Hydrocarbons asphalt

Asphalt Hydrocarbon material ranging in consistency from heavy liquid to a solid. Most common source is residue left after fractional distillation of crude oils used primarily for surfacing roads. Asphyxia Suffocation from lack of oxygen. Chemical asphyxia is produced by a substance, such as carbon monoxide, that combines with hemoglobin to reduce die blood s capacity to transport oxygen. Simple asphyxia is the result of exposure to a substance, such as carbon dioxide, that displaces oxygen. 

Chemical Name Petroleum Representative Chemicals Aliphatic, aromatic, paraffinic hydrocarbons Naphthenic hydrocarbons Asphaltic hydrocarbons Trace metals Chemical Abstracts Service Registry Number CAS 8002-05-9... 

Asphalt Hydrocarbon material ranging in consistency from heavy liquid to a solid. Most common source is residue left after fractional distillation of crude oils used primarily for surfacing roads. 

Figure 2-3 shows the composition of several gasolines. Table 2-2 indicates in a general way the series of hydrocarbons that have been found in Pennsylvania, Mid Continent, and California oils. The C H2n 8, C H n-i2, C H2 -i6, and C H2 2o series were taken from Mabery s study of lubricant and asphaltic hydrocarbons. The ultimate composition of a few petroleums is listed in Table 2-3. 

The decrease in petroleum and natural gas reserves has encouraged interest in and discovery and development of unconventional sources of these hydrocarbons. Principal alternatives to conventional petroleum reserves include oil shale (qv) and tar sands (qv). Oil shale reserves in the United States are estimated at 20,000 EJ (19.4 x 10 Btu) and estimates of tar sands and oil sands reserves are on the order of 11 EJ (10 x 10 Btu) (see Tarsands Shale oil). Of particular interest are the McKittrick, EeUows, and Taft quadrangles of Cahfomia, the Asphalt Ridge area of Utah, the Asphalt, Kentucky area, and related geographic regions. 

Tar Sands. Tar sands (qv) are considered to be sedimentary rocks having natural porosity where the pore volume is occupied by viscous, petroleum-like hydrocarbons. The terms oil sands, rock asphalts, asphaltic sandstones, and malthas or malthites have all been appHed to the same resource. The hydrocarbon component of tar sands is properly termed bitumen. 

The conditions of pyrolysis either as low or high temperature carbonization, and the type of coal, determine the composition of Hquids produced, known as tars. Humic coals give greater yields of phenol (qv) [108-95-2] (up to 50%), whereas hydrogen-rich coals give more hydrocarbons (qv). The whole tar and distillation fractions are used as fuels and as sources of phenols, or as an additive ia carbonized briquettes. Pitch can be used as a biader for briquettes, for electrode carbon after coking, or for blending with road asphalt (qv). 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

Asphalt, prepared from petroleum, often resembles native asphalt. When asphalt is produced by distillation, the product is called residual, or straight-mn, asphalt. However, if the asphalt is prepared by solvent extraction of residua or by light hydrocarbon (propane) precipitation, or if it is blown or otherwise treated, the name should be modified accordingly to qualify the product, eg, propane asphalt. 

In general, when the product is a fraction from cmde oil that includes a large number of individual hydrocarbons, the fraction is classified as a refined product. Examples of refined products are gasoline, diesel fuel, heating oils, lubricants, waxes, asphalt, and coke. In contrast, when the product is limited to, perhaps, one or two specific hydrocarbons of high purity, the fraction is classified as a petrochemical product. Examples of petrochemicals are ethylene (qv), propylene (qv), benzene (qv), toluene, and xylene (see Btx processing). 

Tanks are used to store hquids over a wide temperature range. Cryogerhc hquids, such as hquefied hydrocarbon gases, can be as low as —201 C(—330 F). Some hot hquids, such as asphalt (qv) tanks, can have a normal storage temperature as high as 260—316°C (500—600°F). However, most storage temperatures are either at or a htde above or below ambient temperatures. 

The composition of montan wax depends on the material from which it is extracted, but all contain varying amounts of wax, resin, and asphalt. Black montan wax may be further processed to remove the resins and asphalt, and is known as refined montan wax. White montan wax has been reacted with alcohols to form esters. The wax component of montan is a mixture of long-chain (C24—C q) esters (62—68 wt %), long-chain acids (22—26 wt %), and long-chain alcohols, ketones, and hydrocarbons (7—15 wt %). Cmde montan wax from Germany typically has a melting point of 80°C, an acid number of 32, and a saponification number of 92. 

Asphalt [8052-42-4] is defined by the American Society for Testing and Materials (ASTM) (1) as a dark brown to black cementitious material in which the predominating constituents are bitumens that occur in nature or are obtained in petroleum processing. Bitumen is a generic term defined by ASTM as a class of black or dark-colored (soHd, semisoHd, or viscous) cementitious substances, natural or manufactured, composed principally of high molecular weight hydrocarbons, of which asphalts, tars, pitches, and asphaltites are typical. 

Asphalts characteristically contain very high molecular weight molecular polar species, called asphaltenes, which are soluble in carbon disulfide, pyridine, aromatic hydrocarbons, chlorinated hydrocarbons, and tetrahydrofiiran. 

Bitumen Soluble in Carbon Disuffide (ASTMD4). Asphalt is defined as a mixture of hydrocarbons that are completely soluble in carbon disulfide. Trichloroethylene or 1,1,1-trichloroethane have been used in recent years as safer solvents for this purpose. The procedure for these and other solvents for asphalt with Htde or no mineral matter are described in ASTM D2042. 

Asphalt Asphalt is used as a flexible protective coating, as a bricklining membrane, and as a chemical-resisting floor covering and road surface. Resistant to acids and bases, alphalt is soluble in organic solvents such as ketones, most chlorinated hydrocarbons, and aromatic hydrocarbons. 

Petroleum chemistry is concerned with the origin, composition, and properties of naturally occurring petroleum deposits, whether in liquid (crude oil or petroleum), gaseous (natural gas), or solid (tars and asphalts) form. All of them are essentially mixtures of hydrocarbons. Whereas natural gas contains a few lighter hydrocarbons, both crude oil and tar deposits may consist of a large number of different hydrocarbons that cannot be easily identified for molecular structure or analyzed for composition. 

Nitrogen, Sulfur and Oxygen Compounds. These are usually abbreviated as NSO compounds and sometimes referred to as asphaltics. Although present in small amounts, the N, S, and O atoms contribute greatly to the nonhydrocarbon fraction of a crude oil by their incorporation into hydrocarbon molecules. The residuum contains a high percentage of NSO compounds. 

Liquid propane is a selective hydrocarbon solvent used to separate paraffinic constituents in lube oil base stocks from harmful asphaltic materials. It is also a refrigerant for liquefying natural gas and used for the recovery of condensable hydrocarbons from natural gas. 

Vacuum distillation increases the amount of the middle distillates and produces luhricating oil base stocks and asphalt. The feed to the unit is the residue from atmospheric distillation. In vacuum distillation, reduced pressures are applied to avoid cracking long-chain hydrocarbons present in the feed. 

On the other hand, liquid propane also has a high affinity for paraffinic hydrocarbons. Propane deasphalting removes asphaltic materials from heavy lube oil base stocks. These materials reduce the viscosity index of lube oils. In this process, liquid propane dissolves mainly paraffinic hydrocarbons and leaves out asphaltic materials. Higher extraction temperatures favor better separation of the asphaltic components. Deasphalted oil is stripped to recover propane, which is recycled. 

---