Integrated Hydrotreating Slurry Hydrocracking Coke Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Slurry hydrocracking processes face challenges in achieving high conversion of heavy hydrocarbons while minimizing coke formation, as higher conversion levels often result in increased coke precipitation due to the inherent limitations of catalyst effectiveness and fouling propensity.
Innovation Solution
Integrating a hydrotreating zone before the slurry hydrocracking zone to pre-treat heavy hydrocarbon feeds, using a hydrotreating catalyst with higher hydrogenation activity to reduce coke precursors and enhance hydrogen content, thereby allowing for higher conversion without severe coking by operating at lower hydrocracking severity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher conversion levels are pursued in slurry hydrocracking, then product yield is improved, but coke formation increases
Solution Approach 1:
The hydrocracking process is divided into multiple reactors arranged in series. The first reactor operates at lower severity to convert lighter fractions, while subsequent reactors handle progressively heavier fractions at adjusted severity levels. This segmentation allows high overall conversion without excessive coke formation in any single reactor, as each reactor operates within optimal coke control parameters.
2Productivity
If catalyst loading is increased to control coke formation, then conversion is improved, but process complexity and cost increase
Solution Approach 1:
Different catalysts with optimized properties are used in different reactors of the series. Each catalyst is specifically tailored to the local conditions (feed composition, temperature, pressure) of its respective reactor. This local optimization allows effective coke control without requiring uniformly high catalyst loading throughout the system, thereby reducing overall complexity.
3Reliability
If higher reactor pressure is applied to reduce coke formation, then conversion control is improved, but energy consumption increases
Solution Approach 1:
The process employs dynamic pressure management where each reactor in the series operates at a different pressure level. Pressure is progressively adjusted across the reactor sequence to optimize the balance between conversion and coke control at each stage. This dynamic approach avoids maintaining uniformly high pressure throughout the system, thereby reducing overall energy consumption while maintaining reliable coke control.
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 achieves high overall conversion (up to 97%) with reduced coke formation, improved product quality, and increased hydrogen consumption, facilitating easier downstream processing and reducing chemical hydrogen requirements.
Implementation Method 1
using a hydrotreating catalyst with higher hydrogenation activity to reduce coke precursors and enhance hydrogen content
Implementation Method 2
In SHC, these feedstocks are converted in the presence of hydrogen and solid catalyst particles (e.g., as a particulate metallic compound such as a metal sulfide) in a slurry phase
Data Source
AI summary
Slurry hydrocracking processes are described. The methods include hydrotreating a heavy residual hydrocarbon feed in a hydrotreating zone under residual hydrotreating conditions to form a hydrotreated effluent. The hydrotreated effluent is separated in an first separator to form an overhead vapor stream and a bottoms stream. The bottoms stream is hydrocracked in a slurry hydrocracking zone under slurry hydrocracking conditions. The effluent from the slurry hydrocracking zone is fractionated in a fractionation zone into at least two streams. Slurry hydrocracking apparatus is also described.