Crude physicochemical properties

The primary processes determining the fate of crude oils and oil products after a spill are (1) dispersion, (2) dissolution, (3) emulsification, (4) evaporation, (5) leaching, (6) sedimentation, (7) spreading, and (8) wind. These processes are influenced by the spill characteristics, environmental conditions, and physicochemical properties of the material spilled. 

The discrepancy in numbers between natural and synthetic varieties is an expression of the usefulness of zeolitic materials in industry, a reflection of their unique physicochemical properties. The crystal chemistry of these aluminosilicates provides selective absorbtion and exchange of a remarkably wide range of molecules. Some zeolites have been called molecular sieves. This property is exploited in the purification and separation of various chemicals, such as in obtaining gasoline from crude petroleum, pollution control, or radioactive waste disposal (Mumpton, 1978). The synthesis of zeolites with a particular crystal structure, and thus specific absorbtion characteristics, has become very competitive (Fox, 1985). Small, often barely detectable, changes in composition and structure are now covered by patents. A brief review of the crystal chemistry of this mineral group illustrates their potential and introduces those that occur as fibers. 

Molina Velasco, D., Navarro Uribe, U., and Murgich, J. Partial Least-Squares (PLS) Correlation between Refined Product Yields and Physicochemical Properties with the H Nuclear Magnetic Resonance (NMR) Spectra of Colombian Crude Oils. Energy Fuels 21 (2007) 1674-80. 

Abstract The telomerization of butadiene with alcohols is an elegant way to synthesize ethers with minimal environmental impact since this reaction is 100% atom efficient. Besides telomerization of butadiene with methanol and water that is industrially developed, the modification of polyols is still under development. Recently, a series of new substrates has been involved in this reaction, including diols, pure or crude glycerol, protected or unprotected monosaccharides, as well as polysaccharides. This opens up the formation of new products having specific physicochemical properties. We will describe recent advances in this field, focusing on the reaction of renewable products and more specifically on saccharides. The efficient catalytic systems as well as the optimized reaction conditions will be described and some physicochemical properties of the products will be reported. 

Table 23 gives the main physicochemical properties of a number of naphtha cuts derived from Kirkuk and Hassi-Messaoud crudes. The steam cracking of these naphthas yields a wide variety of products, ranging from hydrogen to highly aromatic heavy liquid fractions. 

A sublibrary L17, made of 42 diverse library individuals (Fig. 11.23), was screened in an in vivo model for the proliferation of fibroblasts, where a high value represented a candidate for the tissue reconstruction process around the medical implant. The screening protocol was performed in parallel, and a correlation was established between the fibroblast proliferation (biological property) and the air-water contact angle (physicochemical property). A crude SAR was assessed for further, more... 

Use of Ultrasonic Vibration Potential To Monitor Coalescence. The complex chemical nature of crude oils makes it difficult to relate the dispersion behavior to the physicochemical properties at the crude-oil-water interface. In addition, the nonpolar and nontransparent nature of the oleic phase provides significant obstacles for studies of the interactions of the suspended water droplets in real systems. Recent development (28, 29) of electroacoustical techniques has shown considerable promise for electrokinetic measurements of colloidal systems and the direct monitoring of the rate and extent of coagulation (flocculation and coalescence) of water droplets in nontransparent water-in-oil media. The electroacoustic measurement for colloidal systems in nonpolar media is based on the ultrasound vibration potential (UVP) mode, which involves the applica-... 

Phosphoadenosine 5 -phosphosulfate (PAPS) is the well-known sulfate donor that occupies a central position in sulfate biochemistry (Balasubrama-nian and Bachhawat, 1970 DeMeoi, 1975 Farooqui, 1980b). It is hydrolyzed into PAP and sulfate by PAPS sulfohydrolase (Balasubramanian and Bachhawat, 1962). Nothing has been reported on the purification of this enzyme, but the crude enzyme preparation shows optimal activity at pH 6.0. It is activated by Co " " and Mn " " and inhibited by ADP, fluoride, and sulfhydryl compounds (Balasubramanian and Bachhawat, 1962). The desulfation of PAPS is a specific reaction. Arylsulfohydrolase A from chicken brain and rabbit kidney cortex does not hydrolyze PAPS to PAP (Farooqui and Bachhawat, 1972 Farooqui and Helwig, unpublished). Because PAPS sulfohydrolase has never been purified from any source, nothing is known about its physicochemical properties. 

The chemical structure and physicochemical properties of asphaltenes and resins are not well understood. The operational definitions of asphaltenes and resins are based on their solubility in different diluents. Asphaltenes are defined as the fraction of crude oil insoluble in excess normal alkanes such as n-pentane but soluble in excess benzene and toluene at room temperature. Resins are defined as the fraction of crude oil insoluble in excess liquid propane at room temperature. Resins are adsorbed on silica, alumina, or other surface-active material. Figure 5.8 shows the precipitation when a bitumen oil is mixed with various diluents. The normal alkanes used are n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane. According to the operational definition stated above, the asphaltene content of the bitumen... 

The ideal crude oil assay should be able to provide on-line, instantaneous and detailed determination of all crude oil properties across the boiling range. Unfortunately, such a method is not yet available. However, several efforts have been made to that end. The most successful approach has been the prediction of the physicochemical properties of crude oils by correlating the data obtained by a rapid, surrogate method (usually spectroscopic) to the data... 

Erspamer developed a very sensitive assay using the isolated rat uterus in oestrus. Vane made use of the rat-stomach fundus cut into narrow strips. The heart of a mollusc, Venus mercenaria, was also utilized by Welsh to detect minute amounts of S-HT in various biological materials (see Erspamer in ref. 4). The specificity of these bioassays should be verified systematically with S-HT antagonists like LSD or BOL since so many factors in crude-tissue extracts can also induce similar biological effects. The biological assays lost some of their value following the development of more sensitive assay techniques based on physicochemical properties of indoles and their derivatives. 

Bruheim P, Bredholt H, Eimhjellen K (1997) Bacterial degradation of emulsified crude oil and the effect of various surfactants. Can J Microbiol 43(l) 17-22 Bunster L, Fokkema NJ, Shippers B (1989) Effect of surfiice-active Pseudomonas spp. on leaf wettability. Appl Environ Microbiol 55 1434-1435 Burd G, Ward OP (1996) Physicochemical properties of PM-fector, a surfece-active agent produced by Pseudomonas marginalis. Can J Microbiol 42 243-252 Calvo C, Martinez-Checa F, Mota A, Bejar V, Quesada E (1998) Effect of cations, pH and sulfate content on the viscosity and emulsifying activity on the Halomonas eurihalina. J Ind Microbiol Biotechnol 20 205-209 Cameron DR, Cooper DG, Neufeld RJ (1988) The mannoprotein of Saccharo-myces cerevisiae is an effective bioemulsifier. Appl Environ Microbiol 54 1420-1425... 

---