Basic processing cost

In order to represent the basic processing cost of an ideal design for a particular process, it is first necessary to identify the factors on which it is dependent. These factors include ... 

Fig. 3.1 Basic processing cost (P ) against annual production quantity (A/) for casting and molding processes.

Figures 3.13, 3.14 and 3.15 show the relative cost consequences of producing specific section/ wall thicknesses for the sample set of processes. Data required are the maximum dimension where the section acts, and the specified section size. Using a process outside its normal size domain can result in an additional cost. In the situation where a process is being considered for a component that is longer or smaller than the size range given in the macro (length, area, volume or weight), the estimate of cost produced is likely to be a lower bound value. Note that for Chemical Milling (CM2.5 and CM5), Cs = 1, as this penalty is taken account of in the formulation of the basic processing cost, Pq.

Note that for Chemical Milling (CM2.5 and CM5), Cft = 1, as the penalty is taken account of in the formulation of the basic processing cost, Pc-... 

In order to determine the basic processing cost. Pc of a simple or ideal design, it is necessary to understand the production factors on which it depends. These are equipment costs including installation, operating costs (labor, supervision and overheads), processing times, tooling... 

Modifications of the basic process are undersoftening, spHt recarbonation, and spHt treatment. In undersoftening, the pH is raised to 8.5—8.7 to remove only calcium. No recarbonation is required. SpHt recarbonation involves the use of two units in series. In the first or primary unit, the required lime and soda ash are added and the water is allowed to settie and is recarbonated just to pH 10.3, which is the minimum pH at which the carbonic species are present principally as the carbonate ion. The primary effluent then enters the second or secondary unit, where it contacts recycled sludge from the secondary unit resulting in the precipitation of almost pure calcium carbonate. The effluent setties, is recarbonated to the pH of saturation, and is filtered. The advantages over conventional treatment ate reductions in lime, soda ash, and COg requirements very low alkalinities and reduced maintenance costs because of the stabiUty of the effluent. The main disadvantages are the necessity for very careful pH control and the requirement for twice the normal plant capacity. 

We only briefly mentioned alkaline stabilization, but in reality this is a variation of sludge pasteurization. The basic process uses elevated pH and temperature to produce a stabilized, disinfected product. The two alkaline stabilization systems most common in the U.S. are a lime pasteurization system and a cement kiln dust pasteurization system. The lime pasteurization product has a wet-cake consistency, while the kiln dust pasteurization has a moist solid like consistency. Both products can be transported to agricultural areas for ultimate use. Literature studies show that the kiln dust product can capture a marketable value of 6.60/Mg ( 6.00/ton) to offset hauling costs, while the lime product does not appear to be able to capture financial credits for product revenues at this point in time. The reasons for this are not entirely clear. 

The process designer must be aware of costs as reflected in the (1) selection of a basic process route (2) the equipment to be used in the process and (3) the details incorporated into the equipment. The designer must not arbitrarily select equipment, specify details or set pressure levels for design wdthout recognizing the relative effect on the specific cost of an item as well as associated equipment such as relieving devices, instruments, etc. 

NOTE The following factors are Battery Limit (process) buildings only and are expressed in per cent of the Building-Architectural Structural cost. They are not related to the Basic Equipment cost. 

The use of heterogeneous basic catalysts for the transesterification of triglycerides has long been considered the main tool to reduce processing costs in the production of biodiesel, as it would lead to simplified operations and eliminate waste streams. 

Based on the results from laboratory-scale equipment and the first production plants, the basic economics of the process were calculated. The processing costs are between 0.15 and 0.60 Euro/kg (composition of costs investment 20%, personell 37%, and operating 43%) and vary depending on the substances to be micronized, the scale of the equipment, etc. 

Highly successful turbojet combustors have been developed through the use of both fundamental principles and cut and try empiricism. The latter approach is costly and time consuming, and it is likely that better combustors could be developed more easily if the exact contribution of each of the several basic processes influencing combustion were known. Therefore, there is a need for a better understanding of these processes and for correlations of this understanding with performance. 

We assume that the reactor is constructed from fairly exotic material and has heat transfer equipment (jacket or coil) and an agitator. So the capital cost is estimated at 10 times the basic vessel cost. The total capital costs of the reactors in the three different flowsheets are 7,429,000, 4,043,000, and 3,657,000 for the 1-CSTR, 2-CSTR, and 3-CSTR processes, respectively. You can see that the reduction in cost between the 2-CSTR and the 3-CSTR processes is quite small. The cost of a 4-CSTR process could be somewhat higher because of having more vessels, even if each is somewhat smaller. 

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