Crude Oil Characterization Using Gel Permeation Chromatography
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Solution Overview
Problem
Conventional crude oil assays are costly and time-consuming, requiring laborious distillation and fractionation processes to determine indicative properties such as cetane number, pour point, cloud point, and octane number.
Innovation Solution
The use of gel permeation chromatography (GPC) analysis to determine the indicative properties of gas oil and naphtha fractions without the need for fractionation or distillation, by correlating GPC data with density and molecular weight to calculate these properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional crude oil assay methods using TBP distillation and fractionation are used, then accurate determination of indicative properties (cetane number, pour point, cloud point, octane number) is achieved, but the process is costly and time-consuming
Solution Approach 1:
The patent extracts and analyzes specific molecular weight fractions of crude oil using GPC chromatography, separating the complex crude oil mixture into manageable size-based fractions. This allows direct determination of indicative properties from the chromatogram without performing time-consuming TBP distillation and multiple fractionation steps, reducing assay time while maintaining accuracy
Solution Approach 2:
The patent replaces the mechanical/thermal separation system (TBP distillation apparatus requiring heat, multiple fractions collection, and sequential analysis) with a chromatographic separation system (GPC) that separates molecules by size in a single operation. The GPC chromatogram directly provides molecular weight distribution data that can be used to calculate all indicative properties simultaneously, eliminating the need for multiple physical separation steps
2Measurement precision
If conventional crude oil assay methods using TBP distillation and fractionation are used, then accurate determination of indicative properties is achieved, but the cost is high
Solution Approach 1:
The patent makes the GPC analysis system multi-functional by showing that a single GPC chromatogram can provide molecular weight distribution data used to calculate multiple indicative properties (cetane number, pour point, cloud point, octane number) simultaneously. This eliminates the need for separate specialized tests for each property, reducing overall assay cost while maintaining accuracy
Solution Approach 2:
The patent extracts the essential molecular weight distribution information directly from crude oil using GPC, obtaining all necessary data in one analysis. This eliminates the need for multiple separate fractionation and analysis steps required by conventional methods, reducing material consumption, labor, and overall assay cost while maintaining measurement precision
3Measurement precision
If conventional TBP distillation and fractionation processes are used, then indicative properties can be determined, but the procedure is laborious and complex
Solution Approach 1:
The patent replaces the complex mechanical system of TBP distillation (requiring fractionation apparatus, multiple collection vessels, sequential processing) with a single GPC chromatographic system that automatically separates and analyzes the entire crude oil sample in one continuous process, significantly simplifying the procedure while maintaining analytical precision
Solution Approach 2:
The patent merges multiple separate analytical procedures (distillation, fractionation, and multiple property determinations) into a single GPC analysis operation. The chromatographic separation and molecular weight distribution analysis combine to provide all necessary information for calculating cetane number, pour point, cloud point, and octane number simultaneously, reducing procedural 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 significantly reduces the time and cost associated with crude oil assays, providing rapid and accurate results within one hour, allowing producers, refiners, and marketers to benchmark oil quality and value without extensive assays.
Implementation Method 1
The use of gel permeation chromatography (GPC) analysis to determine the indicative properties of gas oil and naphtha fractions without the need for fractionation or distillation
Data Source
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AI summary
A system and a method are provided for calculating the cetane number, pour point, cloud point, aniline point, and/or octane number of a crude oil and its fractions from the density and gel permeation chromatography data of a sample of the crude oil.