Slurry Hydrocracking and Solvent Deasphalting for Fuel Metal Reduction
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Solution Overview
Problem
There is a need for an economically viable process to produce hydrocarbon fuel that meets the stringent specifications required for use in gas turbines and marine engines, as existing methods are costly and inefficient in removing sulfur, nitrogen, and metals from heavy oil residues.
Innovation Solution
A process involving slurry hydrocracking (SHC) of heavy hydrocarbon feedstocks to produce a pitch stream and heavy vacuum gas oil (HVGO) stream, followed by solvent deasphalting to blend the pitch with HVGO, resulting in a fuel composition that meets the RME 180 and IFO 180 specifications, with reduced nickel and vanadium content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydroprocessing is used to remove sulfur, nitrogen and metals from heavy oil residues, then purification is improved, but production cost increases significantly
Solution Approach 1:
The process segments the heavy oil residue into two main streams through solvent deasphalting: deasphalted oil (DAO) containing lighter hydrocarbons and asphaltenes, and asphaltene stream containing heavy polar compounds. This segmentation enables selective processing where DAO can be directly blended with fuel oil while asphaltenes are removed, achieving specification compliance at lower cost than conventional hydroprocessing
Solution Approach 2:
The patent extracts and removes asphaltenes from heavy oil residues using a solvent extraction process. The solvent selectively dissolves asphaltenes and heavy hydrocarbons, allowing separation from the lighter fuel-quality components. This extraction approach targets only the harmful heavy fractions rather than requiring expensive comprehensive hydroprocessing of the entire feedstock
2Productivity
If slurry hydrocracking is used to convert heavy feedstocks, then conversion to lighter fractions is improved, but coking occurs requiring heavy VGO recycling
Solution Approach 1:
The patent applies preliminary solvent deasphalting before slurry hydrocracking to remove asphaltenes and heavy polar compounds from the feedstock. This preliminary action reduces the concentration of coking-prone components in the subsequent hydrocracking process, allowing higher conversion efficiency without excessive coking that would require heavy VGO recycling
3Manufacturing precision
If solvent deasphalting is used to separate hydrocarbons, then separation based on solubility is improved, but metal content in DAO increases
Solution Approach 1:
The patent applies local quality by selecting a solvent system with specific solubility characteristics that preferentially dissolves asphaltenes and heavy hydrocarbons while leaving metal-containing lighter fractions in the residue. The solvent choice and extraction conditions are optimized to create local chemical environments that favor separation of asphaltenes from metal-bearing compounds, achieving high separation efficiency while controlling metal content in the DAO stream
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 effectively converts up to 80-95% of low-value vacuum bottoms streams into lighter distillates and a pitch stream, producing a hydrocarbon fuel that is suitable for direct use in gas turbines and marine engines without further upgrading, with improved metal content reduction and excellent fuel properties.
Implementation Method 1
slurry hydrocracking (SHC) of heavy hydrocarbon feedstocks to produce a pitch stream and heavy vacuum gas oil (HVGO) stream
Implementation Method 2
these liquid feedstocks are mixed with hydrogen and solid catalyst particles, e.g., as a particulate metallic compound such as a metal sulfide
Implementation Method 3
SDA separates hydrocarbons according to their solubility in a liquid solvent, as opposed to volatility in distillation
Implementation Method 4
Lower molecular weight and more paraffinic components are preferentially extracted
Data Source
AI summary
Slurry hydrocracking a heavy hydrocarbon feed produces a HVGO stream and a pitch stream. At least a portion of the pitch stream is subjected to SDA to prepare a DAO stream low in metals. The DAO is blended with at least a portion of the HVGO stream to provide turbine or marine fuel with acceptable properties for combustion in gas turbines or for marine fuel grades.