Vent Gas Dioxin Removal via Halogen Adsorption and Thermal Mixing
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Solution Overview
Problem
Existing hydrocarbon conversion process regeneration systems fail to effectively remove undesirable compounds like dioxins and furans from vent gas streams, which can have a negative environmental impact.
Innovation Solution
A process that involves passing a vent gas stream from a catalyst regeneration zone through a halogen removal zone with an adsorbent to adsorb halogens, and then combining it with a heated stream to create a combined stream with a temperature above 150°C and an oxygen content of at least 1% by volume, which is then passed through an elimination zone with a catalyst to remove dioxins and furans.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the vent gas stream is directly discharged from the catalyst regeneration zone, then the process is simple and cost-effective, but undesirable compounds like dioxins and furans are released into the atmosphere causing environmental harm
Solution Approach 1:
The process divides the vent gas treatment into distinct functional zones: a halogen removal zone with adsorbent, a mixing zone where vent gas combines with heated stream, and an elimination zone with catalyst. This segmentation allows each zone to address specific contaminants systematically, transforming harmful dioxins and furans through staged treatment rather than a single complex operation.
Solution Approach 2:
The patent introduces an intermediary heated stream (from heater or cooler) that serves as a mediator between the vent gas and the elimination zone catalyst. This intermediary stream provides the necessary temperature and oxygen content to enable catalytic destruction of dioxins and furans, facilitating the transformation without requiring direct modification of the vent gas composition.
2Object-affected harmful factors
If additional treatment zones are added to remove dioxins and furans, then environmental compliance is improved, but the equipment complexity and capital cost increase
Solution Approach 1:
The elimination zone catalyst serves multiple functions simultaneously: it destroys dioxins and furans, requires specific temperature and oxygen content that are provided by the combined stream, and can operate with existing heater infrastructure. This multi-functionality reduces the need for separate dedicated treatment systems, lowering overall equipment complexity while maintaining effective contaminant removal.
Solution Approach 2:
The patent achieves effective dioxin and furan removal by changing physical and chemical parameters of the vent gas stream - specifically temperature (above 150°C) and oxygen content (at least 1% by volume). These parameter changes enable the elimination zone catalyst to function effectively, providing a straightforward chemical solution rather than complex physical separation or absorption systems.
3Reliability
If the vent gas stream temperature is increased to destroy dioxins and furans, then catalytic destruction effectiveness is improved, but energy consumption increases
Solution Approach 1:
The patent merges the vent gas stream with a heated stream from the heater or cooler in a mixing zone, creating a combined stream that achieves the necessary temperature for catalytic destruction. This merging approach allows the system to utilize existing thermal energy from the heater infrastructure rather than requiring separate high-energy heating of the vent gas, thereby reducing overall energy consumption while maintaining catalytic effectiveness.
Solution Approach 2:
The system uses its own heater infrastructure to provide the necessary thermal energy for dioxin and furan destruction. The heated stream from the heater or cooler serves the dual purpose of maintaining catalyst regeneration temperature and providing the thermal energy needed for elimination zone catalysis, making the system self-sufficient and avoiding additional external energy inputs.
4Use of energy by moving object
If existing heater operations are used for vent gas heating, then energy efficiency is improved, but the heater throughput is limited by regeneration conditions
Solution Approach 1:
The patent introduces dynamic control of stream combination ratios in the mixing zone, allowing the system to adjust the proportion of vent gas to heated stream based on operational conditions. This dynamic adjustment enables the heater to operate at optimized throughput levels while still meeting the temperature and oxygen content requirements for dioxin and furan elimination, effectively decoupling heater capacity limits from elimination zone performance requirements.
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 effectively destroys dioxins and furans, preventing their discharge into the atmosphere and improving existing heater operations by increasing throughput, thus avoiding the need for additional expensive treatments and altering temperature and oxygen content without additional heating costs.
Implementation Method 1
passing a vent gas stream from a catalyst regeneration zone including halogen and at least one of a dioxin and a furan through a halogen removal zone having an adsorbent to adsorb at least one halogen
Implementation Method 2
the combined stream passes through an elimination zone comprising a catalyst to remove at least a portion of at least one of a dioxin and a furan
Implementation Method 3
combining the vent gas stream from the halogen removal zone with a second stream from a heater from the catalyst regeneration zone or a cooler for the vent gas stream from the catalyst regeneration zone wherein the second stream is heated by the vent gas stream to obtain a combined stream at a temperature of above 150°C and an oxygen content no less than 1% by volume
Data Source
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AI summary
One exemplary embodiment is a process for removing at least one of a dioxin and a furan. The process can include: (a) passing a first stream from a catalyst regeneration zone (200) comprising halogen and at least one of a dioxin and a furan through a halogen removal zone (400) comprising an adsorbent to adsorb at least one halogen; and (b) combining the first stream from the halogen removal zone (400) with a second stream from a heater (304) from the catalyst regeneration zone (200) or a cooler (244) for the first stream to obtain a combined stream (404) at a temperature of above 150°C and an oxygen content no less than 1%.