Cyclopentadiene Recovery via Cold Sulfuric Acid Extraction
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Solution Overview
Problem
Current processes for producing cyclopentadiene (CPD) and dicyclopentadiene (DCPD) face challenges such as low yield, high energy consumption, catalyst deactivation due to coking, and inability to use oxygen-containing gases for heat input, along with contamination issues from side reactions and co-dimers, making it difficult to achieve high-purity DCPD industrially.
Innovation Solution
A process involving the conversion of acyclic C5 hydrocarbons to CPD using a catalyst under specific conditions, followed by effective separation to minimize Diels-Alder reactions, allowing for high-yield production of CPD and subsequent high-purity DCPD through dimerization, with the use of hydrogen co-feedstocks to prevent coke formation and optimize reaction conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional distillation is used to recover CPD from product mixture, then separation can be achieved, but the process is not industrially feasible due to close boiling points, azeotropes, and reactivity at distillation temperatures
Solution Approach 1:
The patent changes the separation parameter from thermal distillation to low-temperature extraction using cold sulfuric acid, avoiding the temperature range where CPD reacts with diolefins. This parameter change enables industrial feasibility while maintaining high purity recovery
Solution Approach 2:
The patent introduces cold sulfuric acid as an intermediary substance to selectively extract CPD from the C5 hydrocarbon mixture. The acid forms a complex with CPD that can be separated from other components, then CPD is recovered by basification, achieving both purity and industrial feasibility
2Manufacturing precision
If dimerization process is used to recover CPD, then CPD can be separated from C5 hydrocarbons, but CPD reacts with other diolefins to produce co-dimers that contaminate DCPD
Solution Approach 1:
The patent extracts CPD from the mixture using cold sulfuric acid before dimerization occurs. By removing CPD selectively in its monomeric form at low temperature, subsequent dimerization only produces pure DCPD without co-dimer contamination from other diolefins
Solution Approach 2:
The patent performs preliminary extraction of CPD using cold sulfuric acid before the dimerization step. This preliminary separation prevents unwanted Diels-Alder reactions between CPD and other diolefins that would occur if dimerization were performed on the full mixture
3Productivity
If steam cracking process is used to produce CPD, then CPD can be obtained as byproduct, but yield is low and demand continues to rise
Solution Approach 1:
The patent changes the production approach from byproduct recovery in steam cracking to purposeful production via catalytic dehydrogenation of C5 paraffins. This parameter change from incidental to intentional production dramatically increases both yield and production volume to meet rising demand
4Manufacturing precision
If conventional recovery schemes are used involving multiple dimerization and cracking steps, then DCPD can be produced, but the process is expensive, low in yield, and prone to fouling
Solution Approach 1:
The patent segments the recovery process into distinct stages: (1) cold sulfuric acid extraction of CPD from C5 mixture, (2) basification to liberate CPD, and (3) controlled dimerization to DCPD. This segmentation allows each step to be optimized independently, improving both purity and efficiency while reducing fouling
Solution Approach 2:
The patent uses cold sulfuric acid as an intermediary to selectively complex with CPD, enabling separation from other C5 hydrocarbons. This intermediary approach avoids the need for multiple thermal processing steps, reducing energy consumption and fouling while maintaining high DCPD purity
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 enables the production of CPD at high yield and high-purity DCPD, reducing energy consumption and catalyst deactivation, while minimizing contamination and side reactions, thereby improving the efficiency and cost-effectiveness of the process.
Implementation Method 1
converting C5 hydrocarbons to CPD in a reactor loaded with a catalyst
Implementation Method 2
the inability to use oxygen-containing gas to directly provide heat input to the reactor without damaging the catalyst
Implementation Method 3
effective separation to minimize Diels-Alder reactions
Implementation Method 4
subsequent high-purity DCPD through dimerization
Implementation Method 5
the reaction converting C5 hydrocarbons to CPD is extremely endothermic
Data Source
AI summary
Processes and systems for making cyclopentadiene and/or dicyclopentadiene include converting acyclic C5 hydrocarbon(s) into CPD in a first reactor to obtain a product mixture, separating the product mixture in a separation sub-system such as compression train to obtain a C5-rich fraction comprising CPD and essentially depleted of hydrogen and C1-C4 hydrocarbons, dimerizing the C5-rich fraction in a dimerization reactor to obtain a product effluent comprising DCPD, followed by separating the product effluent to obtain a DCPD-rich fraction. Multiple-stage of dimerization and separation steps can be optionally used to obtain multiple DCPD-rich fractions of various degrees of purity and quantity. C5-rich fractions from various stages of the process may be recycled to the first reactor, or converted into mogas components after selective hydrogenation. C5-rich fractions and mogas components may be optionally separated to produce value-adding chemicals.