SIMULATED DISTILLATION BY GAS CHROMATOGRAPHY

Introduction:

Simulated distillation analysis, or Sim-Dis, is a process that is used to simulate the actual physical distillation of petroleum products by Gas Chromatography. There are four ASTM test methods that are now referred to as Sim-Dis, and these differ from one another as to the type of hydrocarbon product and the temperature range of interest. However, in each method, the non-polar and low polar hydrocarbons are eluted from a gas chromatograph column in a specific boiling point order.

A program of increasing temperature is applied to a GC column and the time axis is converted to temperature by running a calibration standard under the same conditions as the sample, so that the retention times of hydrocarbons are related to their respective boiling points.

Simulated Distillation or Sim-Dis is alternately known as Boiling Range Distribution or Composition Breakdown. The ASTM has at least four approved test procedures for Sim-Dis. These are intended to replace the traditional physical distillation methods such as ASTM D 86 and ASTM D 2892. In fact, ASTM work groups are now giving active consideration to including Sim-Dis as a specification test for such products as diesel fuel, kerosene, jet fuel, and fuel oil.

ASTM Test Methods for Simulated Distillation:

ASTM D 2887 Standard Test Method for Boiling Range Distribution of Petroleum Fractions vy Gas Chromatography.

ASTM D 3710 Standard Test Method for Boiling Range Distribution of Gasoline and Gasoline Fractions by Gas Chromatography.

ASTM D 5307 Standard Test Method for Determination of Boiling Range Distribution of Crude Petroleum by Gas Chromatography.

ASTM D 5399 Standard Test Method for Boiling Point Distribution of Hydrocarbon Solvents by Gas Chromatography.

ASTM D 6352 Standard Test Method for Boiling Range Distribution of Petroleum Distillates in Boiling Range from 174 to 700 C by Gas Chromatography.

ASTM D 6417 Standard Test Method for Estimation of Engine Oil Volatility by Capillary Gas Chromatography.

Other Sim-Dis Test Methods:

Simulated distillation by gas chromatography has become a popular procedure for many other hydrocarbon products which have not yet been standardized. Some of these include:

1. Neer, Lawrence A., and Deo, Milind D., “Simulated Distillation of Oils With a Wide Range of Carbon Number Distribution, “ Journal of Chromatographic Science , Vol 33, No. 3, pp 133 to 138, March 1995. Compounds with carbon numbers from C5 to C90 can be characterized.

2. Raia, Joe C., and Villalanti, Dan C., “Application of High-Temperature Simulated Distillation to the Residuum Oil Supercritical Extraction Process in Petroleum Refining,” Journal of Chromatographic Science, Vol 38, No.1, pp. 1 to 5, January 2000. High Temperature Simulated Distillation (HTSD) is described for solvent deasphalting operations and for products such as lube oil and hydrocracker feedstocks. Over a range from 36C to 733C which covers the boiling range of n-paraffins from C5 to C100.

3. Triton Analytics. High Temperature Simulated Distillation (HTSD) which extends the concepts of ASTM D 2887 to a final boiling point of about 1400 C and provides good resolution of hydrocarbons from C5 to C120 normal paraffins.

4. Fan Li, Li-Ping Chang, Peng Wen, and Ke-Chang Xie, “Simulated Distillation of Coal Tar,” Energy Sources, Vol 23, No 2, pp 189 to 199, February 1, 2002. Gas chromatography was used to obtain boiling point range and aromatic ring distribution of coal tar. The boiling point data from GC and GC-MS techniques have good repeatability and identical agreement with True Boiling Point (TBP) data.

Simulated Distillation Methods in TOL Catalog

Simulated Distillation Method in TOL Catalog. Texas OilTech Laboratories offers seven tests for Sim-Dis and related procedures that we based on the recognized ASTM methods. The temperature range has been extended in several of these tests by applying Sim-Dis procedures.

Test Description	Method
Simulated Distillation, Sim-Dis, Lower Range, 55° to 538°, C 5 to C 44	ASTM D 2887.c
Simulated Distillation, Sim-Dis, High Temperature Range, 360° to 750°C, C 10 to C 50	ASTM D 2887.d
Boiling Range Distribution of Petroleum Fraction by Gas	ASTM D 2887.a
Chromatography Composition Breakdown (C 1 to C 40 ) by Gas Chromatography, Sludge	ASTM D 2887.b
Boiling Range Distribution, Gasoline, by Gas Chromatography	ASTM D 3710
Boiling Range Distribution of Crude Petroleum by Gas Chromatography	ASTM D 5307
Boiling Range Distribution of Petroleum Distillates in Boiling Range from 174° to 700°C by Gas Chromatography	ASTM D 6352

In addition, other Gas Chromatography procedures can be modified to include the principles of Simulated Distillation for a variety of other petroleum products. Please contact Texas OilTech Laboratories to request information regarding Simulated Distillation procedures that can be applied to your product.