Counter-Current Reactor for C5 Hydrocarbon Conversion
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Solution Overview
Problem
Current processes fail to efficiently convert acyclic C5 hydrocarbons to cyclopentadiene with high yield and selectivity, leading to excessive production of C4 cracked products and catalyst deactivation, while also being costly and inefficient in using acyclic C5 feedstocks.
Innovation Solution
A process involving a reactor system where acyclic C5 hydrocarbons are converted to cyclopentadiene using a catalyst material in a counter-current flow configuration, maintaining an isothermal temperature profile to minimize undesirable cracking and catalyst deactivation, and utilizing hydrogen to prevent coke formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalytic dehydrogenation technologies are used to convert acyclic C5 hydrocarbons to cyclic C5 hydrocarbons, then conversion of n-pentane occurs, but selectivity and yield to cyclic C5 products are poor and catalyst deactivation occurs
Solution Approach 1:
The patent employs Pt-Sn/SAPO-35 catalyst which utilizes the unique chaozit framework structure of SAPO-35 with specific pore size and acidity parameters to achieve both high conversion and maintain catalyst stability. The catalyst composition parameters (Pt and Sn ratios, loading amounts) are optimized to balance activity and stability.
Solution Approach 2:
The patent uses a composite catalyst system combining Pt and Sn metals on SAPO-35 support, where Pt provides dehydrogenation activity and Sn enhances stability and selectivity. The composite structure of metal particles on the zeolite framework creates synergistic effects that improve both conversion and catalyst longevity.
2Productivity
If Pt-Sn/alumina and Pt-Sn/aluminate catalysts are used for dehydrogenation, then moderate conversion of n-pentane is achieved, but selectivity and yield to cyclic C5 products are poor
Solution Approach 1:
The patent exploits the local structural features of SAPO-35 with its specific pore geometry and acid site distribution. The chaozit framework provides localized environments that favor cyclization reactions while suppressing cracking, achieving high selectivity to cyclic C5 products.
Solution Approach 2:
The patent changes the support material from alumina/aluminate to SAPO-35, fundamentally altering the catalytic properties. The SAPO-35 support provides different acidity, pore structure, and thermal stability parameters that simultaneously improve conversion and selectivity to cyclic products.
3Productivity
If Pt supported on chlorided alumina catalysts are used for dehydrogenation and cyclization, then C6 and C7 alkanes are converted to aromatic rings, but acyclic C5 conversion to cyclic C5 is less effective and catalyst deactivation occurs within two hours
Solution Approach 1:
The patent replaces the expensive and short-lived chlorided alumina catalyst with Pt-Sn/SAPO-35 that offers extended catalyst lifetime. The SAPO-35 support provides better resistance to deactivation mechanisms, making the catalyst economically viable for continuous operation.
Solution Approach 2:
The patent uses the composite Pt-Sn metal system on SAPO-35 support where the combination of noble metals with the zeolite framework creates a catalyst that is both active for dehydrogenation and stable against deactivation, unlike the chlorided alumina system.
4Productivity
If conventional processes are used to convert acyclic C5 to cyclic C5, then some conversion occurs, but excessive C4 cracked products are produced and production cost is high
Solution Approach 1:
The patent optimizes reaction parameters including temperature, pressure, and weight hourly space velocity (WHV) to maximize cyclic C5 production while minimizing C4 cracking. The Pt-Sn/SAPO-35 catalyst enables operation at conditions that favor cyclization over fragmentation.
Solution Approach 2:
The patent utilizes the specific pore structure of SAPO-35 that provides localized confinement effects, favoring the formation of cyclic C5 products while suppressing the formation of smaller C4 fragments through steric and electronic effects within the pores.
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 conversion rates of acyclic C5 hydrocarbons to cyclopentadiene with reduced C4 byproduct formation and improved catalyst stability, enabling efficient and cost-effective production of cyclopentadiene from abundant C5 feedstocks.
Implementation Method 1
contacting the feedstock and the particulate material in at least one reaction zone under reaction conditions to convert at least a portion of the acyclic C 5 hydrocarbons to a first effluent comprising cyclopentadiene
Implementation Method 2
the feedstock flows counter-current to a direction of a flow of the particulate material, and wherein an isothermal temperature profile is maintained in the at least one reaction zone
Data Source
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AI summary
This invention relates to a process for converting acyclic C5 hydrocarbons to cyclopentadiene in a reactor system, wherein the process comprises: providing to the reaction system a feedstock comprising acyclic C5 hydrocarbons; providing to the reaction system a particulate material comprising a catalyst material; contacting the feedstock and the particulate material in at least one reaction zone under reaction conditions to convert at least a portion of the acyclic C5 hydrocarbons to a first effluent comprising cyclopentadiene; wherein the feedstock flows counter-current to a direction of a flow of the particulate material.