Liquid Phase Alkylation Catalyst Crystal Binder Ratio
Solution Overview
Problem
Existing processes for producing alkylaromatic compounds like ethylbenzene and cumene face challenges in achieving high monoselectivity and low by-product formation, particularly in liquid phase alkylation and transalkylation steps, where current catalysts lack sufficient activity and result in significant production of unwanted by-products like ethylbenzene and n-propylbenzene.
Innovation Solution
A liquid phase or partial liquid phase alkylation process using a catalyst comprising a porous crystalline aluminosilicate and binder in a specific ratio of 20/80 to 60/40, which enhances activity and monoselectivity, reducing the need for transalkylation reactions and minimizing by-product formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If existing catalysts are used in liquid phase alkylation, then the process operates at lower temperature, but monoselectivity is poor and by-product formation is high
Solution Approach 1:
The patent changes the physical-chemical parameters of the catalyst by controlling the crystal size of MCM-22 to be 0.2-2.0 μm and adjusting the crystal-to-binder ratio to 20/80-60/40. These parameter changes enable the catalyst to maintain high activity at lower temperatures while achieving improved monoselectivity and reduced by-product formation in liquid phase alkylation
Solution Approach 2:
The patent utilizes the porous structure of MCM-22 crystalline material with specific surface area of 400-700 m²/g and pore volume of 0.3-0.6 cm³/g. The porous structure provides accessible active sites while controlling reactant diffusion, enabling high monoselectivity in liquid phase alkylation at lower temperatures by favoring monoalkylation over polyalkylation
2Productivity
If existing catalysts are used in transalkylation, then polyalkylated species can be converted, but activity is insufficient and unwanted by-products are produced
Solution Approach 1:
The patent optimizes the crystal size parameter to 0.2-2.0 μm and crystal-to-binder ratio to 20/80-60/40, which significantly enhances transalkylation activity while maintaining high selectivity for cumene. The optimized parameters enable efficient conversion of polyalkylated species to cumene with minimal formation of unwanted by-products like ethylbenzene and n-propylbenzene
Solution Approach 2:
The patent creates local quality differences by using small crystal sizes (0.2-2.0 μm) that provide uniform distribution of active sites throughout the catalyst particle. This ensures that reactants can access internal active sites efficiently, leading to high transalkylation activity and selectivity while minimizing by-product formation through uniform reaction conditions
3Temperature
If liquid phase conditions are used, then lower temperature operation is achieved, but catalyst activity and selectivity requirements increase
Solution Approach 1:
The patent changes the catalyst parameters by controlling crystal size (0.2-2.0 μm) and crystal-to-binder ratio (20/80-60/40), which enables the catalyst to maintain high activity and selectivity under liquid phase conditions at lower temperatures. The optimized parameters ensure reliable performance by maximizing the number of accessible active sites while controlling reaction selectivity
Solution Approach 2:
The patent creates a composite catalyst material combining MCM-22 crystalline material (40-80 wt.%) with binder (20-60 wt.%). This composite structure provides both high catalytic activity from the MCM-22 component and structural stability from the binder, ensuring reliable catalyst performance under liquid phase alkylation conditions at lower temperatures
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 process improves the yield of desired monoalkylated products while significantly reducing the production of di- or polyalkylated species and unwanted by-products, allowing for capacity expansion and lower capital expenses in existing plants.
Implementation Method 1
contacting a feedstock comprising an alkylatable aromatic compound and an alkylating agent to an alkylaromatic conversion product under at least partial liquid phase conversion conditions in the presence of a catalyst comprising a porous crystalline aluminosilicate and binder
Data Source
AI summary
The present invention provides an improved process for conversion of feedstock comprising an alkylatable aromatic compound and an alkylating agent to desired alkylaromatic conversion product under at least partial liquid phase conversion conditions in the presence of specific catalyst comprising a porous crystalline material, e.g. a crystalline aluminosilicate, and binder in the ratio of crystal/binder of from about 20/80 to about 60/40. The porous crystalline material of the catalyst may comprise a crystalline molecular sieve having the structure of Beta, an MCM-22 family material, e.g. MCM-49, or a mixture thereof.