Consideration of Raw Materials

New Routes Towards PHB from Fossil Fuel-Based Monomers 

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Synthesis. Exploratory research has produced a wide variety of odorants based on natural stmctures, chemicals analogous to naturals, and synthetic materials derived from available raw materials and economical processing. As in most areas of the chemical industry, the search for new and useful substances is made difficult by the many materials that have been patented and successfully commercialized (4). In the search for new aroma chemicals, many new materials are prepared for screening each year. Chemists who perform this work are involved in a creative exercise that takes its direction from the commercial sector in terms of desirable odor types and specific performance needs. Because of economic limitations, considerations of raw material costs and available processing methods may play a role eady in the exploratory work. 

The environmental impacts associated with MA production without consideration of raw material production, fiansportation and electricity consumption are found in Table 6.3. Two potential benzene suppliers are considered, benzene can be obtained from a coke plant (Benzene Supplier-Tech 1 -Bz 1), or from a 50 % mixture of ethylene reforming and pyrolysis gasoline (Benzene Supplier-Tech 2-Bz2). For the case of butane production, two suppliers are considered, one that is a proxy model obtained from a European typical refinery (Butane Supplier-Tech -Bt ) (Butane Supplier-Tech 2-Bt2), and another one fi om a mixture of the top 20 organic chemicals. The values were retrieved from Ecoinvent-V 1.3 (2006) using SimaPro 7.1.6... 

Raw materials efficiency. In choosing the reactor, the overriding consideration is usually raw materials efficiency (bearing in mind materials of construction, safety, etc.). Raw material costs are usually the most important costs in the whole process. Also, any inefficiency in raw materials use is likely to create waste streams that become an environmental problem. The reactor creates inefficiency in the use of raw materials in the following ways ... 

In most processes, the largest individual cost is raw materials. Raw materials costs and product prices tend to have the largest influence on the economic performance of the process. The value of raw materials and products depends on whether the materials in question are being bought and sold under a contractual arrangement (either within or outside the company) or on the open market (the spot price). Open-market prices can fluctuate considerably with time. Products are normally sold at below open-market price when under a contractual arrangement. 

Commercial production of acetic acid has been revolutionized in the decade 1978—1988. Butane—naphtha Hquid-phase catalytic oxidation has declined precipitously as methanol [67-56-1] or methyl acetate [79-20-9] carbonylation has become the technology of choice in the world market. By-product acetic acid recovery in other hydrocarbon oxidations, eg, in xylene oxidation to terephthaUc acid and propylene conversion to acryflc acid, has also grown. Production from synthesis gas is increasing and the development of alternative raw materials is under serious consideration following widespread dislocations in the cost of raw material (see Chemurgy). 

AvaUabUity and cost of raw materials and processing equipment Simplicity and cost of manufacture and inspection Manufacturing hazards PropeUant viscosity and flowabUity Environmental considerations... 

Responsible Care is the incentive sponsored by the Chemical Manufacturers Association (CMA). Any CMA company must embrace the philosophy of continuous improvements of health, safety, and environmental efforts accompanied by an open communication to the pubHc about products and their production. Thus the total impact of any product on the environment, from the extraction of raw materials, their beneftciation, transportation, production of final product, and disposal of the product at the end of its useful life, must be taken into consideration. 

Table 6 shows the production of abrasive sihcon carbide in the United States and Canada (131). In 1988, four firms were producing cmde sihcon carbide under various trade names at six plants in the United States and Canada, The Exolon-ESK Co. General Abrasive/Dresser Co. Norton Co. and Superior Graphite Co. Most plants are located in areas where electrical power is, or at one time, was available at relatively low rates. Other considerations are availabihty of labor, reasonable air and water pollution standards, future expansion potential, and proximity of raw materials and markets. 

Process Economics. Relative economics of various ceU culture processes depend heavily on the performance of the ceU line in a system and on the cost of raw materials, particularly the medium. Models are usuaUy developed for the various processes using productivity data obtained from smaU-scale experiments (see Pilot AND MiCROPLANTs). Often, for high value products, the process which ensures the shortest time to market may be the process of choice because of other economic criteria. This is especially tme for pharmaceuticals (qv). RehabUity concerns also often outweigh economic considerations in choosing a process for a high value product. 

Portiand cement clinker structures (18,19) vary considerably with composition, particle size of raw materials, and burning conditions, resulting in variations of clinker porosity, crystallite sizes and forms, and aggregations of crystallites. Alite sizes range up to about 80 p.m or even larger, most being 15—40 )J.m. 

Despite the attractions of economic forces driving environmental protection, some cautions and failures have been noted. Firstly, the export of hazardous waste to countries where costs for treatment are lower enhances environmental risks during transport and has the potential for transboundary export in the event of pollution. At the same time, the loss of raw material may deprive the home market of an adequate supply of feedstock for the home-based industry. Secondly, there is considerable scepticism that self-regulation of TBT-based antifoulants could be achieved in a timely manner by the shipping industry. This is an instance where the cost benehts to one industry are born by another commercial sector, notably aquaculture. Thus, protection of the marine environment is likely to be aided by economic factors but the role of government, via taxation and standard setting, is not likely to be usurped. Public education and, in turn, pressure, can promote and support corporate environmentalism. 

The assessment of transportation risk must include consideration of the capabilities, equipment, and practices of both raw materials suppliers and customers. Some apparently attractive options may need to be discarded because of what suppliers of raw materials or customers... 

Different technical developments have occurred in the coating industry which permit the use of a variety of raw materials. It is possible to formulate surface coatings that are suitable for each and every kind of material. In many cases a number of different coating systems may come into consideration for painting a particular substrate. 

Since that time an enormous number of surfactants covering a wide range of chemical and physicochemical properties have been developed for quite universal as well as specific tasks in domestic and industrial applications. The criteria for selection of a surfactant for industrial production is directly connected with the feasibility of large-scale production. This is determined by several factors including availability and costs of raw materials, cost of manufacture, and performance of the finished products. In addition to these aspects, environmental considerations likewise play an increasingly important role. 

Enzymes sales are estimated to be about 10 /a world-wide. Biocatalysts are subject to a derived-demand arising from the industrial applications in which they are used, for processing raw materials to products that can be sold in their own right. Therefore the commercial importance of biocatalysts is very much greater than these sales of enzymes would indicate. Such sales values are really only of importance to enzyme manufacturer companies. Biocatalysts enable the value of raw materials to be enhanced considerably and the cost of the biocatalyst often represents only a few percent of the final value of product and the total processing costs (Table 13.2). Also, simple enzyme sales values do not include the enzymes that are made and used in-house, as occurs both for many... 

Peeling, one of the most delicate pretreatments, is achieved industrially by abrasion, high-pressure steam, treatment with sodium hydroxide solution, or mechanically. Abrasion is effected by rough, moving surfaces which remove the outer surface of the product, but it has the drawback of considerable loss of raw material. Steam peeling consists of heating the product to... 

Quantitation of components in samples is a general goal of analytical purposes. In the fields of archaeometry, conservation, and restoration, quantitation of analytes is of considerable interest in a wide variety of applications. Thus, the provenance of raw materials, alloy composition, and more, can be crucial for authentication, geographical location, or analysis of the time evolution of works of art, techniques, etc. 

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