Reactors multipurpose

An example of a multipurpose system is a reactor s low pressure coolant injection system which uses one out of four (1/4) pumps for a small LOCA, and three-out-of-four pumps for a large LOCA (3/4). The top event for the small LOCA might be "none of four LPCI pump u1... 

Hoffmann, C., Schmidt, H.W. and Schuth, F. (2001) A multipurpose parallelized 49-channel reactor for the screening of catalysts methane oxidation as the example reaction. J. Catal., 198, 348. 

The case study involves a well published multipurpose facility which is commonly known as BATCH1 in literature (Kondili et al 1993). It mainly consists of 3 chemical reactions which take place in 2 common reactors. In addition to the 2 common reactors, the flowsheet also entails the heater and the separator, before and after the reactors, respectively as shown if Fig. 6.6. The STN and SSN for the literature example are given in Figs. 6.7a and b, respectively. The data for this example appears in Table 6.5. 

In order to illustrate the capability of the proposed technique, this multipurpose example has been enhanced by including compulsory washing operations after each of the reactions in each of the 2 reactors. The philosophy is that the reactors need to be cleaned after each reaction in order to remove contaminants that are formed as byproducts, so as to ensure product integrity. Data pertaining to cleaning tasks is shown in Table 6.6. The variation in performance in the 2 reactors could be ascribed to differences in design, which is indeed a common encounter in practice. In addition to this data, it is known that freshwater cost is 2 cost units per kg of water whilst the effluent treatment cost is 3 cost units per kg. 

A multipurpose mesofluidic flow reactor was developed for the automated synthesis of libraries of 4,5-disubstituted oxazoles. The process was based on the known reaction of alkylisocyanoacetates and acylchlorides <06OL5231>. 

In case of the standard multipurpose batch plant the downtime of the reactors for the product transfer into temporary storage vessels, the transportation of the vessels to the storage and the cleaning of the reactors before product changeover have to be included. This was modelled by an adjustment of the CIP times of the three stations to 60 min. 

As a typical pattern of a multipurpose batch plant, the authors consider a plant with multiple floors that produces various products (e.g., fine chemicals or dyes) in batches and/or semicontinuously. Raw materials are entered into premixing devices and placed together in a reactor where the chemical reaction takes place. The resulting product is separated from the mother liquor by a filter press and then packaged in various types of packaging. The mother liquor is stored and eventually recycled. The same product may even take different paths through the plant by use of alternate devices or production lines. 

Most chiral chemicals are relatively small-scale products (1 to 1000 tonnes per year for pharmaceuticals, 500 to 10000 tonnes per year for agrochemicals) that are usually produced in multipurpose batch equipment This is probably the case for most catalytic reactions described in this chapter however, as a rule very little information on process technology is provided by the manufacturers. Here, we will discuss only briefly the reactor choices for hydrogenation reaction typically carried out in the liquid phase. For a successful implementation the following demands must be met ... 

Batch microwave reactors, reactions in, 16 554-555 Batch mixers, 16 721 Batch mononitrotoluene process, 17 265 Batch multipurpose plants, for fine chemical manufacture, 11 427 Batch nitrobenzene process, 17 252 Batch-operated settling tanks, 22 59 Batch pilot plants, 19 458 Batch plants, certified, 20 703 Batch polymerization, of vinyl acetate, 25 608... 

Pharmaceutical production generally uses multipurpose equipment, and so entrapment behind a membrane would require significant capital expenditure on specialized equipment. In spite of this, the use of membrane reactors in biocatalysis represents an efficient method of enzyme immobilization, given the large molecular weight difference between enzymes (10-150 kDa) and most substrates (300-500 Da). The reader is referred to some recent reviews on the topic. 

Lack of Economy in Size. Fine chemicals are manufactured in discrete campaigns in multipurpose plants. The reactor trains of these plants are similar throughout the industry. Regardless of the size of the companies, their main constituents, the reaction vessels, have a median size in the 4-6m bracket. Therefore, the unit cost per m per hour does practically not vary with the size of the company. 

Train concept—the logical operating unit of the plant is a train. A typical train consists of approximately three multipurpose reactors (up to a maximum volume of 10m each), one filtration unit (nutsche or centrifuge), and one dryer. 

Divi s Laboratories, India, established in 1990, is an example of a company that has installed a very impressive production capacity. At its two sites in Hyderabad and Vishakhapatnam (in Andhra Pradesh), the company has put onstream multipurpose GMP fine-chemical plants with a total reactor volume of 2000 m, far more than any large European fine-chemical company. However their sales of 87 million (2005) translate in a very modest turnover of 43,000 per m of reactor volume. 

Z.H. Liu, S. Macchietto, Model based control of a multipurpose batch reactor - an experimental study, Comp. Chem. Eng. 19(Suppl) (1995) s477-s482. 

FIGURE 1. Typical multipurpose pilot plant reactor package. 

The Chemical Development Drug Evaluation branch of Johnson Johnson Pharmaceutical Research Development LLC in Raritan, USA, tested microreactors for processes at elevated temperatures above the limit of most multipurpose conventional reactors, which is above 140°C [34], Operation above this limit is only possible by means of special reactors equipped with heat transfer units. 

Davidson, R. S. (1989). Using process information to control a multipurpose batch chemical reactor. Computs Chem. Eng., 13(1 /2), 83-84. 

Due to their thermal instability fine chemicals often must be produced in the liquid phase at moderate temperatures. They are generally complex and multifunctional as well as chemo-, regio- and stereoselectivity play an important role. The reactor system of the choice are batch or semi batchwise operated multipurpose units. Bulk chemicals, mostly consisting of relatively small, thermostable molecules, can be produced in continuously operated fixed bed or fluidised bed reactors in the gas-phase allowing much higher space time yields, thus minimising investment costs1. These procedures can hardly be applied to the synthesis of e.g. fine and intermediate chemicals because of the relatively small... 

The tests were run in multipurpose rocket test cells. An overall schematic of the ACR gas-yield test equipment is given in Figure 4. The full-scale equipment was manufactured from uncooled 304 stainless steel. A water-cooled burner was used to supply the cracking steam to the ACR test piece at commercial-scale flow rates, pressures, and temperature. The burner was mated to the ACR venturi test piece through a choked orifice and a diameter transition section. The reactor venturi consisted... 

The importance of high rates of mass transport for a clean and efficient electrosynthesis using a filter press reactor has been stressed, and the effect of inclusion of a platic mesh turbulence promoter considered [56]. A multipurpose filterpress cell for continuous electrolysis of organic compounds has been described [57], and a mathematical model of the startup of a continuous parallel-plate reactor has been published [58]. 

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