Hydrocracking Reactor Segmentation for Heavy Metal Deposit Control
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Solution Overview
Problem
The petroleum industry faces challenges in processing heavy oil feeds due to high concentrations of heavy metals like nickel and vanadium, which lead to deposition in equipment, reducing reaction volume and efficiency.
Innovation Solution
A process involving multiple contacting and separation zones, where a hydrogen-containing gas, heavy oil feedstock, and slurry catalyst are combined under hydrocracking conditions, with the use of water or steam injection to control heavy metal deposits, and recycling of non-volatile streams to reduce catalyst overload and deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heavy oil feedstock is processed using conventional hydrocracking methods, then upgraded products are produced, but heavy metal deposits accumulate in equipment reducing reaction volume and run time
Solution Approach 1:
The reactor is divided into multiple contacting zones (first contacting zone, second contacting zone, etc.) with different temperature profiles. The first zone operates at lower temperature to minimize heavy metal deposition, while subsequent zones operate at progressively higher temperatures to maintain conversion efficiency. This segmentation allows the system to achieve both reduced deposition and sustained productivity.
Solution Approach 2:
The patent implements a temperature gradient across different contacting zones, with the first zone operating at a lower temperature than subsequent zones. This parameter change in temperature distribution allows the system to reduce heavy metal deposition in the front-end zone while maintaining effective hydrocracking in downstream zones, thereby extending reactor run time without sacrificing productivity.
2Productivity
If heavy oil feedstock is processed to achieve high conversion, then more upgraded products are produced, but heavy metal deposition increases reducing available reaction volume
Solution Approach 1:
The reaction system is segmented into multiple contacting zones with progressively increasing temperatures. The first zone operates at lower temperature to minimize deposition, preserving reaction volume, while subsequent zones operate at higher temperatures to drive conversion. This segmentation allows the system to maintain both high conversion and adequate reaction volume.
Solution Approach 2:
Different temperature conditions are applied to different zones within the reactor. The first contacting zone has a lower temperature profile optimized for minimizing heavy metal deposition, while subsequent zones have higher temperature profiles optimized for conversion. This local quality differentiation allows simultaneous achievement of high conversion and preserved reaction volume.
3Productivity
If slurry catalyst is used for hydrocracking, then conversion efficiency is improved, but catalyst overload and deposition occur reducing process performance
Solution Approach 1:
The catalyst is distributed across multiple contacting zones rather than concentrated in a single zone. The first zone receives catalyst at lower temperature, reducing deposition and overload, while subsequent zones receive catalyst at higher temperatures to maintain conversion efficiency. This segmented distribution improves both conversion efficiency and process reliability.
Solution Approach 2:
The temperature parameter is varied across different contacting zones to optimize catalyst performance. Lower temperature in the first zone reduces catalyst deposition and overload, while higher temperatures in subsequent zones maintain conversion efficiency. This parameter change strategy enhances both productivity and reliability.
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 effectively reduces heavy metal deposits in equipment, prolongs reactor run time, and maintains reaction efficiency by controlling temperature and catalyst distribution, achieving a significant decrease in solid deposits and maintaining process performance.
Implementation Method 1
combining a hydrogen containing gas feed, a heavy oil feedstock, and a slurry catalyst in a first contacting zone under hydrocracking conditions to convert at least a portion of the heavy oil feedstock to upgraded products
Implementation Method 2
combining a hydrogen containing gas feed, a heavy oil feedstock, and a slurry catalyst in a first contacting zone under hydrocracking conditions
Implementation Method 3
water and/or steam is mixed with the heavy oil feedstock and preheated prior to feeding to the first contacting zone
Implementation Method 4
water and/or steam is injected into the first contacting zone
Implementation Method 5
in the separation zone, removing the upgraded products with the hydrogen containing gas as an overhead stream, and removing the slurry catalyst and the unconverted heavy oil feedstock as a non-volatile stream
Data Source
AI summary
Systems and methods for hydroprocessing a heavy oil feedstock with reduced heavy oil deposits, the system employs a plurality of contacting zones and separation zones zone under hydrocracking conditions to convert at least a portion of the heavy oil feedstock to lower boiling hydrocarbons, forming upgraded products, wherein the first contacting zone is operated at a temperature of at least 10° F. lower than a next contacting zone. The contacting zones operate under hydrocracking conditions, employing a slurry catalyst for upgrading the heavy oil feedstock, forming upgraded products of lower boiling hydrocarbons. In the separation zones, upgraded products are removed overhead and, optionally, further treated in an in-line hydrotreater. At least a portion of the non-volatile fractions recovered from at least one of the separation zones is recycled back to the first contacting zone in the system.