Hydroprocessing Catalyst Pore Size and Hydrogen Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for hydroprocessing heavy hydrocarbon oils face challenges in efficiently converting high-boiling point fractions into lower boiling point products while minimizing the formation of C4- hydrocarbon compounds and coke byproducts, and in achieving improved catalyst lifetime and selectivity.
Innovation Solution
A process involving the hydroprocessing of a combined feedstock comprising a heavy oil feed and a solvent under specific conditions, including a partial pressure of hydrogen of 1000 psia or less, a temperature of at least 360°C, and a liquid hourly space velocity of the combined feedstock boiling above 1050°F, using a hydroprocessing catalyst with a median pore size of 85-120 Å, and incorporating solvent deasphalting to separate molecules with low hydrogen-to-carbon ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional hydroprocessing is used to convert heavy hydrocarbon fractions, then sulfur and nitrogen removal is achieved, but C4- hydrocarbon compounds and coke byproducts are formed excessively
Solution Approach 1:
The patent applies parameter changes by controlling the hydrogen partial pressure to be relatively low (1000 psia or less) while maintaining a temperature of at least 360°C. This specific parameter combination allows for effective sulfur and nitrogen removal through hydroprocessing while minimizing excessive cracking reactions that would produce C4- hydrocarbons and coke byproducts. The liquid hourly space velocity is also optimized to balance conversion efficiency with selectivity.
2Productivity
If high conversion rates are achieved in hydroprocessing, then heavy oil fractions are converted to lower boiling point products, but catalyst lifetime is reduced
Solution Approach 1:
The patent resolves this contradiction by optimizing the hydrogen partial pressure to 1000 psia or less, which is sufficient to maintain catalyst activity and enable high conversion rates of heavy oil fractions to lower boiling point products, while avoiding conditions that would lead to rapid catalyst deactivation. The temperature of at least 360°C ensures adequate reaction kinetics for high conversion without excessive severity that would shorten catalyst life.
3Manufacturing precision
If selective hydroprocessing is performed to produce specific products, then product selectivity is improved, but hydrogen consumption increases
Solution Approach 1:
The patent achieves improved product selectivity with controlled hydrogen consumption by maintaining a hydrogen partial pressure of 1000 psia or less. This parameter setting provides sufficient hydrogen for the required hydroprocessing reactions to achieve selectivity for desired lower boiling point products, while avoiding excessive hydrogen partial pressure that would drive non-selective hydrogenation reactions and increase overall hydrogen consumption.
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 achieves high conversion rates of heavy oil fractions with reduced sulfur and nitrogen content, extended catalyst lifetime, and improved selectivity, producing a bottoms product with increased wax content and low sulfur fuel oil, while minimizing hydrogen consumption and coke formation.
Implementation Method 1
exposing a combined feedstock comprising a heavy oil feed component and a solvent component to a hydroprocessing catalyst under effective hydroprocessing conditions to form a hydroprocessed effluent
Implementation Method 2
incorporating solvent deasphalting to separate molecules with low hydrogen-to-carbon ratios
Implementation Method 3
hydroprocessing of a combined feedstock comprising a heavy oil feed and a solvent under specific conditions, including a partial pressure of hydrogen of 1000 psia or less
Data Source
AI summary
Heavy oil feeds are hydroprocessed in the presence of a solvent under conditions that provide a variety of benefits. The solvent can be an added solvent or a portion of the liquid effluent from hydroprocessing. The processes allow for lower pressure processing of heavy oil feeds for extended processing times or extended catalyst lifetimes be reducing or mitigating the amount of coke formation on the hydroprocessing catalyst.