Petroleum heavy crude

Cavanaugh, T.A., D.E. Blaser and R.A. Busch (1978), Fluid coking/Flexi-coking, a flexible process for upgrading heavy crudes . Japanese Petroleum Institute (JPI) Conference, Tokyo. 

Characterization of Heavy Crude Oils and Petroleum Residues. Caracterisation des huiles lourdes et des residus petroliers. Symposium international, Lyon, 1984. 

The co-processing of coal with heavy crude oil or its heavier fractions is being developed to lower capital requirements for coal hquefaction and to integrate processing of the products of coal conversion into existing petroleum refineries. This development appears to represent the main route by which coal-based liquid fuels will supplement and perhaps someday displace petroleum-based fuels. 

R. D. Kanakamedala and M. R. Islam. A new method of petroleum sludge disposal and utilization. In Proceedings Volume, volume 2, pages 675-682. 6th Unitar et al Heavy Crude Tar Sands Int Conf (Houston, TX, 2/12-2/17), 1995. 

Developing a bioprocess for removing heteroatoms from petroleum or for upgrading heavy crudes involves two main components. The first is biocatalyst development and second is bioprocess development. Both of these topics are discussed in this book,... 

Aquaconversion A process for converting heavy crude petroleum oils into lighter products which are more easily converted into more valuable products in oil refineries. Intended for use at the well head rather than the oil refinery. Developed by Foster Wheeler USA Corporation, Intevep, andUOP from 1998. 

When petroleum occurs in a reservoir that allows the crude material to be recovered by pumping operations as a free-flowing dark- to light-colored liquid, it is often referred to as conventional petroleum. Heavy oils comprise the other types of petroleum they differ from conventional petroleum in being much more difficult to recover from subsurface reservoirs. The definition of heavy oils is usually based on the API gravity or viscosity value, and the definition is quite... 

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. 

In addition to conventional petroleum (qv) and heavy crude oil, there remains another subclass of petroleum, one that offers to provide some relief to potential shortfalls in the future supply of liquid fuels and other products. This subclass is the bitumen found in tar sand deposits (1,2). Tar sands, also known as oil sands and bituminous sands, are sand deposits impregnated with dense, viscous petroleum. Tar sands are found throughout the world, often in the same geographical areas as conventional petroleum. 

Petroleums also contain compounds in which sulfur, oxygen, and/or nitrogen atoms are combined with carbon and hydrogen. These elements usually are combined with the complex ring structures that make up the larger molecules of petroleums. These larger nonhydrocarbon compounds form a class of chemicals generally called resins and asphal-tanes. The quantity of these compounds in petroleum is often very small however, as much as 50% of the total molecules in some heavy crude oils are resins and asphaltines. 

Percent Vanadium in Each Molecular Weight Category of Vanadyl Compounds in the Four Heavy Crude Petroleums and Their Asphaltenes, Maltenes, Asphaltene Polar Extracts, and Extracted Asphaltenes by 50/100/1000 A SEC-HPLC-GFAA Analysis"- ... 

With all of the scenarios in place, there is no doubt that petroleum and its relatives residua, heavy oil, and extra heavy oil (bitumen) will be required to produce a considerable proportion of liquid fuels into the foreseeable future. Desulfurization processes will be necessary to remove sulfur in an environmentally acceptable manner to produce environmentally acceptable products. Refining strategies will focus on upgrading the heavy oils and residua and will emphasize the differences between the properties of the heavy crude feedstocks. This will dictate the choice of methods or combinations thereof for conversion of these materials to products (Schuetze and Hofmann, 1984). 

Briefly, the asphaltene fraction of crude oil is that fraction which is precipitated by the addition of a large excess of a low-boiling liquid hydrocarbon (usually n-heptane) (Chapter 3). On the other hand, resins are those materials which remain soluble in the pentane but will be adsorbed by a surface-active material such as fuller s earth, while the oils fraction is soluble in pentane but is not adsorbed from the pentane solution by any surface-active material. The asphaltic fraction of any petroleum, heavy oil, or residuum is usually a combination of the asphaltene and resin fraction and, in many instances, may constitute a large portion of a heavy oil or, especially, of a residuum. 

Roadifer, R. E. In Exploration for Heavy Crude Oil and Natural Bitumens Meyer, R. F., Ed. AAPG Studies in Geology 25 American Association of Petroleum Geologists Tulsa 1987 3-23. 

The estimated future U. S. requirements of hydrogen for petroleum refining are based on the forecasted quantities of crude oil, natural gas liquids (NGL), synthetic crudes, and imported crudes shown in Table 4. During the 1980-2000 period, U. S. crude runs will increase from 15.3 to 18.0 million B/D while the total U. S. liquid hydrocarbon supply, including product imports, will increase slightly from 19.7 to 21.1 million B/D. The total liquid supply corresponds to 40 and 43 Quad/year for 1980 and 2000. By the year 2000, there will be a substantial increase in the quantity of residuum converted due to an overall increase in the quantities of heavy crudes in the crude slate. 

Similar to other refining and industrial processes, the decision to construct and operate a coking unit is dependent upon unique economic factors. The price differential between residual fuel oil and crude oil is a major variable, although the relative prices of light and heavy crude, the demand for refined products, as well as the amount and type of conversion unit capacity also affect coking economics. Notice the value of petroleum coke was not included. Cokers have been justified in most cases even though the coke product was assumed to have zero value. 

---