Olefin Production via Catalyst Reduction Pretreatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The circulating fluidized bed process for olefin production has a high hydrocarbon conversion rate but low olefin selectivity due to rapid byproduct generation and catalyst deactivation, leading to inefficient energy use and equipment costs.
Innovation Solution
A method involving reduction pretreatment of an alumina-type catalyst with gases like hydrogen or carbon monoxide, followed by dehydrogenation in the Fast Fluidization Regime, to enhance olefin selectivity and yield, while reducing byproduct generation and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the circulating fluidized bed process is used to achieve short contact time between hydrocarbon and catalyst, then the hydrocarbon conversion rate is improved, but the olefin selectivity deteriorates due to rapid byproduct generation
Solution Approach 1:
The catalyst undergoes reduction pretreatment before the dehydrogenation reaction to transform its surface properties in advance. This preliminary reduction modifies the catalyst's active sites and electronic structure, enabling it to selectively promote olefin formation while suppressing byproduct generation during the subsequent short-contact dehydrogenation process
Solution Approach 2:
The catalyst's chemical state is changed through reduction pretreatment, transforming it from an oxidized to a reduced state. This parameter change in the catalyst's oxidation state fundamentally alters its reactivity and selectivity characteristics, allowing high olefin selectivity to be achieved during the brief contact period
2Productivity
If the catalyst operates for extended periods to maintain continuous production, then the productivity is improved, but catalyst deactivation and excessive coke generation occur, increasing regeneration energy consumption
Solution Approach 1:
The catalyst is reduced and activated before each dehydrogenation cycle to ensure optimal activity from the start. This preliminary preparation maximizes the catalyst's effective operating period and reduces the frequency and intensity of regeneration operations, thereby lowering energy consumption
Solution Approach 2:
The circulating fluidized bed system enables continuous catalyst circulation between the reactor and regenerator. The catalyst automatically undergoes regeneration by burning off coke deposits, then returns to the reactor for another cycle of dehydrogenation, maintaining continuous productivity with optimized energy input
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 increases olefin selectivity, decreases byproduct formation, reduces energy costs, and lowers equipment investment by optimizing catalyst efficiency and reaction conditions.
Implementation Method 1
reduction pretreatment of an alumina-type catalyst with gases like hydrogen or carbon monoxide
Implementation Method 2
dehydrogenation in the Fast Fluidization Regime, to enhance olefin selectivity and yield
Implementation Method 3
Fast Fluidization Regime
Data Source
AI summary
Disclosed is an olefin production method including: pretreating a catalyst by providing reduction gas to an alumina type catalyst to produce olefin from the hydrocarbon including not less than 90 wt % of LPG (Stage 1); producing the olefin by providing the catalyst pretreated at Stage 1 into Riser of Fast Fluidization Regime to dehydrogenate the hydrocarbon (Stage 2); separating the mixture of the produced propylene and the catalyst used at Stage 2, and regenerating the separated catalyst (Stage 3); and recycling the catalyst regenerated at Stage 3 to the process of Stage 1 (Stage 4).