Distillation Bitumen

Athabasca bitumen distillates 13.9 593-693 CoO, NiO and M0O3, on several AI2O3 supports (presulf ided) Part B - Model Compound Studies Furimsky et al. (66)... 

Furimsky, E., R. Ranganathan and B.O. Parsons. Catalytic Hydrodenitrogenation of Basic and Non-basic Nitrogen Compounds in Athabasca Bitumen Distillates. Fuel 57 (1978) 427. 

The distillation of crudes chosen for their yield in heavy fractions is the most common means. Bitumen is extracted from the residue from a vacuum distillation column (a few dozen mm of mercury), the latter being fed by atmospheric distillation residue. Unlike the practice of a decade ago, it is now possible to obtain all categories of bitumen, including the hard grades. 

Solvent deasphalting. This is an extraction of the heaviest fractions of a vacuum residue or heavy distillate. The extract is used to produce the bitumen. The separation is based on the precipitation of asphaltenes and the dissolution of the oil in an alkane solvent. The solvents employed are butane or propane or a butane-propane mixture. By selecting the proper feedstock and by controlling the deasphalting parameters, notably temperature and pressure, it is possible to obtain different grades of bitumen by this process. 

Petroleum refining, also called petroleum processing, is the recovery and/or generation of usable or salable fractions and products from cmde oil, either by distillation or by chemical reaction of the cmde oil constituents under the effects of heat and pressure. Synthetic cmde oil, produced from tar sand (oil sand) bitumen, and heavier oils are also used as feedstocks in some refineries. Heavy oil conversion (1), as practiced in many refineries, does not fall into the category of synthetic fuels (syncmde) production. In terms of Hquid fuels from coal and other carbonaceous feedstocks, such as oil shale (qv), the concept of a synthetic fuels industry has diminished over the past several years as being uneconomical in light of current petroleum prices. 

Large amounts of tar or pitch by-products are produced by industrial processes. The distillation of cmde petroleum (qv) yields a pitch-like residue termed bitumen or asphalt (qv). In the United States, these terms are interchangeable, but in Europe the term asphalt is generally restricted to naturally occurring rock or lake asphalt, whereas the residual product of cmde-od distillation is termed bitumen. Although these are important industrial materials produced in millions of metric tons annually, they are not included herein (see Asphalt Petroleum, products). 

It is incorrect to refer to bitumen as tar or pitch. Although the word tar is somewhat descriptive of the black bituminous material, it is best to avoid its use in referring to natural materials. More correctly, the name tar is usually appHed to the heavy product remaining after the destmctive distillation of coal (qv) or other organic matter. Pitch is the distillation residue of the various types of tar (see Tar and pitch). 

Asphalt (qv) is prepared from petroleum and often resembles bitumen. When asphalt is produced simply by distillation of an asphaltic cmde, the product can be referred to as residual asphalt or straight-mn petroleum asphalt. If the asphalt is prepared by solvent extraction of residua or by light hydrocarbon (propane) precipitation, or if blown or otherwise treated, the term should be modified accordingly to qualify the product, eg, propane asphalt. 

The API gravity of tar sand bitumen varies from 5 to ca 10°API, depending on the deposit, and the viscosity is very high. Whereas conventional cmde oils may have a high (>100 MPa-s(=cP)) viscosity at 40°C, tar sand bitumen has a viscosity on the order of 10-100 kPa-s(10 -10 P) at formation temperature (ca 0—10°C), depending on the season. This offers a formidable obstacle to bitumen recovery and, as a result of the high viscosity, bitumen is relatively nonvolatile under conditions of standard distillation (Table 4) (12,13), which influences choice of the upgrading process. 

Canadian and European practice (2—4) and geologists and archaeologists in the United States use bitumen or asphaltic bitumen as a synonym for asphalt, and apply asphalt to the mixture of bitumen and inorganic matter that is used for paving purposes. On the other hand, pitches and tars are derived from the destmctive distillation of coal, cmde oils, and other organic materials. 

Recovering the bitumen is not easy, and the deposits are either strip-mined if they are near the surface, or recovered in situ if they are in deeper beds. The bitumen could be extracted by using hot water and steam and adding some alkali to disperse it. The produced bitumen is a very thick material having a density of approximately 1.05 g/cm. It is then subjected to a cracking process to produce distillate fuels and coke. The distillates are hydrotreated to saturate olefinic components. Table 1-8 is a typical analysis of Athabasca bitumen. ... 

Part 2. Distillation Experiments. Distillation experiments were performed to determine the fraction of the original mass of bitumen in a calorimetric sample that is available for oxidation at each temperature in the range 155-320°C, to determine the quality of this "fuel" as expressed by the molar ratio of hydrogen to carbon,... 

The classic definition of asphaltenes is based on the solution properties of petroleum residua in various solvents. The word asphaltene was coined in France by J.B. Boussingault in 1837. Boussingault described the constituents of some bitumens (asphalts) found at that time in eastern France and in Peru. He named the alcohol insoluble, essence of turpentine soluble solid obtained from the distillation residue "asphaltene", since it resembled the original asphalt. 

Bitumen contains a solvent-soluble fraction referred to as maltenes, and an insoluble fraction called asphaltenes. The word bitumen is in some cases also used to indicate the residue of the distillation of petroleum. 

For many years, petroleum and heavy oil were very generally defined in terms of physical properties. For example, heavy oil was considered to be a crude oil that had gravity between 10 and 20° API. For example. Cold Lake heavy crude oil (Alberta, Canada) has an API gravity equal to 12°, but extra-heavy oil (such as tar sand bitumen), which requires recovery by nonconventional and nonenhanced methods, has an API gravity in the range 5 to 10°. Residua would vary depending on the temperature at which distillation was terminated, but vacuum residua were usually in the range 2 to 8° API. 

The presence of paraffin wax is usually reflected in the paraffinic nature of the constituent fractions, and a high asphaltic content corresponds with the naphthenic properties of the fractions. As a result, the misconception has arisen that paraffin-base crude oils consist mainly of paraffins and asphalt-base crude oils mainly of cyclic (or naphthenic) hydrocarbons. In addition to paraffin- and asphalt-base oils, a mixed base had to be introduced for those oils that leave a mixture of bitumen and paraffin wax as a residue by nondestructive distillation. 

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). 

In recent years few topics have generated a more spirited discussion among coal scientists than the issue of the putative binary (mobile + network) phase nature of coals (y. Initially based on NMR observations (, the concept of a "mobile phase" in coal soon came to encompass a broad range of more or less readily extractable and/or distillable lower molecular weight (MW) components, variously referred to as "guest molecules" (3), "clathrates" (1,4) or simply, and perhaps most succinctly, "bitumen"... 

Bitumens occur naturally or are formed as the residue in the distillation of coal tar, petroleum, etc. Industrially, the two most important bitumens are asphalt and coal tar. Asphalt is a brown to black tarlike variety of bitumen that again occurs naturally or is the residue of distillation. Coal tar is the black, thick liquid obtained as the residue from the distillation of bituminous coal. 

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