Structure of the 3:1 inclusion complex of urea and 1,6-dichlorohexane. The framework is composed of molecules of urea that are linked by hydrogen bonds, leaving approximately hexagonal channels into which align the molecules of the chlorocarbon. Color scheme: oxygen is red, nitrogen is blue, chlorine is green.[1]
The urea extraction crystallization is a process for separating linear paraffins (n-paraffins, n-alkanes) from hydrocarbon mixtures through the formation of urea-n-paraffin-clathrates. The process is primarily used to lower the pour point of petroleum products, by-products of the process are n-paraffins in high purity. The method may also applied for the separation of fatty acids and fatty alcohols. In addition to urea also thiourea is used in the process.
^Hollingsworth, U. Werner-Zwanziger; Brown, J.D. Chaney; Huffman, K.D.M. Harris (1999). "Spring-Loading at the Molecular Level: Relaxation of Guest-Induced Strain in Channel Inclusion Compounds". J. Am. Chem. Soc. 121 (41): 9732. doi:10.1021/ja9919534.
and 17 Related for: Urea extraction crystallization information
The ureaextractioncrystallization is a process for separating linear paraffins (n-paraffins, n-alkanes) from hydrocarbon mixtures through the formation...
process is called ureaextractioncrystallization. Urea can also be a neutral ligand if it is coordinated to a central metal atom. Urea can form hydrogen...
catalyze the hydrolysis of urea into carbon dioxide and ammonia: (NH2)2CO + H2O urease→ CO2 + 2NH3 The hydrolysis of urea occurs in two stages. In the...
isolated it by fractional crystallization of the acid sulfate. Weissgerber developed a more rapid route in 1914 by selective extraction of coal tar, exploiting...
melamine production is often integrated into urea production, which uses ammonia as feedstock. Crystallization and washing of melamine generates a considerable...
methods of separation include distillation, crystallization, evaporation, magnetic separation and solvent extraction. Organic compounds were traditionally characterized...
salt choline chloride. Smith, Abbott, and Ryder report that a mixture of urea (melting point: 133 °C) and choline chloride (melting point: 302 °C) in a...
often in the presence of infection by urea-splitting bacteria. Using the enzyme urease, these organisms metabolize urea into ammonia and carbon dioxide. This...
on its polarity. For example, a very polar (hydrophilic) solute such as urea is very soluble in highly polar water, less soluble in fairly polar methanol...
TBP-Nitrate solvent extraction process is used for the separation. Zr and Hf can also be separated by fractional crystallization of potassium hexafluorozirconate...
Nitin P. (2015). "Room-temperature crystallization of hybrid-perovskite thin films via solvent–solvent extraction for high-performance solar cells". J...
of product are distinct, but include extraction, precipitation, adsorption, chromatography, and crystallization. In both cases, the isolated substance...
dysentery. Proved that dysentery is caused by intestinal amoebae" "Use of urea as a bacteriocide, and its application in the treatment of wounds (Lancet...
because the chemical is readily available as a byproduct of decaffeination. Extraction of caffeine from coffee, to produce caffeine and decaffeinated coffee...
distinct, but generally involve extraction, precipitation, adsorptions, chromatography, and sometimes crystallizations. In both cases, the isolated substance...
e.g. Madribon (sulfadimethoxime) and –half a century later– the sulfonyl urea herbicides, e.g. Eagle (amidosulfuron) and Londax (bensulfuron-methyl). Benzodiazepine...
with less than 30 percent water of crystallization UN 1386 4.2 Seed cake, containing vegetable oil solvent extractions and expelled seeds, with not more...
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