Petroleum residual, characterization

Characterization of Heavy Crude Oils and Petroleum Residues. Caracterisation des huiles lourdes et des residus petroliers. Symposium international, Lyon, 1984. 

An evaluation of preparation parameters and their impact on catalyst production is presented along with an electron microscopy characterization of the actual active phase generated during hydroconversion of a deasphalted vacuum residue. Finally, the potential interest of this catalytic stem is illustrated by an evaluation of its performance in hydroconversion of a petroleum residue. 

Samples were characterized by XRD (Siemens D5000 XRD spectrometer), FE-SEM (Field Emission Scanning Electron Microscope, Hitachi S-4800), textural properties were determined by N2 adsorption/desorption experiments) and NH3-TPD (temperature-programmed desorption of ammonia). Catalytic properties of samples were tested in the cracking of a Bach Ho petroleum residue from Vietnam (370-500°C fraction) as heavy feedstock using a MAT 5000 micro activity testing system. The reaction conditions were 482°C, WVH=27, catalyst to feedstock ratio 3/1, reaction time 45 sec. 

Typically, petroleum residue is characterized by proximate analysis, which only quantifies the fraction of fuel material (FM), ash and moisture, and elemental (ultimate) analysis (C, H, O, N, S). In the proximate analysis, the fuel fraction is usually divided into two parts fixed carbon (FC) and volatile material (VM). For calculation purposes, both fractions are totalized as ash-free dry fuel matter (expressed in weight%). With the elemental analysis (reported in weight% dry basis for each element), it is possible to obtain the condensed formula of the fuel fraction and thus its molecular weight. 

The most important olefins used for the production of petrochemicals are ethylene, propylene, the butylenes, and isoprene. These olefins are usually coproduced with ethylene by steam cracking ethane, LPG, liquid petroleum fractions, and residues. Olefins are characterized by their higher reactivities compared to paraffinic hydrocarbons. They can easily react with inexpensive reagents such as water, oxygen, hydrochloric acid, and chlorine to form valuable chemicals. Olefins can even add to themselves to produce important polymers such as polyethylene and polypropylene. Ethylene is the most important olefin for producing petrochemicals, and therefore, many sources have been sought for its production. The following discusses briefly, the properties of these olefmic intermediates. 

Simoneit BRT, Organic matter of the troposphere III — Characterization and sources of petroleum and pyrogenic residues in aerosols over the Western United St3X.es, Atmos Environ 18 51-67, 1984. 

Because of the small quantities of organic substances that could be separated from the indurated rock samples, their separation and characterization has been difficult. Most of the organic carbon of the rocks is in a form that cannot be extracted with petroleum solvents, mineral acids, or bases. Of the material that can be so extracted, three general types of substances predominate hydrocarbons, carbohydrate residues, and amino acid residues from protein. These occur in quantities of about 10-150 p.p.m. Other organic matter extracted by petroleum solvents, mineral acids, or bases appears, on the... 

A soln of the substrate (a terminally protected Ser or Thr derivative) (5 mmol), CDI (0.81 g, 5 mmol) and TEA (0.7 mL, 5 mmol) in dry THF (20 mL) was stirred at rt for 4-6 h. The solvent was evaporated in vacuo and the residue chromatographed (silica gel 60, benzene/acetone 8 1) to give DHA derivatives which crystallized (EtOAc/petroleum ether or Et20/petroleum ether mixtures). Characterization of the DHA derivatives is given in Table 4. 

Analytical separation and spectroscopic techniques normally used for petroleum crudes and residues were modified and used to characterize coal liquids, tar sands bitumens, and shale oils. These techniques include solvent extraction, adsorption, ion-exchange, and metal complexing chromatography to provide discrete fractions. The fractions are characterized by various physical and spectroscopic methods such as GLC, MS, NMR, etc. The methods are relatively fast, require only a few grams of sample, provide compound type fractions for detailed characterization, and provide comparative compositional profiles for natural and synthetic fuels. Additional analytical methods are needed in some areas. 

Purify of the crude residue by flash chromatography on silica gel using petroleum ethenethyl acetate (98 2) as eluent to obtain pure r-1-acetyl-1-ethyl-f-2-phenylcyclo propane (19 trans cis = 7.7 1) (0.103 g, 80%) as a clear oil. Characterize the product by 1H NMR, IR spectroscopy, and HRMS spectroscopy. 

The termination of droplet trajectories by a "micro-explosion" of this nature was observed for all of the synthetic fuels and fuel blends tested, but did not occur for the petroleum derived No. 6 oil. With this latter fuel, droplets were seen to bum to extinction and to result in the formation of a carbonaceous residue, usually in the form of cenospheres. The termination of individual droplets was observed, therefore, to be strongly dependent upon fuel type and could be characterized by three distinct types of behavior 1) large (1 mm) micro-explosions with a distinctly directional behavior (SRC process donor solvent blend), 2) smaller micro-explosions (SRC-II middle, heavy, middle/ heavy blend, DFM), and 3) carbonaceous residue formation (Indones-ian-Malaysian No. 6) without micro-explosions. High speed photographs show the micro-explosions to occur in a time span much faster than the camera framing rate (1/5000 sec). 

Other factors, such as the Watson characterization factor, are also used. A highly paraffinic crude oil can have a characterization factor as high as 13, whereas a highly naphthenic crude oil can be as low as 10.5, and the breakpoint between the two types of crude oil is approximately 12. Sulfur content, the carbon residue, and distillation data are also valuable in petroleum evaluation (Speight, 2001). 

Mohammad Fabhat Ah, Ph.D., is Professor of Industrial and Petroleum Chemistry at King Fahd University of Petroleum Minerals in Saudi Arabia. An expert in characterization studies of heavy ends, residues, and asphalt, he is also knowledgeable about crude oils and products, refining process technology, waste oil recycling, and stabihty characteristics of jet fuels. 

From the remaining residue all volatile products are removed in vacuo at 50°/0.04 mbar followed by extraction with 4 x 100 mL of petroleum (bp 40/60). The petroleum and other volatile materials are stripped off in vacuo (0.04 mbar) at 20-50°. Almost pure (95%) chlorobis-[(dichlorophosphino)methyl]phosphine is left behind. Yield 21-30 g (5.4-7.7%). Chlorobis[(dichlorophosphino)methyl]phosphine is a viscous air-and moisture-sensitive liquid that may be characterized by its NMR spectral data H -NMR 8p = 48.6 ppm 73ipj3c = 52.7 Hz 73.p. 3c = 62.3 Hz... 

Detailed analysis of residual products, such as residual fuel oil, is more complex than the analysis of lower-molecular-weight liquid products. As with other products, there are a variety of physical property measurements that are required to determine whether the residual fuel oil meets specification, but the range of molecular types present in petroleum products increases significantly with an increase in the molecular weight (i.e., an increase in the number of carbon atoms per molecule). Therefore, characterization measurements or studies cannot, and do not, focus on the identification of specific molecular structures. The focus tends to be on molecular classes (paraffins, naphthenes, aromatics, polycyclic compounds, and polar compounds). 

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