Catalyst Regeneration System with Variable Oxygen Carrier Fluid
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Solution Overview
Problem
Fluid catalytic crackers (FCC) generate undesirable byproducts like nitrogen oxides (NOx) during catalyst regeneration, which need to be reduced to meet environmental regulations.
Innovation Solution
A catalyst regeneration system that includes a dense phase catalyst bed with a spent catalyst distributor and fluid introduction nozzles, using a carrier fluid with variable oxygen content to combust coke deposits, reducing NOx formation through specific combustion reactions and CO oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If combustion process is used to regenerate catalyst and remove coke, then catalyst activity is restored, but nitrogen oxides (NOx) are generated as undesirable byproducts
Solution Approach 1:
The patent changes the oxygen concentration parameter in the combustion process by introducing a oxygen-enriched stream (containing 2-11 wt% oxygen) to the dense phase catalyst bed. This parameter modification allows combustion to proceed at lower temperatures and with better control, reducing NOx formation while maintaining effective coke removal and catalyst regeneration
Solution Approach 2:
The patent introduces an oxygen-enriched gas stream (more concentrated than ambient air) to accelerate the combustion of coke deposits on the catalyst. This strong oxidant approach enables more efficient coke removal at controlled temperatures, preventing excessive NOx generation while restoring catalyst activity effectively
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
The system effectively regenerates catalysts while minimizing NOx production, achieving NOx concentrations below 50 ppm in the flue gas and maintaining operational temperature limits.
Implementation Method 1
At least a portion of the carbon deposited on the coked catalyst particles can be combusted to provide a flue gas, heat, and a regenerated catalyst
Implementation Method 2
the coke is combusted, oxidized, and/or converted to one or more waste gases
Implementation Method 3
reducing NOx formation through specific combustion reactions and CO oxidation
Data Source
AI summary
Systems and methods for regenerating a spent catalyst are provided. The method can include heating a hydrocarbon and a coke precursor in the presence of catalyst particles to provide a cracked hydrocarbon product and coked catalyst particles. The cracked hydrocarbon product and the coked catalyst particles can be selectively separated to provide a hydrocarbon product and coked catalyst particles. The coked catalyst particles can be mixed with a carrier fluid to provide a mixture. The mixture can be introduced to an upper surface of a dense phase catalyst zone disposed within a regenerator. A gas can be introduced to a lower zone of the dense phase catalyst zone. At least a portion of the carbon deposited on the coked catalyst particles can be combusted to provide a flue gas, heat, and a regenerated catalyst.