Fluidized Catalytic Conversion for Propylene Yield
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Solution Overview
Problem
The petrochemical industry faces challenges in maximizing the production of propylene and improving the selectivity of ethylene and propylene, particularly due to the limitations of traditional steam cracking methods which require high energy consumption and have difficulty in efficiently utilizing heavy crude oil.
Innovation Solution
A fluidized catalytic conversion method is introduced, which involves a two-stage reaction process using a catalytic conversion catalyst at high temperatures. The method includes introducing a heavy feedstock oil into a first reaction zone and a hydrocarbon oil feedstock with high olefin content into a second reaction zone, followed by recycling olefin-rich streams and butylene to enhance propylene production and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam cracking method is used to prepare ethylene and propylene, then the production of ethylene and propylene can be achieved, but the energy consumption is high and the utilization of heavy crude oil is limited
Solution Approach 1:
The patent changes the reaction parameters by using catalytic cracking instead of steam cracking, operating at lower temperatures (500-700°C) compared to steam cracking (800-900°C), thereby reducing energy consumption while maintaining propylene production efficiency
Solution Approach 2:
The patent introduces a catalyst as an intermediary substance to facilitate the cracking reaction of heavy hydrocarbons into ethylene and propylene, enabling the process to proceed at lower temperatures and improving the utilization of heavy crude oil
2Quantity of substance
If traditional cracking method is used with heavy crude oil, then the processing of heavy feedstock is possible, but the selectivity of ethylene and propylene is low
Solution Approach 1:
The patent optimizes reaction parameters including temperature (500-700°C), pressure, and catalyst-to-oil ratio to enhance the selectivity toward ethylene and propylene while processing heavy feedstock, achieving higher manufacturing precision
Solution Approach 2:
The catalyst acts as an intermediary that selectively promotes the formation of ethylene and propylene from heavy hydrocarbons, improving selectivity by facilitating specific reaction pathways while processing large quantities of heavy feedstock
3Productivity
If C4 fraction is recycled for further cracking to improve conversion rate, then the conversion rate of olefin increases, but the ethylene/propylene ratio becomes low and cannot be flexibly adjusted
Solution Approach 1:
The patent segments the reaction process into multiple zones with different functions: a first reaction zone for initial cracking and a second reaction zone for further conversion of C4 fraction, allowing independent control of each zone to optimize both conversion rate and product ratio
Solution Approach 2:
The patent introduces dynamic control by adjusting the flow rates and residence times in different reaction zones, enabling flexible adjustment of the ethylene/propylene ratio while maintaining high overall conversion rate through real-time parameter optimization
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 method effectively increases the yield of propylene while maintaining high ethylene yield and selectivity, and reduces the production of dry gas, thereby improving the overall efficiency and resource utilization in petrochemical processes.
Implementation Method 1
contacting with a catalytic conversion catalyst having a temperature of 650 °C or higher, and reacting under first catalytic conversion reaction conditions
Implementation Method 2
reacting at a reaction temperature of 500-800 °C, a reaction pressure of 0.05-1 MPa, a reaction time of 0.01-100 seconds
Implementation Method 3
separating the effluent of the fluidized catalytic conversion reactor to obtain reaction products and a spent catalyst
Implementation Method 4
carrying out a first separation on the reaction products to obtain ethylene, propylene, butylene, a first catalytic cracking distillate oil and a second catalytic cracking distillate oil
Data Source
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AI summary
Disclosed is a fluidized catalytic conversion method for maximizing the production of propylene, comprising the steps of: 1) contacting a heavy feedstock oil with a catalytic conversion catalyst having a temperature of 650 °C or higher for reaction; 2) contacting a hydrocarbon oil feedstock having an olefin content of 50 wt% or more with the catalytic conversion catalyst after the reaction of step 1); 3) separating a first catalytic cracking distillate oil and a second catalytic cracking distillate oil from the resulting reaction products; 4) separating an olefin-rich stream from the first catalytic cracking distillate oil; and 5) recycling the olefin-rich stream. The method can effectively improve the yield of propylene and realize an effective utilization of petroleum resources.