A type of reactor used commonly in industrial processing is the stirred tank operated continuously. It is referred to as continuous-stirred tank reactor. (CAST), and is used primarily for liquid phase reactions, [l] In a CAST, one or more fluid reagents are introduced into a tank reactor equipped with an impeller while the reactor effluent is removed. The impeller stirs the reagents to ensure proper mixing. Some important aspects of the CAST: * At steady-state, the flow rate in must equal the mass flow rate out, themes the tank will overflow or go empty.
While the reactor is in a transient state the del equation must be derived from the differential mass and energy balances. ;k The reaction proceeds at the reaction rate associated with the final concentration _ * Often, it is economically beneficial to operate several Costs in series. This allows, for example, the first CAST to operate at a higher reagent concentration and therefore a higher reaction rate. * It can be Seen that an infinite number of infinitely small Costs operating in series would be equivalent to a PER.
Many times, reactors are connected in series so that the exit stream of one reactor is the feed stream for another reactor. When this arrangement is used, it is often possible to speed calculations by defining conversion in terms of location at a point rather than with respect to any single reactor. [11 In this experiment the reaction studied is can be considered equiangular and first order with respect to both sodium hydroxide and ethyl acetate, i. E. , second order overall, within the limits of concentration (0-0. M) and temperature (C-ICC) studied. The reaction carried out in a continuous stirred tank reactor or tubular reactor eventually reaches steady state when a certain amount of conversion of the starting reagents has oaken place. The steady-state conditions will vary depending on concentration of reagents, flow rate, volume of reactor, and temperature of reaction. The above reaction can be studies using three CAST in series and extent of conversion can be calculated at each reactor exit by measuring the conductivity of leaving stream.
The final conversion at the exit pithier reactor can be compared with the corresponding conversion of one reactor equal to sum of three reactor volumes connected in series.  * Design equation for CAST Equation (1) is can be used to investigate performance of CAST for the given reaction. Also rate of reaction for reactors connected in series can be calculated. Putting the corresponding rate expression in equation (1) expression for conversion can be found and then theoretical conversion can be calculated. Concentration as function of conductivity Sodium hydroxide (reactant) and sodium acetate (product) being ionic compounds contribute conductance to the reaction solution, whereas ethyl acetate and ethyl alcohol do not. The conductivity of a sodium hydroxide solution at a given concentration and temperature, however, is not the same as that off sodium acetate solution at the same military and temperature, and relationship has been established allowing conversion to be inferred from conductivity.  Conductivity for pure Noah is given by 0=0. 3511 for T 294 And Conductivity of pure COUCH’S c +0. 02840 – 294 (3) As the reaction proceeds sodium hydroxide concentration will be go down and sodium acetate will start forming. Progress of reaction can be monitored by measurement of conductivity contributed by unconsumed sodium hydroxide and formed sodium acetate. Since conductivity changes linearly with concentration, relation between concentration and conductivity can be (unrelated Noah) -e c (formed Cinchona) Conductivity): A (4) Linear relationship between concentration and conductivity And Hence, (5) At infinite time if, then 3.
Apparatus and Procedure (i) Apparatus Figure CAP-MIKE stirred tank reactors unit A self-contained bench mounted small scale unit Fitted with three continuous stirred reactors in series which are fed from two S liter tanks. Each reactor is fitted with a conductivity probe. There are two independent, variable speed feed pumps. A dead-time residence coil can also be attached to the exit of the last reactor in the series.
The Ramified Stirred Tank Reactors in Series unit is signed to follow the dynamics of the perfectly mixed multi-stage process, Dynamic behavior can be studied as can multi-stage chemical reaction. Bench mounted and self-contained, the unit requires only to be connected to a single phase electrical supply for operation. There are three reactor vessels connected in series, each containing a propeller agitator driven by a variable speed electric motor.