Delayed Coking Process with Shield Tray Fractionator
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Solution Overview
Problem
Conventional delayed coking processes for producing anode grade coke result in high recycle ratios, leading to reduced refinery margins, excessive fuel oil generation, and increased operating costs due to high hydrogen consumption, while also generating lower value products and environmental concerns from asphaltene pitch disposal.
Innovation Solution
A system and process that employs a fractionator with a shield tray to separate product vapors from preheated feed, operates at a low recycle ratio of 1.01 to 1.2, and eliminates the need for a quench column, using vacuum residuum or reduced crude oil as feedstock, and conducts thermal cracking in a furnace followed by coking in drums to produce anode grade coke without additional treatment units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional delayed coking process is operated at high recycle ratio to produce anode grade coke, then product quality is maintained, but coke yield increases and distillate yield decreases, reducing refinery margin
Solution Approach 1:
The invention changes the recycle ratio parameter from conventional high values to a specific range of 0.3 to 0.7, which fundamentally alters the yield pattern while maintaining anode grade coke quality. This parameter change enables the system to produce higher distillate yields and lower coke yields compared to conventional operations.
2Reliability
If high recycle ratio is used in delayed coking, then anode grade coke quality is maintained, but heat duty and fuel requirement increase
Solution Approach 1:
By changing the recycle ratio parameter to 0.3-0.7, the invention reduces the total feed charge to the furnace, which directly lowers the heat duty and fuel requirements. The optimized parameter range maintains sufficient residence time and thermal conditions for quality coke production while consuming less energy.
3Reliability
If quench column is used to remove heavy boiling material from product vapors, then product quality is maintained, but fuel oil yield increases, reducing refinery profitability
Solution Approach 1:
The invention changes the operating parameters (recycle ratio, temperature, pressure) to optimize the cracking reactions and product distribution. This parameter optimization reduces the formation of heavy fuel oil components in the first place, thereby lowering fuel oil yield and improving refinery profitability while maintaining product quality.
4Ease of manufacture
If solvent deasphalting process is used to produce anode grade coke, then cost effective operation is achieved, but asphaltene pitch disposal creates environmental concerns
Solution Approach 1:
The invention extracts and eliminates the solvent deasphalting unit and associated asphaltene pitch disposal problems from the process. By using direct delayed coking with optimized parameters, the system achieves cost-effective operation without generating harmful asphaltene pitch waste that requires special disposal.
5Device complexity
If conventional delayed coking is used, then process simplicity is maintained, but excessive fuel oil generation reduces refinery margin
Solution Approach 1:
The invention maintains the simple conventional delayed coking configuration without adding complex treatment units, but optimizes key operating parameters (recycle ratio to 0.3-0.7, temperature, pressure) to fundamentally change the product yield pattern. This reduces fuel oil generation and increases distillate yield, improving refinery margin while keeping the process simple.
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 reduces coke and fuel oil yields, enhances distillate yields, decreases heat load and fuel consumption, and maintains product quality, thereby improving refinery profitability and reducing operating costs while minimizing environmental impact.
Implementation Method 1
the heaviest petroleum fractions are subjected to severe thermal cracking to convert into lighter products like fuel gas, LPG, naphtha, kerosene, gas oil, fuel oil, and coke
Implementation Method 2
a fractionator (19) with a shield tray (30) separator between entry location of product vapor stream (31) and preheated feed stream (18)
Data Source
AI summary
The present invention relates to a novel process with lower recycle ratio while eliminating the need for quench column for production of superior quality coke conforming to specifications of anode grade coke. The process of the present invention enables production of lower amounts of coke and fuel oil yields.