C6 Cut Aromatization for Cumene Production
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Solution Overview
Problem
The commercial production of benzene derivatives like ethylbenzene and cumene through direct alkylation of mixed C6 hydrocarbon feedstreams is inefficient due to the production of undesired by-products and the need for expensive and time-consuming aromatic extraction methods, as well as challenges in controlling the exothermic reaction temperature.
Innovation Solution
A process involving the separation of a mixed hydrocarbon feedstream to obtain a C6 cut, followed by aromatization using a non-acidic Pt/GeZSM-5 catalyst and subsequent alkylation of the aromatization product stream with ethylene or propylene, simplifying reactor design and reducing side-product formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If aromatic extraction methods are used to remove benzene co-boilers from mixed hydrocarbon feedstream, then purity of benzene stream is improved, but process cost and time consumption increase
Solution Approach 1:
The invention extracts and removes naphthenic compounds (cyclohexane, methylcyclopentane) from the mixed hydrocarbon feedstream before the alkylation process. By removing these interfering substances in advance, the process eliminates the need for subsequent aromatic extraction steps to remove benzene co-boilers, thereby reducing both time consumption and process cost while maintaining high product purity
Solution Approach 2:
The invention performs preliminary removal of naphthenic compounds from the feedstream before alkylation occurs. This preliminary action prevents the formation of unwanted by-products that would otherwise require complex separation and purification steps, thus eliminating time-consuming aromatic extraction operations while ensuring high purity of the final alkylated aromatic products
2Temperature
If excess benzene is used as heat sink to control exothermic temperature rise, then temperature control is improved, but formation of polyalkylated by-products increases and separation cost increases
Solution Approach 1:
The invention changes the composition parameter of the feedstream by removing naphthenic compounds before alkylation. This parameter change allows the process to achieve better temperature control with stoichiometric or near-stoichiometric benzene/olefin ratios, rather than requiring large excesses of benzene. The removal of naphthenes prevents side reactions that would otherwise consume benzene and form polyalkylated by-products, thus reducing harmful by-products while maintaining temperature control
Solution Approach 2:
The invention creates a simplified reaction system by removing interfering naphthenic compounds, effectively copying the ideal alkylation conditions without the complications of naphthene present. This allows for stoichiometric feeding with minimal by-product formation while maintaining excellent temperature control, eliminating the need for excess benzene as a heat sink
3Manufacturing precision
If aromatic extraction is used to provide purified benzene stream, then quality of feedstock for alkylation is improved, but process complexity and cost increase
Solution Approach 1:
The invention extracts and removes naphthenic compounds from the mixed hydrocarbon feedstream in a single extraction step before alkylation. By removing these interfering substances upfront, the process provides high-quality feedstock for alkylation without requiring complex multi-step aromatic extraction processes, thus reducing both process complexity and cost while maintaining excellent product quality
Solution Approach 2:
The invention performs preliminary removal of naphthenic compounds from the feedstream before alkylation occurs. This preliminary extraction action provides high-quality feedstock with minimal impurities that would interfere with the alkylation reaction, eliminating the need for subsequent complex aromatic extraction and purification steps, thus simplifying the overall process while ensuring high product quality
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 allows for easier control of the alkylation reaction exotherm, reduces the production of undesired side-products, and enables a simpler reactor configuration, leading to improved efficiency and cost-effectiveness in producing high-purity alkylated aromatics.
Implementation Method 1
aromatization using a non-acidic Pt/GeZSM-5 catalyst
Implementation Method 2
the alkylation of benzene to ethylbenzene or cumene requires a tight control of the reaction exotherm. For instance, the alkylation of benzene with propylene is an exothermic reaction with a reaction heat of −4.3×104 Btu/lbmol
Data Source
AI summary
A process for producing cumene and/or ethylbenzene from a mixed hydrocarbon feedstream comprising subjecting C6 cut separated from said mixed hydrocarbon feedstream to aromatization to provide an aromatization product stream and subjecting the thus obtained aromatization product stream to alkylation to produce an alkylated aromatic stream.