Comparative costing

Figure 5.6 Comparative costs of nonintegrated versus heat-integrated sequences of simple columns. (From Smith and Linnhoff, Trans. IChemE, ChERD, 66 195, 1988 reproduced by permission of the Institution of Chemical Engineers.)...

Economic Aspects. To be useful the raw materials must be recoverable at a cost not greater than the cost of similar terrestrial materials. These costs must include transportation to the point of sale. Comparative costs of recovery are strongly influenced by secondary environmental or imputed costs, such as legal costs or compensatory levies. 

M. Levenson, J. V. C. Trice, and W. J. Mecham, Comparative Cost Study of the Processing of Oxide, Carbide, and MetalFast Breeder Reactor Fuels by Aqueous, Uolatility andPyrochemicalMethods, ANL-7137, Argonne National Laboratory, Argonne, lU., 1966. 

In most ores, sufficient Fe is already present. For some ores, it is necessary to add metallic iron. In practice, the oxidation potential of the solution can be monitored and controlled using the Fe /Fe ratio. Very high leaching efficiencies with H2SO ate common, eg, 95—98% dissolution yield of uranium (39). If acid consumption exceeds 68 kg/1 of ore treated, alkaline leaching is preferred. The comparative costs of acid, sodium hydroxide, and sodium carbonate differ widely in different areas and are the determining factor. 

The substitution of asbestos fibers by other types of fibers or minerals must, ia principle, comply with three types of criteria (36) the technical feasibihty of the substitution the gain ia the safety of the asbestos-free product relative to the asbestos-containing product and the availabiHty of the substitute audits comparative cost. 

Complete Plant Costs It is difficult to compare costs of domestic and overseas plants owing to the wide variation in types of plants and sizes and the rapid changes in technology. Useful data are scarce, and the following comparisons must be used with caution and then only for order-of-magnitude estimates of fixed-capital costs. 

Comparative costs for conveyor systems can be based only on studies of specific problems. For example, belt-conveyor idlers are available in a range of quahties that may make the best unit cost three times as much as the cheapest. Bearing quahty, steel thickness, and diameter of rolls all affect cost, as does design for easy maintenance and repair. Therefore, it is necessary to make cost comparisons on the basis of a specific study for each conveyor application. 

Take the results for questions 4 and 5 and do a comparative cost analysis. First go the the Web and find suitable equipment suppliers that will provide the equipment in the size ranges you have calculated. Obtain some vendor quotes (rough ones will do). Then perform the fowllowing analysis (a) What are the comparative costs between the two oprions for energy use (b) What are the comparative costs between the two options in terms of maintanance and labor costs (c) Can you combine both equipment options into a single process, and if so, can you justify this and how Assume in the above that the reduction in solids concentration must meet the 1 % weirht criteria described in question 4. 

Solar power works well m small tacilities, and it may be comparatively cost-effective when all tactors (transmission, fuel transportation costs, seivice lite, etc.) are taken into consideration. In many instances solar energy is the only viable energy option in the region. 

NOTE Certain speed combinations require dual windings, and others may be either one or two. In the latter case, compare costs of both motors plus their controls. 

Floor treatment/flooring Comparative cost index... 

All coatings cost money and a true appraisal of both the initial and maintenance costs is essential when specifying the protective scheme for a new structure. An example showing the comparative costs of galvanising and painting is given in Section 9.1. 

Detailed economics of individual industrial processes, including SCP processes, are usually regarded as confidential, out of fear that publication may lend advantage to competitors. In addition, economy of scale rule generally applies (that is as the production capacity increases, the cost of the product decreases), so that direct comparisons can only be made between systems of similar capacity. Some economic data on SCP processes have been published and are presented in the Resource Material at the end of this chapter. You should appreciate that the data are outdated by more than a decade, during which time substrate costs will have varied relative to each other, and technology will have improved. This means that the comparative costs presented in Table 4.13, for example, may not be now as presented there. Nevertheless the data presented do provide an outline of the economics of SCP production. The processes referred to in the Resource Material are not necessarily those mentioned in the text and so you may find some differences in detail. 

To demonstrate the use of such a comparative cost analysis, the production of a panel was analyzed according to different processes (Fig. 9-6). In these case studies the following conditions existed (1) the panels measured 61 x 91 cm (24 x 36 in.) with the wall thickness dictated by the process and part requirements so that the weights of the panels differed (2) production was at a level of 40,000/yr. (3) the plastics for all panels were of the same type, except that different grades had to be used, based on the process requirements, so that costs changed (4) each panel received one coat of paint, except that the structural foam also had a primer coating and (5) costs were allocated as needed to those processes that required trimming and other secondary operations. 

A considerable amount of work has already been successfully carried out in HASETRI with naturally occurring oils as eco-friendly process oils in conventional tire recipes [31,32]. These naturally occurring oils were found to be suitable on the basis of low PCA content. Some of the naturally occurring oils showed better processing properties, polymer-filler interaction, and dispersion properties in NR-based truck tire tread cap compound and hence better mechanical and dynamic mechanical properties. As the presently available low PCA oil in the market in the form of MES TDAE and naphthenic oil are comparatively costly, these natural oils can act as the best alternative processing aids for the elastomer industry, especially in developing and underdeveloped countries. 

Another limitation is related to the fact that synthetic poly(amino acids) have rather unfavorable material properties. For instance, most synthetic poly (amino acids) derived from a single amino acid are insoluble, high-melting materials that cannot be processed into shaped objects by conventional fabrication techniques. The often undesirable tendency to absorb a significant amount of water when exposed to an aqueous environment is another common property of many poly (amino acids) (7). Finally, high molecular weight poly-(amino acids) are best prepared via N-carboxyanhydrides which are expensive to make. Hence poly(amino acids) are comparatively costly polymers, even if they are derived from inexpensive amino acids (8). 

Jubran A, Gross N, Ramsdell J, et al. Comparative cost-effectiveness analysis of theophylline and ipratropium bromide in chronic obstructive pulmonary disease. A three-center study. Chest 1993 103 678-84. 

Pure honeys are comparatively costly. Some beekeepers may imlawfully use sweeteners to feed bees to increase honey sweetness. Another unlawful act is to directly add sugars into honey products. Some sweeteners that have been used include acid / inverted sugar syrups, com syrups, maple syrup, cane sugar, beet sugar, and molasses. 

The quantity of a material used will depend on the material density and strength (design stress) and these must be taken into account when comparing material costs. Moore (1970) compares costs by calculating a cost rating factor defined by the equation ... 

The need to compare costs with benefits. Having looked at the real costs of a system one must then be prepared to answer that question, "is it worth it "... 

TABLE 65-1 Comparative Costs of Hormonal Therapy for Advanced Prostate Cancer ... 

Countries that can supply hydrogen at a comparable cost to conventional fuels (maximally twice the price of gasoline without taxes, owing to the double efficiency of fuel cells compared with internal combustion engines). 

It is difficult to compare costs to other disposal options. The Seiber report ( ) listed the capital cost for incineration at 89,550, and yearly operating cost of 106,500, based on 1978 estimates. The capital and operating costs for our UV-ozonation... 

The PBAC assesses applications for listing on the PBS for reimbursement against criteria specified in the National Health Act. These criteria include safety and efficacy compared with other available treatments including non-drug therapies, and comparative cost-effectiveness. 

The PBPA makes recommendations to the Department of Health on the prices for new items that have been recommended for PBS listing by the PBAC. It also reviews the prices for all items listed on the Schedule of Pharmaceutical Benefits at least once per aimum. The PBAC provides advice to the PBPA regarding comparison with other treatments and comparative cost-effectiveness. 

Table 26.1 Healthcare expenditure and medicines expenditure as % GDP and comparative cost of medicines (OECD Health Data 2000 and 2001)...

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