Alternative Carrier Gases for Simulated Distillation Analysis

Crude oil consists of thousands of different hydrocarbons that span a very wide volatility range. In order to efficiently produce quality finished products, refineries depend on simulated distillation (SimDist) analyses to characterize the composition of their crude feedstock prior to processing. SimDist is a gas chromatography (GC) technique that allows fast, reproducible, and easily automated determination of boiling point distribution of crude oil samples. Until recently, helium has been the only accepted gas for ASTM SimDist analysis. The ASTM SimDist committee now has approved the use of alternative carrier gases—nitrogen and hydrogen—for SimDist analyses. This article will explore alternative carrier gas options for SimDist analyses and discuss their various benefits and drawbacks.