Utilities steam cost

A viable electrocatalyst operating with minimal polarization for the direct electrochemical oxidation of methanol at low temperature would strongly enhance the competitive position of fuel ceU systems for transportation appHcations. Fuel ceUs that directiy oxidize CH OH would eliminate the need for an external reformer in fuel ceU systems resulting in a less complex, more lightweight system occupying less volume and having lower cost. Improvement in the performance of PFFCs for transportation appHcations, which operate close to ambient temperatures and utilize steam-reformed CH OH, would be a more CO-tolerant anode electrocatalyst. Such an electrocatalyst would reduce the need to pretreat the steam-reformed CH OH to lower the CO content in the anode fuel gas. Platinum—mthenium alloys show encouraging performance for the direct oxidation of methanol. 

Refrigerant temperatures greater than 32°F suggest the steam jet or lithium bromide absorption system. Between 30°F and —40°F, the ammonia-water absorption or a mechanical compression system is indicated. At less than —40°F, a mechanical compression is used, except in special desiccant situations. The economics of temperature level selection will depend on utility (steam, power) costs at the point of installation and the type of pay-out required, because in some tonnage ranges, the various systems are competitive based on first costs. 

This simplistic approach to costing steam is often unsatisfactory, especially if the utility system already exists. Steam costs will be considered in more detail in Chapter 23. 

Figure 23.41 illustrates the overall trade-offs as a function of the number of intermediate steam mains for the case of maximized energy recovery13. Two curves are shown in Figure 23.41. The upper curve corresponds with minimum fuel requirement and the lower corresponds with minimum utility cost. Both correspond with no condensing power generation from utility steam. Once the number of intermediate mains has been chosen, then the settings for those mains are chosen, either for the upper curve to correspond with the minimum fuel for the utility steam boilers or for the lower curve for minimum utility cost (fuel and power). As the number of intermediate steam mains is increased, the fuel required and the utility cost both decrease. However, the decrease in cost diminishes as the number of steam mains increases.13...

Operating costs include the costs of raw materials, direct operating labor, labor supervision, maintenance, plant supplies, utilities (steam, gas, electricity, fuel), property taxes, and insurance. Sometimes certain operating cost components are directly expressed as a fraction of the capital investment cost. Table B.3 is a brief checklist... 

In order to minimize the tendency of coke formation within the column, steam is utilized. Steam utilization also helps to reduce the absolute pressure of the system to 10 mmHg or less and can help stabilize the desired unit vacuum levels. By operating at low vacuum pressures, the product yield will increase and the operating costs will typically be reduced. 

This suggests the possibility that for original design and synthesis purposes, unit costs such as Xjj = X5 may indeed be kept constant with respect to temperature variations of the steam extracted for components such as Feedwater Heater No. 5 via introducing primary turbine cost formulae which by definition would be insensitive to temperature and pressure—with any inaccuracies in these primary costs being offset through the use of utilization function costs (similar to the one introduced by Boteler, as discussed above) which would account for any anomalies in the effect of the steam temperature and pressure upon turbine cost and performance. 

Through the use of such utilization function costs, the turbine costs are separated into primary turbine costs, which by definition are insensitive to the temperature and pressure of the steam, and secondary turbine costs which are automatically paid for by neighboring components via requiring their purchase of utilization functions. The primary turbine cost formulae then result in equal units costs Xg of the bleed steam essergy for all of the feedwater heaters. Thus Xg is then constant with respect to temperature, thereby meeting the condition of thermo-economic isolation of the feedwater heaters with respect to the turbines. 

The base case" is for payout time of 2yr, steam cost of 0.50/1000 lb, vapor flow rate Ga = 15 lb mol/(hr)(sqft). Although the capital and utility costs are prior to 1975 and are individually far out of date, the relative costs are roughly the same so the conclusions of this analysis are not far out of line. Conclusion For systems with nearly ideal VLB, R is approx. 1.2Rmin and N is approx. 2.0A/min-(Happel and Jordan, Chemical Process Economics, Dekker, New York, 1975). 

Utility unit costs power 0.8c/kw hr, steam 70c/1000 lb. cooling water 0.3c/1000 al. boiler feed water 3.0c/1000 gal. Hydrogen plant feed and fuel for the complex supphed from H-Oil gases, light ends, and 1 BPSD of product fuel oil. 

Table II shows the estimated revenue requirements. Electricity and cogenerated products costs are based on regulated utility financing, while steam costs are based on non-regulated industrial financing. The cogeneration case costs are shown on a total product basis, since two products are involved. Figure 1 shows the selling price of electricity as a function of the selling price of steam for the cogeneration case.

This means that the heat exchanger for both the condenser and the reboiler are getting very large as are the cost of utilities (steam and cooling water). 

The total bare-module cost for the column and its auxiliaries = 2,226,000 The annual heating steam cost for the reboiler is computed = 728,000/yr The annual cooling water cost for the two condensers = 84,000/yr The annual electricity cost for the reflux pump = 38,000/yr The total utility cost = 850,000/yr Compute the annualized cost. 

Please submit a report on the two designs and cost estimates (flxed capital and utility operating costs only). For the capital cost of each of the two alternative sequences, sum the purchase costs of the distillation columns, heat exchangers, and any vacuum equipment. Multiply that cost by the appropriate Lang factor. To annualize the capital cost, multiply by 0.333. Add to this annualized cost the annual utility cost for steam and cooling water. Call this the total annualized cost for the alternative. 

The cost of providing utilities (steam, electric power, and CTW (cooling tower water]) is considerably reduced for treatment of emissions from enclosed vapor degreasers relative to the same from lip vents of open-top vapor degreasers. 

Utility (cooling water/hot steam) cost is given by a function of temperature (see Figure 2)... 

The author strongly recommends that all existing and future sulphuric acid plants should adopt the Cold Process for achieving lower capital, utility maintenance costs, requiring one-third area. Zero Emission of sulphur dioxide and higher cogeneration of steam. 

Insurance companies have paid out more than US 91 billion in losses from weather-related natural disasters in the 1990s [4], whereas direct loss of corrosion in 1994 just in the U.S. industry was US 300 billion [5]. The cost of corrosion has been reported from many studies to be of the order of 4% of the GNP (Gross National Product) of any industrialised country [6]. In the power industry, it has been estimated [7] that corrosion losses in utility steam systems amounted to about USS 1.5 billion of the US 70 billion annual cost of corrosion in the U.S. in 1978. 

Utilities cover costs related to the production of deionized or purified water, WFI, black and clean steam, process air, and pure oxygen or other process gases. Utilities also include the costs of waste disposal and wastewater treatment. 

The use of a water- or glycol-cooled condenser provides good control, but for many small plants some first-cost savings can be realized by utilizing steam condensate or fresh water as reflux. The water is introduced directly to the top plate of the column. The principal problems... 

Calculate the utility steam, cooling water, and electricity requirements of the two schemes, and compare their costs. 

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