Cost estimates, plant Equipment

The technical literature is rife with detailed methods of cost-estimating process equipment. For the purpose of this chapter, the costs assembled in Table 8.1 will orient the novice designer to the approximate price of common types and sizes of plant equipment. The values shown are the purchased, as opposed to the installed, cost of equipment. A few items worthy of note from Table 8.1 are as follows ... 

Multiple-factor methods include the cost contributions for each given activity, which can be added together to give an overall factor. This factor can be used to multiply the total cost of dehvered equipment X (Ce(j)del lo produce an estimate of the total fixed-capital investment either for grass-roots or for battery-hmit plants. The costs may be divided into four groups ... 

IIS estimate the total installed cost for a grass-roots plant producing an organic chemical (S-F process) on a continuous basis. We assume that the total cost of delivered equipment 2, (C )del is 1 million and use suitable factors from Table 9-51. 

Following development of the study direction, the evaluation describes the efforts of obtaining and validating process information, and then discusses equipment specifications and a cost estimate of the feasibility or budget type i.e., with plant costs factored from major material. Finally, project economics and financing complete the evaluation. 

Safety Systems. Major expenditures here include the flare system (the flare structures and large lines extending throughout the plant) and the iirevvater system (high-capacity pumps and extensive piping). Safety systems, fortunately, are usually given particular attention. At this study phase, the main thrust should be to check the completeness of licensor equipment lists for cost estimation purposes. 

Early in the life of a project, information has not been developed to allow definitive cost estimates based on material takeoff and vendor quotes for equipment. Therefore, it is necessary to estimate the cost of a facility using shortcut methods. The first step is to develop or check flow-sheets, major equipment sizes, and specification sheets as described in earlier chapters. From the equipment specification sheets, the cost of each piece of equipment is estimated, using techniques discussed later. Once the major equipment cost has been estimated, the total battery limit plant cost can he quickly estimated using factors developed on a similar project. 

Capital cost estimates for chemical process plants are often based on an estimate of the purchase cost of the major equipment items required for the process, the other costs being estimated as factors of the equipment cost. The accuracy of this type of estimate will depend on what stage the design has reached at the time the estimate is made, and on the reliability of the data available on equipment costs. In the later stages of the project design, when detailed equipment specifications are available and firm quotations have been obtained, an accurate estimation of the capital cost of the project can be made. 

For instance, equipment made of monel generally costs 6.5 times as much as the same item constructed of carbon steel. If 25% of the equipment purchased for a plant were made of monel, this would increase the equipment costs by 237%, and the factor cost estimate would be 2.37 times that for a plant constructed of carbon steel. This is unreasonable, since the cost of buildings, roads, wiring, piping utilities, insulating, and instrumentation are independent of the materials of construction. In fact the only major changes would be in the process piping, which,... 

For this estimate, the prices of all items on the equipment list except those in the 700 and 800 categories were summed to obtain a 1968 F.O.B. cost of 2,203,000. This was increased by the Ohio sales tax of 4% and then by another 5%, to cover freight costs. This results in a delivered equipment cost of 2,400,000. The Lang factor is between that of a fluids plant and a solid-fluids plant. The value selected was 43. This was updated to 1974, and an 8% factor for waste treatment was added The result is a factored cost estimate of 14,400,000. 

Maintenance costs are those involved in keeping the plant equipment in operating order. This cost involves equipment and labor. In Chapter 8 it was noted that the maintenance costs may be estimated as between 6.1% and 7.4% of the total sales or as approximately 5% of the cost of building the plant. 

The investments are estimated on the basis of long-term experience in building hydrogen production plants and on the assumption of budding 10 identical units in order to optimize the construction costs. Table 9.4 gives the plant cost estimate as a percentage of the delivered equipment costs [99]. Such an estimate does not... 

Even before the optimum plant size was determined, a contractor had been selected and process design work was in progress. The contractor was selected on the basis of competitive cost plus fixed-fee bids. The contract was later converted to a turn-key type, based on the competitive-bid fixed-fee percentage and a definitive cost estimate for completion of the job. This saved about 2 months in over-all job completion time. Through duplication of equipment purchases and construction drawings, it was possible to reduce over-all completion time for three subsequent plants by as much as 8 months from the 17 months required for the first module (Fig. 2). About 29 months were required from Geld discovery to startup of the last Exxon treating facility. 

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