Separators, cost

Figure 10.7 Effluent treatment costs should be included with raw materials costs when traded off against separation costs to obtain the optimal recovery. (From Smith and Petela, Chem. Eng., 513 24, 1991 reproduced by permission of the Institution of Chemical Engineers.)...

Dmm diameters are typically 762, 914, or 1219 mm, all of which have been used in the various basic appHcations. In some instances, standardization of diameter is specified because of maintenance considerations. Because these separators are constmcted more mggedly and requHe repulping stages, capital costs are higher than heavy-media separators. Costs in 1995 were approximately 10,000/m of width for single-dmm modules and multiples of the single-dmm module. 

However, it is sometimes quite difficult to separate costs and particularly manufacturing overhead costs into fixed and variable components. In the long term virtually all costs are variable. The difference between the two methods assumes great importance in inventory evaluation. In cost accounting, costs are identified with cost centers. These are accounting devices which may or may not have a physical existence. In the simplest case of a plant manufacturing a single product, the entire plant may be the cost center. 

FIG. 19-48 Influence of drum diameter on separation cost. A, Two stages coarse separation O, three stages fine separation , sum of coarse and fine separations. (Coutiesy of Sala International, Inc.)... 

Product concentration influences the separation cost and the cost of recycling unconverted reactants. Production rate has a strong effect on investment cost for the full synthesis loop. Selectivity sets the raw material... 

To evaluate the economics of this process, a cost model has been developed to estimate the separation costs for a specific racemate [68, 69]. For this purpose, the sensitivity of the separation costs for several key process parameters have been established as compared to a base-case separation in which a purity of 99 % is required at an enantioselectivity of 1.15. The maximum solubility of the drug is set... 

In the simplest cases, the solvent may consist of one specified component, although in fact in a steady-state cyclic process it is highly unlikely that the solvent will ever come back to the initial composition at time zero. Rather, perhaps, one can say that make-up will entail addition of one material only. Again, clearly this need not be a pure compound, but its composition should be consistent. The single solvent offers limited scope for manipulating the system since it alone must meet all process and operational requirements. In other words, it must satisfy all aspects that will lead to an overall viable system. These aspects include selectivity, capacity, solubility, mass transfer, phase separation, costs, among others. The solvent is, therefore, a mixture components. The solvent components are extractant, (ii) diluent, (iii) modifier, and (iv) synergist. 

To improve process conditions and to obtain higher reaction rate, the water/oil ratio was studied. The influence of the oil/water ratio on separation and on the separation cost was studied employing R. erythropolis KA2-5-1 (deposited as FERN P-16277). The use of an oil/water ratio within the range of (3 1) to (8 1) was found to be optimum and was patented [127],... 

The history of the development of methane conversion to synthesis gas is summarized as an introduction to the partial oxidation of methane, which is reviewed with emphasis on hot spots in reactors, major developments in the reduction of O2 separation costs, and reaction mechanisms. The various catalysts employed in CO2 reforming are examined, with emphasis on inhibition of carbon deposition. 2004 Elsevier Inc. 

The purpose of this chapter is to provide a critical assessment of the literature regarding the partial oxidation of methane and the C02 reforming of methane, with emphasis on the following challenging areas hot spots, 02 separation cost, and the issues of reaction pathways and catalyst selection we also address the issue of carbon deposition in the C02 reforming of methane. The reason why we review these two reactions together is that they have many common characteristics, including the catalysts, the products, and CH4 as reactant. 

CO2 capture difficult. It is, therefore, necessary to specify separate cost and efficiency penalties for the different processes. 

When there are more conversions available that are mutually compatible, process technological solutions (e.g., membranes) can further fully exploit low-energy cascade-type reaction sequences (instead of the other way around - non-compatible conversion steps will always demand high separation costs). 

Userguide, FreedomCar Separator Costing Document, February 2003. 

Penicillins available with specific efficacy against Pseudomonas spp. include carbenicillin and ticarcillin. Both are very effective but require high dosage (50 mg/kg). They can also be used concurrently with aminoglycosides but should be injected separately. Cost is a limiting factor in the use of these drugs. 

Such a large excess of methanol increases both the alcohol recovery and separation costs. However, ester formation increases sharply, going from 3 1 (77%) to 6 1 (87.8%), and ultimately reaches a plateau value of 30 1 (98.4%) [13]. 

Detailed economic considerations are the subject of process design courses, where you will learn about net present value, cash flow, and rate of return. Here we are concerned only with technical aspects of design such as achieving maximum production of a particular product with rniriimum reactor volume or designing a reactor with rninimrim heat input required The costs associated with these options and separation costs before and after the reactor obviously must be included to achieve maximum profit in a chemical process. 

Guthrie and Garrett. It uses equipment factors to generate separate costs for each of the "disciplines associated with the installation of equipment, such as installation labor, concrete, structural steel, and piping, to obtain direct field costs for each type of equipment, e.g., heat exchangers, towers, and reactors. 

An economic analysis of the HRD flame reactor technology was performed by the U.S. EPA using 12 separate cost categories. Based on the assumptions made in the economic analysis, the estimated cost for treating secondary lead soda slag (SLS) ranges from 208 to 932 per ton. 

A typical hydride hydrogen separation unit sized to process 10 MMSCFD of H2 would require 50 to 100,000 lbs of hydride forming alloy. Approximately 1/3 of the alloy weight would be a rare earth(s) if AB5 alloys are utilized. A range of alloy compositions is likely to be required to optimize separation costs for different streams. 

For a difficult binary separation when the choices of solvent and stationary phase are already optimal, as shown in Figure 12.10a, the only way to obtain a separation with a reasonable yield using a batch process is to increase the levels of both the stationary phase and eluent relative to the amount of product injected. This leads to an increase in both separation costs and environmental impact. 

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