Asphalt source

A number of laboratory procedures even more rapid than the accelerated Weather-o-meter have been described for the deterrnination of expected weatherabihty of coating asphalts. Research sponsored by the Asphalt Roofing Manufacturers Association describes a stepwise procedure to determine changes in the cmde asphalt source (see Asphalt). 

Apart from Trinidad and Venezuela asphalt, all other natural asphalt sources were used only occasionally in pavement construction. Today, only a few of the abovementioned deposits are currently exploited (mainly deposits of Albania, Romania and Kazakhstan). The reason is the high cost of recovering the asphalt from the rock. 

At the 4th Rubber Modified Asphalt Conference held in Akron, OH, USA in 2009, a wide-ranging paper was presented by Baumgartner [54] that addressed topics such as modified asphalt formulations, optimisation of the process temperature, and the ground tyre rubber loadings and particle size optimisation. The paper showed that rubber crumb produced from whole tyres contains around 30% reactive material for asphalt modification and that the asphalt source and chemistry directly influence the rubber loading and the final properties of the product. The processing time and temperature are also very important, as is the particle size of the crumb, which affects the efficiency of modification and the long-term performance. 

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. 

Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

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). 

Asphalt Roofing Components. Asphalt (qv) is a unique building material which occurs both naturally and as a by-product of cmde-oil refining. Because the chemical composition of cmde oils differs from source to source, the physical properties of asphalts derived from various cmdes also differ. However, these properties can be tailored by further ptocessiag to fit the appHcation for which the asphalt will be used. Softening poiat, ductility, flash poiat, and viscosity—temperature relationship are only a few of the asphalt properties that ate important ia the fabricatioa of roofing products. 

Many agents have been proposed and patented including copper sulfate (34), zinc chloride (35), ferric chloride (36), aluminum chloride (36), and phosphoms pentoxide (37) ferric chloride, zinc chloride, and phosphoms pentoxide have been most widely used. The addition of these agents may vary from 0.1 to 3%, depending upon the feedstock and the desired characteristics of the product (Table 5) and all asphalt feedstocks do not respond to catalysts in the same way. Differences in feedstock composition are important qualifiers in determining the properties of the asphalt product. The important softening point-penetration relationship, which describes the temperature susceptibiUty of an asphalt, also varies with the source of the feedstock. Straight-reduced, air-blown, and air-blown catalytic asphalts from the same cmde feedstock also vary considerably. 

Asphaltenes seem to be relatively constant in composition in residual asphalts, despite the source, as deterrnined by elemental analysis (6). Deterrnination of asphaltenes is relatively standard, and the fractions are termed / -pentane, / -hexane, / -heptane, or naphtha-insoluble, depending upon the precipitant used (5,6,49). After the asphaltenes are removed, resinous fractions are removed from the maltenes-petrolenes usually by adsorption on activated gels or clays. Recovery of the resin fraction by desorbtion is usually nearly quantitative. 

A mobile source of air pollution can be defined as one capable of moving from one place to another under its own power. According to this definition, an automobile is a mobile source and a portable asphalt batching plant is not. Generally, mobile sources imply transportation, but sources such as construction equipment, gasoUne-powered lawn mowers, and gasoline-powered tools are included in this category. 

Fig. 30-5. Batch mix asphalt plant P, denotes fugitive particulate matter emissions. Source Ref. (16),...

Venmri scrubbers have been applied to control PM emissions from utility, industrial, commercial, and institutional boilers fired with coal, oil, wood, and liquid waste. They have also been applied to control emission sources in the chemical, mineral products, wood, pulp and paper, rock products, and asphalt manufacrnring industries lead, aluminum, iron and steel, and gray iron production industries and to municipal solid waste incinerators. Typically, venturi scrubbers are applied where it is necessary to obtain high collection efficiencies for fine PM. Thus, they are applicable to controlling emission sources with high concentrations of submicron PM. 

Outdoor air is generally less polluted than the system return air. However, problems with reentry of previously exhausted air occur as a result of improperly located exhaust and intake vents or periodic changes in wind conditions. Other outdoor contamination problems include contaminants from other industrial sources, power plants, motor vehicle exhaust, and dust, asphalt vapors, and solvents from construction or renovation. Also, heat gains and losses through the building envelope due to heat conduction through exterior walls, floor, and roof, and due to solar radiation and infiltration, can be attributed to effects from external sources. 

Cresylic acid is a commercial mixture of phenolic compounds including phenol, cresols, and xylenols. This mixture varies widely according to its source. Properties of phenol, cresols, and xylenols are shown in Table 4-5 Cresylic acid constitutes part of the oxygen compounds found in crudes that are concentrated in the naphtha fraction obtained principally from naphthenic and asphaltic-based crudes. Phenolic compounds, which are weak acids, are extracted with relatively strong aqueous caustic solutions. 

The field performance of the asphalt-base pipeline enamels was, at one time, erratic, probably because the material had been drawn from varying sources, without a close specification being used. The plasticised coal-tar-base enamel to the American Water Works Association Specification C-203 thus gained some favour in major pipelining organisations. 

Source From AFS, Alternative Utilization of Foundry Waste Sand, final report (Phase I) for Illinois Department of Commerce and Community Affairs, American Foundrymen s Society, Des Plaines, IL, July 1991. Javed, S. and Lovell, C.W., Use of Foundry Sand in Highway Construction, Joint Highway Research Project No. C-36-50 N, Purdue University, West Lafayette, IN, July 1994. Javed, S., Lovell, C. W., and Wood, L.E., Waste Foundry Sand in Asphalt Concrete, in Transportation Research Record, No 1437, Transportation Research Board, Washington, DC, 1994. 

Source From Noureldin, A.S. and McDaniel, R.S., Evaluation of Steel Slag Asphalt Surface Mixtures, presented at the 69th annual meeting, Transportation Research Board, Washington, January 1990. 

Petroleum production technologies, 18 607 Petroleum products, 18 663-674 asphalt, 18 671-673 coke, 18 673-674 fuel oil, 18 669 gasoline, 18 665-667 information sources for, 15 765 kerosene, 18 667-669 liquefied petroleum gas, 18 664-665 lubricating oil, 18 669-670 solvents, 18 667 Petroleum recovery... 

Asphalt (referred to as bitumen in some parts of the world) is produced from the distillation residuum. In addition to road asphalt, a variety of asphalt grades for roofing and waterproofing are also produced. Asphalt has complex chemical and physical compositions, which usually vary with the source of the crude oil, and it is produced to certain standards of hardness or softness in controlled vacuum distillation processes (Barth, 1962 Bland and Davidson, 1967 Speight, 1999, and references cited therein Speight and Ozum, 2002). 

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