S-purification process

Fleming, D.K. and Primack, H.S., "Purification Processes for Coal Gasification", Paper presented at the American Institute of Chemical Engineers, 81st National Meeting, Kansas City, Mo., April 11-14, 1976. 

Before the explosion of the human population and the advent of the Industrial Revolution, natural purification processes were quite adequate to provide ample water of very high purity in all but desert regions. Nature s purification processes can be thought of as massive but somewhat delicate. 

Modem commercial wet-acid purification processes (see Fig. 4) are based on solvents such as C to Cg alcohols, ethers, ketones, amines, and phosphate esters (10—12). Organic-phase extraction of phosphoric acid is accompHshed in one or more extraction columns or, less frequently, in a series of countercurrent mixer—settlers. Generally, 60—75% of the feed acid P2 s content is extracted into the organic phase as H PO. The residual phosphoric acid phase (raffinate), containing 25—40% of the original P2O5 value, is typically used for fertilizer manufacture such as triple superphosphate. For this reason, wet-acid purification units are almost always located within or next to fertilizer complexes. 

Historically, the Redox process was used to achieve the same purification as in the Purex process (97,129). The reagents were hexone (methyl isobutyl ketone) as the solvent, dichromate as an oxidant, and A1(N02)3 as the salting agent. The chief disadvantages of hexone are its flammability and its solubihty in water. However, because A1(N03)3 collects in the highly radioactive waste, thereby impeding the latter s further processing, the Redox process was abandoned in favor of the Purex process. 

A large number of substances are ionisable in aqueous solutions and a knowledge of their ionisation constants, stated as pK (pKa) values, can be of importance not only in their purification but also in their reactivity. Literature values of the pK s have been inserted for ionisable substances, and where values could not be found they were estimated (pKesi)- The estimates are usually so close to the true values as not to affect the purification process or the reactivity seriously. The book will thus be a good compilation of pK values for ionisable substances. 

As a further example of a dog s ability to discriminate certain solvents, it is believed that dogs searching for the explosive C-4 as a target substance may be detecting the presence of cyclohexanone rather that the explosive itself. For example, cyclohexanone is a volatile solvent used in the purification process for... 

Ikeda, S., Nikaido, K., Araki, F K. et al. (2004) Production of recombinant human lysosomal acid lipase in Schizosaccharomyces pombe. development of a fed-batch fermentation and purification process. Journal of... 

The ease with which dissolution of the acetylated products can be achieved is affected by the method of isolation. In the author s experience, drying of the acetate with alcohol and ether results in apparent insolubility (even though the product was soluble at one stage of the purification process), and should be avoided. Drying, under diminished pressure, of the product precipitated by petroleum ether is sufficient. Chloroform is probably the best solvent. Nitroethane, tetrachlorethane, 2,4-pentanedione, pyridine, methyl acetate, ethyl acetate, and benzene, which have also been suggested, have disadvantages in that either they are unstable or they may cause aggregation in solution.44,116 116... 

HPC [Hot potassium carbonate] A generic name for a process for absorbing acid gases by the use of hot aqueous potassium carbonate. Developed by H. E. Benson and J. H. Field at the U.S. Bureau of Mines in the 1950s. Further developed by other organizations, it became the basis for the Benfield, CATACARB, and other gas purification processes. 

On the day of the incident, CSI was producing its first batch of 50% hydroxylamine solution at the new facility. CSI s production process involved the four basic steps of reaction, filtration, distillation, and ion exchange purification. 

Bartelsen, O., Lansmann, S., Nettersheim, M., Lemm, T., Ferlinz, K., and Sandhoff, K., 1998, Expression of recombinant human acid sphingomyeUnase in insect Sf21 cells purification, processing and enzymatic characterization. J Biotechnol 63 29-40. 

FIGURE 1.35 SLM process using O-9-(l-adamantylcarbamoyl)-10,ll-dihydro-ll-octadecylsulfinylquinme and corresponding quinidine derivative as chiral carriers for the preparative separation of enantiomers of Al-derivatized amino acids (e.g., DNB-Leu). (a) ftinciple of the carrier SLM process with carrier-mediated transport (top) and (nonstereoselective) nonspecific transport processes (bottom), (b) General experimental setup of the SLM production unit with two membrane modules, (c) Multistage SLM purification process. P, permeate QD/QN, membrane modnles snpported with quinidine-derived and quinine-derived chiral carriers. R, S, D, L refers to the respective enantiomers of the selectand (DNB-Leu). (Reproduced from A. Maximini et al., J. Membr. ScL, 276 221 (2006). With permission.)... 

B. Analysis of the Effects of the N- and S -Purification on the Regulated CSE Iterative Process... 

Sevag s method, using chloroform and butyl alcohol, has also been used for purification, the purification process being followed by the isoagglutination method. 

Taking into account process integration, i.e. - cultivation and product purification, particle locaHsation is an important issue. Strategies to produce a secreted particle, either by manipulation of its composition or by co-expression of NS protein(s) will be also discussed, since this can lead to an easier purification process and to a decrease in product losses due to intracellular proteolysis. The production of Rotavirus-Hke particles and Bluetongue virus-like particles production will be used as examples to illustrate this point. 

The service provider has developed and installed the improved wastewater purification process at the user s facilities and currently supplies the minimised amounts of required chemicals (FeCI3, NaOH) on the basis of Chemical Leasing. The company also takes care of the user s personnel training in the new process operation, the residual solid wastes transportation and disposal. 

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