Capacity utilization

Woddwide, the production capacity for polyester fiber is approximately 11 million tons about 55% of the capacity is staple. Annual production capacity iu the United States is approximately 1.2 million tons of staple and 0.4 million tons of filament. Capacity utilization values of about 85% for staple and about 93% for filament show a good balance of domestic production vs capacity (105). However, polyester has become a woddwide market with over half of the production capacity located iu the Asia/Pacific region (106). The top ranked PET fiber-produciug countries are as follows Taiwan, 16% United States, 15% People s RepubHc of China, 11% Korea, 9% and Japan, 7% (107—109). Woddwide, the top produciug companies of PET fibers are shown iu Table 3 (107-109). 

Batchwise operated multipurpose plants are per defmitionem the vehicle for the production of fine chemicals. There are, however, a few examples of fine chemicals produced ia dedicated, coatiauous plants. These can be advantageous if the raw materials or products are gaseous or Hquid rather than soHd, if the reaction is strongly exothermic or endothermic or otherwise hazardous, and if the requirement for the product warrants a continued capacity utilization. Some fine chemicals produced by continuous processes are methyl 4-chloroacetoacetate [32807-28-6] C H CIO [32807-28-6], and malononittile [109-77-3] C2H2N2, made by Lonza dimethyl acetonedicarboxylate [1830-54-2] made by Ube and L-2-chloropropionic acid [107-94-8] C2H C102, produced by Zeneca. 

Figure 3 shows the capacity utilization resulting from the production program ia a multipurpose plant. The aimual percentage of occupation is shown on the x-axis reflecting the overall busiaess condition, and the level of equipment utilization is shown on thejy-axis, reflecting the degree of sophistication of the fine chemicals to be produced. Several conclusions can be drawn ...

Fig. 3. Multipurpose plant capacity utilization where D represents products A, B, C, D, and E U the changeovers and X the time the plant was idle.

Optimum capacity utilization ia the two dimensions of time and equipment are cmcial to the overall performance, and miming a fine chemicals company has been described as gap management. Attempts have been made to develop adequate equations for describiag the correlation between... 

Table 11. U.S. Polypropylene Production, Capacity Utilization, and Prices ...

In the 1980s manufacturing capacity for aniline underwent some major changes. It is estimated that aniline capacity utilization was about 50% of nameplate capacity when Aristech s new 91,000 t/yr plant came on stream. That same year American Cyanamid closed its 23,000-t plant at Willow Island, W. Va., and withdrew from the aniline business. Mobay shut down its larger plant (45,000-t) at New Martinsville, W. Va. in 1983 and Du Pont idled its 77,000-tfacihtyinl984. 

Worldwide propylene production and capacity utilization for 1992 are given in Table 6 (74). The world capacity to produce propylene reached 41.5 X 10 t in 1992 the demand for propylene amounted to 32.3 x 10 t. About 80% of propylene produced worldwide was derived from steam crackers the balance came from refinery operations and propylene dehydrogenation. The manufacture of polypropylene, a thermoplastic resin, accounted for about 45% of the total demand. Demand for other uses included manufacture of acrylonitrile (qv), oxochemicals, propylene oxide (qv), cumene (qv), isopropyl alcohol (see Propyl alcohols), and polygas chemicals. Each of these markets accounted for about 5—15% of the propylene demand in 1992 (Table 7). 

Figure 23.18(a) Enhanced capacity utilization of the network with the improved p.f. 

Figure 24.20 Capacity utilization load curves with and without compensation...

Another perspective for production simulation is automatic capacity utilization optimization of multi-product systems. As discussed, this task may be very difficult because of the many different variables and boundary conditions. In an environment integrating optimization and simulation, the optimizer systematically varies the important decision variables in an external loop while the simulation model carries out production planning with the specified variables in the internal loop (see Gunther and Yang [3]). The target function, for example total costs or lead times, can be selected as required. The result of optimization is a detailed proposal for the sequence of the placed orders. 

Production and distribution quantities can vary from a minimum utilization to full capacity utilization... 

Raw material consumption rates in production are variable depending on the degree of capacity utilization... 

Which sales prices are price limits before reducing capacity utilization ... 

Domar assumes at the outset that there is full capacity utilization, and moreover that the fraction of labour force employed is a function of the ratio between national income and productive capacity (ibid. 37). Since the supply side models the economy s capacity to produce output, full employment of the labour force requires that the potential change of output is equal to the change in output demanded via the multiplier. Hence, the full employment balanced rate of growth can be established by setting... 

Thus, at temperatures lower than the liquid us temperature (usually above —20 °C for most electrolyte compositions).EC precipitates and drastically reduces the conductivity of lithium ions both in the bulk electrolyte and through the interfacial films in the system. During discharge, this increase of cell impedance at low temperature leads to lower capacity utilization, which is normally recoverable when the temperature rises. However, permanent damage occurs if the cell is being charged at low temperatures because lithium deposition occurs, caused by the high interfacial impedance, and results in irreversible loss of lithium ions. An even worse possibility is the safety hazard if the lithium deposition continues to accumulate on the carbonaceous surface. 

This sharp decline in cell output at subzero temperatures is the combined consequence of the decreased capacity utilization and depressed cell potential at a given drain rate, and the possible causes have been attributed so far, under various conditions, to the retarded ion transport in bulk electrolyte solutions, ° ° - ° ° the increased resistance of the surface films at either the cathode/electrolyte inter-face506,507 Qj. anode/electrolyte interface, the resistance associated with charge-transfer processes at both cathode and anode interfaces, and the retarded diffusion coefficients of lithium ion in lithiated graphite anodes. - The efforts by different research teams have targeted those individual electrolyte-related properties to widen the temperature range of service for lithium ion cells. 

Herreyre et al., it could be tentatively concluded that longer alkyl chains in the carboxylic acid section of the esters play a critical role in determining the cathodic stability of this component on a graphite anode. The tests in AA-size full lithium ion cells were only reported for EA- and MA-based quaternary electrolytes, and Figure 59 shows the discharging profiles of these cells at —40 °C. Despite their negative effect on anode capacity utilization at room temperature, MA and EA still improved the capacity significantly. 

Fluorinated carbonates were also used by Smart et al. as low-temperature cosolvents (Table 12), in the hope that better low-temperature performances could be imparted by their lower melting points and favorable effects on SEI chemistry. Cycling tests with anode half-cells showed that, compared with the ternary composition with nonfluorinated carbonates, these fluorinated solvents showed comparable and slightly better capacity utilizations at room temperature or —20 °C, if the cells were charged at room temperature however, pronounced differences in discharge (delithiation) capacity could be observed if the cells were charged (lithiated) at —20 °C, where one of these solvents, ethyl-2,2,2-trifluoroethyl carbonate (ETFEC), allowed the cell to deliver far superior capacity, as Figure 63 shows. Only 50% of the capacity deliverable at room temperature was... 

While the consideration of nonflammability and SEI stability favors a high concentration of these organophosphorus compounds in electrolytes, the capacity utilization, rate capabilities, and low-temperature operation require that they be used at minimal concentrations. A compromise would be reached between 15 and 20% TFP or BMP in a binary 1.0 M LiPFe in EC/EMC (1 1) system or at higher than 30% in a ternary 1.0 M LiPFe in PC/EC/EMC (1 1 3) system. Such electrolytes are completely or at least nearly nonflammable. To further alleviate the above tradeoff, Xu et al. suggested that new cosolvents of higher flame retarding ability should be tailor-made. 

Capacity utilization = time based utilization x asset utilization x volume utilization... 

A practical example for capacity utilization of a production train in a MP plant over a 12-month period is shown in Figure 5.6. For the sake of simplicity, only time-based and asset utilization, but not the product concentration, are considered. As shown in the graph, the plant runs flat-out for the first 10 months. Because an order has been canceled, there is no production at all during November and December. At first glance, this would result in a capacity utilization of n or 83% for the full year. However, the reality is quite different, and the actual record of plant performance during the year under review is as follows ... 

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