Cumene Production Process Aromatic Overhead Stream Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing cumene production process using zeolite catalysts results in significant yield loss due to the purge of aromatic compounds like butylbenzene and cymene, which are not fully utilized, leading to a loss of potential cumene precursors.
Innovation Solution
Recycling at least part of the aromatic overhead stream containing butylbenzene and cymene back to the alkylation reactor, where these compounds are converted into cumene precursors, thereby enhancing the overall cumene yield by producing additional cumene through transalkylation reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If aromatic purge is taken to remove butylbenzenes and cymenes from the system, then product purity is improved, but cumene yield deteriorates due to loss of recoverable compounds
Solution Approach 1:
The patent applies the principle of discarding and recovering by taking an aromatic purge to remove excess butylbenzenes and cymenes from the system while simultaneously recovering valuable compounds (cumene and DIPB) that are contained within the purge stream. The purge stream is processed through distillation columns to separate and recover these valuable compounds, converting what would be waste into usable materials that are recycled back to the alkylation reactor, thereby improving cumene yield while maintaining product purity
Solution Approach 2:
The patent implements feedback by recycling the recovered aromatic compounds (cumene and DIPB) from the purge stream back to the alkylation reactor. This creates a closed-loop system where materials that would otherwise be lost are fed back into the process to produce additional cumene, continuously improving yield while the purge mechanism maintains product purity
2Object-generated harmful factors
If aromatic purge concentration is increased to remove more butylbenzenes and cymenes, then harmful factor removal is improved, but loss of recoverable compounds increases
Solution Approach 1:
The patent applies the principle of taking out (extraction) by selectively removing excess butylbenzenes and cymenes from the aromatic stream through the purge mechanism, while simultaneously extracting and recovering valuable compounds (cumene and DIPB) that are present in the same purge stream. This selective extraction approach allows the system to eliminate harmful factors while preserving and recovering valuable materials for reuse
3Productivity
If transalkylation is used to convert PIPB to cumene, then cumene production is improved, but process complexity increases
Solution Approach 1:
The patent applies the principle of merging (combining) by integrating the transalkylation process with the existing alkylation and distillation operations. The transalkylation reactor converts polyisopropylbenzenes to additional cumene, and this stream is combined with the alkylation effluent for joint processing through the existing distillation column system, thereby increasing cumene production without proportionally increasing overall process complexity
Solution Approach 2:
The patent implements universality by using the existing distillation column system to handle multiple streams including both alkylation effluent and transalkylation effluent. The same separation infrastructure serves multiple functions, processing different product streams through a unified system rather than requiring separate dedicated equipment for each process
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 approach improves the cumene yield by converting previously unrecoverable aromatic compounds into valuable cumene precursors, reducing waste and increasing the overall efficiency of the cumene production process.
Implementation Method 1
contacting benzene and a C3 alkylating agent under alkylation conditions with an alkylation catalyst in an alkylation zone to produce an alkylation effluent comprising cumene and alkylaromatic compounds heavier than cumene
Implementation Method 2
contacting the polyisopropylbenzene-containing stream with benzene in the presence of a transalkylation catalyst in a transalkylation zone to produce a transalkylation effluent comprising additional cumene
Implementation Method 3
recovering cumene from the alkylation effluent to leave a byproduct stream containing the alkylaromatic compounds heavier than cumene
Data Source
AI summary
A process is described for producing cumene comprising contacting benzene and a C3 alkylating agent under alkylation conditions with an alkylation catalyst in an alkylation zone to produce an alkylation effluent comprising cumene and alkylaromatic compounds heavier than cumene. Cumene is recovered from the alkylation effluent to leave a byproduct stream containing the alkylaromatic compounds heavier than cumene, which is separated into a polyisopropylbenzene-containing stream, an aromatic overhead stream, and a bottoms product. At least part of the aromatic overhead stream is recycled to the alkylation zone to reduce raw material consumption and improve cumene yield.