Economics of commercial

R.N. Hall and L.H. Yardumian, The Economics of Commercial Shale Production by the Tosco II Process, 61st Annu. Meet., Am. Inst. Chem. Eng. Los Angeles, 1968 (unpublished). 

The alteration of fermentation conditions, such as pH, drastically affects product concentrations. Research with C. ljungdahlii has shown that at high pH values (5.5-6), acetate was the dominant product, while at a lower pH (4-4.5), there was a drastic shift towards the production of ethanol. " Inhibition by end products or intermediates is the principal factor that limits metabolic rates and final product concentrations in many fermentation processes. Product inhibition can greatly affect the economics of commercialization. With regards to ethanol inhibition, growth of B. methylotrophicum was inhibited at alcohol concentrations of 5g/L. " However, a recently isolated clostridial strain was shown to tolerate ethanol concentrations up to 78g/L. Efforts have been made to eliminate the drawbacks of inhibition by improvement of bacterial strains to tolerate higher product concentrations and/or by use of novel separation coupled fermentation processes such as pervaporation, extraction, and membrane separation. 

The economics of commercial-scale plants are demonstrated in this paper for two selected capacities (2060 tonnes/day and 6180 tonnes/day of unleaded premium gasoline from natural gas via methanol). 

These examples demonstrate that the economics of commercial chemical transformations on catalytic surfaces are determined by the reaction conditions as well as both reactor and catalyst design. Thus, it is always prudent to involve catalyst experts when designing new processes and reactors, and due to ever-improving catalyst technology, it is also possible to enhance the economics of an existing process by the further optimization of the catalyst. In this respect, carbon supports provide catalytic chemists with a very flexible and economic platform on which to ply their craft. 

Several groups have tested recycling of ILs as well as separation methods that would be suitable on an industrial scale, such as extraction with benign solvents like water, or SCCO2 or distillation [Itoh et al., 2003]. However the economics of commercially using ILs in industrial processes are still far behind and not clear. The currently published data on IL recovery do not allow for reliable extrapolation to industrial applications scale. However, it is clear that the ionic liquids which are proposed to be used as solvents need to be recycled and reused in order to have commercially attractive processes. 

The derivatives are hydroxyethyl and hydroxypropyl cellulose. AH four derivatives find numerous appHcations and there are other reactants that can be added to ceUulose, including the mixed addition of reactants lea ding to adducts of commercial significance. In the commercial production of mixed ethers there are economic factors to consider that include the efficiency of adduct additions (ca 40%), waste product disposal, and the method of product recovery and drying on a commercial scale. The products produced by equation 2 require heat and produce NaCl, a corrosive by-product, with each mole of adduct added. These products are produced by a paste process and require corrosion-resistant production units. The oxirane additions (eq. 3) are exothermic, and with the explosive nature of the oxiranes, require a dispersion diluent in their synthesis (see Cellulose ethers). 

Since 1960, the Hquid-phase oxidation of ethylene has been the process of choice for the manufacture of acetaldehyde. There is, however, stiU some commercial production by the partial oxidation of ethyl alcohol and hydration of acetylene. The economics of the various processes are strongly dependent on the prices of the feedstocks. Acetaldehyde is also formed as a coproduct in the high temperature oxidation of butane. A more recently developed rhodium catalyzed process produces acetaldehyde from synthesis gas as a coproduct with ethyl alcohol and acetic acid (83—94). 

Until World War 1 acetone was manufactured commercially by the dry distillation of calcium acetate from lime and pyroligneous acid (wood distillate) (9). During the war processes for acetic acid from acetylene and by fermentation supplanted the pyroligneous acid (10). In turn these methods were displaced by the process developed for the bacterial fermentation of carbohydrates (cornstarch and molasses) to acetone and alcohols (11). At one time Pubhcker Industries, Commercial Solvents, and National Distillers had combined biofermentation capacity of 22,700 metric tons of acetone per year. Biofermentation became noncompetitive around 1960 because of the economics of scale of the isopropyl alcohol dehydrogenation and cumene hydroperoxide processes. 

In the 1980s cost and availabiUty of acetylene have made it an unattractive raw material for acrylate manufacture as compared to propylene, which has been readily available at attractive cost (see Acetylene-DERIVED chemicals). As a consequence, essentially all commercial units based on acetylene, with the exception of BASF s plant at Ludwigshafen, have been shut down. AH new capacity recendy brought on stream or announced for constmction uses the propylene route. Rohm and Haas Co. has developed an alternative method based on aLkoxycarbonylation of ethylene, but has not commercialized it because of the more favorable economics of the propylene route. 

H. H. S2mant, Organic BuildingBlocks of the Chemical Indust, ]ohxi Wiley Sons, Inc., New York, 1989, pp. 575—637. Desktop reference on production processes, family trees, and economic aspects of commercially important fine chemicals. 

Natural Gas Upgrading via Fischer-Tropsch. In the United States, as in other countries, scarcities from World War II revived interest in the synthesis of fuel substances. A study of the economics of Fischer synthesis led to the conclusion that the large-scale production of gasoline from natural gas offered hope for commercial utiHty. In the Hydrocol process (Hydrocarbon Research, Inc.) natural gas was treated with high purity oxygen to produce the synthesis gas which was converted in fluidized beds of kon catalysts (42). 

J. E. Duddy, S. B. Panvelker, and G. A. Popper, "Commercial Economics of HRI Coal/Oil Co-Processing Technology," paper presented at 1990 SummerAIChE National Meeting, San Diego, Ca., 1990. 

Table 4 gives typical analyses of some of the commercial manganese ores available ia the world market. Table 5 gives a breakdown of the world s total estimated manganese ore reserves that account for 98—99% of the known world reserves of economic significance. No manganese ores of commercial value are to be found ia the United States. 

Many mercury compounds are labile and easily decomposed by light, heat, and reducing agents. In the presence of organic compounds of weak reducing activity, such as amines (qv), aldehydes (qv), and ketones (qv), compounds of lower oxidation state and mercury metal are often formed. Only a few mercury compounds, eg, mercuric bromide/77< 5 7-/7, mercurous chloride, mercuric s A ide[1344-48-5] and mercurous iodide [15385-57-6] are volatile and capable of purification by sublimation. This innate lack of stabiUty in mercury compounds makes the recovery of mercury from various wastes that accumulate with the production of compounds of economic and commercial importance relatively easy (see Recycling). 

As a result of the need for its disclosure, an inventor must disclose the best mode of practicing the invention that the inventor knows in drafting a patent appHcation. In some instances, the best mode may be the very commercial product developed by the inventor. However, in other instances the best mode may be an article, machine, or process which is economically or commercially impractical. Nonetheless, this embodiment needs to be disclosed in the patent. 

An additional mole of ammonium sulfate per mole of final lactam is generated duting the manufacture of hydroxylamine sulfate [10039-54-0] via the Raschig process, which converts ammonia, air, water, carbon dioxide, and sulfur dioxide to the hydroxylamine salt. Thus, a minimum of two moles of ammonium sulfate is produced per mole of lactam, but commercial processes can approach twice that amount. The DSM/Stamicarbon HPO process, which uses hydroxylamine phosphate [19098-16-9] ia a recycled phosphate buffer, can reduce the amount to less than two moles per mole of lactam. Ammonium sulfate is sold as a fertilizer. However, because H2SO4 is released and acidifies the soil as the salt decomposes, it is alow grade fertilizer, and contributes only marginally to the economics of the process (145,146) (see Caprolactam). 

Some alkylphenols in commercial production have low vapor pressures and/or low thermal decomposition temperatures. Eor these products, the economics of distillation are poor and other recovery processes are used. Crystallisation from a solvent is the most common nondistUlation method for the purification of these alkylphenols. 

Aluminum sulfate is a starting material in the manufacture of many other aluminum compounds. Aluminum sulfate from clay could potentially provide local sourcing of raw materials for aluminum production. Processes have been studied (24) and the relative economics of using clay versus bauxite have been reviewed (25). It is, however, difficult to remove impurities economically by precipitation, and purification of aluminum sulfate by crystallization is not practiced commercially because the resulting crystals are soft, microscopic, and difficult to wash effectively on a production scale (26—28). 

Propylene has many commercial and potential uses. The actual utilisation of a particular propylene supply depends not only on the relative economics of the petrochemicals and the value of propylene in various uses, but also on the location of the supply and the form in which the propylene is available. Eor example, economics dictate that recovery of high purity propylene for polymerisation from a smaH-volume, dilute off-gas stream is not feasible, whereas polymer-grade propylene is routinely recovered from large refineries and olefins steam crackers. A synthetic fuels project located in the western United States might use propylene as fuel rather than recover it for petrochemical use a plant on the Gulf Coast would recover it (see Euels, synthetic). 

Although the volume of commercial pyridine compounds is relatively large, economic aspects resemble those of specialty markets more than those of commodities. Commercial transactions occur withHtde pubHcity, trade secrets are carefully guarded, and patents proliferate, thus obscuring the industrial processes used for their manufacture. 

To date (ca 1996) many potentially usefiil sucrose derivatives have been synthesized. However, the economics and complexities of sucrochemical syntheses and the avadabiLity of cheaper substitutes have limited their acceptance hence, only a few of them are in commercial use. A change in the price and availability of petroleum feedstocks could reverse this trend. Additional impetus may come from regioselective, site-specific modifications of sucrose to produce derivatives to facilitate and improve the economics of sucrochemical syntheses. For example, the microbe yigwbacterium tumifaciens selectively oxidizes sucrose to a three-keto derivative, a precursor of alkylated sucroses for detergent use (50). Similarly, enzymes have been used for selective synthesis of specific sucrose derivatives (21). 

Although no longer of significant commercial interest, the characteristics of some of the amorphous homopolymers commercially available at one time or another are illustrated in Table 4. No crystalline polymers are known to have been commercialized. This lack of commercial success results from the economically competitive situation concerning vinyl ether polymers versus other, more readily available polymers such as those based on acryUc and vinyl ester monomers. 

The only disperse brown of commercial importance is Disperse Brown 1 (101), which in 1988 had sales in excess of 2.3 million (production 317 tons). A method stiU. in use to produce navy and black shades economically on acetate involves formation of the dye direcdy on the substrate (azoic dyeing). 

The original performance of the fresh catalyst can be successhiUy restored by proper regeneration to remove this coke. Regeneration allows continued use of the same catalyst for many years. Thus even expensive and sophisticated catalysts can become economical for commercial use in petroleum refining. 

Because graft copolymers are much "easier" to obtain synthetically than heterogeneous diblock or triblock copolymers, they have also been used as compatibiUzers ia polymer blends. Theoretically, they are not as efficient as the diblocks (60), but they are successhilly and economically used ia a number of commercial systems (61). 

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