Hydroisomerization Process for Base Oil Yield Improvement
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Solution Overview
Problem
Existing processes for producing high-quality lubricating base oils from waxy hydrocarbon feedstocks often result in yield loss due to cracking, with hydrocracking leading to lower molecular weight hydrocarbons and hydroisomerization not fully addressing yield improvement while maintaining smooth operation.
Innovation Solution
A process involving hydroisomerization of waxy hydrocarbon feedstocks in the presence of hydrogen and an inert gas, such as nitrogen, at high pressures (at least 400 psig), which increases base oil yield by maintaining high gas pressure conditions necessary for refinery operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If hydrocracking is used to dewax hydrocarbon feedstock, then the pour point is reduced, but the base oil yield decreases due to production of lower molecular weight hydrocarbons
Solution Approach 1:
The patent changes the reaction parameters by using hydroisomerization conditions (temperature range 300-450°C, pressure 400-3000 psig) with specific catalysts to transform n-paraffins into iso-paraffins, achieving dewaxing without the yield loss associated with hydrocracking
Solution Approach 2:
The patent extracts and removes n-paraffins from the feedstock through selective hydroisomerization, converting them to iso-paraffins that remain in the base oil product, thereby preventing yield loss while achieving the desired pour point reduction
2Quantity of substance
If hydroisomerization is used to dewax hydrocarbon feedstock, then the base oil yield is improved, but the gas pressure requirements for refinery operations may not be satisfied
Solution Approach 1:
The patent combines hydroisomerization with a hydrotreating step in a unified process sequence, where the hydroisomerization zone operates at high pressures (400-3000 psig) to satisfy refinery pressure requirements while simultaneously achieving high base oil yield through iso-paraffin formation
3Ease of operation
If conventional dewaxing processes are used, then the operation is straightforward, but the base oil yield and quality are not optimized
Solution Approach 1:
The patent segments the dewaxing process into distinct functional zones: a hydroisomerization zone with specific catalysts for n-paraffin conversion, and a hydrotreating zone for impurity removal, allowing each zone to be optimized for its specific function while maintaining overall operational simplicity
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 increases the yield of high-quality base oils with improved pour points and viscosity indices, minimizing cracking and preserving the economic value of the feedstock, while maintaining operational efficiency.
Implementation Method 1
converting n-paraffins to a mixture of iso-paraffins
Implementation Method 2
contacting the hydrocarbon feedstock in a hydroisomerization zone under hydroisomerization conditions in the presence of hydrogen
Implementation Method 3
with the total pressure in the hydroisomerization zone being at least 400 psig
Data Source
AI summary
Provided is a process for preparing base oil from a waxy hydrocarbon feedstock by contacting the hydrocarbon feedstock in a hydroisomerization zone under hydroisomerization conditions. The reaction is in the presence of hydrogen and an inert gas, with the total pressure in the hydroisomerization zone being at least 400 psig. A product from the hydroisomerization zone is collected and separated into base oil products and fuel products. The inert gas can comprise any suitable inert gas, but is generally nitrogen, methane or argon. Nitrogen is used in one embodiment.