Fixed-Bed Reactor Gas-Liquid Flow for Cumene Production
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Solution Overview
Problem
The use of acetone as an alkylating agent in the cumene production process leads to water by-products that weaken zeolite catalysts, reducing catalytic activity and requiring larger catalyst amounts and reactors, increasing equipment costs.
Innovation Solution
A process involving a gas-liquid downward concurrent flow mode in a fixed-bed reactor packed with a catalyst comprising a solid acid component and a metal component, such as copper, nickel, or rhenium, with a specific reaction gas flow rate and catalyst layer configuration to produce alkylated aromatic compounds like cumene efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If acetone is used as the alkylating agent in cumene production, then the by-product acetone can be reused without adding steps to the conventional process, but water by-products cover the acid sites of zeolite catalysts and weaken acid strength, reducing catalytic activity and requiring larger catalyst amounts and reactor sizes
Solution Approach 1:
The patent changes the physical state parameters of the reaction system by introducing a gas-liquid downward concurrent flow mode with specific gas flow rates (0.05-0.50 kgm⁻²s⁻¹) to control water distribution and catalyst interaction, thereby maintaining catalytic activity while using acetone as alkylating agent
Solution Approach 2:
The patent introduces gas phase as an intermediary medium that facilitates the removal of water from catalyst surfaces during the reaction process, preventing water from covering acid sites and maintaining catalyst activity
2Ease of manufacture
If acetone is used as the alkylating agent, then the by-product acetone can be reused without adding steps to the conventional cumene process, but larger amounts of catalyst and larger reactor size are required, increasing equipment costs
Solution Approach 1:
The patent optimizes reaction parameters including gas flow rate (0.05-0.50 kgm⁻²s⁻¹), temperature (100-300°C), and pressure (0.1-10 MPa) to achieve high conversion efficiency in a compact reactor configuration
Solution Approach 2:
The patent implements a continuous gas-liquid downward concurrent flow mode that maintains continuous contact between reactants and catalyst while efficiently removing water by-products, achieving high productivity in a smaller reactor volume
3Reliability
If water by-products cover the acid sites of zeolite catalysts, then the catalytic activity is reduced, but the reaction can still proceed with larger catalyst amounts
Solution Approach 1:
The gas phase acts as an intermediary that facilitates water removal from catalyst surfaces, preventing water from covering acid sites and maintaining catalyst activity without requiring additional catalyst
4Productivity
If the reaction is performed in a trickle-bed zone with specific gas flow rates, then high ketone conversion and selectivity are achieved, but the system becomes more complex
Solution Approach 1:
The patent defines specific parameter ranges for gas flow rate (0.05-0.50 kgm⁻²s⁻¹), temperature (100-300°C), and pressure (0.1-10 MPa) that optimize the trickle-bed flow mode to achieve high conversion while maintaining manageable operational complexity
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 achieves high ketone conversion and selectivity for alkylated aromatic compounds, maintaining catalyst activity and reducing equipment costs by recycling acetone without adding steps to the conventional cumene process.
Implementation Method 1
reacting the raw materials while regulating the components constituting the catalyst and the reaction gas flow rate
Implementation Method 2
feeding raw materials including an aromatic compound, a ketone and hydrogen in a gas-liquid downward concurrent flow mode to a fixed-bed reactor
Data Source
AI summary
The process for producing alkylated aromatic compounds includes feeding raw materials including an aromatic compound, a ketone and hydrogen in a gas-liquid downward concurrent flow mode to a fixed-bed reactor packed with a catalyst thereby to produce an alkylated aromatic compound, wherein the catalyst includes a solid acid component and a metal component, the catalyst is loaded in the fixed-bed reactor such that the catalyst forms a catalyst layer, and the reaction gas flow rate defined by Equation (1) below is not less than 0.05 at an entrance of a layer containing the solid acid:ρg·ug·[ρair·ρwater/(ρg·ρl)]1/2 (kgm−2s−1).