Boiling point atmospheric equivalent

Atmospheric equivalent boiling point (AEBP) a mathematical method of estimating the boiling point at atmospheric pressure of nonvolatile fractions of petroleum. 

Boduszynski, M. M. Altgelt, K.H. Composition of heavy petroleum. 4. Significance of the extended atmospheric equivalent boiling point (AEBP) scale. Energy Fuels 1992, 6, 72-76. 

The sample is distilled at an accurately controlled pressure between 0.13 and 6.7 kPa (1 and 50 mm Hg) under conditions that are designed to provide approximately one theoretical plate fractionation. Data are obtained from which the initial boiling point, the final boiling point, and a distillation curve relating volume percent distilled and atmospheric equivalent boiling point temperature can be prepared. 

Chemical and Physical Properties Petroleum fuels contain paraffins, isoparaffins, naphthenes, and aromatics, plus organic sulfur, oxygen, and nitrogen compounds that were not removed by refining. Olefins are absent or negligible except when created by severe refining. Vacuum-tower distillate with a final boiling point equivalent to 730 to 840 K (850 to 1050°F) at atmospheric pressure may contain from 0.1 to... 

U and V respectively. Systeme International (SI) units, described in Appendix B, are used extensively but not slavishly. Chemically convenient quantities such as the gram (g), cubic centimeter (cm ), and hter (L = dm =10 cm ) are still used where useful—densities in g cm , concentrations in mol L , molar masses in g. Conversions of such quantities into their SI equivalents is trivially easy. The situation with pressure is not so simple, since the SI pascal is a very awkward unit. Throughout the text, both bar and atmosphere are used. Generally bar = 10 Pa) is used when a precisely measured pressure is involved, and atmosphere = 760 Torr = 1.01325 X 10 Pa) is used to describe casually the ambient air pressure, which is usually closer to 1 atm than to 1 bar. Standard states for all chemical substances are officially defined at a pressure of 1 bar normal boiling points for liquids are still understood to refer to 1-atm values. The conversion factors given inside the front cover will help in coping with non-SI pressures. 

Normal boiling point the temperature at which the vapor pressure of a liquid is exactly one atmosphere. (16.10) Normal melting point the temperature at which the solid and liquid states have the same vapor pressure under conditions where the total pressure on the system is one atmosphere. (16.10) Normality the number of equivalents of a substance dissolved in a liter of solution. (17.1)... 

In addition to the whole crude oil tests performed as part of the inspection assay, a comprehensive or full assay requires that the crude be fractionally distilled and the fractions characterized by the relevant tests. Fractionation of the crude oil begins with a true boiling point (TBP) distillation using a fractionating column with an efficiency of 14-18 theoretical plates and operated at a reflux ratio of 5 1 (ASTM D-2892). The TBP distillation may be used for all fractions up to a maximum cut point of about 350°C atmospheric equivalent temperature (AET), but a low residence time in the still (or reduced pressure) is needed to minimize cracking. 

With very heavy crude oil or viscous products, a preferred alternate distillation method (ASTM D-5236) should be used (instead of ASTM D-2892) for heavy crude oil above a 400°C (752°F) cut point. In the spinning band method (Fig. 10.3), fractions of feedstocks such as residual fuel oil with an initial boiling point above room temperature at atmospheric pressure can be investigated. For such materials, the initial boiling point of the sample should exceed room temperature at atmospheric pressure. The distillation is terminated at an atmospheric equivalent temperature of 524°C (975°F) and a pot temperature of 360°C (680°F). 

The terms vapor pressure and boiling point of a pure component are two equivalent ways of referring to the same physical state. When the condensed phase is a solid the term sublimation point is usually used instead of boiling point. The boiling (or sublimation) point at one atmosphere is the normal boiling (sublimation) point. 

The surface tension y of about 200 liquids is tabulated here as a function of temperature. Values of y are given in units of mU-linewtons per meter (mN/m), which is equivalent to dyn/cm in cgs units. The values refer to a nominal pressure of one atmosphere (about 100 kPa) except in cases where the indicated temperature is above the normal boiling point of the substance in those cases, the applicable pressure is the saturation vapor pressure at the temperature in question. 

It is recommended that 1 cm of methyl-silicone-coated packing be inserted at the inlet to extend the life of the trap. Method 5030B from the SW-846 series is more specific than Method 502.2 and recommends a 3% OV-1 on Chromosorb-W, 60/80 mesh, or equivalent. Analysts who do not need to quantitate dichlorodifluoromethane do not need to use the charcoal and can replace this charcoal with more Tenax. If only analytes whose boiling points are above 35°C are to be determined, both the charcoal and the silica gel can be eliminated and replaced with Tenax. The trap needs to be conditioned at 180°C prior to use and vented to the atmosphere instead of the analytical GC column. It is also recommended that the trap be reconditioned on a... 

Because of its low purchase price and a calorific value equivalent to kerosine, which makes used white spirit useful as a cement kiln fuel, very little white spirit is recovered. If recovery is attempted its high boiling point makes atmospheric pressure distillation liable to lead to a cracked odour in the distillate. Vacuum distillation or steam distillation does not have this drawback but the latter is costly in steam and the former needs vacuum equipment. 

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