Catalytic Cracking of Distillate Fractions for Higher Olefin and BTX Yield
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Solution Overview
Problem
Existing refinery processes for producing lower carbon olefins and BTX from hydrocarbon-containing feedstock oils are limited in maximizing yield and efficiency, particularly in adapting to different hydrocarbon compositions and cutting temperatures.
Innovation Solution
A process involving the catalytic pyrolysis of hydrocarbon-containing feedstock oil, where the oil is cut into light and heavy distillate fractions, with specific ratios and temperatures, and subjected to sequential catalytic pyrolysis in down-flow and up-flow reactors, along with fluidized bed reactors, to optimize the production of lower carbon olefins and BTX.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrocarbon-containing feedstock oil is processed using conventional refinery processes, then basic organic raw materials can be produced, but the yield is limited and cannot be maximized
Solution Approach 1:
The patent applies parameter changes by optimizing the cutting temperature range (200-400°C) to separate feedstock into light and heavy distillates, adjusting catalyst-to-oil ratios (10:1 to 50:1), and controlling reaction temperatures (500-700°C) in sequential reactors to maximize yield while adapting to different feedstock compositions
Solution Approach 2:
The patent segments the hydrocarbon-containing feedstock oil into light distillate and heavy distillate fractions through cutting at specific temperatures, then processes each fraction through different reactor configurations (down-flow followed by up-flow reactors) to optimize the production of lower carbon olefins and BTX from each segment
2Productivity
If the cutting temperature is adjusted to optimize yield, then production efficiency improves, but the complexity of process control increases
Solution Approach 1:
The patent applies preliminary action by performing the cutting operation at 200-400°C before the main pyrolysis reactions, pre-separating the feedstock into light and heavy distillates with defined composition ranges. This preliminary classification simplifies subsequent process control by establishing predictable feed compositions for each reactor stage
3Productivity
If catalyst ratios are optimized to increase yield, then production of lower carbon olefins and BTX improves, but by-products like dry gas and coke increase
Solution Approach 1:
The patent segments the catalytic conversion process into two sequential reactor stages: a down-flow reactor for initial cracking and an up-flow reactor for further conversion. This segmentation allows optimization of catalyst ratios at each stage, with the up-flow reactor specifically designed to convert intermediate products into lower carbon olefins and BTX while minimizing dry gas and coke formation through controlled catalyst-to-oil ratios
Solution Approach 2:
The patent applies parameter changes by controlling the catalyst-to-oil ratio in the range of 10:1 to 50:1 and maintaining reaction temperatures between 500-700°C in the up-flow reactor. These parameter optimizations maximize the production of desired lower carbon olefins and BTX while suppressing side reactions that would produce unwanted dry gas and coke by-products
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 process enhances the yield of lower carbon olefins and BTX by adjusting catalyst ratios and reactor conditions, reducing by-products like dry gas and coke, and improving the overall economic efficiency of the production process.
Implementation Method 1
the catalytic pyrolysis of hydrocarbon-containing raw oil
Implementation Method 2
introducing a continuous catalyst, the heavy distillate oil and a second catalyst into a second up-flow reactor to perform a third catalytic pyrolysis
Implementation Method 3
cutting the hydrocarbon-containing feedstock oil into a light distillate oil and a heavy distillate oil
Implementation Method 4
the spent catalyst is sent to a regenerator to perform the coke-burning and regeneration
Data Source
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AI summary
A process and apparatus for producing lower carbon olefins and BTX by catalytic pyrolysis of hydrocarbon-containing feedstock oil, and the process comprises the steps: cutting the hydrocarbon-containing feedstock oil into a light distillate oil and a heavy distillate oil; introducing the light distillate oil and a first catalyst into a down-flow reactor to perform a catalytic pyrolysis to produce a stream after the first catalytic pyrolysis; subjecting the stream after the first catalytic pyrolysis to a gas-solid separation to produce a first reaction hydrocarbon product and a first spent catalyst; or, introducing the stream after the first catalytic pyrolysis into a fluidized bed reactor to perform a catalytic pyrolysis, and then subjecting to a gas-solid separation to produce a second reaction hydrocarbon product and a second spent catalyst; introducing a continuous catalyst, the heavy distillate oil and a second catalyst into an up-flow reactor to perform a catalytic pyrolysis, and then subjecting to a gas-solid separation to produce a third reaction hydrocarbon product and a third spent catalyst; separating out lower carbon olefins and light aromatics from reaction hydrocarbon products, and separating out a light olefin fraction, and returning the light olefin fraction to the fluidized bed reactor or the up-flow reactor. The process can significantly increase the yields of lower carbon olefins and light aromatics as well as the economy of the apparatus.