Recycle continuous-flow discussion

Other modes of operation, including recycle and flow reversal schemes and continuous chromatography, are discussed in Ganetsos and Barker (Preparative and Production Scale Chromatography, Marcel Dekker, New York, 1993). 

In this work we present results obtained both with batch and continuous flow operation of the gas-recycle reactor-separator utilizing Ag and Ag-Sm203 electrocatalysts and Sr(lwt%) La203 catalysts, in conjunction with Linde molecular sieve 5A as the trapping material, and discuss the synergy between the catalytic and adsorption units in view of the OCM reaction network. 

A cell for continuous flow operation must be designed with a high electrode surface-electrolyte volume ratio, provided with a feeding system, and, last but not least, connected with suitable auxiliary equipment for continuous removal of the product s) of electrolysis and reestablishment of the electrolyte composition. The continuous workup procedure during electrolysis is somewhat inconvenient in the laboratory, and consequently small continuous flow cells have mostly been operated with recycling to a reservoir before scaling up. Large cells and their industrial applications are discussed in Chapter 31. 

Commonly, trickle beds reported in the literature have diameters of approximately 2.5 cm, with short to medium length beds, about 30 to 200 cm. They are run under a variety of, but usually low, liquid and gas velocities. The catalyst is packed below a calming zone of inert particles. Alternatively, a short bed length is used, but with the catalyst diluted with inert particles such as fine sand. In another type, high liquid velocity is obtained through recycle. Both batch and continuous flow modes have been reported for this latter reactor configuration. Each of these types of reactors will be discussed separately with examples given from the literature to help characterize their performance. 

In this section the model for a continuous evaporative crystallizer is discussed. The crystallizer is of the draft tube baffled (DTB) type and is equiped with a fines removal system consisting of a large annular zone on the outside of the crystallizer (see Figure 1). In order to vary the dissolved fines flow without changing the cut-size of the fines removal system, the flow in the annular zone is kept constant and the flow in the dissolving system is varied by changing the recycle flow rate. The model assumptions are ... 

Bench-scale kinetic experiments can be conducted in batch, continuous stirred-tank, tubular plug-flow, or differential reactors. The last of these can be operated with once-through flow or recycle. The advantages and disadvantages of the various types are discussed in Section 3.1. 

A recycle reactor is a mathematical model describing a steady plug-flow reactor where a portion of the outlet is recycled to the Met, as shown schematically in Figure 9.5. Although this reactor configuration is rarely used in practice, the recycle reactor model enables us to examine the effect of mixing on the operations of continuous reactors. In some cases, the recycle reactor is one element of a complex reactor model. Below, we analyze the operation of a recycle reactor wifii multiple chemical reactions, derive its design equations, and discuss how to solve fiiem. 

Bench-scale kinetic experiments can be conducted in batch, continuous stirred-tank (CSTR), tubular plug-flow, or differential reactors. The last of these can be operated with once-through flow or recycle. Advantages and disadvantages of the various types are discussed. In particular Batch reactors are inexpensive, but require attention to rapid attainment of reaction conditions at start CSTRs are excellent for gas-liquid, but less so for gas-phase reactions tubular reactors are especially suited for reactions of heterogeneous catalysis and differential reactors operated "once through" are best for measurement of initial rates. 

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