Reactor train

Results of the intermediate conversions in a reactor train of CFSTRs involving the second order irreversible reaction kinetics A + B products... 

Recipe ingredients can also be added at intermediate points along the reactor train. Continuous-flow tubular reactors can be used in series with the tanks, usually as a prereactor in front of the tanks. 

Compositional drift in continuous reactor trains can be altered by introducing feed streams of the more reactive monomer between reactors. This procedure is equivalent to programmed addition of the more reactive monomer in a semi-continuous system. 

Example 4.10 Consider a reactor train consisting of a CSTR followed by a piston flow reactor. The total volume and flow rate are fixed. Can series combination offer a performance advantage compared with a single reactor if the reaction is autocatalytic The reaction is... 

Figure 4. Emulsion PVC production in the new continuous latex reactor train.

Polymerization proceeds stepwise through a train of reactors. This reactor system contributes significantly to the high degree of flexibility of the overall plant in producing different grades of rubber. The reactor train is capable of producing either cold (277-280 K, 103-206 kPa) or hot (323 K, 380-517 kPa) rubber. The cold SBR polymers, produced at the... 

The monomers are piped from the tank farm to the caustic soda scmbbers where the inhibitors are removed. Soap solution, catalysts, and modifiers are added to produce a feed emulsion which is fed to the reactor train. Fewer reactors are normally used than the number required for a cmmb product line. When polymerization is complete, the latex is sent to a holding tank where stabilizers are added. 

Lack of Economy in Size. Fine chemicals are manufactured in discrete campaigns in multipurpose plants. The reactor trains of these plants are similar throughout the industry. Regardless of the size of the companies, their main constituents, the reaction vessels, have a median size in the 4-6m bracket. Therefore, the unit cost per m per hour does practically not vary with the size of the company. 

Fig. 4.2-7. In-line safety- and side-stream valve (PN 2500, DN 60/32, adopted from BOHLER). 1, Tubular reactor train 2, In-line valve 3, Hydraulic actuator 4, Side outlet (inlet).

The in-line safety valve [45] as shown in Fig. 4.2-7 is used in LDPE plants during emergency situations in order to depressurize the system by the outlet (2). The valve is directly included in the tubular reactor train (1) in a manner to avoid dead spaces where harmful decomposition of the polymer could take place. The control of the safety valve is effected again by a special... 

Two independent supercritical water oxidation (SCWO) reactor trains are located in separate rooms in the SCWO... 

The use of a precision digital density meter as supplied by Mettler Instruments (Anton Paar, Ag.) appeared attractive. Few references on using density measurements to follow polymerization or other reactions appear in the literature. Poehlein and Dougherty (2) mentioned, without elaboration, the occasional use of y-ray density meters to measure conversion for control purposes in continuous emulsion polymerization. Braun and Disselhoff (3) utilized an instrument by Anton Paar, Ag. but only in a very limited fashion. More recently Rentsch and Schultz(4) also utilized an instrument by Anton Paar, Ag. for the continuous density measurement of the cationic polymerization of 1,3,6,9-tetraoxacycloundecane. Ray(5) has used a newer model Paar digital density meter to monitor emulsion polymerization in a continuous stirred tank reactor train. Trathnigg(6, 7) quite recently considered the solution polymerization of styrene in tetrahydrofuran and discusses the effect of mixing on the reliability of the conversion data calculated. Two other references by Russian authors(8,9) are known citing kinetic measurements by the density method but their procedures do not fulfill the above stated requirements. 

Figure 1. Typical continuous reactor train for emulsion polymerization...

These responses are similar to the response of a single adiabatic reactor system except now the upstream reactors alfect the downstream reactors. For example, the increase in the exit temperature of the first reactor at 30 min produces an increase in the exit temperature of the second reactor, which then produces an even larger increase in the exit temperature of the third reactor. Thus these disturbances are amplified as they move down the reactor train. Similar results occur for a decrease in recycle flow. 

Pure SO2 is injected to achieve the desired concentration in the flue gas. Regeneration of spent scrubbing liquor is performed in the four-tank-in-series reactor train with a total residence time of 80 minutes. Limestone is fed to the first reactor as 45% slurry. 

For the capacity of the proposed plant in this study, we have chosen to use two SGP reactor trains feeding into one scrubber. The units downstream of the SGP would be single train. 

Dualforming A process that enables a petroleum refiner to improve the catalytic reforming step at minimal capital cost. A new reactor with continuous catalyst recirculation is integrated into the existing reactor train. Developed and offered by Axens. 

The stirred-tank reactor and the tubular reactor are two basic reactors used for continuous processes, so much of the experimental and theoretical studies pubhshed to date on continuous emulsion polymerization have been conducted using these reactors. The most important elements in the theory of continuous emulsion polymerization in a stirred-tank reactor or in stirred-tank reactor trains were presented by Gershberg and Longfleld [330]. They started with the S-E theory for particle formation (Case B), employing the same assumptions as stated in Sect. 3.3, and proposed the balance equation describing the steady-state number of polymer particles produced as ... 

Before true continuous reactor trains became common, many were operated in a semi-continuous mode. Typically, there were three or four reactors in series and the styrene would be polymerized to a certain degree of conversion and transferred to the next vessel. This would allow reactants to be transferred into the vacated vessel and batch polymerization begun. This scheme was successful in normal operation, but a surge vessel was needed in case there was a problem with any of the reactors in sequence. 

Reactors and Catalysts. The reactor configuration consists of two reactor trains of two reactors in series each with two beds (8). Since the reactors are adiabatic, each bed temperature, except the first bed, is controlled by recycle hydrogen gas. However, as shown in Figure 1, the bed temperatures increase with reactor depth. A maximum reactor inlet temperature is set to avoid coking in the furnace coil and the first bed. A maximum reactor outlet temperature is limited by reactor shell metallurgy. The hydrodesulfurization catalyst, which occupies about 70% of a total catalyst volume, is packed in a lower half of the second bed and the whole third and fourth beds. The rest is the hydrodemetallation catalyst. We have used Orient Catalyst HOP-802 as the hydrodesulfurization catalyst, which contains about 2% Ni and 8% Mo on an alumina support. 

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