Fluidized Bed Combustion Device for Light Olefin Production
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Solution Overview
Problem
The thermal energy produced during catalyst reactivation in fluidized-bed catalytic cracking units is insufficient to meet the energy demand, leading to hotspot formation and catalyst deactivation, and existing methods for supplementing energy, such as torch oil injection, result in incomplete combustion and equipment damage.
Innovation Solution
A high-performance combustion device with a plurality of lances for injecting heating oil, which is burned efficiently to complement the energy demand, avoiding hotspots and complete combustion within the fluidized bed, using a combination of steam and air to ensure thorough mixing and rapid vaporization of oil droplets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If heating oil is injected to supplement energy demand, then energy supply is improved, but hotspots and catalyst deactivation occur
Solution Approach 1:
The combustion device is divided into multiple injection zones with several lances positioned at different locations within the fluidized bed. This segmentation distributes the heating oil injection points throughout the bed volume, preventing concentration of energy input in a single location and thereby avoiding hotspot formation while still meeting the overall energy demand.
Solution Approach 2:
Different regions of the fluidized bed receive heating oil through strategically positioned lances to create localized combustion zones. The injection strategy ensures that each local region receives appropriate energy supplementation without creating excessive temperature concentrations, maintaining uniform heat distribution across the bed while preventing catalyst deactivation.
2Use of energy by moving object
If heating oil is burned to meet energy demand, then thermal energy is improved, but incomplete combustion and equipment damage occur
Solution Approach 1:
Heating oil is preheated before injection into the fluidized bed, ensuring it reaches optimal temperature for complete combustion. This preliminary heating action prepares the fuel for efficient burning, reducing the risk of incomplete combustion and associated equipment damage while maximizing thermal energy generation.
Solution Approach 2:
The fluidized bed catalyst acts as an intermediary medium that facilitates complete combustion of heating oil. The catalyst particles provide a large surface area for heat transfer and promote thorough oxidation of the injected oil, ensuring complete combustion and preventing the formation of harmful byproducts that could damage equipment.
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 solution ensures complete combustion of heating oil, maintaining heat balance, minimizing catalyst deactivation and equipment damage, while promoting uniform energy distribution and efficient heat exchange within the combustion device.
Implementation Method 1
rapid vaporization of oil droplets
Implementation Method 2
burning of which is able to complement the energy demand
Implementation Method 3
using a combination of steam and air to ensure thorough mixing and rapid vaporization of oil droplets
Implementation Method 4
efficient heat exchange within the combustion device
Implementation Method 5
promoting uniform energy distribution and efficient heat exchange
Data Source
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AI summary
The present invention relates to a combustion device for meeting the energy demand of processes for producing light olefins (ethylene and propene) in fluidized-bed catalytic cracking units. Said combustion device is used to burn heating oil and to keep burning the coke deposited on the catalyst, with a view to heating it to meet the energy demand of the reaction, combustion taking place smoothly and uniformly, preventing the formation of hotspots within the catalytic bed and in the dilute phase following combustion (afterburning), thereby minimizing deactivation of the catalyst and the risk of damage to the equipment inside of the combustion device.