Naslov
APPLICATION OF CHROMATOGRAPHIC METHODS (HPLC, GC) IN CHARACTERISATION OF FCC PRODUCTS

Autori
Tomic, Tatjana ; Telen, Sanda ; Šegudovic, Nikola ; Fabulic-Ruszkowski, Maja.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
HTC8 8th International symposium on hyphenated techniques in chromatography and hyphenated chromatographic analysis, CD ROM / Smith Robert - Briž : Royal Society of Chemistry and Royal Flrmish Chemical Society, 2004, 112-112

Skup
HTC8 8th International symposium on hyphenated techniques in chromatography and hyphenated chromatographic analysis

Mjesto i datum
Brugge, Belgija, 04.02.2004. - 06.02.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
FCC process; FCC products; GC of FCC Products; HPLC of FCC Products

Sažetak
The process of fluid catalytic cracking (FCC) is the main process of converting heavy-petroleum fractions with high contents of sulphuric and nitrogen compounds into lighter fractions. The liquid products of catalytic cracking, FCC gasoline and light cyclic oil, are used in blending of automotive petrol and diesel fuels. Chromatographic techniques enable observing the changes in the content of various hydrocarbon groups during catalytic reactions. Determination of group-type composition of refinery products provides information concerning the conversion efficiency. In order to comply with the stringent environmental requirements of European specifications, it is necessary to reduce the sulphur content and the almost incombustible aromates and olefines in automotive fuels. This paper presents determination of group-type composition of FCC gasoline by means of gas chromatography, as well as determination of the aromates content in FCC gasolines, their fractions, and in light cyclic oil by means of liquid chromatography. Compared were FCC products obtained from feeds of various origins (high-sulphur and low-sulphur petroleum). By means of high-production liquid chromatography for normal phases (HPLC-NP), the aromate content of the mentioned samples was observed. Separation was performed on a polar or a modified polar column (silica, amino-silica or amino/cyano-silica) with a non-polar carrier phase (n-heptane), and with the use of a refractometer. The column does not show affinity to saturated hydrocarbons (aliphatic and cyclic), but it shows emphasised affinity and selectivity to aromatic hydrocarbons. As a result of selectivity, the aromates were separated from the saturated, and mutually separated by clearly outstanding peaks according to the number of rings, i.e. as mono-, di-, and tri+ aromates. Tri+ aromates elute as a separate sharp peak owing to the use of the return valve, which after elution of di-aromates, changes the mobile phase’ s flow direction. Some doubts observed in determination of group-type composition using the RI detector were overcome by hyphenating the DAD to the chromatographic system. By means of high-resolution gas chromatography with a 60-m capillary column, the FCC samples separated into more than 300 components. Single-component structure was identified, while the group-type composition was determined based on single-component data. From one single gas-chromatographic analysis performed on one column, it is possible to obtain simultaneous data on the n-paraffin, iso-paraffin, cyclo-paraffin, olefin, and aromate content, and if necessary, data on the concentrations of single components contained in one of the mentioned hydrocarbon groups. The gas-chromatographic analysis conditions were adjusted to present the optimum ratio between peak-separation quality, analysis duration, and applied conditions.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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