SARA separation

SARA separation a method of fractionation by which petroleum is separated into saturates, aromatics, resins, and asphaltene fractions. 

Rock samples were extracted using methylene chloride and a Soxhlet apparatus and the resulting extract was further fractionated by a semi-quantitative SARA separation. After asphaltenes were removed from the concentrated extract by precipitation with excess pentane, the pentane soluble portion of the sample was separated by medium-pressure liquid chromatography (MPLC) using a deactivated silica gel precolumn and an activated silica gel main column by eluting the saturate and aromatic hydrocarbon fractions from the activated silica column with hexane in the forward and back-flush modes respectively. Polar nonhydrocarbons were backflushed from the precolumn with methylene chloride-methanol. Carbon isotopes were done on a subset of hydrocarbon fractions at Coastal Sciences Labs, Austin, TX (Table 3). 

Sample code Structural Trend-Reservoir Compartment-Well Number (s), short string, production from the top of the oil eolumn (light oil) (1), long string, production from the base of the oil column (heavy oil). TVD SSL, total vertical depth sub-sea level. Based on stabilization results prior to SARA separation. 

Galya, L.G., Suatonl, J.C. (1980) Rapid SARA separations by high performance liquid chromatography. Journal of Liquid Chromatography, 3,229-232. 

Figure 55. Separation of the overall oxidation curve into its two components a relaxation part [according to Eq. [30]] responsible for the initial shape of the curve, and a diffusion part [Eq. [39]], which controls the final shape of the chronocoulogram. (Reprinted from T. F. Otero and H.-J. Grande, Reversible 2D to 3D electrode transition in polypyrrole films. Colloid Surf. A. 134, 85, 1998, Figs. 4-9. Copyright 1998. Reproduced with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 Amsterdam, The Netherlands.)...

AQUATECH Systems is a state-of-the-art bipolar membrane separation technology which exemplifies "pollution prevention" technology rather than "end of the pipe" regulation compliance. Consistent with SARA s definition of treatment, AQUATECH Systems is a technology "that in whole or in part will result in a permanent and significant decrease in the toxicity, morbidity or volume" of a hazardous waste material. 

Fig. 1 Optimized separation of alcohols. Column, HPX-87 H (300 X 7.8-mm ID) column temperature, 50°C mobile phase, 0.01 N sulphuric acid flow rate, 0.7 ml/min refractive index detection. For peak identification, see Table 1. (Reprinted from Ref. 13 with the kind permission of Elsevier Science—NL, Sara Burgerhartstraat 25, 1055 KV Amsterdam, The Netherlands.)...

Confirmation of FLU in catfish muscle by electrospray LC/MS was done (199). Residues of CIPRO, ENRO, SARA, and DIFLX were positively identified at 10-80 /ug/kg. The extraction procedure was based on LLE with acidic ethanol. Extracts were cleaned up on a PRS SPE cartridge. Analytes were eluted with 30% ammonium hydroxide-MeOH (1 4). Chromatographic conditions were optimized to be compatible with the electrospray interface. To obtain maximum sensitivity, separate MS acquisition programs were developed for CIPRO/ENRO and SARA/ DIFLX pairs. This method was used to confirm residues in tissues fortified in the 10-80-ppb range. All relative abundances were within 10% of the value calculated for standard compounds. 

In general terms, group-type analysis of petroleum is often identified by the acronyms for the names PONA (paraffins, olefins, naphthenes, and aromatics), PIONA (paraffins, Ao-paraffins, olefins, naphthenes, and aromatics), PNA (paraffins, naphthenes, and aromatics), PINA (paraffins, Ao-paraffins, naphthenes, and aromatics), or SARA (saturates, aromatics, resins, and asphaltenes). However, it must be recognized that the fractions produced by the use of different adsorbents will differ in content and will also be different from fractions produced by solvent separation techniques. 

First Results at Systeme Accelerateur Rhone-Alpes (SARA) with a He-Jet Coupled to a High-Current Mass Separator Source... 

Similar solubility phenomena can also be observed for the resins. The sample for resin separation after removal of asphaltenes is normally applied as a solution in nC5. However, after the removal of the oil, the fractions obtained from the ion exchangers show a marked decline in solubility in the same solvent. Also, if resin separation is done by the SARA method, the tetrahydro-furan fraction is hardly soluble in nC5. This again shows the solubility criterion to be a function of several variables the removal of some of the solubilizing components of the resins renders the remainder insoluble. 

Important analyses for the whole crude are as follows, including a liquid chromatographic separation adapted from the published SARA procedure (Saturates-Aromatics-Resins-Asphaltenes) for isolation of seven classes of compounds from mid-distillate (9). 

In a separate study, Sara Lazar, Ph.D., and her colleagues at Massachusetts General Hospital discovered that brain regions associated with sensory processing and attention were thicker in the subjects who meditated, documenting for the first time this link between brain structure and meditation. Further, they found that cortical thickness... 

Hazardous Decomp. Prods. None known HMIS Health 1, Flammability 0, Reactivity 0 Storage Store in cool, dry area away from incompat. materials si. hygroscopic prevent moisture pickup and caking Uses Plutonium separation hydrolysis of ribonucleic acid absorbent Regulatory SARA 302/311/312/313 nonreportable... 

Uses Fire extinguisher fluid ingred. solvent for fats, waxes, resins synthesis intermediate reagent heavy liq. for min. and salt separations and in org. synthesis Regulatory SARA 313 reportable Manuf./Distrib. AccuStandard http //www.accustandard.com, Acros Org. http //www.acros.be, Aldrich http //www.sigma-aldrich.com, Alfa Aesar http //www.alfa.com, Fluka http //www.sigma-aldrich.com Fluorochem USA... 

Uses Removal aid for organic substances from aq. foods porous beads as adsorbent for sol. orgs. from polar solvents, for separating aromatic compds. from hydroxylic soivs, and for adsorbing steroids and emulsifiers Regulatory FDA 21CFR 173.65 SARA 313 reportable... 

Asphalt is thought of as a colloidal system similar to petroleum, the difference being that the lighter molecules have been removed from asphalt during the refining process. Asphalt can be fractionated into four important fractions saturates, aromatics, resins, and asphaltenes by either the SARA method or the ASTM D4124 process (standard test method for separation of asphalt into four fractions). The fractionated part of saturates and aromatics is generally considered to be gas-oil. The polarity of these four fractions increases from saturates —> aromatics —> resins —> asphaltenes. 

Muller et al. used SCS derivatives to study the effects of hydrodesulfurization (HDS) on polycyclic aromatic sulfur heterocycles (PASHs) in bitumen residua. Their experiments concentrated on PASHs, which is a predominant class of SCS in vacuum residue bottoms. Asphaltenes were removed by precipitation, followed by the separation of aromatic fractions from saturated fractions by the saturates, aromatics, resins, and asphalts (SARA) method. Several methods can be deployed as the SARA method depending on the type of petroleum sample, one of the more common for more viscous oils is a combination of two methods ASTM D2007 and ASTM D893. Pentane-insoluble (PI) method ASTM D893 is used first to identify the asphaltene content then ASTM D2007 is used to calculate the saturates, aromatics, and resins. 

Conversion (upgrading) of bitumen and heavy oils to distillate products requires reduction of the MW and boiling point of the components of the feedstocks. The chemistry of this transformation to lighter products is extremely complex, partly because the petroleum feedstocks are complicated mixtures of hydrocarbons, consisting of 10 to 10 different molecules. Any structural information regarding the chemical nature of these materials would help to understand the chemistry of the process and, hence, it would be possible to improve process yields and product quality. However, because of the complexity of the mixture, the characterization of entire petroleum feedstocks and products is difficult, if not impossible. One way to simpHfy this molecular variety is to separate the feedstocks and products into different fractions (classes of components) by distillation, solubility/insolubility, and adsorption/desorption techniques. For bitumen and heavy oils, there are a number of methods that have been developed based on solubility and adsorption. The most common standard method used in the petroleum industry for separation of heavy oils into compound classes is SARA (saturates, aromatics, resins, and asphaltenes) analysis. Typical SARA analyses and properties for Athabasca and Cold Lake bitumens, achieved using a modified SARA method, are shown in Table 1. For comparison, SARA analysis of Athabasca bitumen by the standard ASTM method is also shown in this table. The discrepancy in the results between the standard and modified ASTM methods is a result of the aromatics being eluted with a... 

The chemistry of resid upgrading is extremely complicated. " This is in part due to the complexity of the ehemical nature of the feedstoeks. In order to understand the chemistry of upgrading, it would be helpful to reduee this complexity prior to reaction, by separating the feedstocks (bitumen and heavy oils) into well-known components such as SARA - saturates, aromatics, resins and asphaltenes - which are useful tools in understanding bitumen chemistry. 

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