Batch methodology

Acebal, C., M. Insausti, M. Pistonesi et al. 2010. A new automated approach to determine monosodium glutamate in dehydrated broths by using the flow-batch methodology. Talanta 81 116-119. 

Chapter 2 developed a methodology for treating multiple and complex reactions in batch reactors. The methodology is now applied to piston flow reactors. Chapter 3 also generalizes the design equations for piston flow beyond the simple case of constant density and constant velocity. The key assumption of piston flow remains intact there must be complete mixing in the direction perpendicular to flow and no mixing in the direction of flow. The fluid density and reactor cross section are allowed to vary. The pressure drop in the reactor is calculated. Transpiration is briefly considered. Scaleup and scaledown techniques for tubular reactors are developed in some detail. 

Solution The obvious way to solve this problem is to choose a pressure, calculate Oq using the ideal gas law, and then conduct a batch reaction at constant T and P. Equation (7.38) gives the reaction rate. Any reasonable values for n and kfCm. be used. Since there is a change in the number of moles upon reaction, a variable-volume reactor is needed. A straightforward but messy approach uses the methodology of Section 2.6 and solves component balances in terms of the number of moles, Na, Nb, and Nc-... 

The industrial process for which this methodology was developed comprised polymerizing a monomer in the presence of a mixed solvent, the catalyst and other Ingredients. Once the batch polymerization is complete, the product requires removal of the solvents to a specified level. The solvents, an aromatic Cy and aliphatic Cy compounds, are removed by a two-step process schematically shown in Figure 1. As shown, the polymer slurry is initially flashed to a lower pressure (Pj ) in the presence of steam and water. The freely available solvent in the polymer-solvent mixture is removed by the shift in thermodynamic equilibrium. Solvent attached to the surface of the polymer particle is removed by the steam. In this first step, 90% of the total solvents are recovered. The remaining solvents are recovered in the second flash, where the effluent is almost all water with very low concentrations of the solvents. 

The experimental method used for this kinetie study is reaetion ealorimetry. In the ealorimeter, the energy enthalpy balance is continuously monitored the heat signal can then be easily converted in the reaction rate (in the case of an isothermal batch reactor, the rate is proportional to the heat generated or consnmed by the reaction). The reaction orders and catalyst stabihty were determined with the methodology of reaction progress kinetic analysis (see refs. (8,9) for reviews). 

Battelle has developed an efficient process for the thermo-catalytic conversion of succinate into pyrrolidones, especially N-methyl-2-pyrrolidone. The process uses both novel Rh based catalysts and novel aqueous process conditions and results in high selectivities and yields of pyrrolidone compounds. The process also includes novel methodology for enhancing yields by recycling and converting non-useful side products of the catalysis into additional pyrrolidone. The process has been demonstrated in both batch and continuous reactors. Additionally, stability of the unique Rh-based catalyst has been demonstrated. 

The direct whole-cell method of Holland et al. was extremely rapid, even in comparison to Lubman s MALDI analysis of fractions collected after bacterial sonnication. With the whole-cell approach bacteria were simply sampled from colonies on an agar plate, mixed with the matrix, air-dried, and introduced in batches into the mass spectrometer for analysis. In all of the spectra obtained in these and later experiments, each bacterial strain showed a few characteristic high-mass ions that were attributed to bacterial proteins. Studies demonstrating the whole cell methodology for strain-level differentiation were reported independently by Claydon et al. at almost the same time.18 Shortly thereafter a third study on whole-cell MALDI included bacteria from pathogenic and nonpathogenic strains appeared.19... 

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