Heavy Oil Hydrocracking Process Using Two-Stage Thermo-Catalytic Conversion
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Solution Overview
Problem
Current processes for converting heavy hydrocarbonaceous fractions, particularly those boiling above 1000° F, face challenges in achieving high conversion to stable, quality products due to instability and condensation reactions, leading to low-value fuel oil and coke formation, with high investment and operating costs, and difficulties with high metal content feedstocks.
Innovation Solution
A two-stage close-coupled thermo-catalytic and catalytic-hydrotreating process using a liquid catalyst precursor that converts to very fine catalyst particles, minimizing solid impact and controlling asphaltene condensation, with coal added to promote and absorb heavy oil metals, and a hydrotreating zone for stabilization and heteroatom removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If severe conditions are applied to achieve high conversion, then lighter fractions are produced, but thermally cracked fragments and unstable asphaltenes form leading to condensation reactions and coke formation
Solution Approach 1:
The conversion process is divided into two distinct stages: a thermal cracking stage operating at severe conditions to achieve high conversion, followed by a catalytic stabilization stage to control condensation reactions. This segmentation allows each stage to be optimized independently, resolving the contradiction between high conversion and product stability.
Solution Approach 2:
A catalyst is introduced as an intermediary substance in the second stage to mediate the stabilization of thermally cracked fragments. The catalyst prevents unwanted condensation reactions and coke formation while preserving the benefits of high conversion achieved in the first stage.
2Productivity
If slurry reactor technology with dispersed catalyst systems is used, then high conversion is achieved, but investment and operating costs increase
Solution Approach 1:
The complex dispersed catalyst system is replaced by extracting the essential function into a simpler two-stage process where thermal cracking is separated from catalytic stabilization. This reduces device complexity while maintaining high conversion through the sequential arrangement of simpler units.
Solution Approach 2:
The process changes operating parameters between stages: severe conditions (high temperature) in the first stage for maximum conversion, then milder catalytic conditions in the second stage for stabilization. This parameter modulation achieves high conversion without requiring complex dispersed catalyst systems throughout.
3Manufacturing precision
If multi-stage conversion processes are applied, then product quality improves, but process complexity and costs increase
Solution Approach 1:
The multi-stage process is segmented into exactly two functional stages: thermal cracking and catalytic stabilization. This minimal segmentation achieves product quality improvement without excessive complexity, as each stage has a single, well-defined function.
Solution Approach 2:
Each stage is designed with local quality optimized for its specific function: the first stage is optimized for maximum cracking activity under severe conditions, while the second stage is optimized for stabilization and coke prevention. This localized optimization achieves high product quality without requiring complex integration across multiple stages.
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 process achieves high yields of high-quality products boiling below 1000° F, with reduced heteroatom content and condensed molecules, making them more suitable for further processing into finished fuels, while minimizing coke formation and metal fouling.
Implementation Method 1
The liquid catalyst precursor converts into very fine catalyst particles under the conditions in the thermo-catalytic zone
Implementation Method 2
coal added to promote and absorb heavy oil metals
Implementation Method 3
convert a significant amount of hydrocarbons in the feedstock boiling above 1000° F. to hydrocarbons boiling below 1000° F
Implementation Method 4
catalytic-hydrotreating process... hydrotreating zone for stabilization and heteroatom removal
Data Source
AI summary
A process for the production of high yields of high quality products from heavy hydrocarbonaceous feedstock comprising a two-stage, close-coupled process. The first stage comprises a thermo-catalytic zone into which is introduced a mixture comprising the feedstock, coal, a liquid catalyst precursor, and hydrogen. The second, close-coupled stage comprises a catalytic-hydrotreating zone into which substantially all the effluent from the first stage is directly passed and processed under hydrotreating conditions.