Distillation Fractions Of Oil Research Articles

Industrial Distillation Fractions of Garlic Essential Oil, Design, Synthesis, and Antifungal Activity Evaluation of Aliphatic Substituted Trisulfide Derivatives.

Garlic oil has a wide range of biological activities, and its broad-spectrum activity against phytopathogenic fungi still has the potential to be explored. In this study, enzymatic treatment of garlic resulted in an increase of approximately 50 % in the yield of essential oil, a feasible GC-MS analytical program for garlic oil was provided. Vacuum fractionation of the volatile oil and determination of its inhibitory activity against 10 fungi demonstrated that garlic oil has good antifungal activity. The antifungal activity levels were ranked as diallyl trisulfide (S-3)>diallyl disulfide (S-2)>diallyl monosulfide (S-1), with an EC50 value of S-3 against Botrytis cinerea reached 8.16 mg/L. Following the structural modification of compound S-3, a series of derivatives, including compounds S-4~7, were synthesized and screened for their antifungal activity. The findings unequivocally demonstrated that the compound dimethyl trisulfide (S-4) exhibited exceptional antifungal activity. The EC50 of S-4 against Sclerotinia sclerotiorum reached 6.83 mg/L. SEM, In vivo experiments, and changes in mycelial nucleic acids, soluble proteins and soluble sugar leakage further confirmed its antifungal activity. The study indicated that the trisulfide bond structure was the key to good antifungal activity, which can be developed into a new type of green plant-derived fungicide for plant protection.

Boiling point modeling for petroleum speciation data

An empirical model is presented for generating the boiling curve of a petroleum sample based on parameters that are experimentally available using typical speciation techniques. The approach estimates the boiling point distribution of the detected components and allows a comparison with the simulated distillation profile of the sample. The model is shown to predict the boiling behavior of the speciation-derived average components in crude oil distillation fractions, which match the measured average distillation temperature of the fractions. The model is then applied to generate boiling distributions, based on mass spectrometric and gas chromatographic speciation data, which match the measured simulated-distillation curves with less than 20 °C difference. The model is also applied to the isolated fraction of saturated compounds, where the modeled boiling profile matches well with the measured distillation profile of the entire sample. This confirms that the model, although built using Fourier transform ion cyclotron resonance mass spectrometry data of aromatic compounds, extends to data obtained using comprehensive 2-dimensional gas chromatography, and also describes the boiling behavior of saturated compounds speciated by field desorption time of flight mass spectrometry. Consequently, the modeled boiling distribution enables an assessment of how well a speciation measurement describes the sample, and provides an estimation of lower and higher-boiling portions that have been omitted in the data set.

Research and Application of Modified ZSM-5 for the Process of Alkylation of Oil Distillate Fractions

In the oil distillate fraction alkylation process, a modified Zr zeolite ZSM-5 was obtained and studied. The modification was executed using a method that impregnated ZSM-5 with a 5% solution of ZrOCl<sub>2</sub>∙6H<sub>2</sub>O. X-ray diffraction studies were conducted on zeolite ZSM-5, zirconyl chloride modifier ZrOCl<sub>2</sub>∙6H<sub>2</sub>O, and modified zeolite ZSM-5-ZrO<sub>2</sub>, which was calcined at temperatures of 200, 400, and 550°C. The results revealed that the phase composition of modified ZSM-5-ZrO<sub>2</sub> zeolite samples varied depending on the calcination temperature. It was determined that only at a temperature of 550°C did the modified ZSM-5 catalyst contain three phases belonging to ZrSi<sub>24</sub>O<sub>50</sub>, ZrO<sub>2</sub>, and ZSM-5. The emergence of the ZrO<sub>2</sub> phase occurred at a calcination temperature of 550°C. An increase in temperature from 200 to 550°C facilitated the transition of the amorphous phase to the crystalline phase. The crystal structure of the ZSM-5-ZrO<sub>2</sub> catalyst, calcined at 550°C, contributed to a rise in its activity. Consequently, during alkylation with catalytic cracking gases, the viscosity-temperature properties of the T-30 turbine oil distillate fraction significantly improved (the viscosity index increased from 49.9 to 137). An increase in zeolite ZSM-5 activity was demonstratd due to the introduction of zirconium and an elevated calcination temperature to 550°C.

Физико-химическая характеристика образцов нефти Тагульского месторождения

The article presents the data of a comprehensive study of three samples of high-viscosity borehole oil of the Tagulskoye field. Using the instrumentation and methodological base of JSC «MidVolgaNIINP», information was obtained on the composition and properties of samples of high-viscosity oil (HVO) after preliminary dehydration and desalination, as well as oil distillate fractions and residues from distillation obtained in laboratory conditions according to GOST 11011, ASTM D 2892/5236. In addition, it is shown that the objects of the study have valuable properties: a low content of total sulfur, a low content of paraffins and a fairly low pour point for heavy oils. The authors have proposed options for further use of the studied objects. In general, valuable basic information has been obtained for the long-term planning of production and the choice of options for the use /processing of unique raw materials.

On the Possibilities of Multidimensional Equidistant Absorption Spectroscopy in a Wide Frequency Range in Studies of Fractions of Thermal Distillation of Oil

The features and possibilities of absorption molecular spectroscopy of complex mixtures of organic compounds have been studied by the example of fractions of thermal distillation of oil. Oil samples were taken from a pipeline through which oil comes from various fields. To ensure independent (relative to the field) sampling of oil, sampling was carried out with an interval of three months. The task of studying the spectra of oil fractions as a single integral object (i.e., without studying the molecular composition) of complex molecular composition was directly solved. In connection with this, multidimensional equidistant spectra were subjected to processing in a wide spectral range. Measurements were made under the following conditions: frequency range of from 500 to 1500 cm–1, spectral resolution of 1 cm–1 and frequency change step of 0.5 cm–1. The studied objects were 33 fractions of thermal distillation of oil. The processing of the results of spectroscopic measurements was carried out using multivariate mathematical statistics methods. The efficiency of using molecular absorption spectroscopy in the mid-IR region to study and control the optical characteristics (absorption spectra) of thermal oil distillation fractions is shown.

Assessment of antioxidant activity of citronellal extract and fractions of essential oils of Citrus hystrix DC

Purpose: To evaluate the antioxidant activities and chemical compositions of citronellal extract and fractions of essential oils of Citrus hystrix.Methods: Antioxidant activity was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Essential oil was produced by steam distillation while isolated citronellal and fractional distillates were obtained on a PiloDist 104-VTU fractional column at 5 mBar pressure and a reflux ratio of 20:10. Gas chromatography-mass spectrometry was used to determine their chemical composition.Results: All the essential oils produced from parts of C. hystrix, i.e., twigs oil (CHT), leaves-twigs oil (CHTL), leaves oil (CHL), and fruit peels oil (CHP), citronellal extract of CHL oil (CHLCE) and the distillation fractions of CHT oil (F1–F9), exhibited antioxidant activity. CHP exhibited the highest antioxidant activity. The chemical composition of CHT, CHTL and CHL was dominated by oxygenated monoterpenes (OMs), whereas that of CHP and F1 comprised mainly of a hydrocarbon monoterpene (HM).Conclusion: The antioxidant activities of essential oils from parts of C. hystrix and the fractions produced by essential oil fractional distillation exhibited a combination of HMs and OMs. Essential oils of CHP and F3 produced from the essential oil fractional distillation of CHT with a nearly equal composition of HM and OM compounds had higher antioxidant activity than the other essential oils and fractions, with IC50 values of 6.43 and 2.40 μL/mL, respectively.Keywords: Citrus hystrix, Essential oil, Hydrocarbon monoterpene, Oxygenated monoterpene, Antioxidant

Characterization of upgraded fast pyrolysis oak oil distillate fractions from sulfided and non-sulfided catalytic hydrotreating

Catalytic hydroprocessing of pyrolysis oils from biomass produces hydrocarbons that can be considered for liquid fuel production. This process requires removal of oxygen and cracking of the heavier molecular weight bio-oil constituents into smaller fragments at high temperatures and pressures under hydrogen. We present in this paper the characterization of a group of five distillate fractions from each of two types of hydroprocessed oils from oak pyrolysis oil: a low oxygen content (LOC, 1.8% O, wet basis) oil and a medium oxygen content (MOC, 6.4% O, wet basis) oil. The LOC oil was generated using a sulfided hydrotreating system consisting of RuS/C and xMoS/Al2O3 while the MOC was produced using non-sulfided catalysts, Ru/C and Pd/C. Elemental analysis and 13C NMR (nuclear magnetic resonance) results suggest that the distillate fractions from both oils become more aromatic/unsaturated as they become heavier. Carbonyl and carboxylic groups were found in the MOC light fractions, while phenols were present in the heavier fractions for both MOC and LOC. Paraffin, iso-paraffin, olefin, naphthene, aromatic (PIONA) analysis of the light LOC fraction shows a predominance of paraffins with a minor amount of olefins. Sulfur analysis showed the comparative concentration of sulfur in the different fractions as well as the surprising similarity in content in some sulfided and non-sulfided fractions. These results can be used to direct future research on refinery integration and production of value-added product from specific upgraded oil streams.

Oils and lubricants based on high-viscosity heavy crude oil from the Ashal’chinskoe field

The potential content and properties of oil distillate fractions of heavy crude oil from the Ashal’chinskoe field are analyzed. The properties of the lubricants obtained from these fractions are studied. Theoretical possibility of use of this type of hydrocarbon feedstock for production of commercial motor oils and conserving lubricants is shown.

Distillation fraction-specific ecotoxicological evaluation of a paraffin-rich crude oil

Crude oil is a complex mixture of petroleum hydrocarbons (PHC) with distinct chemical, physical and toxicological properties relevant for contaminated site risk assessment. Ecotoxicological effects of crude oil distillation fractions on luminescent bacteria (Vibrio fischeri), earthworms (Dendrobaena hortensis) and invertebrates (Heterocypris incongruens) were tested using two spiked soils and their elutriates. Fraction 2 (F2) had an equivalent carbon number (ECN) range of >10 to 16, and F3 from >16 to 39. F2 showed a substantially higher ecotoxicological effect than F3 for Vibrio and Dendrobaena. In contrast, severe inhibition of Heterocypris by the poorly soluble F3 is attributed to mechanical organ blockage. Immediate sequestration of PHC to the organic matter-rich soil effected reduced toxicity for all organisms. This study indicates that a more differentiated consideration (i) of PHC mixtures based on ECN range and (ii) of model soil properties employed for ecotoxicity testing should be included into PHC-contaminated site risk assessment.

Frankincense essential oil prepared from hydrodistillation of Boswellia sacra gum resins induces human pancreatic cancer cell death in cultures and in a xenograft murine model

BackgroundRegardless of the availability of therapeutic options, the overall 5-year survival for patients diagnosed with pancreatic cancer remains less than 5%. Gum resins from Boswellia species, also known as frankincense, have been used as a major ingredient in Ayurvedic and Chinese medicine to treat a variety of health-related conditions. Both frankincense chemical extracts and essential oil prepared from Boswellia species gum resins exhibit anti-neoplastic activity, and have been investigated as potential anti-cancer agents. The goals of this study are to identify optimal condition for preparing frankincense essential oil that possesses potent anti-tumor activity, and to evaluate the activity in both cultured human pancreatic cancer cells and a xenograft mouse cancer model.MethodsBoswellia sacra gum resins were hydrodistilled at 78°C; and essential oil distillate fractions were collected at different durations (Fraction I at 0–2 h, Fraction II at 8–10 h, and Fraction III at 11–12 h). Hydrodistillation of the second half of gum resins was performed at 100°C; and distillate was collected at 11–12 h (Fraction IV). Chemical compositions were identified by gas chromatography–mass spectrometry (GC-MS); and total boswellic acids contents were quantified by high-performance liquid chromatography (HPLC). Frankincense essential oil-modulated pancreatic tumor cell viability and cytotoxicity were determined by colorimetric assays. Levels of apoptotic markers, signaling molecules, and cell cycle regulators expression were characterized by Western blot analysis. A heterotopic (subcutaneous) human pancreatic cancer xenograft nude mouse model was used to evaluate anti-tumor capability of Fraction IV frankincense essential oil in vivo. Frankincense essential oil-induced tumor cytostatic and cytotoxic activities in animals were assessed by immunohistochemistry.ResultsLonger duration and higher temperature hydrodistillation produced more abundant high molecular weight compounds, including boswellic acids, in frankincense essential oil fraactions. Human pancreatic cancer cells were sensitive to Fractions III and IV (containing higher molecular weight compounds) treatment with suppressed cell viability and increased cell death. Essential oil activated the caspase-dependent apoptotic pathway, induced a rapid and transient activation of Akt and Erk1/2, and suppressed levels of cyclin D1 cdk4 expression in cultured pancreatic cancer cells. In addition, Boswellia sacra essential oil Fraction IV exhibited anti-proliferative and pro-apoptotic activities against pancreatic tumors in the heterotopic xenograft mouse model.ConclusionAll fractions of frankincense essential oil from Boswellia sacra are capable of suppressing viability and inducing apoptosis of a panel of human pancreatic cancer cell lines. Potency of essential oil-suppressed tumor cell viability may be associated with the greater abundance of high molecular weight compounds in Fractions III and IV. Although chemical component(s) responsible for tumor cell cytotoxicity remains undefined, crude essential oil prepared from hydrodistillation of Boswellia sacra gum resins might be a useful alternative therapeutic agent for treating patients with pancreatic adenocarcinoma, an aggressive cancer with poor prognosis.

Determination of antibacterial activity of vacuum distillation fractions of lemongrass essential oil

Essential oils are natural substances composed of terpenoids and phenylpropanoid molecules that have many biological activities. Because of their activity, essential oils are widely used in foods, cosmetics, and pharmaceutical products, but new applications of such mixtures are still dependent on separation processes that are able to produce compounds with specific standardized and reproducible compositions. This work studies the fractionation of lemongrass essential oil by vacuum distillation with the goal of obtaining an antimicrobial fraction that acts against Salmonella choleraesuis, Pseudomonas aeruginosa and Staphylococcus aureus. The samples were analyzed by gas chromatography–mass spectrometry and evaluated for antimicrobial activity using the indirect bioautography method and minimum inhibitory concentrations. Vacuum distillation was found to be an efficient method for obtaining distinct fractions with increased antimicrobial activity. The fractions that showed the best response against the three microorganisms tested were F3b, F3a1, F2, F3a2 and F1, with the most effective being F3a2, which also presented the highest yield.

Analysis of Oxygenated Compounds in Hydrotreated Biomass Fast Pyrolysis Oil Distillate Fractions

Three hydrotreated bio-oils with different oxygen contents (8.2, 4.9, and 0.4 w/w) were distilled to produce light, naphtha, jet, diesel, and gas oil boiling range fractions that were characterized for oxygen-containing species by a variety of analytical methods. The bio-oils were originally generated from lignocellulosic biomass in an entrained-flow fast pyrolysis reactor. Analyses included elemental composition, carbon type distribution by 13C nuclear magnetic resonance, acid number, gas chromatography/mass spectroscopy, volatile organic acids by liquid chromatography, and carbonyl compounds by 2,4-dinitrophenylhydrazine derivatization and liquid chromatography. Acid number titrations employed an improved titrant–electrode combination with faster response that allowed the detection of multiple end points in many samples and allowed for acid values attributable to carboxylic acids and to phenols to be distinguished. The results of these analyses showed that the highest oxygen content bio-oil fractions contained oxygen as carboxylic acids, carbonyls, aryl ethers, phenols, and alcohols. Carboxylic acids and carbonyl compounds detected in this sample were concentrated in the light, naphtha, and jet fractions (<260 °C boiling point). The carboxylic acid content of all of the high oxygen content fractions was likely too high for these materials to be considered as fuel blendstocks, although the potential for blending with crude oil or refinery intermediate streams may exist for the diesel and gas oil fractions. The 4.9% oxygen sample contained, almost exclusively, phenolic compounds found to be present throughout the boiling range fractions, which imparted measurable acidity primarily in the light, naphtha, and jet fractions. Additional study is required to understand what levels of the weakly acidic phenols could be tolerated in a refinery feedstock. The diesel and gas oil fractions from this upgraded oil had low acidity but still contained 3–4 wt % oxygen present as phenols that could not be specifically identified. These materials appear to have excellent potential as refinery feedstocks and some potential for blending into finished fuels. Fractions from the lowest oxygen-content oil exhibited some phenolic acidity but generally contained very low levels of oxygen functional groups. These materials would likely be suitable as refinery feedstocks and potentially as fuel blend components. Paraffins, isoparaffins, olefins, naphthenes, and aromatics (PIONA) analysis of the light and naphtha fractions showed benzene contents of 0.5 and 0.4 vol % and predicted (research octane number (RON) + motor octane number (MON))/2 of 63 and 70, respectively.

Characterization of Athabasca Bitumen Heavy Vacuum Gas Oil Distillation Cuts by Negative/Positive Electrospray Ionization and Automated Liquid Injection Field Desorption Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

We have analyzed eight heavy vacuum gas oil (HVGO) distillation fractions, initial boiling point (IBP)−343, 343−375, 375−400, 400−425, 425−450, 450−475, 475−500, and 500−525 °C, of an Athabasca bitumen by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Acidic, basic, and nonpolar components were detected by negative-ion and positive-ion electrospray ionization (ESI) and automated liquid injection field desorption ionization (LIFDI) positive-ion FT-ICR MS. Ultrahigh mass resolving power (m/Δm50% ≈ 350 000) and high mass accuracy (<500 ppb) facilitate the assignment of a unique elemental composition to each peak in the mass spectrum. Thus, each distillate was characterized by mass, heteroatom class, type (number of rings and double bonds), and carbon number distribution to correlate compositional changes with increased boiling point. Negative-ion ESI FT-ICR MS identifies high relative abundance nonaromatic O2 species that span the entire distillation range. All ionization methods re...

Tertiary recycling of PVC-containing plastic waste by copyrolysis with cattle manure

The corrosion from pyrolysis of PVC in plastic waste was reduced by copyrolysis of PVC with cattle manure. The optimization of pyrolysis conditions between PVC and cattle manure was studied via a statistical method, the Box-Behnken model. The pyrolysis reaction was operated in a tubular reactor. Heating rate, reaction temperature and the PVC:cattle manure ratio were optimized in the range of 1-5 degrees C/min, 250-450 degrees C and the ratio of 1:1-1:5, respectively. The suitable conditions which provided the highest HCl reduction efficiency were the lowest heating rate of 1 degrees C/min, the highest reaction temperature of 450 degrees C, and the PVC:cattle manure ratio of 1:5, with reliability of more than 90%. The copyrolysis of the mixture of PVC-containing plastic and cattle manure was operated at optimized conditions and the synergistic effect was studied on product yields. The presence of manure decreased the oil yield by about 17%. The distillation fractions of oil at various boiling points from both the presence and absence of manure were comparable. The BTX concentration decreased rapidly when manure was present and the chlorinated hydrocarbon was reduced by 45%. However, the octane number of the gasoline fraction was not affected by manure and was in the range of 99-100.

Self-Association of Organic Acids in Petroleum and Canadian Bitumen Characterized by Low- and High-Resolution Mass Spectrometry

We examine solution-phase aggregation for a whole crude oil, whole bitumen, and bitumen distillate fractions by negative-ion electrospray ionization [(−) ESI] detected by both high-resolution [Fourier transform ion cyclotron resonance (FT-ICR)] and low-resolution [linear quadrupole ion trap (LTQ)] mass spectrometry (MS). Aggregate formation for both crude oil and bitumens is concentration-dependent. At high concentrations (i.e., >1 mg/mL), the disruption of noncovalent interactions between heteromultimers by low-energy collision-activated dissociation (CAD) yields LTQ dissociation mass spectra with molecular-weight distributions identical to those observed by FT-ICR MS analysis at lower concentrations for purely monomeric species. These materials can exist as aggregates in solution even at high dilution (less than 0.1 mg/mL). We demonstrate the concentration and boiling point dependence for multimerization of polar acidic species in the Athabasca bitumen and bitumen distillates. Interestingly, the lowest boiling distillation cut (375−400 °C) displays the highest aggregation tendency, with dimers at concentrations as low as 0.05 mg/mL. Higher boiling point distillation cuts display a decreased aggregation tendency with an increasing cut point. High-resolution negative-ESI FT-ICR MS of the bitumen distillation fractions reveals the elemental composition, and thus the class, type, and carbon number of the multimeric species. Acidic heteroatomic classes for the distillation cut multimers include O4, S1O4, O3, S1O3, N1O2, and N1S1O2. The most abundant multimers for the 375−400 °C distillation cut are O4 species, whereas the 450−475 °C cut contains N1O2 multimers in the highest relative abundance. Changes in multimer heteroatom content as a function of the monomer composition and distillation cut suggest that aggregation depends upon the chemical functionalities of the monomer species.

Nonpolar Compositional Analysis of Vacuum Gas Oil Distillation Fractions by Electron Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

We analyzed three vacuum gas oil distillation fractions, 295−319 °C, 319−456 °C, and 456−543 °C, with a home-built external electron ionization (EI) 7 T Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. EI at 10 eV allows soft ionization of aromatic compounds in the vacuum gas oil range. Unambiguous elemental composition assignment provides insight into compositional variations at the molecular level; for example, ultrahigh resolving power (m/Δm50% ≈ 300 000 at m/z 300) and mass accuracy (<0.4 ppm) readily resolve C3/SH4 doublets (3.4 mDa mass difference) across the full m/z range of interest. To our knowledge, this is the first time that hydrocarbons and sulfur-containing hydrocarbons have been completely mass-resolved across the full VGO range. Aromatic hydrocarbons are the major detected components in all three samples. In addition, many sulfur-, nitrogen-, and oxygen-containing compounds were directly observed. The concentrations of the heteroatomic species increase with boiling po...

Structural Studies of Vacuum Gas Oil Distillate Fractions of Kuwaiti Crude Oil by Nuclear Magnetic Resonance

Nitrogen-free vacuum gas oil (VGO) distillate was separated, using preparative column chromatography, into five hydrocarbon groups: saturates (SAs), monoaromatics (MAs), diaromatics (DAs), polycyclic aromatic hydrocarbons (PCAHs), and polar hydrocarbons (POLHs). The hydrocarbon groups MA, DA, PCAH, and POLH were separated into low- and high-sulfur compounds (LSCs and HSCs, respectively) on silica gel impregnated with PdCl2 (aqueous). SAs and LSCs obtained from MAs, DAs, PACHs, and POLHs were further fractionated into subfractions using gel permeation chromatography (GPC), based on their molecular size in solution. All the GPC subfractions were analyzed for elemental carbon, hydrogen, nitrogen, and sulfur, and for molecular weight. Nuclear magnetic resonance (NMR) spectroscopic techniques also were applied to elucidate the average molecular structure of selected GPC subfractions, POLHs, and HSCs. The SAs had average alkyl chain lengths of n = 13−15 and two naphthenic rings, and they were free of aromatics. The average molecule in the three groups (MAs, DAs, and PCAHs) contained (i) one aromatic ring, two cyclo-paraffinic rings, two alkyl groups on aromatic rings, and no bridged aromatic carbon; (ii) two aromatic rings, two naphthenic rings, five alkyl-substituted groups, and two bridged aromatic C atoms; or (iii) three aromatic rings, one naphthenic ring, four bridged aromatic C atoms, and four alkyl-substituents attached to the aromatic or naphthenic ring(s), with an average chain length of seven C atoms. The average molecule of the POLH group contained one S atom, four aromatic rings, four naphthenic rings, five bridged aromatic C atoms and four alkyl substituents attached to the aromatic or naphthenic ring with an average chain length of seven C atoms.

04/00670 FT-Raman and photoacoustic infrared spectroscopy of syndcrude heavy gas oil distillation fractions: Michaelian, K. H. et al. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy, 2003, 59A, (4), 811–824

04/00670 FT-Raman and photoacoustic infrared spectroscopy of syndcrude heavy gas oil distillation fractions: Michaelian, K. H. et al. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy, 2003, 59A, (4), 811–824

FT-Raman and photoacoustic infrared spectroscopy of syncrude light gas oil distillation fractions

FT-Raman and photoacoustic (PA) infrared spectra of 12 distillation fractions derived from Syncrude light gas oil (LGO), which has a boiling range from 195 to 343 °C, were analyzed in detail in this study. In the fingerprint region (200–1800 cm −1) most of the information is obtained from the FT-Raman spectra, which display 36 bands that are assignable to various alkyl or aryl functional groups. Monocyclic, bicyclic and tricyclic aromatics in the 12 fractions were also characterized using Raman bands in this region. The corresponding section of the infrared spectra is much simpler, displaying a relatively small number of bands due to either aromatic or aliphatic CH n ( n=1, 2 or 3) groups. The CH stretching region in both FT-Raman and PA infrared spectra of the LGO distillation fractions was curve-fitted according to procedures established in previous investigations of Syncrude samples with various boiling ranges. The PA spectra of the LGO fractions were also analyzed using an accepted integration strategy that requires no a priori assumptions with regard to the number of constituent bands or their shapes. The curve-fitting results show that the frequencies of the 11 Raman and eight infrared bands used to model the aliphatic (∼2775–3000 cm −1) parts of the respective spectra decrease systematically as the median boiling points of the LGO fractions increase. These band positions are consistent with those determined in earlier studies of other distillation fractions. Both curve fitting and integration show that the abundance of CH 2 groups increases at the expense of CH 3 groups as the boiling points of the fractions increase within the LGO region.

FT-Raman and photoacoustic infrared spectroscopy of Syncrude heavy gas oil distillation fractions

FT-Raman and photoacoustic (PA) infrared spectra of six distillation fractions derived from Syncrude heavy gas oil (HGO), which has a boiling range from 343 to 524 °C, were analyzed in detail in this study. Most of the information on the fingerprint region (200–1800 cm −1) is provided by the FT-Raman spectra, which display approximately 30 bands that are assignable to functional groups in alkanes or aromatics. Monocyclic, bicyclic and tricyclic aromatics in the six fractions were also monitored using bands in this region. The CH stretching region in both the FT-Raman and PA infrared spectra of the HGO distillation fractions was analyzed according to a curve-fitting algorithm used in previous investigations of samples with lower boiling points. The PA spectra of the HGO fractions were also analyzed by integration. The curve-fitting results show that the frequencies of the 11 Raman and 8 infrared bands used to model the aliphatic (∼2775–3000 cm −1) parts of the respective spectra are approximately constant across the entire HGO boiling range. These band positions are consistent with the results obtained in earlier studies of other distillation fractions obtained from Syncrude sweet blend. Both curve-fitting and integration show that the respective proportions of CH 2 and CH 3 groups do not vary significantly within the HGO region.