Page 30 - Characterization and Properties of Petroleum Fractions - M.R. Riazi

P2: IML/FFX
T1: IML
QC: IML/FFX
P1: IML/FFX
14:26
June 22, 2007
AT029-Manual-v7.cls
AT029-01
AT029-Manual
10 CHARACTERIZATION AND PROPERTIES OF PETROLEUM FRACTIONS
their viscosity index. Lubricants have structure similar
to isoparaffinic compounds. Additives used for lubricants In general, more than 2000 petroleum products within some
20 categories are produced in refineries in the United States
are viscosity index additives such as polyacrylates and [1, 19]. Blending techniques are used to produce some of these
olefin polymers, antiwear additives (i.e., fatty esters), an- products or to improve their quality. The product specifica-
tioxidants (i.e., alkylated aromatic amines), corrosion in- tions must satisfy customers’ requirements for good perfor-
hibitors (i.e., fatty acids), and antifoaming agents (i.e., poly- mance and government regulations for safety and environ-
dimethylsiloxanes). Lubricating greases are another class ment protection. To be able to plan refinery operations, the
of lubricants that are semisolid. The properties of lubri- availability of a set of product quality prediction methods is
cants that should be known are viscosity index, aniline therefore very important.
point (indication of aromatic content), volatility, and car- There are a number of international organizations that are
bon residue. known as standard organizations that recommend specific
4. Petroleum waxes are of two types: the paraffin waxes in characteristics or standard measuring techniques for various
petroleum distillates and the microcrystalline waxes in pe- petroleum products through their regular publications. Some
troleum residua. In some countries such as France, paraf- of these organizations in different countries that are known
fin waxes are simply called paraffins. Paraffin waxes are with their abbreviations are as follows:
high melting point materials used to improve the oil’s pour
point and are produced during dewaxing of vacuum dis- 1. ASTM (American Society for Testing and Materials) in the
tillates. Paraffin waxes are mainly straight chain alkanes United States
(C 18 –C 36 ) with a very small proportion of isoalkanes and 2. ISO (International Organization for Standardization),
cycloalkanes. Their freezing point is between 30 and 70 C which is at the international level
◦
and the average molecular weight is around 350. When 3. IP (Institute of Petroleum) in the United Kingdom
present, aromatics appear only in trace quantities. Waxes 4. API (American Petroleum Institute) in the United States
from petroleum residua (microcrystalline form) are less 5. AFNOR (Association Francaise de Normalisation), an offi-
defined aliphatic mixtures of n-alkanes, isoalkanes, and cy- cial standard organization in France
cloalkanes in various proportions. Their average molecular 6. Deutsche Institut fur Normung (DIN) in Germany
weights are between 600 and 800, carbon number range is 7. Japan Institute of Standards (JIS) in Japan
alkanes C 30 –C 60 , and the freezing point range is 60–90 C ASTM is composed of several committees in which the D-02
◦
[13]. Paraffin waxes (when completely dearomatized) have committee is responsible for petroleum products and lubri-
applications in the food industry and food packaging. They cants, and for this reason its test methods for petroleum ma-
are also used in the production of candles, polishes, cos- terials are designated by the prefix D. For example, the test
metics, and coatings [18]. Waxes at ordinary temperature of method ASTM D 2267 provides a standard procedure to de-
25 C are in solid states although they contain some hydro- termine the benzene content of gasoline [22]. In France this
◦
carbons in liquid form. When melted they have relatively test method is designated by EN 238, which are documented
low viscosity. in AFNOR information document M 15-023. Most standard
5. Asphalt is another major petroleum product that is pro- test methods in different countries are very similar in prac-
duced from vacuum distillation residues. Asphalts contain tice and follow ASTM methods but they are designated by
nonvolatile high molecular weight polar aromatic com- different codes. For example the international standard ISO
pounds, such as asphaltenes (molecular weights of several 6743/0, accepted as the French standard NF T 60-162, treats
thousands) and cannot be distilled even under very high all the petroleum lubricants, industrial oils, and related prod-
vacuum conditions. In some countries asphalt is called ucts. The abbreviation NF is used for the French standard,
bitumen, although some suggest these two are different while EN is used for European standard methods [18].
petroleum products. Liquid asphaltic materials are in- Government regulations to protect the environment or to
tended for easy applications to roads. Asphalt and bitu- save energy, in many cases, rely on the recommendations
men are from a category of products called hydrocarbon of official standard organizations. For example, in France,
binders. Major properties to determine the quality of as- AFNOR gives specifications and requirements for various
phalt are flash point (for safety), composition (wax con- petroleum products. For diesel fuels it recommends (after
--`,```,`,``````,`,````,```,,-`-`,,`,,`,`,,`---
tent), viscosity and softening point, weathering, density or 1996) that the sulfur content should not exceed 0.05 wt% and
specific gravity, and stability or chemical resistance. the flash point should not be less than 55 C [18].
◦
6. There are some other products such as white oils (used in
pharmaceuticals or in the food industry), aromatic extracts
(used in the paint industry or the manufacture of plastics), 1.2 TYPES AND IMPORTANCE
and coke (as a fuel or to produce carbon elecrodes for alu- OF PHYSICAL PROPERTIES
minum refining). Petroleum cokes generally have boiling
points above 1100+ C(∼2000+ F), molecular weight of On the basis of the production and refining processes de-
◦
◦
above 2500+, and carbon number of above 200+. Aromatic scribed above it may be said that the petroleum industry
extracts are black materials, composed essentially of con- is involved with many types of equipment for production,
densed polynuclear aromatics and of heterocyclic nitrogen transportation, and storage of intermediate or final petroleum
and/or sulfur compounds. Because of this highly aromatic products. Some of the most important units are listed below.
structure, the extracts have good solvent power.
1. Gravity decanter (to separate oil and water)
Further information on technology, properties, and test- 2. Separators to separate oil and gas
ing methods of fuels and lubricants is given in Ref. [21]. 3. Pumps, compressors, pipes, and valves

Copyright ASTM International
Provided by IHS Markit under license with ASTM Licensee=International Dealers Demo/2222333001, User=Anggiansah, Erick
No reproduction or networking permitted without license from IHS Not for Resale, 08/26/2021 21:56:35 MDT