion performance through localized catalytic sites.

Inventive Principle:
Principle #3Local quality

3Productivity

If molecular sieve catalyst compositions are used, then light olefin production is improved, but catalyst durability decreases due to particle breakdown

Engineering Contradiction:
Improvelight olefin productionVSAvoidcatalyst durability
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent incorporates a matrix material that acts as a protective framework before the molecular sieve particles are subjected to mechanical stress in the reactor. This pre-established structural support cushions the molecular sieve particles against attrition and particle breakdown, thereby extending catalyst durability while maintaining light olefin production capability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 composition exhibits improved attrition performance and lower slurry viscosity, leading to increased durability and reduced operating costs, with enhanced conversion efficiency of oxygenates to light olefins like ethylene and propylene.

Implementation Method 1

an oxygenate, typically mostly methanol, is converted into primarily ethylene and/or propylene in the presence of a molecular sieve

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

Molecular sieves, such as zeolites or zeolite-type molecular sieves, carbons and oxides, are porous solids having pores of different sizes that selectively adsorb molecules that can enter the pores, and exclude other molecules that are too large

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

combining an over-flocculated molecular sieve with a phosphorous compound, such as phosphoric acid

Methodology Applied
Scientific EffectChemical interaction: Chemical Bonding

Data Source

PatentUS7449611B2Molecular sieve catalyst composition, its making and use in conversion processes
Publication Date: 2008.11.11 EXXONMOBIL CHEMICAL PATENTS INC

AI summary

A catalyst composition that comprises an over flocculated molecular sieve and a phosphorous compound and, optionally, a non-over flocculated molecular sieve. A method of preparing a catalyst composition that comprises mixing an over flocculated molecular sieve and a phosphorous compound and, optionally, a non-over flocculated molecular sieve.