Ebullated Bed Hydroconversion for Residuum Upgrading
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Solution Overview
Problem
Current hydroconversion processes for heavy hydrocarbon fractions, such as residuum hydrocarbons, face limitations in achieving high conversion rates and sulfur removal, with existing methods like RDS and SDA units only achieving conversions up to 35-40% and 1 wt% sulfur fuel production.
Innovation Solution
A multi-step process involving ebullated bed hydroconversion reactors with varying reaction severities, followed by solvent deasphalting and further processing in separate units, to enhance hydrocarbon conversion and sulfur removal, including contacting residuum hydrocarbons with hydrogen and specific hydroconversion catalysts at specific conditions to achieve higher molecular weight reduction and contaminant removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional RDS units are used for hydroconversion of residuum hydrocarbons, then sulfur removal is achieved, but conversion rate is limited to 35-40%
Solution Approach 1:
The process segments the hydroconversion operation into multiple ebullated bed reactors operating in series, each contributing to incremental conversion. This segmentation allows achieving over 75% overall conversion by passing the feed through multiple reaction zones, overcoming the 35-40% conversion limit of single-stage RDS units while maintaining continuous sulfur removal capability.
Solution Approach 2:
The process employs parameter changes by operating different ebullated bed reactors at varying severities (reaction conditions). By adjusting temperature, pressure, and catalyst types across multiple reactors, the system optimizes both sulfur removal efficiency and hydrocarbon conversion rate, achieving high conversion without sacrificing desulfurization performance.
2Device complexity
If single-stage hydroconversion is used, then process simplicity is maintained, but conversion rate and sulfur removal are limited
Solution Approach 1:
The hydroconversion process is segmented into multiple ebullated bed reactors operating in series, with each reactor contributing to incremental conversion and sulfur removal. This multi-stage segmentation achieves over 75% conversion rate while maintaining operational simplicity through standardized reactor design and continuous process flow.
Solution Approach 2:
The ebullated bed reactor configuration serves multiple functions simultaneously: it provides high conversion rates through extended residence time, achieves superior sulfur removal via catalyst contact, and maintains operational flexibility through adjustable severity conditions. This multi-functionality eliminates the need for separate specialized units.
3Productivity
If higher conversion rates are achieved through increased reactor volume, then hydrocarbon conversion improves, but capital investment increases
Solution Approach 1:
The process achieves high conversion rates by changing operational parameters (temperature, pressure, catalyst composition) rather than simply increasing reactor volume. The ebullated bed reactors operate at optimized severity conditions that maximize conversion efficiency per unit volume, reducing the total capital investment required compared to low-severity designs.
Solution Approach 2:
The use of porous catalyst materials in the ebullated bed reactors increases the effective catalytic surface area within compact reactor volumes. This allows achieving high conversion rates without proportionally increasing reactor size, thereby reducing capital investment while maintaining productivity.
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 process achieves higher hydrocarbon conversion rates, up to 75 wt%, and significant sulfur removal, exceeding previous limits, while maintaining operational continuity and reducing capital investment by optimizing reactor volume and catalyst usage.
Implementation Method 1
contacting a residuum hydrocarbon fraction and hydrogen with a first hydroconversion catalyst in a first ebullated bed hydroconversion reactor system
Implementation Method 2
contacting a residuum hydrocarbon fraction and hydrogen with a first hydroconversion catalyst
Implementation Method 3
first ebullated bed hydroconversion reactor system
Data Source
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AI summary
A process for upgrading residuum hydrocarbons is disclosed. The process may include: contacting a residuum hydrocarbon fraction and hydrogen with a first hydroconversion catalyst in a first ebullated bed hydroconversion reactor system; recovering a first effluent from the first ebullated bed hydroconversion reactor system; solvent deasphalting a vacuum residuum fraction to produce a deasphalted oil fraction and an asphalt fraction; contacting the deasphalted oil fraction and hydrogen with a second hydroconversion catalyst in a second hydroconversion reactor system; recovering a second effluent from the second hydroconversion reactor system; and fractionating the first effluent from the first ebullated bed hydroconversion reactor system and the second effluent from the second hydroconversion reactor system to recover one or more hydrocarbon fractions and the vacuum residuum fraction in a common fractionation system.