Semicontinuous stirred tank reactor

The semicontinuous stirred-tank reactor is the reactor that fulfils the best of these requirements and it is the most widely used. For very large tonnages of a small number of grades. 

In a scenario of increasing international competition, margin reduction and public sensitivity to environmental issues, emulsion polymer producers are forced to achieve an efficient production of high-quality materials in a consistent, safe and environmentally friendly way [83]. Most emulsion polymers are produced in semicontinuous stirred-tank reactors. Therefore, this discussion is focussed on these reactors. 

Model 3 The Ideal Semicontinuous Stirred Tank Reactor (SCSTR) with V = Variable... 

ALLreviations reactors Latch (B), continuous stirred tank (CST), fixed Led of catalyst (FB), fluidized Led of catalyst (FL), furnace (Furn.), multituLular (MT), semicontinuous stirred tank (SCST), tower (TO), tuLular (TU). Phases liquid (L), gas (G), Loth (LG). Space velocities (hourly) gas (GHSV), liquid (LHSV), weight ( VHSV). Not available, NA. To convert atm to kPa, multiply Ly 101.3. 

Example 7.4-1. Cycle time versus size of stirred-tank reactor operated in hatch or semicontinuous mode Consider enamelled jacketed stirred-tank reactors of the AE series (DIN standards) for which Table 7.4-2 gives characteristics. ... 

Reactors batch (B), continuous stirred tank (CST), fixed bed of catalyst (FB), fluidized bed of catalyst (FL), furnace (Furn.), multitubular (MT), semicontinuous stirred tank (SCST), tower (TO), tubular (TU). 

Commercial implementation of emulsion polymerization is mostly carried out in stirred-tank reactors operated semicontinuously. Continuous stirred-tank reactors (CSTRs) are used for the production of some high-tonnage emulsion polymers such as SBR. Batch processes are only used to polymerize monomers with similar reactivities and low heat generation rate (e.g., acrylic-fluorinated copolymers for textile apphcations). 

Typically, emulsion polymerization is carried out in stirred-tank reactors, which commonly operate in a semicontinuous mode, although both batch and continuous operations are also used. 

Batch-, stirred-tank-, extractive semibatch-, recirculating batch-, semicontinuous flow-, continuous packed-bed-, and continuous-membrane reactors have been used as enzyme reactors, with dense gases used as solvents. 

Three major types of chemical reactor systems are used to produce emulsion polymers batch, semicontinuous, and continuous. Batch reactors usually consist of stirred tanks with various forms of heat removal... 

Batch or semicontinuous processing is appropriate for many laboratory scale operations. However, continuous processes are typically used by industry to allow higher throughput with smaller equipment size. To gain scale-up information, the importance of relatively inexpensive but fully operable pilot plants (or miniplants) cannot be overestimated. Many types of continuous reactors (fixed bed, fluidized bed, continuous stirred tank CSTR) can be adapted for high pressure service. 

Batch, recirculating batch, extractive semibatch, semicontinuous flow, continuously stirred tank (CSTR) and continuous packed bed reactors have alt been succesfully tested as enzyme reactors for SCFs (Figure 4.9-1). References to helpful descriptions for designing small-scale reactors for enzymatic studies are collected in Table 4.9-1. 

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