Additive costs

The first criterion was associated with improved secondary and tertiary petroleum recovery processes. This is the justification for the patent appHcations issued to the Dow (50) and Exxon (51) corporations. The additional costs of production and the increased adsorption of such modified water-soluble polymers are detrimental to the commercial appHcation of such polymers and even the academic studies in this area have decreased in recent years. 

The exterior form of MDF is used in special appHcations requiring durabiHty and resistance to water or weather exposure. Highway signs would be an example of this use of exterior MDF. It is an extremely expensive product and thus is used only for special appHcations requiring its special properties. Another example of use would be where a customer would be willing to pay the additional cost to use a composite which has the exceptional quaHties of MDF, but also has virtually no formaldehyde emissions. 

Natural gas upgra ding economics may be affected by additional factors. The increasing use of compressed natural gas (CNG) directiy as fuel in vehicles provides an alternative market which affects both gas price and value (see Gasoline and other motor fuels Gas, natural). The hostility of the remote site environment where the natural gas is located may contribute to additional costs, eg, offshore sites require platforms and submarine pipelines. 

The cheat/server model oftea allows easier iategratioa with other aetwork apphcatioas (eg, fiaance, project management, or human resources) which typically operate ia the environment of the server component of the cheat/server system. Gheat/server can be gradually iatroduced ia an existing minicomputer environment, often with httie adverse incremental impact ia terms of retraining and additional cost. 

The basic seed processing plant design is based on 70% removal of the sulfur contained in the coal used (Montana Rosebud), which satisfies NSPS requirements. Virtually complete sulfur removal appears to be feasible and can be considered as a design alternative to minimize potential corrosion problems related to sulfur in the gas. The estimated reduction in plant performance for complete removal is on the order of 1/4 percentage point. The size of the seed processing plant would have to be increased by roughly 40% but the corresponding additional cost appears tolerable. The constmction time for the 500 MW plant is estimated to be ca five years. 

However, since the naphthalene produced from petroleum is of high purity and quaUty, the production of refined naphthalene by such chemical treatments essentially has ceased in the United States. Not only are such treatments expensive, but they also generate a significant amount of waste sludge, which creates additional costs for appropriate waste-disposal faciUties. 

The uses of spunbonded fabrics as coverstock in diapers and other personal absorbent devices will most likely remain unchallenged for the near term. Virtually any other nonwoven production method appears to be at a cost disadvantage opposite spunbonded polypropylene. There have been composite products developed from meltblown and spunbonded combinations, where areas of either improved hydrophobicity or hydrophilicity are desired. These products can be produced on-line at relatively low additional cost and offer high value to diaper manufacturers. Any competitive threat is likely to come from advances in film technology such as large improvements in perforated film used in segments of absorbent product appHcations, particularly sanitary napkins. 

Further Modifications. There have been attempts to improve the pulp strength and decrease the energy requirement of the groundwood process by the addition of chemicals, eg, sodium carbonate or sodium sulfite. Although some benefits can be obtained, the additional costs and chemical disposal problems have not been justified. Presteaming of wood is practiced in Europe to add moisture and to soften the lignin, which is especially advantageous for certain hardwoods. 

Spill Prevention and Detection. It is far better to prevent a leak or a spik than to clean one. The fundamental rule of leak and spik prevention is to reduce the possibkity for contamination by directing resources as close to the source as possible (Fig. 11). In addition to increasing the effectiveness of a spik and leak prevention program, the costs are lower if the focus is placed on preventing the occurrence in the first place. Regulatory trend, however, is to requite methods that respond to leaks after they occur. In addition to being more costly, this type of requirement is often a disincentive to prevent the leaks in the first place, because of the additional cost. 

In some ED plants, strong mineral acids, such as sulfuric or hydrochloric, are added to the brackish water which flushes the cathodes. These acids prevent precipitation but are an additional cost and an iaconvenience particularly for small plants. 

A robot often can be economically justified when the task of doing a certain packaging operation is an yzed in detail. For example, the palletizing of the fiber drums can be accomplished by human labor but work aids would be necessaiy in order to have acceptable production rates, reasonable operator fatigue, and a safe working environment. When the work aids are considered and their cost determined, the additional cost for providing robot capability is often of a small magnitude, which justifies its use to replace human labor. 

Bioprocess Control An industrial fermenter is a fairly sophisticated device with control of temperature, aeration rate, and perhaps pH, concentration of dissolved oxygen, or some nutrient concentration. There has been a strong trend to automated data collection and analysis. Analog control is stiU very common, but when a computer is available for on-line data collec tion, it makes sense to use it for control as well. More elaborate measurements are performed with research bioreactors, but each new electrode or assay adds more work, additional costs, and potential headaches. Most of the functional relationships in biotechnology are nonlinear, but this may not hinder control when bioprocess operate over a narrow range of conditions. Furthermore, process control is far advanced beyond the days when the main tools for designing control systems were intended for linear systems. 

The scheme will also facilitate conservation of regenerative energy if there are more of such drives without any additional cost. 

The additional costs for incorporating the systems are also shown in Figure 2-45. The cost per KW for the steam injection and the Heated and... 

Pollutants that require an unusually high level of control or that require the fabric filter bags or the unit itself to be constructed of special materials, such as Gore-Tex or stainless steel, will increase the costs of the system. The additional costs for controlling more complex waste streams are not reflected in the estimates given below. For these types of systems, the capital cost could increase by as much as 75 % and the operational and maintenance (O M cost could increase by as much as 20%. 

On small installations an elevated tank above the furnace would be used (refer to Figure 37). The savings from eliminating the pumps, valving, and slurry lines are offset by the additional cost of a structure to support the tank and a rotary feed valve. The tank is fitted with a screened overflow. A dewatering screw conveyor is used for feeding the furnace. 

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