Pilot plant extraction

As an example, measurements are tabulated in Table II which were obtained from a pilot plant (extraction volume 200 1) and a production plant (extraction volume 2000 1) during the extraction of oenothera... 

Figure 6 Semicontinuous pilot-plant extraction system.

Because of the apparent low concentration of the active component(s) in the brassins complex, it was necessary to plan for the extraction of a large quantity of rape pollen. Honeybee-collected rape pollen was available from Canada since pollen is used in specialty-type natural food products, for example baked goods. Arrangements were made (not without some difficulty) to obtain a large lot (over 1/4 ton ) of rape pollen from Canada for a pilot plant-scale extraction at ERRC. Earlier work by Mandava et al. (16) was the basis for the pilot plant extraction procedure that was developed and used (21). Contributors to the project, in addition to M. Kozempel and N. Mandava, were H. Kenney of ERRC J.F. Worley, D. Matthees, J.D. Warthen, Jr., M. Jacobson and G.L. Steffens of BARC and M.D. Grove, NRRC. 

Pilot Plant Extraction - ERRC An outline of the pilot plant extraction steps is shown in Figures 1 and 2. Batches of pollen (5 batches of 45.5 kg each, for a total of 227 kg pollen) were extracted first with deionized water in a 227 L kettle to remove simple sugars. The aqueous slurry was filtered via a Sparkler filter and the filter cake continuously washed with water until the filtrate was clear and colorless. The washed pollen (filter cake) was then freeze-dried, moved back to the extraction kettle and extracted with 114 L of 2-propanol. The slurry was pumped to a Sparkler filter, allowed to soak, and the 2-propanol drained off. The pollen cake was extracted in this manner 7 more times and then it was recycled to the extraction kettle where it was again extracted with 114 L of 2-propanol. After filtration, the pollen was washed twice with 2-propanol and then recycled to the extraction kettle for a final 2-propanol extraction (a total of eleven 2-propanol extractions). The 2-propanol was evaporated in a glass evaporator at <40°C to yield ca. 7.6 L of concentrate... 

Figure 2. Diagram showing the pilot plant extraction process. (Reproduced from reference 21. Copyright 1978 American Chemical Society.)...

Abscisic acid (ABA) levels in rice plants, 308,31Or levels in squash hypocotyls, 315/.316 Active component of brassins identification, 9,lQf pilot plant extraction, 6,7/,8 solvent partition and column chromatography, 8 Adventitious root(s) development, 233,234r,235 formation, 247 Agriculture, application of 24-epibrassinolide, 280-290 22-Aldehydes, synthesis of brassinosteroids, 47-50f a hormone function, description for brassins, 4... 

Intense structural-elucidation and synthetic activity has continued, no doubt as a consequence of the significant antitumour activity of this class of alkaloids. A pilot-plant extraction of harringtonine (13a), isoharringtonine (13b), and homoharringtonine (13c) from Cephalotaxus harringtonia using counter-current distribution has been described.This method provides 36 g of the three alkaloids in pure form from 455 kg of plant material. 

To illustrate the practical application of fluid flow rate, the required efficiency of extraction, and other operational SFE parameters, data are given in Table 1 for the pilot plant extraction of soybean flakes. Extraction time, CO2 flow rate, weight percent of oil recovered based on the initial weight of the flake charge into the extractor, and several weight percent data for residual oil in the extracted flakes are presented. It is obvious from... 

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). 

A modification of the conventional soy protein isolate process has been investigated on a small pilot-plant scale. It is based on the absorption of water from the aqueous protein after extraction at pH 8.5 using temperature-sensitive polyisopyropylacrylamide gels, followed by spray drying to give a 96% protein isolate (111). 

The concern by consumers about cholesterol has stimulated the development of methods for its removal. Three principal approaches are in the pilot-plant stages use of enzymes, supercritical fluid extraction, and steam distillation. Using known techniques, it is not possible to remove all cholesterol from milk. Therefore, FDA guidelines identify cholesterol-free foods as containing less than 2 mg cholesterol per serving, and low cholesterol foods as containing from 2 to 20 mg (37). 

A pilot plant ia India has been estabUshed to extract fiber, pulp, and juice from the leaves of sisal plants. The fiber is sold direcdy or used to manufacture rope, the cmshed pulp is used ia paper processiag, and the juice is an excellent source of hecogenin. During a three- to five-day fermentation of the juice, partial enzymatic hydrolysis causes hecogenin to precipitate as the hemisaponin ia the form of a fine sludge. This sediment is hydrolyzed with aqueous hydrochloric acid, neutralized, and filtered. This filter cake is washed with water and extracted with alcohol. The yield of hecogenin varies between 0.05 and 0.1% by the weight of the leaf (126). 

It would be desirable to reinterpret existing data for commercial tower packings to extract the individual values of the interfacial area a and the mass-transfer coefficients fcc and /c in order to facilitate a more general usage of methods for scaling up from laboratory experiments. Some progress in this direction has afready been made, as discussed later in this section. In the absence of such data, it is necessary to operate a pilot plant or a commercial absorber to obtain kc, /c , and a as described by Ouwerkerk (op. cit.). 

The other common objective for calculating the number of countercurrent theoretical stages (or mass-transfer units) is to evaluate the performance of hquid-liquid extraction test equipment in a pilot plant or to evaluate production equipment in an industrial plant. Most liq-uid-hquid extraction equipment in common use can oe designed to achieve the equivalent of 1 to 8 theoretical countercurrent stages, with some designed to achieve 10 to 12 stages. 

The pilot plant stage Is vital in the scale-up of any new resin process, and in this paper we discuss the design philosophy of pilot plants and then describe two fully Instrumented and computer data logged reactors. Some indication is given of the use of the extracted data for both modelling and scale up. Both controlled and data logged parameters are tabulated and an example of data extraction for heat balance is illustrated. 

Nagel, V. Gilmore, M. Scott, S. Bateman pulsed column pilot-plant campaign to extract cobalt from the nickel electrolyte stream at Anglo Platinum s base metal refinery. International Solvent Extraction Conference, Cape Town, South Africa, Mar. 17-21, 2002, pp 970-975. 

ESTER A batch process for immobilizing nuclear waste in a borosilicate glass for longterm disposal. Developed in Italy in the 1970s and installed at the Euratom Research Centre, Ispra, in 1981. Intended for use in the radioactive pilot plant (Tmpianto Vetrificatione Eurex, IVEX) at the European Extraction Plant (UREX) at Saluggia, Italy. 

K-Process [Kalocsai or Kaljas] A process for extracting gold from ores, concentrates, tailings, and scrap by means of a proprietary solution containing a bromide and an oxidizing agent. Invented in 1983 by G. I. Z. Kalocsai and developed by Kaljas Pty, Australia. A pilot plant was under construction in 1987. 

The initial bench-scale experimental investigations into solvent extraction processes are conducted with small apparatus, such as separating funnels. Following the successful completion of these tests, when the best reagent and other conditions for the system have been established, small-scale continuous operations are run, such as in a small mixer-settler unit. The data so obtained are used to determine scale-up factors for pilot plant or plant design and operation (see Chapters 7 and 8). 

Inclusion of this practice in all solvent extraction studies will ensure that the solvent is not discarded as being unsuitable, and that problems in pilot plant or continuous operations are not the result of impurities that were present in the bench-scale test work. 

Because of the diversity of contacting equipment available, it is unlikely that all these contactors will be available in any one laboratory or pilot plant. Consequently, unless test work is carried out on similar contactors, the system may not be optimized. Since mixer-settlers are the easiest to construct, are simple to operate, and require little room and low-flow rates, these contactors are, in many cases, the only ones used to investigate a continuous solvent extraction process. This is by no means ideal and may result in abandonment of a process that, using another type of contactor, could be found to be entirely satisfactory. 

The data obtained from small-scale continuous operations will be required to determine whether the process should be investigated on a larger scale, such as a pilot plant. These data should be sufficient to draw a conceptual flow sheet, which will include a number of stages for extraction, scrubbing [10], and stripping the flow rates, size and type of equipment, and the various parameters considered earlier in this chapter. Another important aspect should also be considered in the continuous test work, and that is chemical analysis of both the aqueous and organic phases for their various components. 

Pilot plant operations, as we have noted previously, can vary between extremes of flow rates. It is necessary, therefore, that the feed and reagent volumes be large enough that the pilot plant may be operated for a sufficient length of time to obtain meaningful data. For example, if the aqueous feed to the solvent extraction (SX) circuit is being produced batchwise, variations between batches are bound to occur. Such variations should be controlled as much as possible. Batchwise production of the feed solution may be very different from feed to the actual plant, especially if the plant process involves continuous production of the feed to the SX circuit. 

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