Chemicals operating costs

Use of a blended makeup water will often reduce the stress loading on the chemical treatment program, so a choice can often be made concerning improved chemical product performance or lower chemical operating costs. 

These mixing systems offer high flexibility because they can be operated in batch, semibatch, or continuous modes. Adequate mixing is a prerequisite for the success of chemical processes in terms of rninirnizing investment and operating costs. In addition, chemical reactions with... 

Producers have developed specific cell configurations to optimise electricity consumption, cell capital, and operating costs. Pacific Engineering Corp., Kerr-McGee Chemical Corp., Chedde Pechiney, Cardox Corp., Electrochemie Turgi, American Potash and Chemical, and I. G. Earbenindustrie each has a unique cell design. 

In converting ESBR latex to the dry mbber form, coagulating chemicals, such as sodium chloride and sulfuric acid, are used to break the latex emulsion. This solution eventually ends up as plant effluent. The polymer cmmb must also be washed with water to remove excess acid and salts, which can affect the cure properties and ash content of the polymer. The requirements for large amounts of good-quaUty fresh water and the handling of the resultant effluent are of utmost importance in the manufacture of ESBR and directly impact on the plant operating costs. 

Ca.ta.lysts, A catalyst has been defined as a substance that increases the rate at which a chemical reaction approaches equiHbrium without becoming permanently involved in the reaction (16). Thus a catalyst accelerates the kinetics of the reaction by lowering the reaction s activation energy (5), ie, by introducing a less difficult path for the reactants to foUow. Eor VOC oxidation, a catalyst decreases the temperature, or time required for oxidation, and hence also decreases the capital, maintenance, and operating costs of the system (see Catalysis). 

Operating Costs Power cost for a continuous thickener is an almost insignificant item. For example, a unit thickener 60 m (200 ft) in diameter with a torque rating of 1.0 MN-m (8.8 Mlbf in) will normally require 12 kW (16 hp). The low power consumption is due to the very slow rotative speeds. Normally, a mechanism vi l be designed for a peripheral speed of about 9 m/min (0.5 ft/s), which corresponds to only 3 r/h for a 60-m (200-ft) unit. This low speed also means veiy low maintenance costs. Operating labor is low because little attention is normally required after initial operation has balanced the feed and underflow. If chemicals are required for flocculation, the chemical cost frequently dwarfs all other operating costs. 

Vataviik, W. M., and R. B. Neveril, Factors for Estimating Capital and Operating Costs, Chemical Engineering, November 3, 1980, pp. 157-162. Vogel, G. A. andE. J. Martin, Hazardous Waste Incineration, Chemical Engineering, September 5, 1983, pp. 143-146 (part 1). 

UltrafiUration is a preferred alternative to the conventional systems of chemical flocculation and coagulation followed by dissolved air flotation. Ultraflltration provides lower capital equipment, installation, and operating costs. 

TAG - Annualized fixed cost of modules -f Annualized fixed cost of pump -f Annualized fixed cost of turbine -H Annual operating cost of pump -h Annual operating cost of chemicals — Operating value of turbine... 

Annual operating cost of pretreatment (chemicals) - 0,03/m of feed. 

The reason for this is simple. If the reaction chemistry is not "clean" (meaning selective), then the desired species must be separated from the matrix of products that are formed and that is costly. In fact the major cost in most chemical operations is the cost of separating the raw product mixture in a way that provides the desired product at requisite purity. The cost of this step scales with the complexity of the "un-mixing" process and the amount of energy that must be added to make this happen. For example, the heating and cooling costs that go with distillation are high and are to be minimized wherever possible. The complexity of the separation is a function of the number and type of species in the product stream, which is a direct result of what happened within the reactor. Thus the separations are costly and they depend upon the reaction chemistry and how it proceeds in the reactor. All of the complexity is summarized in the kinetics. 

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