Pilot-Plant Testing

As mentioned in the previous subsection, kinetic data are needed for both the chlorination and pyrolysis reactors, as well as to determine the rate of carbon deposition. In all three cases, it is unlikely that adequate data can be located in the open literature. Consequently, unless sufficient data exist in company files, or were taken in the laboratory and are judged to be adequate, pilot-plant testing is needed. Generally, the pilot-plant tests are conducted by a development team working closely with the design team. As the data are 

As mentioned in connection with the need for laboratory experiments, pilot-plant tests also help to identify potential problems that arise from small quantities of impurities in the feed streams, and when unanticipated byproducts are produced, usually in small quantities, that have adverse effects, such as to impart an undesired color or smell to the product. When a catalyst is used, the impact of these species needs to be studied, and, in general, the useful life of the catalyst needs to be characterized. Pilot plants can also verify separation schemes developed during process design. 

As mentioned throughout the discussion of preliminary process synthesis and the creation of the process flow diagram, the process simulator usually plays an important role, even if a simulation model is not prepared for the entire flowsheet. When parts of a simulation model exist, it is common for the design team to assemble a more comprehensive model, one that enables the team to examine the effect of parametric changes on the entire process. In other cases, when the process simulators have not been used for design, a simulation model is often created for comparison with the pilot-plant data and for parametric studies. 

6 SUMMARY Having studied this chapter, the reader should 

Be able to create a preliminary database for use in preliminary process synthesis. 

In some practical kinds of dryers, the flow patterns of gas and solid are so complex that the kind of rate equation discussed in this 

Such pilot plant data are cited for the rotary dryer of Example 9.6. For the pneumatic conveying dryer of Example 9.8, the tests establish heat and mass transfer coefficients which can be used to calculate residence time under full scale operation. 

The smallest pilot spray dryer supplied by Bowen Engineering Co. is 30 in. dia by 2.5-6.0 ft high. Atomization is with 15 SCFM of air at lOOpsig. Air rate is 250 actual cfm at 150-1000°F. Evaporation rates of 15-80 lb/hr are attained, and particles of product range from 5 to 40. um. 

A pilot continuous multitray dryer is available from the Wyssmont Co. It is 4 ft dia by 5 ft high with 9 trays and can handle 25-200 lb/hr of feed. 

Batch fluidized bed dryers are made in quite small sizes, of the order of 100 lb/hr of feed as the data of Table 9.14(a) show, and are suitable for pilot plant work. 

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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). 

Both the Toth and Alcoa processes provide aluminum chloride for subsequent reduction to aluminum. Pilot-plant tests of these processes have shown difficulties exist in producing aluminum chloride of the purity needed. In the Toth process for the production of aluminum chloride, kaolin [1332-58-7] clay is used as the source of alumina (5). The clay is mixed with sulfur and carbon, and the mixture is ground together, pelletized, and calcined at 700°C. The calcined mixture is chlorinated at 800°C and gaseous aluminum chloride is evolved. The clay used contains considerable amounts of silica, titania, and iron oxides, which chlorinate and must be separated. Silicon tetrachloride and titanium tetrachloride are separated by distillation. Resublimation of aluminum chloride is requited to reduce contamination from iron chloride. 

Laboratory or pilot plant tests are usually conducted on individual ores to determine the number of dmms required to obtain optimum concentration results. Dmms that are 914 or 1219 mm in diameter are usually used in cobbing service. 

A pressure leaching system to handle copper sulfide called the Sherritt-Cominco (SC) copper process was developed by these two Canadian firms. Pilot-plant testing was completed in 1976 (29), but commercial appHcation of this technology has not been achieved. 

Design Methods for Continuous Tunnel Dryers In actual practice, design of a continuous through-circulation diyer is best based upon data taken in pilot-plant tests. Loading and distribution of solids on the screen are rarely as nearly uniform in commercial installations as in test diyers 50 to 100 percent may be added to the test diying time for commercial design. 

In most cases, direct-heat rotary dryers are still sized on the basis of pilot-plant tests, because rarely is all the moisture to be removed truly Tree moisture, and residence time for diffusion is frequently needed. 

Pilot plant tests are conducted using the actual plant materials since small amounts of contaminents can have significant effects on throughput and efficiency. These tests are usually conducted in columns ranging from 0.075-0.15 m diameter the column height (and therefore number of compartments) should be sufficient to accomplish the separation desired this may require several iterations on column height. 

As with the design of the other columns described above, the design of a Scheibel column must be based on pilot plant tests and scale-up, The following procedure is recommended ... 

The depth of cut involved in precoat filtration is a veiy important economic factor. There is some disagreement as to the method required to accurately predic t the minimum permissible depth of cut. Some investigators maintain that the depth of cut can be evaluated only in a quah-tative manner during bench-scale tests by judging whether the process solids remain on the surface of the precoat beck This being so, they indicate that it is necessaiy to run a continuous pilot-plant test to determine the minimum permissible depth of cut. The use of a continuous pilot-plant filter is a veiy desirable approach and will provide accurate information under a variety of operating conditions. 

However, it is not always possible to run a pilot-plant test in order to determine the depth of cut. A well-accepted alternative approach makes use of the more sophisticated test leaf illustrated in Fig. 18-97. This test leaf is designed so that the cake and precoat are extruded axially out the open end of the leaf. The top of the retaining wall on this end of the leaf is a machined surface which serves as a support for a... 

Continuous pilot-plant test runs are generally recommended to verify the laboratory results and to estabhsh criteria for plant design. Facihties for these runs are available at a number of minerals-processing research centers. 

Many operating data for carbonate plants are cited by Kohl and Riesenfeld (Gn.s Purification, Gulf, 1985) but not including tower heights. Pilot plant tests, however, are reported on 0.10- and 0.15-m (4- and 6-in) columns packed to depths of 9.14 m (30 ft) of Raschig rings hy Benson et al. (Chem. Eng. Prog., 50, 356 [1954]). 

Follow the example of Reference [32], using scale-up rules. A pilot plant test run has been conducted using a laboratory equipped test vessel. Design equivalent process results for a 10,000 gallon tank are ... 

A sulfuric acid drying tower uses 98% acid for drying an incoming air stream. The pilot plant tests show that 15 ft of 1-in. ceramic Intalox packing will do this job. The plant scale rates are ... 

This is a report on the basic work done in the laboratory to develop the catalysts for the methanation of synthetic gas from coal, and it also reports on the development of an applicable kinetic system. This report does not include any of the subsequent pilot plant test work. 

Synthesis of Methane in Hot Gas Recycle Reactor Pilot Plant Tests... 

Considerably trailing behind VjOj but only slightly behind CeO is FejOj, which shows an onset temperature for HjS release of approximately 520 C. This means Fe Oj is not expected to be able to adequately catalyze step 3 in the FCCU riser environment because of short contact time [5], even though the temperature at the very bottom of the riser exceeds 530 C. In fact, the result of our pilot plant test of such a catalyst is in agreement with this assessment. Thus, it is quite clear that the onset temperature for HjS release is more critical than the rate of take-off in determining the catalyst efficiency for step 3. 

As was stated in Section 1.2.1, the project design should start with a clear specification defining the product, capacity, raw materials, process and site location. If the project is based on an established process and product, a full specification can be drawn up at the start of the project. For a new product, the specification will be developed from an economic evaluation of possible processes, based on laboratory research, pilot plant tests and product market research. 

Pilot plant tests, and laboratory corrosion tests under simulated plant conditions, will help in the selection of suitable materials if actual plant experience is not available. Care is needed in the interpretation of laboratory tests. 

The overriding factor will be the filtration characteristics of the slurry whether it is fast filtering (low specific cake resistance) or slow filtering (high specific cake resistance). The filtration characteristics can be determined by laboratory or pilot plant tests. A guide to filter selection by the slurry characteristics is given in Table 10.3 which is based on a similar selection chart given by Porter et al. (1971). 

The drying characteristics of the material can be investigated by laboratory and pilot plant tests which are best carried out in consultation with the equipment vendors. 

Chang, J.-S., Urashima, K., Tong, Y.X. et al. (2003) Simultaneous removal of NOx and S02 from coal boiler flue gases by DC corona discharge ammonia radical shower systems Pilot plant tests, J. Electrostatics 57, 313-23. 

A phenomenon observed in both laboratory and pilot plant testing of ores with phosphonic acid collectors is complete cassiterite flotation at a pH below 4.0. In fundamental practice, it indicates that a pH region below 4 is the region of maximum flotation. However, in plant practice, at a low pH (below 4), loss of flotation occurred. The loss of flotation at a low pH has not been established. It is, however, postulated that loss of flotation is believed to be associated with complex solution chemical interaction between phosphonic acid collectors and cationic species, in particular, those of iron, which is always present in industrial flotation pulp. 

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