Characterization of Engine Fuels by Hydrocarbon Group Type Using Gas Chromatography

Topics Covered

Introduction to Multi-Dimensional Gas Chromatography

Theory of PIONA Gas Chromatography

Applications of PIONA gas Chromatography

Key Benefits of PIONA+™Analyzer

About Bruker CAM

Introduction to Multi-Dimensional Gas Chromatography

“Multi-dimensional” gas chromatography has been applied to hydrocarbon (specifically PNA) analysis since the 1980’s and since this time has grown in accuracy and prevalence. It is now a common technique used in refinery laboratories around the world. Yet, despite many improvements since its first use, the basic chromatographic selectivity required to use this technique has been left fundamentally unchanged.

This is now set to change with the introduction of the innovative PIONA+™Analyzer produced by Bruker CAM. This analyser will allow quantitative data to be obtained regarding the hydrocarbon group types being analysed, allowing the characterisation of engine fuels.

The Bruker PIONA+™Analyzer is based on the 450-GC and contains the Galaxie Data System

Theory of PIONA Gas Chromatography

Gas chromatography is a hugely important analytical technique that is used in a wide sphere of applications. There are many different forms of gas chromatography, including inverse gas chromatography, thin layer chromatography and PIONA chromatography. These analytical techniques do have certain aspects in common however, as they all separating compoenets that have been vaporised and analysing these via detectors.

Specifically, PIONA gas chromatography can be used to characterize petroleum streams by hydrocarbon group type. PIONA is an acronym that stands for Paraffins, Iso-paraffins, Olefins Naphthenes and Aromatics in gasoline-range materials.

PIONA is the preferred technique today to characterise petroleum streams by hydrocarbon group type. The PIONA technique uses complex gas chromatography to separate the substance being analysed into its individual hydrocarbon groups using a fully automated, multidimensional approach.

An up-close photograph of the traps (detectors) in a gas chromatograph

Applications of PIONA gas Chromatography

PIONA gas chromatography is in common use in refineries world-wide and hydrocarbon group-type data can be obtained for paraffins, iso-paraffins, naphthenes, olefins, aromatics and oxygenated components.

This makes the technique perfect for use in the analysis of engine fuels, such as spark emission fuels.

A graph from a chromatogram of conventional calibration mix

Table 1a. Example of a Mass% Report


Group
Carbon Number
Paraffins
Napthalenes
Olefins
Cyclic Olefins
Aromatics
1
0.00




2
0.00

0.00


3
0.03
0.00
0.00
0.00

4
0.91
0.00
0.09
0.00

5
16.84
0.43
0.46
0.15

6
9.85
2.18
1.09
0.24
0.84
7
7.14
3.59
0.66
0.30
6.37
8
6.94
0.49
0.67
0.13
15.45
9
1.17
0.15
0.17
0.10
11.26
10
0.28
0.03
0.00
0.00
3.74
Total
43.16
6.87
3.14
0.92
37.66
BP > 185°C
1.01

Oxygenates

O-content
MTBE
7.24
1.32
Tot. Oxygen
1.32


Table 1b. Example of a Volume% Report


Group
Carbon Number
Paraffins
Napthalenes
Olefins
Cyclic Olefins
Aromatics
1
0.00




2
0.00

0.00
0.00

3
0.05
0.00
0.00
0.00

4
1.17
0.00
0.11
0.11

5
20.00
0.43
0.52
0.52

6
11.07
2.13
1.19
1.19
0.70
7
7.72
3.51
0.69
0.69
5.44
8
7.30
0.47
0.69
0.69
13.19
9
120
0.14
0.17
0.17
9.55
10
0.29
0.02
0.00
0.00
3.12
Total
48.80
6.70
3.37
3.37
32.00
BP > 185°C
0.89

Oxygenates

MTBE
7.24

Key Benefits of PIONA+™Analyzer

The PIONA+™Analyzer has a number of advantages, which are specific to the engine fuel industry. These are highlighted below:

· Reduced analysis time using ‘concurrent’ heating- This system has a concurrent heating system, achieved by optimising the temperature settings of the various traps and columns. This allow a reduction in analysis time, in some cases from 180 minutes to 95 minutes.

chromatogram of a calibration mix using concurrent heating

· Operational flexibility: The PIONA+™Analyser allows, due to the inherent flexibility of the analyzer’s design, the operator to conduct in different operational modes which are often used in industry. These include: PNA, PONA, PIONA,O-PONA and O-PIONA.

· Compliant with industry standard methods: The operational flexibility allows it to be used for the most common industry methods of analysis. Examples include: ASTM D6839, ASTM EN-ISO-22854, ASTM D5443, ASTM D1319, IP-382, IP-526, EN 14157, UOP 870 and DIN-51448.

· A complete and fully integrated solution: The Bruker’s PIONA+™Analyser is based on the 450-GC gas chromatograph, but also includes Galaxie™ chromatography data handling software, dedicated PIONA+ data analysis and report generation software. Furthermore, the "olefin trap" of the PIONA+ Analyzer can analyze streams with olefin content as high as 35-40% or more.

· Ease of Use: Bruker’s high performance 450-GC, ultrastable columns and traps and powerful Galaxie data system with built-in PIONA+ software all contribute to the analyzer’s ability to generate outstanding analysis results day after day. However, a powerful system does not necessarily have to mean that only highly skilled operators are able to use it.

  Saturates     Unsaturates     Saturates    
Carbon Cyclic Iso Normal Cyclic Iso Normal Aromatics Oxyg Total
3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.06 0.00 0.03 0.54 0.00 0.00 0.64
5 0.31 11.33 2.98 0.87 9.91 7.57 0.00 0.03 32.99
6 3.17 9.95 1.40 2.40 8.58 4.40 1.72 0.04 31.67
7 4.31 6.77 0.00 2.14 4.76 1.91 7.4 6 27.35
8 1.42 3.12 0.00 0.39 2.06 0.00 0.07 0.00 7.05
9 0.01 0.00 0.00 0.04 0.02 0.00 0.03 0.00 0.10
10 0.01 0.00 0.00 0.09 0.00 0.03 0.01 0.00 0.13
11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Total 9.23 31.17 4.43 5.93 25.36 14.46 9.29 0.07 99.93

About Bruker CAM

Bruker is the new name in chemical analysis. Accurate and comprehensive analysis of exogenous and discrete elements in a wide range of sample matrices are key applications for many analytical chemistry groups. To address the needs and challenges of analysts working in those areas, Bruker has expanded their product family to provide, and expertly support, a series of fully integrated solutions including:

· Gas Chromatography-Mass Spectrometers (GC/MS and GC/MS/MS)

· Inductively Coupled Plasma Mass Spectrometers (ICP-MS)

· Gas Chromatography Systems (GC)

Widely used in food and consumer safety testing, forensic, industrial, environmental, and clinical laboratories, these systems are well accepted and established market leaders that universally deliver outstanding performance at a premium value.

This information has been sourced, reviewed and adapted from materials provided by Bruker CAM

For more information on this source, please visit Bruker CAM.

Date Added: Jun 15, 2012
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