Equation, product cost

Despite their flaws, batch processes have stood the test of time for a number of reasons, the most important of which is the flexibihty it brings to the manufacturer in terms of the range of products that the plant can produce, the feedstocks used to produce them, and the speed at which they can be brought to market with very limited information on physical properties, reaction kinetics, and so on (very few, if any, Michelin-starred chefs have ever measured the rheology or kinetics of their latest culinary creation). This flexibility, however, has a price which comes in the form of lower efficiencies in terms of production, energy, labor, and so on, and ultimately efficiency equates to cost However, one should never underestimate the pull of flexibility particularly, as discussed earlier in the examples of fermentation, where control of important parameters is difficult to achieve. 

Assume that the annual production cost in the objective function is proportional to the number of production runs required. The cost per run is assumed to be a linear function of D, given by the following equation ... 

Equations (3.12) and (3.13) calculate the costs caused by transferring production of a product to another plant (scale-up). These costs are incurred in the form of expatriates, trainings, etc. The costs of production trials are contained in the variable production costs of the site via equations (3.22/3.23) and (3.40/3.41). 

Equation 11 can be considered as a fundamental equation for minimizing product cost by variations of process parameters or by changing the flow sheet during the design procedure. 

The cost of the product of an energy conversion system must equal the sum of fuel expenses and capital (and labor.) charges. It is often convenient to express the product cost in terms of the average.unit cost of product, Ap, and the total amount of product, Pp,.or prc(duct = pp Similarly the fuel costs may be expressed as fuel = A-fPf- Equation 25 may now be written as... 

As far as the utilization of chlorine is concerned, Liebig s method is very uneconomic. As we can see from the equation (XVII-7), only one sixth of the chlorine introduced is utilized for the manufacture of chlorate, whilst the remaining five sixths are converted into almost worthless calcium chloride. Therefore this method is seldom used, as it cannot compete with the modern electro-lytical method of manufacturing chlorate the production costs of which are only one third of the cost of the Liebig method. 

This process was of course uneconomical beoause it involved high production costs and high consumption of sulphuric acid. The lye, however, may be electro-chemioally regenerated in a more simple way by allowing the Cr++ ions to be anodically oxidized according to equation ... 

The equations that describe these graphs are entirely adequate to evaluate the production cost in the optimization program, and comprised a total of fewer than 50 FORTRAN statements, even with provisions for multiple options and constraints. 

Methyl methacrylate (MMA) is an important commodity since it is polymerized to give poly methylmethacrylate (PMMA), a strong, durable and transparent polymer sold under the trade-names Perspex and Plexiglas. Since the conventional routes to MMA involve either the reaction of acetone with HCN to give the cyanohydrin (which has environmental problems), or the oxidation of isobutene, alternative carbonylation routes to MMA are being developed. One of these is the Lucite Alpha process which is claimed to decrease production costs by ca. 40%. This first synthesizes methyl propionate by a methoxycarbonylation of ethylene (Equation 23), using a palladium catalyst with very high (99.8%) selectivity. In the second step, MMA is formed in 95% selectivity by the reaction of methyl propionate with formaldehyde (Equation 24). 

Where P, the unit production cost of the production of interest (ethylene say), is equal to the sum of the unit feedstock costs (F), the unit capital costs (C) and the unit non feedstock operating costs (O). This can he expressed as a fixed-variable equation with the fixed part of the equation representing the return on capital (the unit capital costs, C, independent of tax considerations) together with all the unit nonfeedstock operating costs (O). 

Once the fixed variable relationships are derived the equation can be used to estimate the production cost for any given feedstock price. By comparing the estimated production cost with traded prices for the product, the viability of a particular project can be determined. By considering alternative technologies at similar feedstock prices, alternative approaches can be critically compared. 

Because some of the terms in the sum for TPC depend upon TPC, a key to the solution is expressing the total product cost in equation form as ... 

Table XV. Basic Equations and Estimated Production Costs for Converting Ethylene to Vinyl Acetate ...

The cash cost of production is the sum of the fixed and variable production costs (equation 6.2) ... 

Cost Reduction As productivity Increases, cost reduction should automatically follow. By how much Although an exact answer can t be given unless actual accounting figures are obtained, It Is possible to get a reasonable Idea of what the reduced cost might be. One appraoch to this economic question can be made by equating unit cost to both variable and fixed costs In a simplfied way. 

Suppose, as a prominent industrial chemist at the turn of the twentieth century, you are asked to design an efficient procedure for synthesizing ammonia from hydrogen and nitrogen. Your main objective is to obtain a high yield of the product while keeping the production costs down. Your first step is to take a careful look at the balanced equation for the production of... 

The best inemals and the optimum values of pressure, vapor velocity, and reboil vapor ratio are those that permit production of heavy water at minimum cost. The initial cost of the plant depends on a number of factors including the total number of towers, the total amount of reboiler and condenser surface, and the total volume of tower internals. The principal operating cost is for power, which is proportional to total loss in availability of steam as it flows through the towers. A complete minimum-cost analysis requires knowledge of the unit cost of all the important cost components and is beyond the scope of this book. Design for minimum volume of tower internals or minimum loss in availability due to tower pressure drop and for minimum cost of these two important contributors to total cost can be carried out without complete unit-cost data and will be discussed. Because the same choice of reboil vapor ratio minimizes the number of towers, their volume, and the loss of availability within them, this reboil vapor ratio is close to that which leads to minimum production cost. An equation for this optimum reboil vapor ratio will now be derived, and expressions will be developed for the total volume of towers and the total loss in availability in towers designed for the optimum ratio. 

Rate constants are determined by variation of experimental conditions and chemical composition of the reaction mixture. Data are measured by application of a variety of modem analytical methods. Modem numerical approaches of curve fitting and/or solution of differential equations are applied. Results and consequences influence chemical reaction engineering as well as production costs. Many books cover these formal thermal kinetics in detail, but most are restricted to simple mechanisms. In contrast, analogous treatments of photochemical reactions are restricted to publications of special reactions and examinations. Therefore this book aims to supply an overall treatment of formal photokinetics beyond the scope of normal books on kinetics. 

Equation (2) is not actually used by H2Sim, as H2Sitn calculates hydrogen production costs for all assumed capital costs. Rather, this equation is useful for considering questions of scale, including the projected capital costs associated with smaller, distributed reformers. 

The electricity production costs estimated in H2Sim are the levelized costs of electricity over the life of the plant. LCOE often are used as an economic measure of electricity costs as they allow for comparison of technologies with different capital and operating costs over time, as well as different construction times, capacity factors, and plant lives. The LCOE methodology is identical to that used for calculating hydrogen production costs [Equations (l)-(3)]. 

In determining the overall product price, a capital recovery factor (CRF) is first applied to the SCC to obtain a capital charge in dollars per million Btu of product energy. The maintenance and feedstock costs are added to this, resulting in the following product cost equation ... 

It is clearly shown by equation (2) that the accuracy requirements on the analytical monitors are determined by the product of exponential factors. It is not necessary to use analytical techniques of higher accuracy than that determined by the equation, as they would unnecssarily increase production costs. For the other two categories it is very important to achieve the highest possible accuracy. 

The model equations employing biokinetics of Groot et al. and PV data of Gudernatsch et al. were solved using an iterative procedure in a computer program to optimize process parameters for minimum total cost. The hybrid PV + distillation process yields better utilization of the sugar in the feed because of decrease in inhibition. The results indicated that the raw material and membrane fixed cost contribute more than 80% of the direct production cost. Further, the direct production cost of EtOH cost for the hybrid process was found to be 12%-16% lower than the conventional process. 

For the crude preheat train in the refinery plant, three beneficial modifications are identified. Modifications 1 and 2 add a new shell to each of the feed preheat exchangers serviced by the diesel pump-around (PA). Modification 3 adds surface area to the diesel product run down heat exchanger. Before implementing these changes, it is crucial to make sure that the existing pump can handle the increased diesel PA flow and the increase can be tolerated in product cut points. These modifications can save 47 million Btu/h of fuel in the crude heaters, equating to cost savings of 2.3 million per year. With only a 2.2 million installed cost, this project provides a fast payback. 

Equation 2.27 represents the objective function, which is the sum of the production cost, production changeover cost, and inventory shortage costs. Equation 2.28 is the demand/inventory balance constraint. If the unrestricted variable yi is replaced by the difference of two non-negative variables as... 

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