Volatility asphalt

The products could be classified as a function of various criteria physical properties (in particular, volatility), the way they are created (primary distillation or conversion). Nevertheless, the classification most relevant to this discussion is linked to the end product use LPG, premium gasoline, kerosene and diesel oil, medium and heavy fuels, specialty products like solvents, lubricants, and asphalts. Indeed, the product specifications are generally related to the end use. Traditionally, they have to do with specific properties octane number for premium gasoline, cetane number for diesel oil as well as overall physical properties such as density, distillation curves and viscosity. 

Asphalts develop an internal stmcture with age, steric hardening (3), in which viscosity can increase upon aging without any loss of volatile material (73,83). Those with a particularly high degree of gel stmcture exhibit thixotropy. 

Distillation (ASTMD402). Approximate amounts of volatile constituents are deterrnined by this test which is particulady appHcable to cutback asphalt and road oils. 

Heavier Fuel Oils and Lubricating Oils Low volatility distillates, e.g., motor oil. Asphalts and Tars Lowest volatility and generally a smelly, sticky mess filled with impurities. 

The very volatile gases (compounds with four or fewer carbons), crude oil, and the sohd asphaltic materials are not included in this discussion of analytical methods but are included elsewhere (Chapters 7 and 9). 

Asphalt or petroleum coke Non-volatile esidue Polycyclic structures... 

Exposure limits Potential occupational carcinogen. No individual standards have been set however, as a constituent in coal tar pitch volatiles and asphalt products, the following exposure limits have been established (mg/m ) NIOSH REL TWA 0.1 (cyclohexane-extractable fraction), IDLH 80 OSHA PEL TWA 0.2 (benzene-soluble fraction) ACGIH TLV TWA 0.2 (benzene... 

Processing. Early asphaltic crudes, such as Panuco (Mexican) and Heavy Californian, yielded up to 65% asphalt (4), and were fairly readily processed in horizontal, direct-fired batch stills as shown in Figure 2. Usually steam was introduced to assist in the vaporization of the volatile constituents. The temperature at the termination of the process varied between 600° and 750° F., and the time of distillation was between 12 and 36 hours. These batch stills were replaced by continuous stills of similar construction. The oil flows from one still to another, with each still producing a predetermined grade of distillate. 

The use of cutback asphalts has increased remarkably from 130,000 tons in 1929 (39) to about 2,390,600 tons in 1949 (126). Since these consist of paving asphalt, temporarily liquefied by means of a volatile petroleum solvent to facilitate application and manipulation in construction, control of the rate of hardening by solvent evaporation is necessary. Normally, hardening characteristics have been determined and specified by means of a distillation test, but this procedure has come to be considered inadequate. Martin (68) has suggested the evaporation index, as an improved method, and other methods are under consideration by Committee D-4 of the American Society for Testing Materials. 

In the noble metals and in many minerals the elements were believed to be so well combined that heat could not separate them. Other minerals, as sulphur, orpiment, asphalt, etc., when heated in the air are partly broken down, the aerial element, not being so firmly united to the earth, being driven off as vapor and mingling with the particles of the atmosphere. This process was interpreted by the Greek alchemists and their Arabian successors as the separation of the spirit from the body, and such substances as were volatilized or burned with formation of gaseous products—as sulphur, arsenic (sulphides), sal ammoniac, quicksilver—were called spirits, while the metals and minerals which, when heated in the air did not volatilize nor disappear in gaseous products, were called bodies (corpora). 

ASPHALT (or Asphaltuim). [CAS 8052-42-4]. A semisolid mixture of several hydrocarbons, probably formed because of the evaporation of the lighter and more volatile constituents, It is amorphous, of low specific gravity, 1-2, with a black or brownish-black color and pitchy luster. Notable localities for asphaltum are the Island of Trinidad and the Dead Sea region, where Lake Asphaltites were long known to the ancients. See also Coal Tar and Derivatives and Petroleum. 

BITUMEN. Natural flammable substances of a wide range of color, hardness, and volatility, constituted mainly of a mixture of hydrocarbons and essentially free from oxygenated bodies. Petroleums, asphalts, natural mineral waxes, and asphaltites arc considered bitumens. See also Tar Sands. 

Approximately two thousand years ago, Arabian scientists developed methods for the distillation of petroleum and other naturally occurring organic products and these methods were introduced into Europe by way of Spain. This represents another documented use of the volatile derivatives of petroleum in addition to the nonvolatile fractions that were used as construction materials. The discovery of distillation led to an interest in the thermal product of petroleum (nafta naphtha) when it was discovered that this material could be used as an illuminant and as a supplement to asphalt incendiaries in warfare. 

The volatile products from the soaking drum enter the fractionator where the distillates are fractionated into desired product oil streams, including a heavy gas oil fraction. The cracked gas product is compressed and used as refinery fuel gas after sweetening. The cracked oil product after hydrotreating is used as fluid catalytic cracking or hydrocracker feedstock. The residuum is suitable for use as boiler fuel, road asphalt, binder for the coking industry, and as a feedstock for partial oxidation. 

Cutback asphalt asphalt liquefied by the addition of a volatile liquid such as naphtha or kerosene that, after application and on exposure to the atmosphere, evaporates leaving the asphalt. 

Waysbort, D., E. Manisterski, H. Leader, B. Manisterski, and Y. Ashani. 2004. Laboratory set-up for long-term monitoring of the volatilization of hazardous materials Preliminary tests of O-ethyl S-2- (N,N-diisopropylamino)ethyl methylphosphonothiolate on asphalt. Environmental Science and Technology 38(7) 2217-2223. 

The word asphaltene was coined in France by J. B. Boussingault (1) in 1837. Boussingault described the constituents of a number of bitumens (asphalts) found at that time in eastern France and in Peru. After separation of the components of an asphalt by distillation, he named the volatile oily... 

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