Pilot testing

Apart from laboratory tests, the most significant experience with a pilot plant has been carried out by Statkraft with the first prototype PRO installation in Tofte, Norway, inaugurated 

The whole membrane module is composed of six racks, each of them consisting of eleven pressure vessels, operated in parallel, designed to house one spiral wound membrane each. The pressure vessels were originally equipped with cellulose acetate membranes specifically developed for PRO. During the first period, the plant operation has been optimized and the performance has been monitored, resulting in a power density lower than 0.5 W/m. Next, thin film composite membranes developed for PRO were installed in early 2011. So far the measured power density has reached nearly 1 W/m, which is a major improvement compared to the cellulose acetate membranes originally installed. Based on this preliminary experience, Statkraft plans to build a full-scale 25 MW osmotic power plant by 2015 [20]. 

Various small scale test units and procedures are available to determine slurry characteristics and suitability for a particular application. Buchner funnel, and vacuum leaf test units can be purchased or rented fi om vendors to perform in-house tests, or one can have tests conducted at the vendor s facility. Pilot testing on the actual equipment would be the optimum with a rental unit in the plant. In either case, slurry integrity must be maintained to ensure accurate filtration data. 

Slurry taken fresh from the process in-house will yield the best results as product degradation over time, process temperature, effects of process agitators, pumps, etc., must be taken into consideration when shipping product to vendors for conducting tests. Should the particles suddenly be smaller, slower than usual filtrations will be seen and vice versa. 

Of course, if equipment is presently in operation at the plant on the particular product, invaluable data can be obtained. Optimization of the filter should be done, perhaps with the vendor s help, to be sure that over-sizing of the next piece of equipment does not occur. Variance of precoat, cake thickness, wash, etc., if not already done on the process, will enable fine-tuning of the process as well as confirm the data for the next system s design. 

Successful installation, or roll-out, of your PSM systems requires sound planning and effective execution. No matter how diligent you have been, or how receptive and well-managed your company may be, no system as complex as PSM can work perfectly the first time. As every project manager knows, it s impossible to anticipate every outcome or contingency—especially when human behavior is involved. Pilot testing a new system provides the opportunity to identify weaknesses under controlled conditions this in turn enables you to fix problems before the system becomes fully operational. Once these problems are corrected, the pilot test produces a template for installation that can be replicated elsewhere. 

In the case of PSM, pilot testing yields other benefits as well this approach 

Strengthen buy-in through increased participation and awareness. Up until now, your compan) s PSM efforts—even if they have been well publi- 

Few performance data of leaching equipment have found their way into the open literature, but since these processes have long been exploited, a large body of information must be in the files of manufacturers and users of such equipment. 

It is highly recommend that all new extraction processes be pilot-tested before commercialization. Design models are especially useful when coupled with experimental verification. Use pilot tests to address four critical issues  

Detect the effects of impurity buildup in the extraction loop. 

Carefully analyze pilot data and evaluate scale-up of the contacting device (e.g., the packing material). 

In general, an extraction process involves an extractor and a solvent-recovery operation. The recovered solvent is recycled back to the extractor, making an extraction loop necessary. The feasibility of the loop must be demonstrated. This is especially important for chemical systems with complex and poorly understood phase equilibria. For example, a systems where the slope of the equilibrium line changes significantly with solute concentration may be prone to pinching. 

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Amoco developed polybutene olefin sulfonate for EOR (174). Exxon utilized a synthetic alcohol alkoxysulfate surfactant in a 104,000 ppm high brine Loudon, Illinois micellar polymer small field pilot test which was technically quite successful (175). This surfactant was selected because oil reservoirs have brine salinities varying from 0 to 200,000 ppm at temperatures between 10 and 100°C. Petroleum sulfonate apphcabdity is limited to about 70,000 ppm salinity reservoirs, even with the use of more soluble cosurfactants, unless an effective low salinity preflush is feasible. 

Design criteria for carbon adsorption include type and concentration of contaminant, hydrauhc loading, bed depth, and contact time. Typical ranges are 1.4—6.8 L/s/m for hydrauhc loading, 1.5—9.1 m for bed depth, and 10—50 minutes for contact time (1). The adsorption capacity for a particular compound or mixed waste stream can be deterrnined as an adsorption isotherm and pilot tested. The adsorption isotherm relates the observed effluent concentration to the amount of material adsorbed per mass of carbon. 

Pilot Studies. AppHcations requiring the reduction of VOC emissions have increased dramatically. On-site pilot tests are beneficial in providing useful information regarding VOC emission reduction appHcations. Information that can be obtained includes optimum catalyst operating conditions, the presence of contaminants in the gas stream, and the effects of these contaminants (see Pilotplants and microplants). 

D. M. VanBenshchoten, "On-Site Pilot Testing Demonstrates Catalytic Emission Control Technology for New VOC AppHcations," paper... 

Design Methods for Turbo-Tray Dryers The heat- and mass-transfer mechanisms are similar to those in batch tray diyers, except that constant turning over and mixing of the solids significantly improves diying rates. Design must usually be based on previous installations or pilot tests by the manufacturer apparent heat-transfer... 

As stated above, the design of an RDC contactor usually involves the performance of pilot tests due to the large number of factors whicF can influence performance. These pilot plant data must then be scaled-up to Rill commercial size. The following procedure is recommended. 

Pilot tests are usually conducted in 0,075-m diameter columns the column should contain a sufficient number of stages to complete the extraction this may require several iterations on column height,... 

The scale-up of the Scheibel column is still considered proprietary, and therefore the vendor (Glitsch Process Systems Inc.) should be consulted for the final design. From pilot tests in 0.075-m diameter column, industrial columns up to 3 m in diameter and containing 90 actual stages have been provided. 

As with the other extractors, the final design of a Karr column depends on the scale-up from a pilot test. The following procedure is recommended. 

Pilot Tests In some cases, it is possible to perform pilot tests on a small-scale version of the equipment to be used in production. Much useful information can be found here but the following must be borne in mind ... 

Discs range in size from laboratory models 30 cm in diameter up to production units of 10 meters in diameter with throughputs of 100 ton/hr. Figure 20-82 shows throughput capacities for discs of varying diameter tor different applications and formulation feed densities. When scaling up from laboratoiy or pilot tests it is usual to keep the... 

Much of the experience and data from wastewater treatment has been gained from municipal treatment plants. Industrial liquid wastes are similar to wastewater but differ in significant ways. Thus, typical design parameters and standards developed for municipal wastewater operations must not be blindly utilized for industrial wastewater. It is best to run laboratory and small pilot tests with the specific industrial wastewater as part of the design process. It is most important to understand the temporal variations in industrial wastewater strength, flow, and waste components and their effect on the performance of various treatment processes. Industry personnel in an effort to reduce cost often neglect laboratory and pilot studies and depend on waste characteristics from similar plants. This strategy often results in failure, delay, and increased costs. Careful studies on the actual waste at a plant site cannot be overemphasized. 

Pilot-scale studies for demonstrated technologies can cost from 25,000 to more than 100,000 and typically require 2-12 weeks. For innovative technologies, the cost for pilot testing can start at 100,000 and exceed 1,000,000 and require 3 to 12 months. 

Aside from size considerations, the primary difference between bench-scale and pilot-scale work is that bench-scale tests are conducted in the laboratory pilot-scale testing is usually carried out on the site. Pilot tests are subject to a whole range of problems, such as siting, health and safety, obtaining clearances, installation and operation. However, the data obtained from pilot-scale tests are much more appropriate and useful because they reflect what is actually occurring in the field. 

Solidification/stabilization processes are not "off-the-sbelf technologies, thus, it is not unusual for modifications to the additives required for a specific waste. For this reason, some pilot testing of the solidification reagents may be required to develop the ultimate characteristics desired in the final product. 

A suspension of aluminum hydroxide in water is to be filtered imder constant pressure in a batch Nutsch filter having a filtering area of 1 m. Each filter cycle is estimated to separate out 0.5 m of suspension. The operating temperature is 25° C. The following expression for the cake resistance was empirically determined from pilot tests ... 

The team will develop a detailed plan, including timetable and cost estimates. In the meantime, it is estimated that the process, from start through pilot testing, will require about 120 staff-months over a period of approximately 18 months, including time from corporate division and facility personnel. A more rigorous estimate will be made before we move into PSM system development. 

Piiot Testing. Pilot testing of each PSM system will be performed at two locations to be selected by the project team. The test period will be two months. During the test period, the project team will monitor the PSM system to assure that procedures are clear and do not conflict with other procedures. 

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