Old processes

The design of apparatus to facilitate rapid and efficient removal of the heat produced during nitration was not known at that time. Solution of these difficulties was therefore sought in modification of the manufacturing process itself, as eiiorowetoH tw Bmitmv and Fancher 132], They divided the nitrating process into two 

The greater part of the heat is produced during the relatively safe process (1). The amount of heat developed during nitration proper (2) is therefore relatively small and the temperature can be controlled easily even if primitive methods of cooling are used. 

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Furan hot-box resins are used in both ferrous and nonferrous foundries (66,67). In this process, resin and catalyst are intimately mixed with dry sand and then blown into heated metal boxes containing a cavity the shape of the desired core. In seconds, the surface of the sand mass hardens and, as soon as the core has cured sufficiently to be rigid and handleable the box is opened and the core removed. Automotive cores with exceUent dimensional accuracy and high strengths are made via this forty-year-old process. 

Aniline Oxidation. Even though this is quite an old process, it still has limited use to produce hydroquinone on a commercial scale. In the first step, aniline is oxidized by manganese dioxide in aqueous sulfuric acid. The resulting benzoquinone, isolated by vapor stripping, is reduced in a second step by either an aqueous acidic suspension of iron metal or by catalytic hydrogenation. 

The synthesis of chlorarul [118-75-2] (20) has been improved. The old processes starting from phenol or 2,4,6-trichlorophenol have been replaced by new ones involving hydroquinone chlorination. These processes allow the preparation of chlorarul of higher purity, avoiding traces of pentachlorophenol. Different types of chlorination conditions have been disclosed. The reaction can be performed according to the following stoichiometry, operating with chlorine in aqueous acetic acid (86,87), biphasic medium (88), or in the presence of surfactants (89). 

Ladle metallurgy, the treatment of Hquid steel in the ladle, is a field in which several new processes, or new combinations of old processes, continue to be developed (19,20). The objectives often include one or more of the following on a given heat more efficient methods for alloy additions and control of final chemistry improved temperature and composition homogenisation inclusion flotation desulfurization and dephosphorization sulfide and oxide shape control and vacuum degassing, especially for hydrogen and carbon monoxide to make interstitial-free (IF) steels. Electric arcs are normally used to raise the temperature of the Hquid metal (ladle arc furnace). 

The age-old process of preparing cocoa beans for market involves specific steps that allegedly promote the activities of certain enzymes. Various methods of fermentation are used to the same end. 

In some cases, the least expensive control is achieved by abandoning the old process and replacing it with a new, less polluting one. Any increased production and/or recovery of material may help offset a portion of the cost. It has proved to be cheaper to abandon old steel mills and to replace... 

PrH A improves the safety, reliability and quality of the design and construction of a new or old process. P IDs must be correct as constructed operating, startup and shutdown procedures must be validated, and the operating staff must be trained before startup. Incident inr estigation recommendations, compliance audits or PrHA recommendations need resolution before startup. 

Old processes use a zinc-chromium oxide catalyst at a high-pressure range of approximately 270-420 atmospheres for methanol production. 

CODH and ACS are important from an evolutionary point of view. It has been considered that CODH/ACS are the extant survivors of a 3- to 4-billion-year-old process that could have given rise to the first metabolic reactions that eventually led to life on this planet. Possibly, it was involved in the first metabolic pathway (2, 107). 

Potassium metal prepared by the old process of distilling an intimate mixture of the carbonate and carbon contained some carbonylpotassium (actually potassium benzenehexoxide), and several explosions with old samples of potassium may have involved this compound (or, perhaps more likely, potassium superoxide). 

Isolation and characterization of new indole alkaloids remains a fruitful avenue for the discovery of agents with the potential for biomedical application. The virtues of this age-old process, in light of advances in combinatorial chemistry, were brought to the community as part of the 231 ACS National Meeting symposium, Modern Natural Products Chemistry and Drug Discovery <06ORGN467>. 

This interesting derivative of ketene is also obtained from benzilic acid by the old process of Staudinger the add is converted, by the action of phosphorus pentachloride, into diphenylchloracetyl chloride from which the two chlorine atoms are removed by means of zinc. (Formulate this equation.) What is carbon suboxide For information about the ketenes see H. Staudinger, Die Ketene, Stuttgart, 1912. 

FIGURE 7 (a) Impurity profile of Intermediate produced by the new process. Peaks after 8 min were impurities that were not previously observed when the Intermediate was produced via the old process, (b) Chromatogram of the drug substance made from intermediate of poor quality. Peak at 22 min retention time is the drug substance Impurity at 36 min retention time was a new impurity and failed specifications. 

Newman DJ. (2008) Natural products as leads to potential drugs An old process or the new hope for drug discovery J Med Chem 51 2589-2599. 

Figure 9 (a) The old process flow diagram and (b) the new process modiflcation for steam segregation... 

For many years benzene was made from coal tar even as late as 1949, when all of it was made by this old process. New processes began to take over in the 1950s, which were used for 50% of the benzene in 1959, 94% in 1972, 96% in 1980, and near 100% in the 1990s. These new processes consist of catalytic reforming of naphtha and hydrodealkylation of toluene in a 70 30 capacity ratio. 

The ethyl alcohol fermentation is of course an age-old process and is so well known that little need be said about it here. The acetone-butanol fermentation is perhaps the next most important industrial fermentation process, although starch in the form of maize has been largely used as the basic material more recently suitably treated molasses has been used. The fermentation, a relatively rapid process requiring about thirty hours, produces about 60 parts of butanol, 30 parts of acetone and 10 parts of ethyl alcohol. These products already have large uses in industry and other uses are being explored. One possibility is the use of butanol in motor fuel. Jean has described a fuel, called Jeanite, consisting mainly of butanol and ethyl alcohol, which shows some promise. Of course the admixture of ethyl alcohol with petroleum is well known and an increased use of this mixture is probable. 

In 1746 Dr. John Roebuck (1718-1794), of Birmingham, and Samuel Garbett substituted lead chambers, each about six feet square, for the glass globes introduced six years previously by Joshua Ward (22), an improvement which cut down the cost of producing the acid to one-fourth of its former amount (12, 13). Three years later, after the substitution of sulfuric acid for sour milk in the old process of bleaching had created a demand for the acid, Roebuck and Garbett erected a sulfuric acid plant at Prestonpans, on the east coast of Scotland (14). Since a salt industry also flourished there, Prestonpans was named for the salt pans. 

An additional improvement has been the chemical yield. From early runs, experience led us to expect about one-third of the actual amount recovered from the new process. From this and the fact that we had obtained 90% yield from the new process, we estimate the chemical yield of the old process to be roughly 30%. 

On the other hand, sulphates of tervalent metals dissociate easily. The old process for the preparation of H2S04 was based on the dissociation of ferric sulphate, the SOs being absorbed in moderately dilute sulphuric acid. In this manner fuming sulphuric, or Nord-hausen, acid can be prepared. 

S, G. Archibald, of Newfoundland, has devoted much attention to the improvement of the mothod of extracting seal oil, and states that the different kinds of seals fat, if taken whilo fresh, and subjected to a process of artificial heat, are capable of yielding not only a uniform quality of oil but the oil so obtained is much better in quality than the best prepared by the old process, and free from the unpleasant smell common to all Beal oil. He afterwards invented a steam apparatus for rendering seal and other oils, which is.said to answer the purpose admirably. 

In extensive manufactories where machinery is used, the beautifol apparatus patented by Messrs. Need-IUM and Kite, for consolidating tho slip by pressure, is being introduced, and Is a decided Improvement upon the old process Of evaporation by heat. 

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