Decolorizing agents

Problem definition Ever since a production plant started using a new supplier of a carbon decolorizing agent, consistently acceptable polymer has not been obtained. The plant s technical director recently read an article about the power of new mass spectrometric techniques, so she sends you an urgent e-mail and sends a sample of the offending carbon and a retained sample of the previous supply. The technical director asks you to find the impurity in the new, ineffective decolorizing carbon. 

The resulting PI is very novel and useful. It is an important product for your company. The polymer and its production process are relatively new and suffer from several problems, including variability in the quality of the DA monomer. To produce DA monomer, it is crystallized from alcohol using a decolorizing carbon. Last month, your supplier of the carbon-decolorizing agent went out of business, so your company... 

Hypothesis The new source of carbon decolorizing agent leads to inconsistent production of PI. 

Copper(I) chloride is used as a catalyst in the production of chlorine hy oxygenation of hydrogen chloride. Other important apphcations are in the petroleum industry as a desulfurization and decolorizing agent as a condensing agent for fats and oils as a fungicide and as an ahsorhent for carhon monoxide in gas analysis. It occurs in nature as mineral nantokite. 

A true colorless glass such as an optical glass must be made with very low iron materials since decolorizing agents would reduce the transmission. The main physical decolorizers are manganese, selenium, cobalt and neodymium oxides. Manganese with a little cobalt is effective in complimenting the iron in the ferric state. 

D. M. Kehl Application of carbons of animal origin for the removal of colors from sugar. The English sugar industry used charcoal as a decolorization agent in 1794 1793... 

It may appear on first consideration that neutral sulphite of lime, which is very little soluble in water, could have but little effect on the chlorine combined with the fibre but the fact that hydrochloric acid dissolves ueutral sulphite of lime with formation of soluble bisulphite of lime, will readily explain its action. Now hydrochloric acid is invariably gaueratad. whenever ohlorine gas acts as a decoloring agent on organic substances. 

Currently, a wide range of technological applications is based on the sorptive and catalytic properties of sepiolite [2], Sepiolite is increasingly being used as a decolorizing agent [3], as a catalyst or catalyst carrier [4-6], and as odorant adsorbents in environmental applications [7-9], Several papers have appeared recently that examine the structural, textural and sorptive properties of untreated sepiolite [10-12] and of sepiolite subjected previously to acid and/or thermal treatment [13-16], Sepiolite has also been used recently as... 

Refined arsenic trioxide is used both as a fining and decolorizing agent in glass, As Og and arsenic acid are used in the manufacture of chroma ted copper arsenate, which is used extensively as a wood preservative. 

DECOLORIZING AGENTS. A substance that removes color by a physical or chemical action. Charcoals, carbon blacks, clays, earths, activated alumina or bauxite, or other materials or highly adsorbent character ate used to remove undesirable colors (and often odors) front sugar, vegetable and animal fats and oils, and other substances. In a broad sense, decolorizing agents also embrace bleaches, which usually remove Color by chemical reaction. 

Since the solution is usually discolored, it is advisable to treat it at this point with adsorbent charcoal (Norit). After heating the solution for 15 minutes, the decolorizing agent is removed by filtration, and the solution concentrated on the steam bath to a volume of 60 ml. The concentrate is cooled to room temperatures, and 10 ml. of concentrated hydrochloric acid added. Further cooling in an ice-salt mixture results in the crystallization of the dihydrochloride. The addition of ethanol to the mother liquor causes more complete precipitation. The crystalline... 

A mixture of 34.4 g (100 mmol) 5-benzoyl-N-methyl-N-phenyl-2,3-dihydro-lH-pyrrolizine-l-carboxamide, 25 g sodium hydroxide in 25 mL water, and 80 mL methanol was refluxed for 5 hours. The mixture was cooled to room temperature, stirred under nitrogen for sixteen hours, and then diluted with 80 mL of water. The mixture was extracted with toluene, and the aqueous and organic phases were separated. The aqueous phase was acidified with 6 N hydrochloric acid. The resulting precipitate was extracted with dichloromethane. The combined extract was treated with activated clay decolorizing agent (4.5 g) for 30 minutes, filtered, and concentrated by... 

Activated carbon is a finely divided form of amorphous carbon manufactured from the carbonization of an organic precursor, which possesses a microporous structure with a large internal surface area. The ability of the hydrophobic surface to adsorb small molecules accounts for the widespread applications of activated carbon as gas filters, decoloring agents in the sugar industry, water purification agents, and heterogeneous catalysts. 

With the decoloration method, it is not possible to reach equally well-defined values for the mixing time. In order to approach this as closely as possible one can, however, add a well-measured excess of decolorizing agent to the batch. Decoloration then occurs at places where the concentration is differed by only, say, +25% from the final step. In this way it is also possible to find mixing times 075, being the time required for the bulk of the liquid to be decolorized. There are, however, parts of the liquid near fixed walls that often do not decolorize, which makes the decolorization method somewhat subjective. However, it can be said that the 9P value approaches the desired value 6r p, with r = p, rather closely, because to bring the concentration in the bulk of the liquid to within +(100 — p)% of the final value, the tracer has to be spread over at least p% of the vessel volume. 

Function Decolorizing agent taste- and odor-removing agent purification agent in food processing. 

Current uses of arsenic are in pesticides, cotton desiccants, and wood preservatives. Arsenic is also used as a bronzing and decolorizing agent in the manufacture of glass, and in the production of semiconductors (Tanaka, 2004), as a desiccant and defoliant in agriculture, and as a byproduct of the smelting of nonferrous metals, particularly gold and copper, from coal residues (Hall, 2002). 

Clean-up. Charcoal is the favorite adsorbent for the first steps in the authors clean-up procedures (31, 32). It is an excellent decolorizing agent and removes much of the large-molecule interferences. When it was initially used, there was a problem of reproducibility. Heavy metal cations, especially iron, were chelating with or tying up the insecticides... 

A common charcoal is Norit, frequently used as a decolorizing agent in the synthetic laboratory. A plot of the zeta potential of Norit versus pH is shown in Fig. 9.10.26 This charcoal has an lEP at about pH 4.5 and can adsorb cations from solutions having a pH between 6-8. 

In addition to the main components listed in Table 11, glasses may also contain minority components, e.g. colouring and decolorizing agents, the residues of refining substances and dissolved gases (H2O, SO3 and others). 

Use Pigments, ceramic enamels, aniline colors, decolorizing agent in glass, insecticide, rodenticide, herbicide, sheep and cattle dip, hide preservative, wood preservative, preparation of other arsenic compounds. 

Use Manufacturing activated carbon decolorizing agent and filtering medium, cementation reagent, adsorptive medium in gas masks, paint and varnish pigment clarifying shellac, water purification. 

Use Catalyst, preservative and fungicide, desulfurizing and decolorizing agent in petroleum industry, absorbent for carbon monoxide. 

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