Pilot Plant Trials

The enzymatic resolution of (R,S)-2-ethoxycarbonyl-3,6-dihydropyran has been carried out repeatedly in a pilot plant on a 100-125 kg scale. The conditions of pH, agitation, concentration, and enzyme/substrate ratio have been further optimized, but for the most part conditions developed during the laboratory optimization studies have been found to work well. This technology is currently being used to produce ton quantities of (S)-4. It has to be pointed out that no major difficulties were encountered during the scale-up. The work-up of the product in this process, unlike in many other enzyme-catalyzed processes, is quite simple and volume efficiencies are better than some chemical reactions. The recovery and recycling of the enzyme is not needed since it is commercially available and relatively inexpensive. 

As an alternative to hydrolysis of the racemic ester in water, we investigated the possibility of resolving the alcohol (R,S)-5 obtained by the reduction of (R,S)-4, by enzymatic trans esterification in organic solvents as shown in Fig. 6. High rates and selectivities of enzymatic acylation of unhindered alcohols can be achieved in an organic solvent using vinyl acetate as an acyl donor [14]. 

The racemic alcohol was prepared by lithium aluminum hydride reduction of (R,S)-4. An abbreviated library of commercially available enzymes (entries 1-11 in Tab. 1) was used to screen the vinyl acetate acylation. Enzymes in entries 2, 3, 4, 8, and 11 catalyzed the acylation with a relatively fast rate ( 20% conversion in 

2 hours) however none did so with an E value exceeding 3. These results confirmed our initial selection of (R,S)-4 as the best substrate for enzymatic resolution. 

---

From diese various estimates, die total batch cycle time t(, is used in batch reactor design to determine die productivity of die reactor. Batch reactors are used in operations dial are small and when multiproducts are required. Pilot plant trials for sales samples in a new market development are carried out in batch reactors. Use of batch reactors can be seen in pharmaceutical, fine chemicals, biochemical, and dye industries. This is because multi-product, changeable demand often requues a single unit to be used in various production campaigns. However, batch reactors are seldom employed on an industrial scale for gas phase reactions. This is due to die limited quantity produced, aldiough batch reactors can be readily employed for kinetic studies of gas phase reactions. Figure 5-4 illustrates die performance equations for batch reactors. 

At Rohm and Haas a committee of several experts contributed to the successes described In this paper. Discussions with Prof. John MacGregor (HcHaster University), Jeff Nathanson, Tom Shannon and Tom Throne were especially Important. Special thanks are due to Chris Altomare, who always had the proper equipment and Instrximentatlon ready for the pilot plant trials. We also would like to acknowledge Prof. Don Watts (Queens University) for assisting with the time series modeling and Prof. 

The global rates of heat generation and gas evolution must be known quite accurately for inherently safe design.. These rates depend on reaction kinetics, which are functions of variables such as temperature, reactant concentrations, reaction order, addition rates, catalyst concentrations, and mass transfer. The kinetics are often determined at different scales, e.g., during product development in laboratory tests in combination with chemical analysis or during pilot plant trials. These tests provide relevant information regarding requirements... 

Fine-chemical/custom manufacturing companies (discussed in Section 2.1) are active in process scaleup, pilot plant (trial) production, and industrial-scale exclusive and nonexclusive manufacture contract research organizations are discussed in Section 2.2, and laboratory chemical suppliers are discussed in Section 2.3. 

Our first experience with hydrocyclones was with pilot plant trials of the Serck-Baker Oilspin developed as a result of an extensive research program conducted at Southampton U. J While these tests, carried out oo the Murchison and Hutton platforms in early 1983, were not an unqualified success, they demonstrated the equipment s potential and enough encouragement for us to commit to die first Mi-scale commercial application of the Vortoil four-t in-one 35-nun (l.4-in. hydrocyclone later that year. 

Because this was the first worldwide application of the four-in-one 35-mm [1.4-in.] hydrocyclooe coocept, a rigorous test program was developed to confirm its suitability for the demanding North Sea environment and to advance the knowledge gained from earlier pilot-plant trials in Bass Strait. Australia. 

Consequently, these models often require model tuning through semiempirical correlations and data integration. Such tasks are time-consuming and problem specific as they often require information from additional experiments and pilot plant trials, with missing information leading to start-up and operational risks. The incorporation of more accurate multi-scale phenomena (at device-, meso- and even molecular scales) captured by reduced-order models (ROMs) will overcome these limitations (Lang et al., 2009, 2011). 

Pertraction (PT) can be realized through a liquid membrane, but also through a nonporous polymeric membrane that was applied also industrially [10-12]. Apart from various types of SLM and BLM emulsion liquid membranes (ELM) were also widely studied just at the beginning of liquid membrane research. For example, an emulsion of stripping solution in organic phase, stabilized by surfactant, is dispersed in the aqueous feed. The continuous phase of emulsion forms ELM. Emulsion and feed are usually contacted in mixed column or mixer-settlers as in extraction. EML were applied industrially in zinc recovery from waste solution and in several pilot-plant trials [13,14], but the complexity of the process reduced interest in this system. More information on ELM and related processes can be found in refs. [8, 13-16]. 

The fluidized dram granulation process had not been used before to produce granular AN. However, it had been used to fatten urea prills. Extensive pilot plant trials were carried out to define the parameters for granulating AN. The... 

At the end of the pilot plant trial period a series of four tests was carried out under comparable conditions. By providing a comparison between the two disinfection systems employed, these tests show the characteristics of each. 

One of the goals of successful process development is to design and introduce a smooth-running manufacturing process. Effective laboratory effort prior to scale-up, e.g., pilot plant trials, will pay off by establishing a manufacturing process... 

Second step pilot plant trial - and error - assays to optimize performance. 

MTG catalyst life is represented by the number of days on stream for progressive cycles (Fig 7). This graph of the actual cycle times achieved, follows a similar pattern to the aging rates predicted by pilot plant trials. 

J Simms, F Azizian. Pilot-plant trials on removal of arsenic from potable water using activated alumina. American Water Works Association Water Quality Technology Conference, Denver, CO, 1997. 

Sell M., Bischoff M. and Bonse D. 1992. Catalytic nitrate reduction in drinking water. Results and experiences from pilot plant trials, Vom Wasser, 79, 129-144. 

After these laboratory investigations, pilot plant trials were carried out on a modified process. After formation of the monolithium acetylide in stage I, ammonia is distilled off and replaced by solvent I. The distillative removal of ammonia must be carried out at a controlled heating rate so that the monolithium acetylide-ammonia complex, which is not very stable, does not decompose. The distillation is interrupted at exactly 5 °C. In order to facilitate drying of the solvent, a further solvent change is carried out after condensation, since solvent II can easily be dried and is also used in the following step of the process [213],... 

Especially for smaller scale applications, pilot plant trials can be done at the industrial scale. 

There are two different catalyst mannfacturers whose products are being considered for use in a commercial-scale reactor facility. Both products are 3.2-mm-diameter spherical pellets that are believed to be essentially the same in chemical composition. Resnlts of pilot-plant trials indicate that the deactivation characteristics of the two catalysts are somewhat different. The same gas pressure, feed composition, and molar feed rate were employed in all trials. For an inlet temperature of 550°C, the behavior indicated in Figure PI 2.9 was observed. 

Cleavage of Epoxidized HOSME with HOSFA Results of a Pilot Plant Trial (1 kg) ... 

Applications for OSN have been under pilot-plant trial or demonstrated in laboratory experiments in solvent deoiling, homogeneous catalyst recovery, separation of phase-transfer agents, and solvent exchange. "... 

A continuous cooling crystallizer is required to produce potassium sulphate crystals (density pc = 2660kgm, volume shape factor a = 0.7) of 750pm median size Lm at the rate Pc = 1000 kg h. On the basis of pilot-plant trials, it is expected that the crystallizer will operate with steady-state nucleation/ growth kinetics expressed (equation 9.39 with j = 1 and i = 2) as B = 4 X IO MtG m s. Assuming MSMPR conditions and a magma density Mt = 250 kg m, estimate the crystallizer volume and other relevant operating conditions. 

These studies, associated with pilot-plant trials, indicated that Sirosmelt technology, because of its flexibility, versatility and simplicity, was the most suitable process to replace the conventional sinter machine-blast furnace. The process has been optimized since the start-up of the furnace based on increased industrial experience and pilot plant trials at the Metaleurop Research Centre. Improved automation and expert systems are necessary to stabilize the process because of the short residence times involved. The bath smelting process operates with a large range of primary and secondary feed materials, and carries out different metallurgical operations in the same reactor.The exhaust gases produced are processed in a sulfuric acid plant, and final SO2 conversion efficiencies of more than 99.5 % are achieved. All the emissions have been drastically reduced CO2 emissions have decreased by 60 %. 

Obvionsfy, this discusaod suggests that where possible, pilot plant trials are recommended br vacuum systeus particulaify in upward filtering systems and attatition should be directed to cake loss eflEects in scale-i ipplicationsL... 

Escobar et al (2001) did a complete study in which pilot plant trials were conducted in a corn wet mill with a 7000-L membrane recycle bioreactor (MRB) that integrated ceramic microflltration membranes in a semi-closed loop configuration with a stirred-tank reactor. Residence times of 7.5-10 h... 

There is no way to predict the effect of contaminants on reactor performance prolonged pilot plant trials are necessary. Contaminants may cause modifications in the selectivity of a reaction and reduce overall production capacity. For example, in the reduction of acetophenone to ethylbenzene, reaction selectivity was almost halved from its initial high value after only a few hours of operation, due to adsorption effects on the electrode surface. 

Bubble behavior Fluid mechanics Pilot-plant trials... 

Note The scale is the amount of polyethylene provided from a developmental program. A pilot plant trial may last 3-7 days and provide sufficient material for fabrication into the end-use product. A commercial trial affords sufficient material for customer evaluation on commercial-scale equipment. 

However, once a catalyst is identified for additional studies, usually a 1-10 gram quantity of catalyst is required and these preparations are carried out in dedicated catalyst preparation apparatus and are then evaluated in a 1-4 liter polymerization autoclave designed to produce 40-400 grams of polyethylene, which is required for a more detailed evaluation of polymer properties. Catalysts that provide polymer with improved properties are then scaled up for a pilot plant evaluation which is usually similar to commercial equipment already in operation. Approximately 100-1,000 grams of catalyst is required for a pilot plant study, which provides 10-100 Ibs/hour of polyethylene. A pilot plant trial will usually take place in a continuous mode lasting 1-5 days and producing a total of 200-1,000 lbs of polyethylene. 

---