Reactive processing batch reactors

OS 41a] ]R 19] ]P 30] Ten different substrates (C4-C8 alcohols) were reacted with rhodium(I)-tris(fn-sulfophenyl)phosphane [110]. The variance in conversions (ranging from about 1-62%) determined was explained by differences in the solubility of the alcohols in the aqueous catalytic layer and by their different intrinsic activities. Chain length and steric/electronic effects of the different alcohols affected their reactivity in a well-known pattern (Figure 4.63). The results obtained correspond to the conversions achieved in a well-mixed traditional batch reactor (40 cm ). They further agreed with data from mono-phasic processing. 

The process is operated in heated, batch reactors under an inert atmosphere. Two companies (Deeside Titanium, North Wales, and New Metals Industries, Nihongi, Japan) operate a one-stage process. Reactive Metals Industries Company, Ashtabula, OH, operates a two-stage process in the first stage, at 230°C, the trichloride and dichloride are formed. In the second, more sodium is added and the temperature is raised to 1,000°C. The sponge product is mixed with sodium chloride, which is leached out with dilute hydrochloric acid. Based on the work by M. A. Hunter at Rensselaer Polytechnic, New York in 1910. See also Kroll. 

Case G GlaxoSmithKline Fine Chemical from Carbonyl Process (41). The fine chemical is produced in a high-heat exchange reactor. The residence time is thereby reduced by a factor of 1800( ) compared to a conventional batch reactor. The reactive content is thereby considerably reduced hence the process is safer. 

Lehtonen et al. (1998) considered polyesterification of maleic acid with propylene glycol in an experimental batch reactive distillation system. There were two side reactions in addition to the main esterification reaction. The equipment consists of a 4000 ml batch reactor with a one theoretical plate distillation column and a condenser. The reactions took place in the liquid phase of the reactor. By removing the water by distillation, the reaction equilibrium was shifted to the production of more esters. The reaction temperatures were 150-190° C and the catalyst concentrations were varied between 0.01 and 0.1 mol%. The kinetic and mass transfer parameters were estimated via the experiments. These were then used to develop a full-scale dynamic process model for the system. 

All the methods mentioned above use a mathematical model of the copolymerisation process in one way or another to arrive at a control policy for the production of compositionally homogeneous products. In this work use is made of a dynamic model of the process to control the feed rate of the more reactive monomer to a semi-batch reactor. Feedback from the process comes from an off-line model. The method is a general one and can be readily extended to accomodate feedback loops using on-line measurement devices with an experimental reactor. 

Through the use of a model for a batch reactor for a particularly complex reaction, we have demonstrated the value of modeling in optimization of process conditions and in evaluation of possible hazards. For a very complex system like the present one, it is most probably easier and more cost effective to do the modeling than to run the experiments needed for proper analysis. To save laboratory data acquisition time, it is always better to plan an experimental strategy based on the anticipated need in advance. This model has been successfully used in two scale-ups. Data from these scale-ups have been used to refine the model. These refinements included a better understanding of the chemistry of the process. Plots similar to the ones presented in Figures 6-10 were used in the Reactive Chemicals Review of the present process. 

A second possible problem with batch reactors is composition drift of copolymer systems. As with bulk, solution, and suspension systems, the more reactive monomer polymerizes first, and the least reactive polymerizes last. Two additional factors must be considered in emulsion polymerization. First, the water solubilities of the monomers can influence the course of the polymerization because of reaction in the water phase to produce copolymer oligomers or even water-soluble polymer. These molecules can be rich in the water-soluble monomer even if its reactivity is relatively low. Second, the high degree of subdivision achieved by producing small polymer particles can lead to phase domains that are smaller than those in copolymer produced by other processes. 

Dependence of degradation rates on flow velocity indicates rate limitation by transport processes, e.g. reported by Sivavec and Homey (1995) or Burris et al. (1995) for the degradation of trichloroethene (TCE) by zerovalent iron in batch reactors. Even if there has been no real explanation for the different degradation behaviour at the two column experiments, it must be dependent on the characteristics of the granular iron, because of the similar experimental conditions. The diverse granulate shape or the distribution of reactive surface as well as mineral precipitations usually present in iron... 

Flowsheets for processes are sometimes generated without following the hierarchy of properties described previously. As an example, Siirola [20] proposed a reactive-distiUation solution to make methyl acetate. Unit operations that combine the property differences present abrupt departures from common methodologies. With the advent of various pieces of equipment, such as differential side-stream feed reactors (i.e., semicontinuously fed batch reactors), continuous evaporator-reactors (e.g., wiped-film evaporators), and reactive distillation columns, one can consider these unit operations in the development of conceptual designs. As an example, Doherty and Malone [21] have presented systematic methods for reactive distillation design. 

The acid-epoxide reaction is straightforward and is catalysed by tertiary amines, phosphines or ammonium salts. Vinyl ester resins are diluted with a reactive monomer such as styrene, vinyl toluene or dicyclopentadiene acrylate. Similar to other unsaturated polyesters, the production of vinyl esters is carried out in batch reactors. The basic steps of the process are ... 

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