Plant medium scale

Capital Costs A typical medium-scale RO seawater plant might produce 0.25 mVs (6 MGD). For a plant with an open sea intake, seawater salinity of 38 g/1, and conversion of 45 percent, the overall cost woiild be 26.5 miUiou (1996). A capital breakdown is given in Table 22-18. Capital charges are site specific, and are sensitive to the salinity of the feed. A plant of this size would likely contain six trains. For seawater RO, the Best estimate for the slopes of the family of lines in Fig. 22-55 is —0.6 for the equipment and 0.95 for the membranes. Capital charges, shown in TaBle 22-19, usually dominate the overall economics the numbers presented are only an example. Seawater economics are based on Shields and Moch, Am. Desalination Assn. Conf. Monterey CA (1996). 

Chemical flowshops are widely used in industry for the medium-scale synthesis of chemicals. In a flowshop, a number of different physical units, such as reactor vessels, ovens, dryers, and distillation columns are placed in a serial, or largely serial, arrangement. Rather than being devoted to the preparation of a single chemical, many different chemicals are synthesized one after another in a flowshop by feeding in the appropriate precursors and reagents as the intermediates pass through most or all of the units. This mode of operation is an effective use of the physical plant because no part... 

Another decision for the design engineer is the selection of the operation mode, whereby he can choose between the single- and cascade-mode of operation. In principle this is valid for multipurpose plants of medium scale, such as plants to extract spices and/or herbs. Fig. 8.1-6 gives data on the different production costs for a plant with a total extraction volume of 600 1, operated in different modes, but with the same capacity. The investigation is based on equal batch times (in our case 4 hours), equal mass-flow per kg of raw material and, of course, equal extraction- and separation conditions. 

Combustion can be carried out on a small scale (for household heat production), on a medium scale (in hospitals, government offices, etc.) and on a large scale (in combustions plants for industrial purposes) (McKendry, 2002). 

Plantations for land rehabilitation are generally grown at a small to medium scale because they usually require intensive initial care, often including external inputs (mycor-rhiza inoculation, use of fertilizers or herbicides). In some cases, initial intercropping with annual plants can help to offset costs. 

An air fired, atmospheric pressure system suitable for small and medium scale energy producers such as industrial steam plants or hot gas generators,... 

Currently, there are many research institutes and companies around the world working on the market introduction of CPV. The experimental set-ups of the last 30 years are now replaced by small- and medium-scale PV power plants as shown... 

In the case of small- and medium-scale plants, the reactor may need to have adequate flexibility to produce various similar/different compounds, so a broad-based design is necessary. 

Pilot or prototype plants are complete, medium-scale processing units containing all essential product-producing elements, including control. 

The SiC FET devices as high-temperature gas sensors are commercially available in sensor systems for combustion control in small- and medium-scale power plants. Recent research and development which started in 2009 has realized tailor-made sensing layers for oxygen and carbon dioxide detection. Smart sensor operation using only one sensor may detect the NOj... 

In this chapter, the methods for shortcut C R analysis, using the results of steady-state simulations, have been described. The methods require the use of software for the solution of material and energy balances in process flowsheets (e.g., ASPEN PLUS, HYSYS.Plant) and for controllability and resiliency analysis (i.e., MATLAB). The reader is now prepared to tackle small- to medium-scale problems, and in particular should... 

Existing transportation infrastructure, such as road n works, navigable rivers, and railways, presents a great advantage for locating a fertilizer plant. Today even medium-scale plants should expect to transport more than 1 million tonnes of material per year. Therefore, access to a transportation network is very important for investment costs and future farm-gate fertilizer prices. Constmetion of a 1-km (6-m width) road may cost from US 1-3 million, and no investor would be able to recover these costs from the profits of fertilizer production. Construction of railway or port facilities should... 

Figure 12.3 Medium scale chemical disinfection plant. 1981 design. Semi-automatic control. Polycarbonate/glass fibre construction. F, vent filter SP, sample point SP, discharge to drain. For symbols, see Figure 12.4.

A direct ethylene oxidation process for the acetic acid production was commercialized by Denko in 1997. This process is only competitive for small- or medium-scale plants. The raw material ethylene is more expensive than methanol and carbon monoxide, but the investment costs of these plants are much lower. Table 6.15.1 gives an overview of the catalysts, reaction conditions, yield, and byproducts for the major acetic add processes. The different processes are discussed in more detail in Sections 6.15.1-6.15.4. 

It is well known that the conversion of hydrogen and nitrogen per pass is only 20%-30% for the present catalytic ammonia synthesis technology (Table 1.4). Most synthesis gases need to be returned to the reaction system, which increases power consumption. In order to increase conversion per pass, it must increase the outlet ammonia concentration of reactor. Accordingly, it can be seen from Table 1.4 that it is necessary to increase reaction pressure for small and medimn scale aimnonia plants and Topspe process, or to reduce the content of inert gas in sjmthesis gas for Topspe and Braun processes, or to reduce ammonia concentration in the inlet of converter for small and medium scale ammonia plants and Kellogg process. But all of these operations will add the power consumption or unit gas consumption. 

Processes Small and medium scale ammonia plants Kellogg Topsoe Braun ICl AMV... 

Therefore, in industrial installations, the reduction rate and quality of catalysts is ensured by the strict controlling of the concentration of water vapor. Generally, the vapor concentrations are limited in < (0.7 — 1.0) g/m for small and medium-scale ammonia plants, and <3.0g/m for large-scale ammonia plants. 

In plants without a methanation process, such as small and medium-scale plants, there is no Ni catalyst serving as a protection for the Fe catalyst, the latter is under the threat of sulfur. As a result, sulfur is the main reason for the deactivation of catalyst in these plants. Table 8.31 shows the measurements of organic sulfur for several plants. The sulfur content in the fresh syngas is 0.29-0.88g-m (standard). The shortest life of the catalysts is only 41 days, the longest only 264 days (Table 8.32), which are fully expected. The average sulfur content found in the waste catalysts... 

Classical iron Small- and medium-scale plant 30.4 54... 

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