Catalytic Cracking Regenerator Control for Low-Coke Aromatics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The processing of linear hydrocarbon streams with 5 to 18 carbon atoms in catalytic cracking faces an energy deficit due to low coke formation potential, leading to increased production of light olefins and gases, and existing solutions fail to effectively maximize aromatic production without causing thermal shock or energy imbalance.
Innovation Solution
Operating the regenerator at a lower temperature range of 480° C. to 620° C., preferably 500° C. to 600° C., with a catalyst regeneration temperature 40° C. to 100° C. higher than the reaction temperature, and using intermediate pore zeolites to maintain catalyst circulation and energy balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalytic cracking is used with light hydrocarbon streams (5-18 carbon atoms), then the process operates at high reaction temperatures (around 540°C), but the low coke formation potential creates an energy deficit that cannot meet the thermal demand of endothermic cracking reactions
Solution Approach 1:
The patent changes the operating parameters by reducing the regenerator temperature from conventional high temperatures to a lower range (480-620°C), while maintaining the reaction temperature around 540°C. This parameter change allows the system to operate with light hydrocarbon streams that have low coke potential, as the lower regenerator temperature reduces the thermal shock to catalysts and allows for better energy balance while still achieving effective cracking and aromatic production
Solution Approach 2:
The patent introduces dynamic control of the temperature difference between regenerator and reactor, maintaining it at 40-100°C higher than reaction temperature. This dynamic approach allows the system to adapt to varying feed compositions and maintain optimal energy balance, enabling continuous operation with light streams that would otherwise create energy deficits
2Productivity
If high reaction temperatures (around 540°C) are used to process light hydrocarbon streams, then cracking reactions proceed effectively, but the low coke deposition reduces the ability to provide necessary heat for endothermic reactions
Solution Approach 1:
The patent uses an intermediate temperature regime in the regenerator (480-620°C) that acts as a mediator between the reaction temperature (540°C) and the thermal demand. This intermediate temperature allows sufficient heat transfer to meet endothermic reaction requirements while preventing excessive thermal shock and maintaining energy balance with low-coke feedstocks
3Reliability
If conventional regeneration temperatures (around 700°C) are used, then catalyst activity is restored effectively, but thermal shock occurs and energy balance is disrupted for light hydrocarbon processing
Solution Approach 1:
The patent applies preliminary anti-action by pre-heating the regenerator to a controlled lower temperature (480-620°C) before catalyst introduction, and maintaining this temperature regime consistently. This prevents thermal shock to the catalyst during regeneration while still effectively restoring catalyst activity, and avoids the energy balance disruption that occurs with conventional high-temperature 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 enhances aromatic production and octane rating of naphtha while minimizing gas production and catalyst deactivation, optimizing the catalytic cracking process for streams with low coke potential.
Implementation Method 1
The catalyst is burned with air in a regeneration section at temperatures around 700° C.
Implementation Method 2
The cracking reactions are endothermic, and the increased severity of the reaction makes it difficult to meet this energy demand.
Implementation Method 3
The heated catalyst can be returned to the reaction section and provide the necessary heat for endothermic reactions.
Implementation Method 4
The used catalyst must contain a molecular sieve with pores of intermediate size.
Data Source
AI summary
The present invention addresses to a process for the production of aromatic compounds from streams containing linear chains with 5 to 18 carbon atoms, of fossil or renewable origin, and application in the field of catalytic cracking aiming at a regenerator operation at much lower temperature, between 480° C. and 620° C., preferably the temperature should be between 500° C. and 600° C. The coked catalyst generated by the cracking of light streams with low potential for delta coke generation can have the combustion effected at a lower temperature. The regeneration temperature must be at least 40° C. and at most 100° C. higher than the reaction temperature, keeping the catalyst circulation high to maintain the energy balance in the reaction section. The minimum regeneration temperature can be ensured by installing an air preheating furnace before entering the regenerator and passing through the air distributor inside the regenerator. The used catalyst must contain zeolite with pores of intermediate size. Such conditions greatly favor the production of aromatics and the octane rating of the produced naphtha.