Jul-2022

Analysis of gasoline blends and finished gasoline using Reformulyzer M4 according to ASTM D6839 & EN ISO 22854

With the introduction of the 4th generation AC Analytical Controls (AC) Reformulyzer M4, group type analysis of finished gasoline and its precursors & blend streams has become easier and much faster than before.

Article Summary

The Reformulyzer M4 benefits from the use of capillary/Micropacked columns and traps, resulting in unprecedented speed of analysis, the widest analytical range and excellent precision. It complies with key methods EN ISO 22854 and ASTM D6839 and derived methods. 

Depending on the sample stream or product, a range of analytical modes can be used, ensuring shortest possible runtimes, and data as required for that specific product. See Table 1. 

This application note describes the quantitative determination of hydrocarbon types and oxygenates in Gasoline Blends and Finished Gasoline using the AC Reformulyzer M4.

Intrumental 

The determination of different hydrocarbon types and oxygenates is achieved by separation and elution on a series of designed traps and columns. The flow diagram for Reformulyzer M4 is shown below in Figure 1, and the analysis schedule used for this specific method is in Table 2. The Polar Column separates the Paraffins and Naphthenes from the Aromatics while Heavy Aromatics and Alcohols are retained on the Pre-Column. Ethers pass unretained and are trapped on the Ether/Alcohol-trap to be analysed on the Boiling Point column. Paraffins and Naphthenes pass the Olefin trap where Olefinic components are trapped. Further separation of Saturates is on the 13X Column resulting in a carbon number distribution. By using multiple valves and columns the Aromatics, PolyNapthenes and Alcohols are analysed on a Boiling Point Column in two different Aromatic fractions. Between two aromatic fractions the Olefin trap is desorbed in backflush and Olefins are separated on 13X column. The Micropacked traps and columns are located in the left side and have separate heater elements for individual temperature programming. This allows heating and/or cooling of traps simultaneous, resulting in total analysis runtime of 39 minutes.

Gravimetric Blends and a Gasoline N Certified Reference Materials (CRM) were analysed using the Reformulyzer M4 in Gasoline mode. Representative chromatograms are shown in Figures 3 and 4 and typical report outputs from the analysis for the CRM are in Tables 3 and 4.

Chromatograms show clear group separations for Paraffins, Naphthenes, Aromatics, Olefins and Oxygenates, and %Weight and %Volume by carbon numbers are well within specifications for this particular CRM. Reported are compositions in Weight% and Volume%.

Conclusion

The Reformulyzer M4 provides reports group type data in full accordance with key methods EN ISO 22854 and ASTM D6839. 
Weight% and Volume% profile reports are generated grouping Naphthenes, Paraffins, Olefins, Aromatics and Oxygenates by carbon number as well as the totals of the different groups and the totals by carbon number.

Through the use of Capillary and Micropacked columns and Traps The Reformulyzer M4 takes only 39 minutes to produce reliable results in Gasoline mode.