ASTM distillation methods

Ma.nufa.cture. The preparation of sulfuryl chloride is carried out by feeding dry sulfur dioxide and chlorine into a water-cooled glass-lined steel vessel containing a catalyst, eg, activated charcoal. Alternatively, chlorine is passed into Hquefted sulfur dioxide at ca 0°C in the presence of a dissolved catalyst, eg, camphor, a terpene hydrocarbon, an ether, or an ester. The sulfuryl chloride is purified by distillation the commercial product is typically 99 wt % pure, as measured by ASTM distillation method D850. 

Usually, product specifications for a crude distillation unit are expressed in terms of the products 15/5 or ASTM distillation curves. The prediction of a product 15/5 distillation is accomplished simply by blending the quantities of the pseudo components in the stream so as to form a true boiling point, 15/5 equivalent, distillation curve. This curve can then be converted to an ASTM type distillation using an empirical method. Figure 5 illustrates how a typical ASTM curve compares to the 15/5 curve for the same material. 

D-86 is a common ASTM test method that measures the boiling point of light liquid hydrocarbons at various volume percent fractions. The sample is distilled at atmospheric pressure, provided its final boiling point (end point) is less than 750°F. 

By conducting a calibration curve based on the boiling points of n-alkanes, it is possible to estimate the distillation temperatures according to the ASTM D2887 method. Figures 4 and 5 show the calibration and the... 

Boiling-point basis Volumetric average boiling point, which is equal to graphical integration of the differential ASTM distillation curve (Van Winkle s exact method ). 

According to the Part 9 of ISO 787, a 10% suspension of filler is made up in freshly distilled water at room temperature and pH measurement of suspension is made. In an ASTM standard method, a suspension is made with warm water and cooled to room temperature for measurement. An alternative method allows one to use colorimetric indicators in the measurement. 

The different methods for measuring gas composition include absorption, distillation, combustion, mass spectroscopy, infrared spectroscopy, and gas chromatography (ASTM D-2163, ASTM D-2650, and ASTM D-4424). Absorption methods involve absorbing individual constituents one at a time in suitable solvents and recording of contraction in volume measured. Distillation methods depend on the separation of constituents by fractional distillation and measurement of the volumes distilled. In combustion methods, certain combustible elements are caused to burn to carbon dioxide and water and the volume changes are used to calculate composition. Infrared spectroscopy is useful in particular applications. For the most accurate analyses, mass spectroscopy and gas chromatography are the preferred methods. 

Kerosene, because of its higher density and viscosity, tends to retain fine particulate matter and water droplets in suspension for a much longer time than gasoline. Free water in kerosene can be detected by the use of a Dean and Stark adaptor (ASTM D-4006, IP 358) (Fig. 7.3), by the Karl Fischer titration method (ASTM D-1744, ASTM D-6304), by the distillation method (ASTM D-95, IP 74), or by a series of alternate tests (ASTM D-4176, ASTM D-4860). The standard water reaction test method (ASTM D-1094, IP 289) can also be used. 

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). 

A similar method to the above distillation method is described in ASTM D 95 (2013). 

Distillation may be carried out by several ASTM test methods, including ASTM D 86, D 850, D 1078, and D 1160. 

Assay analyses of whole crudes are done by combining an atmospheric and vacuum distillation run. These two runs when combined will provide a TBP (True Boiling Point Curve). While these batch distillation methods are labor intensive, taking between three to five days, they allow the collection of distillation fractions that can be utilized for testing. While each of the distillations techniques have been standardized by ASTM, cut schemes tend to mimic Refinery product classifications and there is no standardization of the individual inspection formats. Each corporation tends to perform both physical and chemical testing that best meet the needs of their refining operations and product suites. 

In this part will be discussed methods for estimating the yields and properties of the various products which can be produced off the atmospheric tower. The general method of attack will be to determine distillation properties of the desired products and apply these to the whole crude TBP curve in order to estimate volumetric yields. Volumetric yields are then used to obtain product gravities, molecular weights and other properties from the crude assay. There are many ways to define a product slate, but most of these are based on specifying certain ASTM distillation tern-... 

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