[Development and application of two-dimensional liquid chromatography for the analysis of polycyclic aromatic sulfur heterocycles in heavy oil].

A two-dimensional liquid chromatographic (2D LC) system was developed for the analysis of polycyclic aromatic sulfur heterocycles (PASHs) in heavy oil. The first dimension is a ligand-exchange chromatographic column packed with a palladium chloride/silica (PdCl2-SiO2) stationary phase, while the second dimension is a Spherisorb-NH2 column. The PASHs in vacuum gas oil were enriched online, and polycyclic aromatics hydrocarbons (PAHs) were separated according to their aromatic ring numbers. These separated fractions were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and detailed molecular characterization of PASHs and PAHs was achieved. Typical molecular structures of PASHs and PAHs in these fractions could be provided, and the side chain as well as the core structures were predicted. It is significant for the feedstocks selection and optimization of the hydrodesulfurization process by using these molecular characterization information.

[Identification of isoparaffin components in petroleum middle fractions].

The identification of isoparaffin components in petroleum middle fractions including kerosene and diesel fuels was investigated by gas chromatography-mass spectrometry (GC/MS). The isodewaxing middle fraction and distilled diesel were selected as the objective samples for identification. It was shown that the isoparaffin components in middle fraction were well separated with their branched alkyl substituent numbers on a capillary chromatographic column in selected ion monitoring (SIM) mode of GC/MS. The identification for C10-C24 isoparaffins was realized with the technique of GC/MS, such as the fragmentation pathways of electron ionization and SIM technique, boiling point rule, published retention indices and theoretical rules about component retention behavior in GC including carbon number rule etc. Finally, the retention indices for the mono-substituted, di-substituted and multi-substituted isoparaffins from C10 to C24 were presented, which could provide an overall knowledge of isoparaffin distribution at carbon number level in fuels. Meanwhile, the peaks that could be well resolved in each isoparaffin group were also identified, and the detailed data for about 80 C10-C21 methyl-substituted isoparaffins and isoprenoid biomarkers were also given. The results showed that in isodewaxing middle fraction studied, the mono-substituted and di-substituted isoparaffins were the main paraffins, whereas in distilled diesel studies, the mono-substituted isoparaffins and isoprenoid biomarkers were the main ones.

[Recent development in petroleomics based on the high-resolution mass spectrometry].

As the increase of the remaining reserves of the heavier/sourer crude oil and the requirement of the clean energy, it is significant to sufficiently characterize the molecular composition of the petroleum for the selection of the refining processes and the realization of the economic value of the crude oil. Petroleomics, which is based on the high-resolution mass spectrometry platform, is a powerful tool to achieve this goal. In this paper, the analytical technology applied in petroleomics and its most recent development are reviewed, and the perspective of petroleomics is also discussed.

[Investigation and application of gasoline sample identity technique].

Chemometrics method was used to solve the problem of automatic selecting model for the detailed hydrocarbon analysis (DHA) of gasoline samples by gas chromatography/ flame ionization detection (GC/FID). The 29 peaks in GC/FID DHA chromatogram and their amounts were selected as the discriminating parameters to establish the five pattern models for different gasoline samples, such as fluid catalytic cracking (FCC) gasoline, coking gasoline, straight run gasoline, reformed gasoline, and alkylation gasoline. The principle component analysis (PCA) and Soft Independent Modeling of Class Analogies (SIMCA) were used to classify the gasoline samples and to identify the unknown samples according to the above pattern models. One hundred gasoline samples, derived from known resources, were employed to validate the reliability of the sample identity technique. With the help of the pattern identity method referred here, the automation of GC/FID DHA method becomes possible.

[Investigation of fuzzy-clustering in octane number prediction model based on detailed hydrocarbon analysis data].

A method to establish octane number prediction model based on detailed hydrocarbon analysis (DHA) data is presented. The techniques of fuzzy-clustering and the Euclidian distance are employed to select the samples needed in pattern establishment. One hundred and fifty gasoline samples and an amount of 140 characteristic components in the DHA chromatogram of each sample are used for the fuzzy-clustering research. It is found that the 3 - 10 samples, which have the nearest Euclidian distance ( < 1.5) to the prediction sample in the same cluster, are enough to build the octane number prediction model. The experimental results proved that the model obtained according to the above method has more predictable accuracy, wider application range and higher data resource utility compared with the current prediction method.

[Analyses of gasoline range hydrocarbons by gas chromatography].

Analyses of gasoline range hydrocarbons by gas chromatography are reviewed with 66 references. Methods of high resolution capillary gas chromatography, multidimensional gas chromatography, and gas chromatography with atomic emission detection after bromination are summarized respectively. The advantages and limitations of each method are discussed and solutions for some existing problems are proposed.

[Alkene bromination used for detailed hydrocarbon and bulk hydrocarbon group-type analysis of gasolines containing alkenes].

The optimized reaction conditions of selective alkene bromination for gasolines containing aromatics and saturated hydrocarbons are presented. By this way, the interfering problem in alkene determination from coeluting saturated hydrocarbons has been solved. So the detailed hydrocarbon analysis can be improved by a simple system containing polar and non-polar columns or by a gas chromatograph coupled with an atomic emission detector (GC-AED). Under the optimized conditions, it was found that the alkene compounds were selectively and completely brominated but the aromatics and alkane compounds were remained unaffected. A simple treatment, 90 s-120 s for reaction and 10 s-20 s for removing the excess bromine, can be easily realized. The treatment is applied for the different types of gasoline containing 0-100% alkene. Besides, one of the most important applications of this treatment is to analyse the hydrocarbons in detail from the fluid catalytic cracking (FCC) gasoline. The samples in these cases may not be accurately analyzed when using the traditional method of hydrocarbon analysis because of the presence of coeluted interfering olefins above C7.