Isomerization Drier Regenerant Flow Control
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Solution Overview
Problem
Isomerization processes for light paraffins in gasoline production face challenges due to water poisoning of reactor catalysts, leading to reduced reactor life and disruptions in downstream operations caused by regenerants used in drier regeneration, which affect gas flow and pressure controls.
Innovation Solution
The process involves recycling used regenerants upstream of the drying zone to dilute them with incoming reactants, using a fluid tapering device to regulate flow and reduce pressure, thereby minimizing upsets in downstream operations by gradually integrating the regenerant into the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If water is removed from the feed and gas streams before they reach the reactor, then the life expectancy of the reactor catalyst is improved, but separate drier units must be added to the process
Solution Approach 1:
The patent combines the drier units into a single integrated unit with multiple beds that can operate in alternating cycles. Instead of requiring separate drier units for feed and gas streams, the invention uses a unified system where one bed dries while another regenerates, reducing overall process complexity while maintaining catalyst protection.
Solution Approach 2:
The drier unit operates in periodic cycles where different beds alternate between drying mode and regeneration mode. This periodic operation allows continuous water removal from both feed and gas streams while enabling self-regeneration of the drying agent, eliminating the need for external regeneration systems and reducing process complexity.
2Ease of operation
If regenerant is flushed out of the drier after regeneration, then the drier is ready for service, but downstream vessels experience upsets in gas flow and pressure controls
Solution Approach 1:
The patent introduces a transition period where the regenerant is not immediately discharged to the reactor but is first mixed with the feed stream in the drier outlet. This intermediary mixing zone allows gradual introduction of regenerant components, preventing sudden upsets in downstream vessels while ensuring the drier is properly prepared for service.
Solution Approach 2:
Before the regenerant reaches the reactor, the system performs preliminary mixing and dilution in the drier outlet region. This preliminary action prepares the stream by gradually introducing regenerant components, preventing downstream pressure and flow control upsets while maintaining drier operational readiness.
3Duration of action of stationary object
If gas regenerant replaces hydrogen in the reactor, then the drier is regenerated, but the hydrogen:hydrocarbon mole ratio is disrupted and reaction temperatures drop
Solution Approach 1:
The patent extracts the harmful effect of regenerant discharge by separating the regeneration process from the reactor feed stream. The regenerant is discharged to a separate line or burned in a flare system rather than being introduced to the reactor, eliminating disruption to the hydrogen:hydrocarbon mole ratio and reaction temperature while completing drier regeneration.
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 reduces the impact of regenerant upsets on downstream vessels by diluting the used regenerant with incoming reactants, stabilizing gas flow and pressure controls, and extending the life of isomerization reactor catalysts.
Implementation Method 1
water is a poison that can reduce the life expectancy of the reactor catalyst. As such, it is desirable to remove water before the hydrogen rich gas and/or the paraffin feed reaches the reactor. Consequently, typically both the feed and the gas are passed through separate drier units to remove water.
Implementation Method 2
The fluid tapering device may perform at least one of regulating the flow and reducing the pressure of the regenerant to the vessel.
Data Source
AI summary
One exemplary embodiment can be an apparatus for isomerizing a hydrocarbon stream rich in a C4 hydrocarbon and/or at least one of a C5 and C6 hydrocarbon. The apparatus can include:a vessel containing a fluid including at least one reactant; a fluid transfer device receiving the fluid including at least one reactant from the vessel; at least one drier receiving the fluid including at least one reactant from the fluid transfer device; and a reactor communicating with the at least one drier to receive the fluid including at least one reactant. In addition, the at least one drier may communicate with the vessel at least by sending the fluid including at least one reactant or the regenerant through a fluid tapering device for at least one of regulating the flow and reducing the pressure of the regenerant to the vessel.