Hydrocarbons, heavy Petroleum

Rubbers. Plasticizers have been used in mbber processing and formulations for many years (8), although phthaHc and adipic esters have found Htde use since cheaper alternatives, eg, heavy petroleum oils, coal tars, and other predominandy hydrocarbon products, are available for many types of mbber. Esters, eg, DOA, DOP, and DOS, can be used with latex mbber to produce large reductions in T. It has been noted (9) that the more polar elastomers such as nitrile mbber and chloroprene are insufficiendy compatible with hydrocarbons and requite a more specialized type of plasticizer, eg, a phthalate or adipate ester. Approximately 50% of nitrile mbber used in Western Europe is plasticized at 10—15 phr (a total of 5000—6000 t/yr), and 25% of chloroprene at ca 10 phr (ca 2000 t/yr) is plasticized. Usage in other elastomers is very low although may increase due to toxicological concerns over polynuclear aromatic compounds (9). 

There are different sources for obtaining synthesis gas. It can be produced by steam reforming or partial oxidation of any hydrocarbon ranging from natural gas (methane) to heavy petroleum residues. It can also... 

DCC [Deep catalytic cracking] A general term for processes which convert heavy petroleum feedstocks and residues to hght hydrocarbons. One such process, for making C3-C5 olefins, was developed by the Research Institute of Petroleum Processing, China, and licensed through Stone Webster. Five units were operating in China in 1997. 

Demex [Demetallization by extraction] A process for removing metal compounds from heavy petroleum fractions, after vacuum distillation, by solvent extraction and supercritical solvent recovery. The solvent is typically a mixture of octanes and pentanes. Developed jointly by UOP and the Institute Mexicano del Petroleo seven units were operating in 1988. Hydrocarbon Process., 1988, 67(9), 66. 

Endewax [National Chemical dewaxing] A process for dewaxing heavy petroleum fractions by treatment with a catalyst which converts the long-chain hydrocarbons to shorter ones. The catalyst is a ZSM-5 -type zeolite in which some of the aluminum has been replaced by iron. Developed by the National Chemical Laboratory, Pune, India, and piloted in 1991. 

Method 5520D wastewater hydrocarbons. Method D is the method of choice when relatively polar, heavy petroleum fractions are present, or when the levels of nonvolatile greases may challenge the solubility of the solvent. 

The most common method for GC/MS analysis of semivolatile compounds (EPA SW-846 8270) includes 16 polycyclic aromatic compounds, some of which commonly occur in middle distillate to heavy petroleum products. The method also quantifies phenols and cresols, compounds that are not hydrocarbons but may occur in petroleum products. Phenols and cresols are more likely found in crude oils and weathered petroleum products. 

Producing relatively accurate dry-weight values for heavy petroleum hydrocarbons but questionable dry weight values for lighter, more volatile compounds. Note Different labs dry the samples in different ways and a sample with lots of lighter-fraction hydrocarbons is more prone to hydrocarbon loss the variable loss of volatile hydrocarbons in a drying step is therefore an additional area of lab and data variability). 

Transalkylation involves the transfer of alkyl groups between aromatic nuclei, usually in the presence of strong Lewis acids. Heredy and Neuworth used this reaction to "depolymerize" coal. As a result of the reaction of coal with BF3 and phenol, the solubility of coal in phenol or pyridine increased substantially. Various modifications of this reaction have since been reported . Transall lation reactions in the presence of trifluoromethane sulfonic acid and aromatic hydrocarbons have recently been used by Benjamin et al. and Farcasiu et al. to identify structural features in coals and heavy petroleum ends, respectively. 

A species frequently maintains phase equilibrium while it is reacting in one phase. An example is hydrocracking of heavy hydrocarbons in petroleum refining, where H2 from the vapor dissolves into the liquid hydrocarbon phase, where it reacts with large hydrocarbons to crack them into smaller hydrocarbons that have sufficient vapor pressure to evaporate back into the vapor phase. As long as equilibrium of the species between phases is maintained, it is easy to calculate the concentrations in the hquid phase in which reaction occurs. 

In summary there is not enough information published regarding the production of light hydrocarbon molecules (petroleum) or very heavy ones (coal) in geologic time. It is not possible at present to determine whether time, temperature or pressure plays a role, predominant or minor, in the evolution of the organic debris incorporated in sediments. It is certain that the interaction of silicate equilibria and transformations... 

The physical processes by which natural gas liquids are recovered include phase separation, cooling, compression, absorption, adsorption, refrigeration, and any combination of these. Obviously the definition already stated excludes refinery light volatiles produced by the destructive decomposition of heavy petroleum fractions and it also excludes liquids that may be produced synthetically from natural gas. These distinctions are of economic importance in considering our basic energy reserves. Both the refinery volatiles and the synthetic liquids represent conversion products from other hydrocarbons and the conversion is usually attended by a considerable loss. Thus it has been stated that only about 47% (17) of the energy of natural gas is realized in the liquid hydrocarbon products of the Fischer-Tropsch type of synthesis. 

Studiengesselschaft Kohle m.b.H. (2) reported the effect of temperature on solubility level in supercritical gas. The solubility is highest within 20 K of the critical temperature and decreases as temperature is raised to 100 K above the critical temperature. At temperatures near the critical temperature, a sharp rise in solubility occurs as the pressure is increased to the vicinity of the critical pressure and increases further as the pressure is further increased. Less volatile materials are taken up to a lesser extent than more volatile materials, so the vapor phase has a different solute composition than the residual material. There does not seem to be substantial heating or cooling effects upon loading of the supercritical gas. It is claimed that the chemical nature of the supercritical gas is of minor importance to the phenomenon of volatility amplification. Ethylene, ethane, carbon dioxide, nitrous oxide, propylene, propane, and ammonia were used to volatilize hydrocarbons found in heavy petroleum fractions. 

In this chapter, we will discuss the basic controls on the transport of some of these contaminants mentioned above in the water column and sediments of estuaries. While there are five general classes of contaminants (petroleum hydrocarbons, halogenated hydrocarbons, heavy metals, radionuclides, and litter) considered to be critical in coastal environments (Waldichuk, 1989), the primary focus will be on the biogeochemical dynamics of a select group of contaminants as they relate to other stressors, such as nutrients, in this chapter. For a more comprehensive assessment of the actual statistics on toxicity and surveys of the distribution and loading rates of all the aforementioned contaminants in estuaries, please refer to Kennish (1997). 

In some oil producing countries (e.g. U.S.S.R.), toluene is obtained from aromatic fractions of petroleum or by aromatization of heavy petroleum hydrocarbons by cracking processes (in Poland studies on aromatization of petroleum were carried out by K. Smolenski [1] between 1922 and 1939). In war-time the demand for toluene for nitration was so large, that these two sources were inadequate. During World War II new methods of toluene manufacture on an industrial scale were developed starting from benzene and methyl alcohol and from n-heptane. 

Xylene obtained by cracking heavy petroleum hydrocarbons has approximately ... 

Pyrolysis. One type of thermal dissociation a reaction in which complex molecules (as of a heavy petroleum hydrocarbon) split into relatively simple fragments under the application of heat. 

When considering the higher hydrocarbons present in natural gas it is probably best to recall that a continuum exists in oil and gas reservoirs from almost pure methane to heavy petroleum oils and waxes. In general, hydrocarbon deposits do not span to the extremes higher hydrocarbon free natural gas is not commonly accounted although there are some very large natural gas deposits which comprise almost entirely methane . Thus many oil reserves have considerable quantities of associated gas and most gas reserves have associated with them light oil (condensate) deposits. 

PROP Colorless, oily liquid practically tasteless and odorless. D 0.83-0.86 (light), 0.875-0.905 (heavy), flash p 444°F (OC), ULC 10-20. Insol in water and ale sol in benzene, chloroform, and ether. A mixture of liquid hydrocarbons from petroleum. IDLH 2500 mg/m3,... 

Chapters 10-12 cover important aspects of coke formation in metal tubular reactors during pyrolysis of hydrocarbons. Chapters 13 and 14 are concerned with coal and lignite pyrolysis. Chapters 15 and 16 deal with pitch formation from, respectively, heavy petroleum fraction and tar sand bitumen. Chapters 17 and 18 cover studies on the mechanisms of thermal alkylation and hydropyrolysis. Chapters 19 and 20 on oil shale deal with the properties of oil shale and shale oil as developed by techniques of microwave heating and thermal analysis. 

Diesel fuels are complex mixtures of hydrocarbons defined by physical and chemical properties. Petroleum diesel fuels are based on molecules with 9 to 20 carbon atoms and a boiling range between 170°C and 350°C (10). These fuels are produced by sequential chemical treatments and refining of heavy petroleum oils followed by distillation. In general, specifications for fuels are inclusive so as not to exclude compositions with similar operational characteristics. However, environmental concerns regarding toxic emissions from diesel engines have led to legislation that has forced manufacturers to modify diesel fuel chemistry (11). 

Baseline Studies of Pollutants in the Marine Environment (Heavy Metals, Halogenated Hydrocarbons and Petroleum), background papers for a workshop sponsored by the N.S.F. OfiBce for the I.D.O.E., Brookhaven Natl. Lab., 24-26 May, p. 231, 1972. 

Activated charcoal and/or emesis may be indicated in some hydrocarbon ingestions in which absorption may produce systemic effects. Agents such as asphalt, tar, heavy lubricants, vaseline, and mineral oil are considered relatively nontoxic and do not require removal. Chlorinated hydrocarbon solvents or any hydrocarbon or petroleum distillate with a potentially dangerous additive (camphor, pesticide, and heavy metals) in some cases may be treated with activated charcoal or emesis. Petroleum naphtha derivatives, gasoline, kerosene, and mineral seal oil (or signal oil) as found in furniture polish and oil polishes produce severe and often prolonged chemical pneumonitis. These compounds are poorly... 

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