Economic advantage

The propylene-based process developed by Sohio was able to displace all other commercial production technologies because of its substantial advantage in overall production costs, primarily due to lower raw material costs. Raw material costs less by-product credits account for about 60% of the total acrylonitrile production cost for a world-scale plant. The process has remained economically advantaged over other process technologies since the first commercial plant in 1960 because of the higher acrylonitrile yields resulting from the introduction of improved commercial catalysts. Reported per-pass conversions of propylene to acrylonitrile have increased from about 65% to over 80% (28,68—70). 

Electrolytic Cell Operating Characteristics. Currently the greatest volume of chlorine production is by the diaphragm ceU process, foUowed by that of the mercury ceU and then the membrane ceU. However, because of the ecological and economic advantages of the membrane process over the other systems, membrane ceUs are currently favored for new production facHities. The basic characteristics of the three ceU processes are shown in Eigure 5. 

Much of the work with regard to this process was done by the French Petroleum Institute (113) and by the Kuraray Co. (108). In the CIS, a sinulat process which begins with cmde C s was developed (114). A one-step process that begins with isobutylene and methanol has been disclosed (108,115). This process is beheved to have significant economic advantages over the original route. 

Considerable research is currendy directed toward development of novel technologies that may present economic advantages with respect to the conventional acetone cyanohydrin (ACH) route. Mitsubishi Gas Chemical Co. has developed and patented a modified acetone cyanohydrin-based route... 

If an opportunistic preconcentration of the feed is used instead, an entirely different flow sheet results. In this case the MSA composition is a two-phase mixture of methylene chloride and water. Detailed simulations ate requited to determine which of these (or other) 2-ptopanol dehydration flow sheet alternatives is the economically advantaged process. 

If the fractional inflation rate is a fractional interest rate on a loan can be corrected to an effective rate of interest by Eq. (9-116) with ii substituted for (DCFRR). The effect of various amounts of loan, borrowed at various interest rates ii, on the net present value of a particular, fairly simple project is shown in Fig. 9-37. Thus, if 25,000 were borrowed at an interest rate of 15 percent for the project, the (NPV) would be about 43,000 at a zero inflation rate. But if the inflation for goods and services i, is 10 percent, the effective interest rate for that loan can be calculated from Eq. (9-116) to be only 4.55 percent. It is seen from Fig. 9-37 that this increases the (NPV) of the project to 48,000. This confirms the economic advantage of borrowing at a fixed interest rate in a time of general inflation. 

Site Size Most MF processes require a smaller footprint than competing processes. Reduction in total-area reqmremeuts are sometimes a decisive economic advantage for MF. It may be apparent that... 

Economic concerns. Many companies are unaware of the economic advantages associated with poUiition prevention. Legitimate concerns may include decreased profit margins or the lack of funds required for the initial capital investment. 

Finally, pollutiou-preveutiou measures can provide a company with the opportunity of looking their neighbors in the eye and truthfully saying that all that can reasonably Be done to prevent pollution is being done. In effect, the company is doing right by the environment. Is there an economic advantage to this It is not only a difficult question to answer quantitatively but also a difficult one to answer quahta-tively. The reader is left to ponder the answer to this question. 

If all these process and economic advantages are reahzed, the cost of electricity l be lowered, making circulating PFBC an extremely attractive coal-fired option for power generation. 

For the preliminary estimate of the expected efficiency of expansion turbines, in most cases it is sufficient to neglect Reynolds number effects (Rg > 10 ) and use the efficiency and specific speed correlations shown in Figure 2-12 for partial admission axial impulse, reaction radial inflow and full admission impulse and reaction axial turbines. Due to the economic advantage of the radial turbine, die radial inflow turbine is die best selection when operating in die specific speed range 20 < Nj < 140, whereby die optimum efficiency will be achieved at N, = 80. 

Gas turbines are used as prime movers for pumps, electric generators, and large rotating machinery. Their main economic advantage is driving... 

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