Pilot-plants

It may be necessary to construct a pilot plant if one of the following conditions applies 

The operation of the pilot plant should clarify all the issues which have not been fully 

A pilot plant should be designed as a scaled-down version of the industrial-scale plant and not as a larger copy of the existing miniplant. Nowadays it costs almost as much to design, construct, and operate a pilot plant as an industrial-scale plant. The decision to build a pilot plant results in considerable costs. As a rule of thumb, the initial investment is at least 10% of the investment costs of the subsequent industrial-scale plant. Moreover, if they use particularly toxic substances, pilot plants now often require approval, and this may considerably lengthen the time required to put them into operation. 

Once process development on a pilot scale has been successfully concluded, the pilot plant must be kept on stand-by until the industrial-scale plant is running satisfactorily. Normally, when the larger plant is started up, the pilot plant is operated simultaneously so that any problems which occur in the former can be dealt with rapidly. Furthermore, licensing questions can also be dealt with there. 

In spite of all the know-how of process engineering, very expensive flops on an industrial scale can not be ruled out, and numerous examples of these can be found in the history of the chemical industry. 

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PALLUZi Pilot Plant Design, Construction, and Operation... 

This approach is particularly useful when one wishes to characterize pilot plant effluents whose daily production can be less than a liter. 

Pilocarpine [92-32-7] Piloted airblast atomizer Pilot-plant Pilot plants Pilsner Pimaric acid [127-27-5]... 

Asahi Chemical Industry Company Ltd. was working to develop an adsorption process in the late 1970s and early 1980s that was to produce high purity EB as well as PX (100—103). In 1981 they reported that pilot plants results were being confirmed in larger equipment. However, this process does not appear to have been commercialized. 

Determination of separation efficiencies from pilot-plant data is also affected by axial dispersion. Neglecting it yields high or values. Literature data for this parameter have usually not been corrected for this effect. 

After development of a new process scheme at laboratory scale, constmction and operation of pilot-plant faciUties to confirm scale-up information often require two or three years. An additional two to three years is commonly required for final design, fabrication of special equipment, and constmction of the plant. Thus, projections of raw material costs and availabiUty five to ten years into the future become important in adopting any new process significantly different from the current technology. 

Dehydrogenation of Propionates. Oxidative dehydrogenation of propionates to acrylates employing vapor-phase reactions at high temperatures (400—700°C) and short contact times is possible. Although selective catalysts for the oxidative dehydrogenation of isobutyric acid to methacrylic acid have been developed in recent years (see Methacrylic ACID AND DERIVATIVES) and a route to methacrylic acid from propylene to isobutyric acid is under pilot-plant development in Europe, this route to acrylates is not presentiy of commercial interest because of the combination of low selectivity, high raw material costs, and purification difficulties. 

Ethylbenzene Separation. Ethylbenzene [100-41-4] which is primarily used in the production of styrene, is difficult to separate from mixed Cg aromatics by fractionation. A column of about 350 trays operated at a refluxTeed ratio of 20 is required. No commercial adsorptive unit to accomplish this separation has yet been installed, but the operation has been performed successhiUy in pilot plants (see Table 5). About 99% of the ethylbenzene in the feed was recovered at a purity of 99.7%. This operation, the UOP Ebex process, requires about 40% of the energy that is required by fractional distillation. 

Table 5. Ethylbenzene Separation, Pilot-Plant Scale...

The UOP Sarex process has been used since 1978 for the separation of high purity fmctose from a mixture of fmctose, glucose, and polysaccharides (87,88). The pilot-plant performance of fmctose—glucose separation is given in Table 6. 

Aromatic and Nonaromatic Hydrocarbon Separation. Aromatics are partially removed from kerosines and jet fuels to improve smoke point and burning characteristics. This removal is commonly accompHshed by hydroprocessing, but can also be achieved by Hquid-Hquid extraction with solvents, such as furfural, or by adsorptive separation. Table 7 shows the results of a simulated moving-bed pilot-plant test using siHca gel adsorbent and feedstock components mainly in the C q—range. The extent of extraction does not vary gready for each of the various species of aromatics present. SiHca gel tends to extract all aromatics from nonaromatics (89). 

The alkalized zinc oxide—chromia process developed by SEHT was tested on a commercial scale between 1982 and 1987 in a renovated high pressure methanol synthesis plant in Italy. This plant produced 15,000 t/yr of methanol containing approximately 30% higher alcohols. A demonstration plant for the lEP copper—cobalt oxide process was built in China with a capacity of 670 t/yr, but other higher alcohol synthesis processes have been tested only at bench or pilot-plant scale (23). 

Fig. 17. Pilot-plant ammoniator—granulator, (a) Side view, showiag placement of acid and ammonia spargers, and (b) feed end view (71,72).

Both American Enka (87) and Courtaulds set up pilot-plant work in the eady 1980s with the objectives of developing fiber spinning and solvent... 

Product innovation absorbs considerable resources in the fine chemicals industry, in part because of the shorter life cycles of fine chemicals as compared to commodities. Consequently, research and development (R D) plays an important role. The main task of R D in fine chemicals is scaling-up lab processes, as described, eg, in the ORAC data bank or as provided by the customers, so that the processes can be transferred to pilot plants (see Pilot PLANTS AND microplants) and subsequently to industrial-scale production. Thus the R D department of a fine chemicals manufacturer typically is divided into a laboratory or process research section and a development section, the latter absorbing the Hon s share of the R D budget, which typically accounts for 5 to 10% of sales. Support functions include the analytical services, engineering, maintenance, and Hbrary. 

In the laboratory or process research section a laboratory procedure for a fine chemical is worked out. The resulting process description provides the necessary data for the determination of preliminary product specifications, the manufacture of semicommercial quantities in the pilot plant, the assessment of the ecological impact, an estimation of the manufacturing cost in an industrial-scale plant, and the vaHdation of the process and determination of raw material specifications. 

The development section serves as an intermediary between laboratory and industrial scale and operates the pilot plant. A dkect transfer from the laboratory to industrial-scale processes is stiH practiced at some small fine chemicals manufacturers, but is not recommended because of the inherent safety, environmental, and economic risks. Both equipment and plant layout of the pilot plant mirror those of an industrial multipurpose plant, except for the size (typically 100 to 2500 L) of reaction vessels and the degree of process automation. 

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