Integrating Hydrocracking and Coking Units to Mitigate Fouling
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Solution Overview
Problem
Coker units and residue hydrocracking units operate as separate systems, leading to frequent shutdowns due to fractionation section fouling, which requires costly cleaning and reduces refinery throughput, as they process vacuum residue material independently without effective fouling mitigation.
Innovation Solution
Integration of residue hydrocracking and coker units to share a common fractionation system, utilizing a straight run vacuum residue to mitigate fouling, allowing for continuous operation with reduced capital and environmental impact, and a smaller footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coker units and residue hydrocracking units operate as separate systems with dedicated fractionation sections, then each unit can be independently operated and maintained, but the fractionation section fouls frequently requiring shutdowns for cleaning
Solution Approach 1:
The patent merges the fractionation sections of the coker unit and residue hydrocracking unit into a single integrated system. The vacuum tower serves both units, with the hydrocracker effluent fed to the vacuum tower along with straight run vacuum residue. This combination allows continuous operation by using the fresh vacuum residue to prevent fouling while processing hydrocracker effluent, eliminating the need for periodic shutdowns to clean the fractionation section.
Solution Approach 2:
The patent introduces straight run vacuum residue as an intermediary substance that mitigates fouling in the fractionation section. This fresh vacuum residue acts as a cleaning agent or mediator that prevents the accumulation of fouling materials in the vacuum tower, allowing the system to operate continuously without shutdowns for maintenance.
2Adaptability or versatility
If separate fractionation sections are used for coker and hydrocracking units, then each unit has dedicated processing capability, but capital expenses and plot space footprint increase
Solution Approach 1:
The patent makes the vacuum tower universal by having it serve dual functions: processing hydrocracker effluent and processing straight run vacuum residue. This multi-functional vacuum tower replaces what would traditionally be two separate fractionation sections, reducing capital expenses and plot space footprint while maintaining the ability to process different feedstocks effectively.
3Reliability
If straight run vacuum residue is added to the fractionation section to mitigate fouling, then fouling is reduced, but the unit cannot operate without sufficient vacuum residue storage
Solution Approach 1:
By merging the processing streams of the hydrocracker and the vacuum residue feed into a single integrated fractionation system, the patent creates a synergistic effect where the hydrocracker effluent and straight run vacuum residue work together to prevent fouling. This integration allows the system to operate flexibly as long as hydrocracking is occurring, generating the effluent needed for fouling mitigation, rather than requiring large storage facilities.
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 integrated process enhances operating factors, reduces downtime, lowers capital expenses, and minimizes the CO2 footprint by leveraging the solubility effect of straight run vacuum residue to prevent fouling, thereby improving refinery efficiency and reducing equipment needs.
Implementation Method 1
residue hydrocracking reactor system configured to receive a hydrocarbon feedstock, comprising a residuum hydrocarbon fraction, and to convert hydrocarbons therein
Implementation Method 2
separating the hydrocracked effluent into one or more distillate hydrocarbon fractions and a vacuum residue fraction
Implementation Method 3
separation system configured for receiving and separating the hydrocracked effluent
Implementation Method 4
coker system configured for receiving and converting the vacuum residue fraction into a coke product and a coker vapor effluent
Implementation Method 5
separating the coker vapor effluent in the flash drum to recover a coker liquid fraction and a coker vapor fraction
Implementation Method 6
hydroprocessing reactor system configured for hydroprocessing the one or more distillate hydrocarbon fractions
Data Source
AI summary
Integrated processes and systems for the production of distillate hydrocarbons and coke. The process may include feeding a hydrocarbon feedstock, comprising a residuum hydrocarbon fraction, to a residue hydrocracking reactor system to convert hydrocarbons therein, producing a hydrocracked effluent. The hydrocracked effluent may then be fed to a separation system, separating the hydrocracked effluent into one or more distillate hydrocarbon fractions and a vacuum residue fraction. The vacuum residue fraction may be fed to a coker system, converting the vacuum residue fraction into a coke product and a coker vapor effluent, recovering the coke product, and feeding the coker vapor effluent to the separation system. The one or more distillate hydrocarbon fractions are hydroprocessed to produce a hydroprocessed effluent, and the hydroprocessed effluent is separated into product distillate hydrocarbon fractions.