From distillation

Dryers are different in characteristic from distillation columns and evaporators in that the heat is added and rejected over a large range of temperature. Changes to dryer design can be directed by the plus/minus principle. 

Influence of the feed coke produced from distillation residue is less structured, less crystalline than that from a cracking residue. If the residue feeding the unit is highly contaminated with sulfur and metals, it is still coke, but is disqualified for certain applications. 

Medium 10-15 Filtration of crystalline precipitates. Removal of floaters from distilled water. 

Pharmaceutical Industry. In the pharmaceutical industry, sterility of deionized water systems is maintained by using an ozone residual. The ozone residual concentration is maintained at >0.3 ppm ppm in the water recirculation loop. Prior to product compounding, the ozone residual is removed by contact with uvirradiaton for <1 s. Ozone also is used to oxidize pyrogens from distilled water destined for intravenous solutions. 

Domestic fuel oils are those used primarily in the home and include kerosene, stove oil, and furnace fuel oil. Diesel fuel oils are also distillate fuel oils, but residual oils have been successhjlly used to power marine diesel engines, and mixtures of distillates and residuals have been used on locomotive diesels. Heavy fuel oils include a variety of oils, ranging from distillates to residual oils, that must be heated to 260°C or higher before they can be used. In general, heavy fuel oil consists of residual oil blended with distillate to suit specific needs. Heavy fuel oil includes various industrial oils and, when used to fuel ships, is called bunker oil. 

Backset. Backset is the screened aqueous by-product from distillation. It is recycled and added to the cooked grain mash prior to fermentation. 

Reverse Osmosis. A reverse osmosis (RO) process has been developed to remove alcohol from distilled spirits without affecting the sensory properties (14). It consists of passing barrel-strength whiskey through a permeable membrane at high pressure, causing the alcohol to permeate the membrane and concentrating the flavor components in the retentate. 

An important characteristic of pervaporation that distinguishes it from distillation is that it is a rate process, not an equilibrium process. The more permeable component may be the less-volatile component. Perv oration has its greatest iitihty in the resolution of azeotropes, as an acqiinct to distillation. Selecting a membrane permeable to the minor corTiponent is important, since the membrane area required is roughly proportional to the mass of permeate. Thus pervaporation devices for the purification of the ethanol-water azeotrope (95 percent ethanol) are always based on a hydrophihc membrane. 

Present-day nomenclature is partly the result of the conflict and interplay of two functions the need to communicate in speech and on the printed page on the one hand, and the need for archival storage of information and its efficient, reliable retrieval. The former function came first, and laid the basis for the nomenclature most commonly used even today, and gave birth to a wealth of trivial names (i.e. names that give little or no information on structure). These were often coined on the basis of the origin of the substance, as in the case of collidine, obtained from distillation of bones in glue factories, or were derived from a special characteristic, as in the case of skatole, which has a fecal odor. Such names are short and generally euphonious, but they must be memorized they cannot be deduced from the structure. 

Crystd from aqueous soln, containing 20mL of cone HCl per L, then crystd from distilled water, and dried in a vacuum desiccator over Sicapent. 

Triglycyl glycine (tetraglycine) [637-84-3] M 246.2, m 270-275°(dec). Crystd from distilled water (optionally, by the addition of EtOH). 

Tropaeolin 000 (see Orange II p. All in Chapter 5). Purified by salting out from hot distilled water using sodium acetate, then three times from distilled water and twice from EtOH. 

Ammonium nitrate [6484-52-2] M 80.0, m 210 (dec explosively), d 1.72. Crystd twice from distilled water (ImL/g) by adding EtOH, or from warm water (0.5mL/g) by cooling in an ice-salt bath. Dried in air, then under vacuum. After 3 recrystns of ACS grade it contained Li and B at 0.03 and 0.74 ppm resp. 

Ammonium perchlorate [7790-98-9] M 117.5, d 1.95, pK -2.4 to -3.1 (for HCIO4). Crystd twice from distilled water (2.5mL/g) between 80° and 0°, and dried in a vacuum desiccator over P2O5. Drying at 110° might lead to slow decomposition to chloride. POTENTIALLY EXPLOSIVE. 

Ammonium sulfate [7783-20-2] M 132.1, m 230 (dec), 280 (dec), d 1.77. Crystd twice from hot water containing 0.2% EDTA to remove metal ions, then finally from distilled water. Dried in a desiccator for 2 weeks over Mg(C104)2. After 3 recrystns ACS grade had Ti, K, Fe, Na at 11, 4.4, 4.4, 3.2 ppm resp. 

Lead (II) chloride [7758-95-4] M 278.1, m 501°. Crystallised from distilled water at 100° (33mL/g) after filtering through sintered-glass and adding a few drops of HCl, by cooling. After three crystns the solid was dried under vacuum or under anhydrous HCl vapour by heating slowly to 400°. 

Potassium bromide [7758-02-3] M 119.0, m 734°, d 2.75. Crystd from distilled water (ImL/g) between 100° and 0°. Washed with 95% EtOH, followed by Et20. Dried in air, then heated at 115° for Ih, pulverised and heated in a vacuum oven at 130° for 4h. Has also been crystd from aqueous 30% EtOH, or EtOH, and dried over P2O5 under vacuum before heating in an oven. 

Potassium iodate [7758-05-6] M 214.0, pK 0.80 (for HIO3). Crystd twice from distilled water (3mL/g) between 100° and 0°, dried for 2h at 140° and cooled in a desiccator. Analytical reagent grade material dried in this way is suitable for use as an analytical standard. 

Potassium iodide [7681-11-0] M 166.0, pK -8.56 (for HI). Crystd from distilled water (0.5mL/g) by filtering the near-boiling soln and cooling. To minimise oxidation to iodine, the crystn can be carried out under N2 and the salt is dried under vacuum over P2O5 at 70-100°. Before drying, the crystals can be washed with EtOH or with acetone followed by pet ether. Has also been recrystallised from water/ethanol. After 2 recrystns ACS/USP grade had Li and Sb at <0.02 and <0.01 ppm resp. 

Potassium peroxydisulfate (potassium persulfate) [7727-21-1] M 270.3. Crystd twice from distilled water (lOmL/g) and dried at 50° in a vacuum desiccator. 

Potassium phenol-4-sulfonate (4-hydroxybenzene-l-sulfonic acid K salt) [30145-40-5] M 212.3. Crystd several times from distilled water at 90°, after treatment with charcoal, by cooling to ca 10°. Dried at 90-100°. 

Potassium sodium tartrate (4H2O) [6381-59-5 (4H2O) 304-59-6 (R.R)] M 282.3. Crystd from distilled water (1.5mL/g) by cooling to 0°. 

Cyanoacetic acid was obtained from Distillation Products Industries, Rochester, New York, and used without further purification. 

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