Hydrocracking VGO and Wax Feedstock for High Cetane Base Oils
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Solution Overview
Problem
There is a need for an efficient, simple, and economic method to produce high-quality middle distillates and very high viscosity index lubricant base oils in high yields from available feasible feeds, while also upgrading product quality to meet increasing demands for purity, emissions, cold flow properties, and lubricity.
Innovation Solution
A method involving the use of a feedstock composed of vacuum gas oil (VGO) and wax in the hydrocracking and catalytic dewaxing process, where the wax is introduced as a minor component to improve catalyst performance and extend catalyst life, allowing for the production of middle distillates with improved cetane number and base oils with increased viscosity index without compromising yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional hydrocracking uses only VGO feedstock, then the process is simple and economic, but the product quality (cetane number) and catalyst life are limited
Solution Approach 1:
The patent applies composite feedstock by combining VGO with wax (paraffinic feedstock) to create a mixed feed composition. This composite approach allows the wax component to donate n-paraffins that convert to high-cetane alkylates, thereby improving diesel cetane number while the VGO provides the base for other valuable products. The synergistic combination resolves the contradiction by achieving higher product quality without excessive complexity.
Solution Approach 2:
The patent changes the feedstock composition parameters by introducing wax as a supplementary component with specific properties (high n-paraffin content). By adjusting the ratio of VGO to wax and controlling hydrocracking conditions, the process optimizes cetane number while managing feedstock complexity. This parameter adjustment allows quality improvement without requiring complete process redesign.
2Productivity
If catalyst is used for extended periods to improve productivity, then production efficiency increases, but catalyst performance degrades due to fouling and deactivation
Solution Approach 1:
The patent applies preliminary action by introducing wax as a feedstock component before hydrocracking begins. The wax serves as a protective agent that preemptively manages catalyst fouling by providing a controlled source of paraffins that can be converted to valuable products. This preliminary incorporation of wax prevents severe coking and deactivation that would otherwise occur during extended operation, thereby maintaining catalyst reliability while enabling continuous production.
Solution Approach 2:
The patent converts the potential harm of extended catalyst use (fouling and deactivation) into a benefit by using wax as a feedstock additive. The wax component, when hydrocracked, produces high-cetane alkylates that improve diesel quality while simultaneously acting as a mild cleaning agent that prevents severe coking. This transforms the challenge of long-term catalyst operation into an opportunity for both improved product quality and extended catalyst life.
3Manufacturing precision
If wax is added to VGO feedstock, then cetane number and viscosity index improve, but the feedstock processing becomes more complex
Solution Approach 1:
The patent changes feedstock composition parameters by adding wax to VGO, specifically targeting the paraffinic content to enhance cetane number and viscosity index. By controlling the wax addition level and its chemical composition, the process achieves desired product specifications without requiring complex processing equipment modifications. This parameter adjustment approach resolves the contradiction by achieving quality improvement through compositional control rather than equipment complexity.
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 method efficiently produces high-quality middle distillates and base oils with enhanced cetane number and viscosity index, allowing for the use of lower quality VGO and higher quality wax, providing an economic advantage and improved product quality.
Implementation Method 1
Cracking is achieved by breaking the carbon-carbon bonds in the hydrocarbon chain of C15 to C45 typically in the presence of a cracking catalyst
Implementation Method 2
The purpose of the hydrogenation is to remove heteroatoms, such as oxygen, sulphur and/or nitrogen, and also to saturate aromatics typically present in the hydrocarbon feed
Implementation Method 3
The solvent dewaxing process is typically performed by mixing a suitable solvent with the waxy petroleum feed, then cooling the mixture and separating the waxes as solid wax crystals, for example by filtration
Data Source
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AI summary
The invention provides a method of producing oil-based components, comprising the steps of: providing VGO and wax; combining the VGO as a major component and the wax as a minor component to provide a feedstock; subjecting the feedstock to a hydrocracking step to provide a first effluent; fractionating the first effluent to provide at least a bottom fraction and a middle distillate fraction; recovering the bottom fraction and the middle distillate fraction. The invention further provides a method for improving the viscosity index of base oil, comprising the steps of: providing VGO and wax; combining the VGO as a major component and the wax as a minor component to provide a feedstock; subjecting the feedstock to a hydrocracking step to provide a first effluent; fractionating the first effluent to provide at least a bottom fraction and a middle distillate fraction; subjecting the bottom fraction to a dewaxing step to provide a second effluent; fractionating the second effluent to provide at least a middle distillate and base oil; recovering the middle distillate and the base oil.