Distillation Reboiling via Immiscible Heating Medium Pool
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reboilers in distillation processes face scaling issues due to the formation of solids in process fluids, and existing methods require complex equipment designs, high recycle rates of heating mediums, and stripping zones prone to corrosion and safety concerns.
Innovation Solution
The system and method involve direct introduction of the process stream into a liquid pool where it is mixed with a less volatile and immiscible heating medium, allowing partial vaporization within the liquid pool without a stripping zone, and using a pump-around loop to maintain the heating medium's temperature, eliminating the need for pre-treatment and reducing equipment complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mixing zone is used for vaporization outside the liquid pool, then vaporization can occur, but the equipment becomes difficult to design and prone to scaling and plugging
Solution Approach 1:
The patent extracts the vaporization function from a separate mixing zone and integrates it directly into the liquid pool where vaporization occurs naturally during reboiling. This eliminates the need for a complex external mixing zone design while maintaining reliable operation without scaling and plugging issues.
Solution Approach 2:
The patent merges the vaporization function with the liquid pool reboiling process, combining what were previously separate functions (vaporization in mixing zone + separation in liquid pool) into a single integrated process occurring within the liquid pool itself.
2Reliability
If a light heating medium is used to limit temperature difference, then thermal degradation is avoided, but the recycle rate must be at least ten times the process feed rate
Solution Approach 1:
The patent changes the key parameter from using a light heating medium with high recycle rate to using a heavy heating medium with low recycle rate. This parameter change maintains thermal degradation prevention while dramatically improving productivity by reducing the recycle rate requirement.
Solution Approach 2:
The patent applies local quality by allowing different regions of the liquid pool to have different temperatures, with the heating medium at the bottom providing localized heating. This enables effective reboiling without requiring uniform temperature control across the entire system, reducing the need for high recycle rates.
3Reliability
If a stripping zone is used for solids removal, then solids can be separated, but the zone becomes prone to corrosion and presents safety concerns due to higher temperature oil contacting water
Solution Approach 1:
The patent extracts the solids separation function from a dedicated stripping zone and integrates it into the liquid pool where solids naturally settle during reboiling. This eliminates the need for a separate stripping zone, removing the associated corrosion and safety risks while maintaining effective solids separation.
Solution Approach 2:
The patent converts the potential harm of high-temperature oil-water contact in a stripping zone into a benefit by allowing the heavy heating medium to remain at the bottom of the liquid pool, naturally separating from the process stream and preventing harmful interactions while still providing effective heating and solids separation.
4Productivity
If pre-mixing is done at high levels to enhance vaporization, then vaporization efficiency improves, but scaling and fouling increase
Solution Approach 1:
The patent changes the mixing intensity parameter from high-level pre-mixing to gentle mixing within the liquid pool. This parameter change maintains sufficient vaporization efficiency while preventing the excessive mixing that causes scaling and fouling, achieving an optimal balance between productivity and reliability.
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 simplifies the reboiling process, reduces costs, minimizes scaling and fouling, and allows for efficient partial vaporization without the need for high recycle rates or stripping zones, enhancing safety and operational reliability.
Implementation Method 1
mixing the stream with a heating medium
Implementation Method 2
partially vaporize a process stream
Implementation Method 3
The resulting stream is then transferred to the separator vessel in which the vapor is separated
Data Source
AI summary
A system and method to reboil a process or feed water stream in a distillation system does so in a liquid pool zone of a vessel as the stream is removed from a distillation column and comes into contact with a heating medium that is immiscible with and less volatile than the process stream. To keep the pool hot, the heating medium can be recirculated through a heater of a pump-around loop or a heater can be placed in the liquid pool. As the process stream is partially vaporized, any solids present in the process stream together with the unvaporized process or feed water stream move into the heating medium. These solids and unvaporized liquids may be further removed from the heating medium in the pool or in the pump-around loop. The vaporized stream is returned to the distillation column.