Showing 11 - 20 of 72 results

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Analysis of Greenhouse Gases by Gas Chromatography, May 2019.1 [AN012]

INTRODUCTION: Nitrous Oxide (N2O), Carbon Dioxide (CO2) and Methane (CH4) are considered to be very powerful greenhouse gases. These gases reflect in the atmosphere, stopping the incoming and outgoing radiation that warms the Earth, thus causing the greenhouse effect. Continuously measuring the greenhouse gases gives insight into the source of the emissions, helping us fight climate change. A SCION 456 GC was custom configured specifically for the
analysis for all three gases in a single matrix of atmospheric air containing water vapour.

274 KB

Analysis of Low Level Oxygenates (LOWOX) in Liquefied Petroleum Gas (LPG), May 2019.1 [AN009]

Introduction: The determination of sub to high ppm levels of ethers, alcohols, aldehydes and ketones in different hydrocarbon matrices is a recurring challenge in the petroleum refining and petrochemical industry. The SCION low level oxygenates analyser is designed and optimised to quantify ppm and sub levels of ethers, alcohols, ketones and hydrocarbons in gas, liquid and LPG samples. Oxygenates can be present in hydrocarbon streams for a variety of reasons. For example, methanol is added to crude oil to reduce the formation of hydrates during transportation and storage. Clean up processes like
hydro -treating are used in an attempt to remove oxygenated compounds. Even at sub ppm trace levels, oxygenates quickly degrade or destroy expensive
catalysts in downstream polymerisation processes.

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Analysis of Mineral Oils Utilising Temperature Programmed Large Volume Injection, May 2019.1 [AN020]

INTRODUCTION: Mineral oil hydrocarbons are typically found in water, foods and soils. These hydrocarbons can be extracted using a variety of solvents, with the most popular being hexane and petroleum ether. As concentrations can be very low, sample enrichment is often required. However, SCION instruments developed a method that simply uses a Large Volume Injection (LVI) technique to simplify sample pre-treatment whilst dramatically increasing throughput. The Hydrocarbon Index (HOI) is the total amount of compounds which can be extracted from water samples using a non-polar solvent. The solvent must have a boiling point between 39℃ and 69℃, thus replacing the use of halogenated solvents. Halogenated solvents and high concentrations of polar substances can interfere with the determination of the HOI. In addition, the compounds must not absorb on Florisil and must elute between ndecane and n-tetracontane. The method is suitable for HOI determinations in concentrations above 0.1mg/L in water samples.

This application note describes the highly efficient analysis of mineral oil hydrocarbons in water using the SCION 456 GC equipped with a Programmable Temperature Vaporiser (PTV). The system is very well suited to the DIN-EN-ISO 9377 method.

516 KB

Analysis of Sulphur Compounds in Various Liquefied Petroleum Gases, May 2019.1 [AN006]

The low-level analysis of sulphur containing components such as Hydrogen Sulphide (H2S), COS (carbonyl sulphide) and mercaptans, in liquified petroleum gas (LPG), is challenging. First of all, the system has to be inert; stainless steel adsorbs H2S and other sulphur containing components. Secondly, the column used must be able to separate the components of interest. Although a highly selective pulsed flame photometric detector (PFPD) is used in sulphur mode, the bulk hydrocarbons tends to quench the PFPD signal.

325 KB

Analysis of Total Petroleum Hydrocarbons using Temperature Programmed Large Volume Injection, May 2019.1 [AN010]

INTRODUCTION: Mineral oils are typically found in water, foods and soils. These mineral oils can be extracted using different solvent; most popular are hexane and petroleum ether. As concentrations can be very low, some sort of sample enrichment is often used, e.g. rotary evaporation. If, however, a Large Volume Injection (LVI) technique is used, sample pretreatment becomes easier and sample throughput can be increased significantly. This application note describes the analysis of mineral oils (or Total Petroleum Hydrocarbons / TPH) using the Scion 456-GC gas chromatograph equipped with a Programmable Temperature Vaporizer (PTV) Injector and the Select™ Mineral Oil column. The column stationary phase was tuned for separation and stabilised for high
temperature operation. The upper temperature limit of the column is 400 °C. This system is suited to the DIN-ENISO 9377-2 method that replaced DIN H53.

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Boiling Point Distribution in Petroleum Fractions using Simulated Distillation (ASTM D2887) [AN_0008]

Introduction
In many regions ASTM D2887 may be used for determining the boiling point distribution of petroleum products, feedstocks and fractions that have a final boiling point of 538°C or lower. This provides insight into composition and determining intrinsic product value.
Even though Physical Distillation is still considered the reference method for distillation, and therefore mandatory in many countries for qualifying fuels, Simulated Distillation (SIMDIST) by gas chromatography offers some significant advantages over the physical procedure, making this technique valuable.
Analysis by GC typically has the better precision, more throughput, less hands-on time and lower cost per sample. Lastly, SIMDIST requires considerable less sample and should generally be considered the safer of the two techniques.
In addition to the standard method (procedure A), a second procedure has recently been added into D2887, the accelerated or fast method (procedure B).
This application note demonstrates a solution for D2887 procedure A for analysing Petroleum products covering a boiling point range of 36°C to 545°C. This procedure is not suited for biodiesels. For gasolines, method D7096 should be used.

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Comparing ASTM D8071 (GC-VUV) & ASTM D6730 (DHA) for Hydrocarbon Analysis, May 2019.1 [AN025]

INTRODUCTION: There are many challenges within the petrochemical industry and associated GC analysis methods, for the analysis of hydrocarbons in spark ignition fuels. As regulations continuously drive down the accepted levels of impurities in gasolines, lower detection and quantification levels must be observed when using GC as a method for analysis. Fuel impurities must be removed whilst also retaining and characterising paraffins, iso-paraffins,
olefins, napthenes and aromatics (PIONA) as well as other hydrocarbon classes to maintain the octane value of the system.
ASTM D6730 is the standard test method for the determination of individual components in spark ignition fuels using GC-FID. However, this detailed hydrocarbon analysis (DHA) is time consuming with long analyses, column tuning and extensive post processing times. DHA is reliant on reproducible retention index values; requiring optimal controlled operating, flow and temperature conditions, for identification and quantification

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Detailed Hydrocarbon Analysis of Spark Ignition Engine Fuels by GC using ASTM D6729, May 2019.1 [AN003]

It is vital for quality control purposes that spark ignition engine fuels are analysed via ASTM D6729. This application note covers the determination of individual hydrocarbon component of spark ignition engine fuels, commonly known as detailed hydrocarbon analysis (DHA). The method is applicable to gasolines containing oxygenate blends (MTBE, ETBE, TAME and ethanol), with boiling point ranges up to 225°C and other light liquid hydrocarbon
mixtures typically encountered in petroleum refining operations such as blending stocks (naphtha’s, reformates and alkylates).

Showing 11 - 20 of 72 results