Feasibility economic

Fowler and Stepan-Sarkissian (142) estimated total costs of about U.S. 35,000/kg for the production of 375 kg/year of serpentine. Drapeau et al. (143) reported a cost estimate for commercial-scale production of ajmalicine-rich Catharanthus rose us biomass. At the current state of technology the cost would be approximately U.S. 3215/kg ajmalicine. They suggest the coproduction of catharanthine could relieve the cost of ajmalicine production. 

Relationship between estimated market price and market volume of a number of different plant products. The upper line represents the relation between the cost-price of a product produced by means of plant cell biotechnology and yearly production, at the current state of the art. The lower line is calculated from more optimistic figures and therefore represents a future situation. Products situated between the lines might be interesting goals for plant cell biotechnology in the near future. 

Parameters Used for Estimation of Costs of Ajmalicine Production by Cell Cultures of Catharanthus roseus 

Specific productivity in case of spontaneous product release 2.36 X 10 kg/kg hr 

Final tumalicine content of the biomass in case of forced release 0.009 kg/kg 

There are several reasons for oil recovery not being feasible (a) people are not motivated enough to resort to simple home-methods of oil extraction (b) the seed may be too hard or the oil content may be too low to make the operation feasible (c) some of the oils are poorly digested, of low nutritional quality or even toxic to some people (d) some highly desirable fats or oils are found in plants that are not grown in sufficient quantities to warrant building processing plants. The initial cost of the nuts and their preparation for oil recovery, as compared with other sources, does not normally justify the operation. Oil millers cannot pay fresh-market prices for nuts to extract oil. Since about 1950, the author has known several instances where it was feasible to commercially recover oil from nuts. 

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Aluminum can now be produced from clay, but the process is not economically feasible at present. Aluminum is the most abundant metal to be found in the earth s crust (8.1%), but is never found free in nature. In addition to the minerals mentioned above, it is found in granite and in many other common minerals. 

The large heat of vaporisation of water can reduce the economic feasibility of water in industrial processes. 

DifficultSepa.ra.tions, Difficult separations, characterized by separation factors in the range 0.95 to 1.05, are frequentiy expensive because these involve high operating costs. Such processes can be made economically feasible by reducing the solvent recovery load (260) this approach is effective, for example, in the separation of m- and -cresol, Hnoleic and abietic components of tall oil (qv), and the production of heavy water (see Deuteriumand TRITIUM, deuterium). 

Uranium is present in small (50—200 ppm) amounts in phosphate rock and it can be economically feasible to separate the uranium as a by-product from the cmde black acid (30% phosphoric acid) obtained from the leaching of phosphate for fertilizers (qv). The development and design of processes to produce 500 t U Og per year at Ereeport, Louisiana have been detailed (272). 

Manufacture and Economics. Nitrogen tritiuoride can be formed from a wide variety of chemical reactions. Only two processes have been technically and economically feasible for large-scale production the electrolysis of molten ammonium acid fluoride and the direct fluorination of the ammonia in the presence of molten ammonium fluoride. In the electrolytic process, NF is produced at the anode and H2 is produced at the cathode. In a divided cell of 4 kA having nickel anodes, extensive dilution of the gas streams with N2 was used to prevent explosive reactions between NF and H2 (17). 

Yields of algae grown in outdoor pond cultures (Table 1) are on the order of 15-40 g/(m -d) (24 short tons pet acre pet year). Higher yields can be obtained under artificial illumination, but growth of algae under these conditions is not economically feasible. 

The direct splitting of H2S, analogous to the splitting of water, is not economically feasible because of the high energy iaput requirement for the endothermic reaction. 

Other methods have been tested by various companies and governmental agencies (57), but none have proven economically feasible. 

Less propane and butanes are produced compared to natural gas Hquids by the adsorption process than are obtained normally for the same gas by the oil-absorption process. Because adsorption efficiency increases with a decrease in temperature, the adsorption cycle should operate at the lowest temperature that is economically feasible. 

The concentration of most metals in the earth s cmst is very low, and even for abundant elements such as aluminum and iron, extraction from common rock is not economically feasible. An ore is a metallic deposit from which the metal can be economically extracted. The amount of valuable metal in the ore is the tenor, or ore grade, usually given as the wt % of metal or oxide. Eor precious metals, the tenor is given in grams per metric ton or troy ounces per avoirdupois short ton (2000 pounds). The tenor and the type of metallic compounds are the main characteristics of an ore. The economic feasibihty of ore processing, however, depends also on the nature, location, and size of the deposit the availabihty and cost of a suitable extraction process and the market price of the metal. 

The development of selective extractants for copper has made extraction from dilute solutions (1—5 kg/m ) economically feasible. Transfer of the copper by stripping to a more concentrated sulfuric acid solution, ie, 30—40 kg/m for Cu " and 150—170 kg/m for H2SO4, from which the copper is recovered by electrowinning. The simplified reaction,... 

Fused-salt electrolysis of K2NbFy is not an economically feasible process because of the low current efficiency (31). However, electrowinning has been used to obtain niobium from molten alkaU haUde electrolytes (32). The oxide is dissolved in molten alkaU haUde and is deposited in a molten metal cathode, either cadmium or zinc. The reaction is carried out in a ceramic or glass container using a carbon anode the niobium alloys with the cathode metal, from which it is freed by vacuum distillation, and the niobium powder is left behind. 

The commercial production of shale oil as an alternative energy source has not been economically feasible. As of 1995, all commercial oil shale operations in the world (Petrobras, Bra2il PAMA, Israel The Chinese Petroleum Corporation, Fushun and Maoming, China KivioH Oil Shale Processing Plant, Kohda-Jarve, Estonia) receive some sort of economic incentives or assistance from the countries in which they are operating. 

The main objectives of RCRA ate to protect pubHc health and the environment and to conserve natural resources. The act requires EPA to develop and adininistet the following programs soHd waste disposal practices providing acceptable protection levels for pubHc health and the environment transportation, storage, treatment, and disposal of hazardous wastes practices that eliminate or minimize hazards to human health and the environment the use of resource conservation and recovery whenever technically and economically feasible and federal, state, and local programs to achieve these objectives. 

The physical form of the thermocouples varies significantly according to appHcations. Most spacecraft power suppHes utilize separate thermocouples that can be checked for performance at successive stages of manufacturing and be replaced if necessary. This approach fits in very well with the extremely high rehabihty requirements imposed on such systems. In terrestrial systems where such individualized attention is not economically feasible, modular assembhes are generally used, which can contain tens to hundreds of couples in a single unit. 

Ocean Disposal. Disposal of raw or treated sludge by barging to sea was practiced for many years by some coastal cities, but today is highly controversial, and it appears that this method will be no longer economically feasible. Federal regulations require that sludge be taken to disposal sites about 160 km from the coast, whereas formerly, disposal sites were permitted within 20 km offshore. Transportation costs are expected to be so high that ocean disposal will be discontinued. 

Although the hydrolysis of wood to produce simple sugars has not proved to be economically feasible, by-product sugars from sulfite pulping are used to produce ethanol and to feed yeast (107). Furthermore, a hemiceUulose molasses, obtained as a by-product in hardboard manufacture, can be used in catde feeds instead of blackstrap molasses (108). Furfural can be produced from a variety of wood processing byproducts, such as spent sulfite Hquor, bquors from the prehydrolysis of wood for kraft pulping, hardboard plants, and hardwood wastes (109). 

The choice of the strain of microorganism is one of the important variables in the process. The strains to be used in manufacture are mutants of the original producer, which are chosen as the result of a planned program of mutant selection. Sometimes a spontaneous mutation occurs usually, it is induced by mutagenic agents or irradiation of various sorts. The choice of the best strain depends on its abiUty to produce large amounts of the proper antibiotic in a reasonable time from ingredients that are economically feasible (73). 

The number of columns ia a multicomponent train can be reduced from the N — 1 relationship if side-stream draw-offs are used for some of the component cuts. The feasibiUty of multicomponent separation by such draw-offs depends on side-stream purity requirements, feed compositions, and equihbrium relationships. In most cases, side-stream draw-off distillations are economically feasible only if component specifications for the side-stream are not tight. If a single component is to be recovered ia an essentially pure state from a mixture containing both lower and higher boiling components, a... 

Biocatalytic ledox reactions offer great synthetic utility to organic chemists. The majority of oxidase-catalyzed preparative bioconversions are still performed using a whole-ceU technique, despite the fact that the presence of more than one oxidoreductase in cells often leads to product degradation and lower selectivity. Fortunately, several efficient cofactor regeneration systems have been developed (160), making some cell-free enzymatic bioconversions economically feasible (161,162). 

Ethylene. Where ethylene is ia short supply and fermentation ethanol is made economically feasible, such as ia India and Bra2il, ethylene is manufactured by the vapor-phase dehydration of ethanol. The production of ethylene [74-85-1] from ethanol usiag naturally renewable resources is an active and useful alternative to the pyrolysis process based on nonrenewable petroleum. This route may make ethanol a significant raw material source for produciag other chemicals. 

Specialty plants. These plants are capable of producing small amounts of a variety of products. Such plants are common in fine chemicals, pharmaceutic s, foods, and so on. In specialty plants, the margins are usually high, so factors such as energy costs are important but not life-and-death issues. As the production amounts are relatively small, it is not economically feasible to dedicate processing equipment to the manufac ture of only one product. Instead, batch processing is utilized so that several products (perhaps hundreds) can be manufactured with the same process equipment. The key issue in such plants is to manufacture consistently each product in accordance with its specifications. 

Although it is difficult to carry out economic-feasibility studies on projec ts in a time of high inflation, it is important to try to predict inflation rates and allow for them in such studies. 

The growing shortage of hardwood has increased the cost of wooden pallets to a point at which plastic pallets and composites of wood, paper, and plastics are economically feasible. Much development work is being done on plastic-pallet design to handle typical loadings. Because of the cost of disposing of expendable pallets, returnable ones are often Justified. 

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