Chemical industry reduction

In the fine chemical industry, reduction of carbonyl groups mainly relies on the use of complex metal hydrides sodium dihydrobis-(2-methoxyethoxy)-aluminate, commercialized as RedAl or Vitride is one of the most used (4). 

Thus, in the fine chemicals industry, reduction of ketones and aldehydes relies mainly on the use of complex metal hydrides that require time-consuming workup of reaction mixtures and produce significant amounts of inorganic and organic wastes. Similarly, the oxidation of alcohols into carbonyls is traditionally performed with stoichiometric inorganic oxidants, notably Cr(VI) reagents or a catalyst in combination with a stoichiometric oxidant [1]. 

Christ, C. (ed.), Production-Integrated Environmental Protection and Waste Management in the Chemical Industry, Reduction of waste production and energy consumption in the production of fatty-acid methyl esters (Henkel), Wiley-VCH, Weinheim, Germany, 1999... 

Production of Eastman s entire acetic anhydride requirement from coal allows a reduction of 190,000 m /yr (1.2 million barrels/yr) in the amount of petroleum used for production of Eastman chemicals. Now virtually all of Eastman s acetyl products are made in part from coal-based feedstocks. Before the technology was introduced, these chemicals had been made from petroleum-based acetaldehyde. Reduced dependence on petroleum, much of which must be obtained from foreign sources, is important to maintain a strong domestic chemical industry. 

The U.S. chemical industry achieved an annual reduction of 4.2% in energy input per unit of output for the period 1975—1985 (2). This higher reduction resulted from cost optimization, the tradeoff of increased capital for reduced energy use, that was driven by energy prices (4). In contrast, from 1985 to 1990, the energy input per unit of output has been almost flat (2) as a consequence of falling prices. The average price the U.S. chemical industry paid for natural gas fell by one-third between 1985 and 1988 (1,5). 

Advanced Cracking Reactor. The selectivity to olefins is increased by reducing the residence time. This requires high temperature or reduction of the hydrocarbon partial pressure. An advanced cracking reactor (ACR) was developed jointly by Union Carbide with Kureha Chemical Industry and Chiyoda Chemical Constmction Co. (72). A schematic of this reactor is shown in Figure 6. The key to this process is high temperature, short residence time, and low hydrocarbon partial pressure. Superheated steam is used as the heat carrier to provide the heat of reaction. The burning of fuel... 

Aldehydes and ketones are among the most important of ail compounds, both in biochemistry and in the chemical industry. AUdehydes are normally prepared in the laboratory by oxidation of primary alcohols or by partial reduction of esters. Ketones are similarly prepared by oxidation of secondary alcohols or by addition of diorganocopper reagents to acid chlorides. 

The purpose of this article is to indicate and illustrate the very wide range of factors, apart from and beyond questions of underlying chemistry and chemical specificity, that determine or constrain the utility of various investigative efforts in catalyst research they also define the continuing and progressive contributions to the chemical industry which the catalyst chemist can make. The ultimate criteria are nearly always found in cost reduction and/or in product diversification and improvement. 

As described in Section 4-1. one important class of chemical reactions involves transfers of protons between chemical species. An equally important class of chemical reactions involves transfers of electrons between chemical species. These are oxidation-reduction reactions. Commonplace examples of oxidation-reduction reactions include the msting of iron, the digestion of food, and the burning of gasoline. Paper manufacture, the subject of our Box, employs oxidation-reduction chemishy to bleach wood pulp. All metals used in the chemical industry and manufacturing are extracted and purified through oxidation-reduction chemistry, and many biochemical pathways involve the transfer of electrons from one substance to another. 

Figure 3.1 Reduction in environmental impact of the European Chemical Industry. ...

The urgency of the need for waste reduction is readily appreciated by considering the amount of waste generated per kg product, designated as the E factor solvents (Sheldon, 1992, 1992a, 1993, 1994, 1996, 1997, 1997a) in various segments of the chemical industry (Table 2.7). 

Ethylhexan-1 -ol is a useful building block for the pharmaceutical, food, cosmetic and chemical industries. The reduction of 2-ethylhex-2-enal to CS )-2-ethylhexan-l -ol by baker s... 

Carbon dioxide and water are the major waste products from most natural and industrial processes and hence are found in large quantities in the environment. If an efficient and cheap means could be found, the reduction of C02 could provide a potentially rich source of carbon for utilisation in the production of, for example, synthetic hydrocarbon fuels to replace petroleum, formic and oxalic acids for the chemical industries and foodstuffs such as glucose. 

Previous production of pentachlorophenol, as well as the bleaching process in pulp and paper mills, has been shown to be a major source. Changes in industrial processes have resulted in a reduction of PCDD/PCDFs concentration in products. Whereas in the past the chemical industry and, to a lesser extent, the pulp and paper industry were considered to be the main sources of PCDD/PCDFs (and also the cause of many of today s contaminated sites in several industrialized countries), today s dioxin input is mainly due to thermal processes. There is still a considerable focus on waste incineration but, owing to requirements for dioxin reduction in stack gases set by several national authorities, the importance of this category has declined during the last years. Examples can be seen especially in the European emission inventories... 

Unit operations are almost entirely physical in nature - for example, distillation, filtration, grinding, crystallization, etc. Chemical unit processes on the other hand, are the common standardized processes used in the chemical industry - for example, oxidation, reduction, halogenation, hydration, nitration, esterification, etc. 

Besides these processes, several reduction methods or hydrogenation technologies of dienes and polyenes are used for the fine chemicals industry. 

Given the wide utility of biocatalysis in the fine chemical industry, why is there such an in-house reliance on classical methods of enantioseparation In fact, why is biocatalysis not applied more generally as a replacement for atom-inefficient or hazardous reactions that are intensively used in the pharmaceutical industry, such as amidation, reduction and oxidation ... 

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