Cleaner production

Since the late 1980s, several developed countries have made major public sector commitments to build awareness of cleaner production, also referred to as pollution prevention and waste minimization. These commitments, most notably in Denmark, the Netherlands, the U.K. and the U.S., have led the private sector to investigate and implement pollution prevention measures for existing processes and products. As a result, cleaner production is now seen in these countries as a potentially cost-effective complement to pollution abatement in meeting environmental standards. 

There have been several efforts to transfer the experience of developed countries in this field to developing countries. All of these efforts are examples of technology transfer (i.e., the transfer of knowledge, skills, equipment and so on) to achieve a particular objective the reduction of pollution intensity in the industrial sector of developing countries. 

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This reaction sequence is much less prone to difficulties with isomerizations since the pyridine-like carbons of dipyrromethenes do not add protons. Yields are often low, however, since the intermediates do not survive the high temperatures. The more reactive, faster but less reliable system is certainly provided by the dipyrromethanes, in which the reactivity of the pyrrole units is comparable to activated benzene derivatives such as phenol or aniline. The situation is comparable with that found in peptide synthesis where the slow azide method gives cleaner products than the fast DCC-promoted condensations (see p. 234). 

A variation of this method involves the conversion of the amine into the amine hydrochloride prior to treatment with phosgene. This method has the advantage of producing generally cleaner products by retarding the secondary reaction of the free amine with carbamoyl chloride. 

The schemes depicted in Figure 7 contrast two complimentary approaches to cefotiam (50) in which the timing of the introduction of the C-3 substituent differs. In Route A the heterocycHc thiol C-3 substituent is introduced even before the removal of the aminoadipoyl acyl side chain. The acetonylacetyl C-3 substituent was introduced because it gave considerably higher yields and cleaner product in the nucleophilic displacement step than the corresponding acetoxy, and the starting material, deacetylcephalosporin C (5) was readily available from a fermentation process (190,191). 

Deall lation. Chloroformates such as vinyl chloroformates (40) are used to dealkylate tertiary amines. Chloroformates are superior to the typical Von Braun reagent, cyanogen bromide, because of increased selectivity producing cleaner products. Other chloroformates such as aHyl, methyl, phenyl, and trichloroethyl have also been used in dealkylation reactions. Although the dealkylation reaction using chloroformates is mostiy carried out on tertiary amines, dealkylation of oxygen or sulfur centers, ie, ethers or thioethers, can also be achieved. a-Chloroethyl chloroformate [50893-53-3] (ACE-Cl) (41,42) is superior to all previously used chloroformates for the dealkylation reaction. ACE-Cl has the advantage that the conditions requked for ACE... 

Manual Component Separation The manual separation of solid-waste components can be accomplished at the source where solid wastes are generated, at a transfer station, at a centralized processing station, or at the disposal site. Manual sorting at the source of generation is the most positive way to achieve the recoveiy and reuse of materials. The number and types of components salvaged or sorted (e.g., cardboard and high-quality paper, metals, and wood) depend on the location, the opportunities for recycling, and the resale market. There has been an evolution in the solid waste indus-tiy to combine manual and automatic separation techniques to reduce overall costs and produce a cleaner product, especially for recyclable materials. 

Dimethyl-2-sila-l,3-dithiane, BF3 Et20, CH2CI2, 0°, 82-99% yield. This method was reported to be superior to the conventional synthesis because cleaner products are formed. Aldehydes are selectively protected in the presence of ketones, which do not react competitively with this reagent. 

The ether should be reagent grade but not sodium-dried. The traces of water present destroy excess reagent, leading to a cleaner product. 

Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. The primary treatment technologies afforded to this manufacturing include the following ... 

Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. The following production-related targets can be achieved by measures such as those described above. The numbers relate to the production processes before the addition of pollution control measures. In sulfuric acid plants that use the double-contact, double absorption process, emissions levels of 2 to 4 kilograms of sulfur dioxide... 

A pesticide manufacturing plant should prepare a hazard assessment and operability study and also prepare and implement an emergency preparedness and response plan that takes into account neighboring land use and the potential consequences of an emergency. Measures to avoid the release of harmful substances should be incorporated in the design, operation, maintenance, and management of the plant. Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. 

Pollution prevention is always preferred to the use of end-of-pipe pollution control facilities. Therefore, every attempt should be made to incorporate cleaner production processes and facilities to limit, at source, the quantity of pollutants generated. The choice of flash smelting over older technologies is the most significant means of reducing pollution at source. Sulfur dioxide emissions can be controlled by ... 

By converting the plant to natural gas, we displace the use of coal and eliminate the hazardous air emissions associated with its combustion — but we need to invest into a new technology. The new process is generically referred to as cleaner production, simply because it is inherently cleaner or less polluting, and the technology is referred to as green technology. ... 

Pollution Prevention and Abatement Handbook 1998 — Toward Cleaner Production. Washington The World Bank Group, 1999. 

A few international journals are available that have LCA as a theme, including the International Journal of LCA and the Journal of Cleaner Production. The Journal of Industrial Ecology sometimes contains LCA articles. 

Chlorotris(diethylamino)titanium24 is prepared directly from diethylamine, lithium and tilani-um(IV) chloride in the presence of styrene as reducing agent25. However, a metathesis reaction between tetrakis(diethylamino)titanium26 28 and titanium(lV) chloride gives a cleaner product and is thus preferred. Bromotris(diethylamino)titanium is prepared similarly7,29. 

Apart from the provision of various permutations of (chemical-based) boiler water programs, it is common to find water treatment companies supplying value adding chemicals and services in other boiler plant-related areas where their expertise in applied chemical technology can deliver additional economic benefit. Such areas typically include cleaning services for boiler waterside and fireside and the provision of fuel treatments and combustion additives, dust suppressants (for coal and ash handling), acids, and cleaner products. 

Another series of pyrroles, structurally related to amino acids, was obtained in a microwave-assisted solvent-free condensation of a-amino acid methyl esters with chloroenones, which provided the four-carbon unit of the pyrrole. The reaction was carried out by mixing the reagents on silica gel and irradiating for 2-6 min inside a multimode microwave cavity (Scheme 7). The authors reported higher yields and cleaner products when microwaves were used instead of conventional heating [34],... 

Phenol is the starting material for numerous intermediates and finished products. About 90% of the worldwide production of phenol is by Hock process (cumene oxidation process) and the rest by toluene oxidation process. Both the commercial processes for phenol production are multi step processes and thereby inherently unclean [1]. Therefore, there is need for a cleaner production method for phenol, which is economically and environmentally viable. There is great interest amongst researchers to develop a new method for the synthesis of phenol in a one step process [2]. Activated carbon materials, which have large surface areas, have been used as adsorbents, catalysts and catalyst supports [3,4], Activated carbons also have favorable hydrophobicity/ hydrophilicity, which make them suitable for the benzene hydroxylation. Transition metals have been widely used as catalytically active materials for the oxidation/hydroxylation of various aromatic compounds. 

Robert, K.-H., Schmidt-Bleek, B., Alois de Larderel, J. et al. (2002) Strategic Sustainable Development - Selection, Design and Synergies of Applied Tools. Journal of Cleaner Production, 10, 197. 

Think about the product in terms of the leasing model. This is already widely done in the catalyst industry for precious metal catalysts, and is being promoted by the UN Industrial Development Organisation (UNIDO) as part of its Cleaner Production Initiative. 

Jodicke, G., Zenklusen, O., Weidenhaupt, A., Hungerbiihler, K. (1999) Developing Environmentally-Sound Processes in the Chemical Industry A Case Study on Pharmaceutical Intermediates. Journal of Cleaner Production, 7, 159-166. 

Countries need to build the technical and scientific institutional capacity to develop, absorb, and diffuse pollution prevention techniques and cleaner production processes essential for a successful program. This could be done by the following9 ... 

Providing technical support for the design, establishment, operation, evaluation, and monitoring of pollution prevention techniques and cleaner production processes and technologies... 

The United Nations Industrial Development Organization (UNIDO) defines cleaner production as the conceptual and procedural approach to production that demands that all phases of the life-cycle of products must be addressed with the objective of the prevention or minimization of short- and long-term risks to humans and the environment. A total societal commitment is required for effecting this comprehensive approach to achieving the goal of sustainable societies. 9... 

The UNIDO program links existing sources of information on low and nonwaste technologies and promotes cleaner production worldwide through four primary activities the International... 

Cleaner Production Information Clearing house (ICPIC), expert working groups, a newsletter, and training activities. 

The UNIDO project Demonstration of Cleaner Production Techniques 11 demonstrates that the concept of preventing wastes at their source as opposed to end-of-pipe treatment is as applicable and profitable in developing countries as in developed countries. The experience gained as well as the demonstrations produced will be of great value in the promotion and implementation of a Cleaner Production Program. 

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