Quantitative Measurement of Mass and Aromaticity Distributions for Heavy Distillates 1. Capabilities of the HPLC-2 System

Abstract

This is the first in a series of papers describing a high-performance liquid chromatography (HPLC) system for quantitative measurement of the distribution of both aromatic carbon and mass in heavy distillates. Unique detector algorithms are applied to quantitate the aromaticity and mass of six groups (saturates, 1-4 ring aromatics, and polars) separated from oils using solvent gradients on coupled columns. Separation efficiencies (ring purities) are verified by alternate separations and mass spectra, the aromaticities derived from ultraviolet spectra are validated with 13C-nuclear magnetic resonance, and the evaporative mass detector results are verified by weighing isolated fractions from multiple runs. Both single- and interlaboratory precision are established at ∼10% (1σ relative standard deviation). Several examples are provided to illustrate the utility of HPLC-2 data in refining heavy distillates.