Batch Reactors
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Transcript of Batch Reactors
ZAIN AHMED SIDDIQEE CE_E07_103
INTRODCTION:In a batch reactor the reactants and the catalyst are placed in the reactor which is then closed to transport of matter and the reaction is allowed to proceed for a given time whereupon the mixture of unreacted material together with the products is withdrawn. Provision for mixing may be required.
BATCH REACTOR
Typical diagram of batch reactor
•In all batch type reactor there is a feed line from where the reactants enters inside chamber•There is a vent and product out line as well •There is a stir used for agitation and throw out mixing which is controlled •The pressure line is supplied from the top to maintain required pressure needed•The temperature control element is also required with sensor normally thermocouple or thermometer•Sometimes a cooling or insulation jacket is also supllied and in some cases heat exchanger coil all around the vessel
Typical diagram of batch reactor
Sequencial Batch Reactors(used in water treatment in mostly)
Different types of batch reactors
Fed-batch reactors•Fed-batch is a production technique in between batch and continuous fermentation. A proper feed rate, with the right component constitution is required during the process.
•It is mostly use in fermentation technique and different chemical processes having long residence time
FED Batch
Stirred Batch Reactor:•It contains catalyst dispersed as slurry
•There is a better contact b/w reactants and catalyst in this type of reactor
•This reactor is useful for substrate solutions of high viscosity and for immobilized enzymes with relatively low activity
Stirred batch reactors
•A semi-batch reactor is operated with both continuous and batch inputs and outputs. A fermenter, for example, is loaded with a batch, which constantly produces carbon dioxide, which has to be removed continuously. Analogously, driving a reaction of gas with a liquid is usually difficult, since the gas bubbles off. Therefore, a continuous feed of gas is injected into the batch of a liquid. An example of such a reaction is chlorination.
Semi Batch Reactor
1. Small scale production
2. Intermediate or one shot
production
3. Pharmaceutical
4. Fermentation
Usage of batch reactors
1. Gas phase
2. Liquid phase
3. Liquid Solid
Kinds of Phases Present
Mathematical Formulii
The advantages of the batch reactor
lie with its versatility. A single vessel
can carry out a sequence of different
operations without the need to break
containment. This is particularly
useful when processing, toxic or
highly potent compounds.
Advantages
1. High conversion per unit volume
for one pass
2. Flexibility of operation-same
reactor can produce one product
one time and a different product
the next
3. Easy to clean
Advantages
1. High operating cost
2. Product quality more
variable than with
continuous operation
Disadvantages
The following are the reaction variables control in batch process :
Batch Reactor Control
ICI CHEMICALS PAKISTAN•chemicals used in a variety of industries including fertilizer, cement, polyester, oil and gas, plastics, non-chemical products like specialized fibers, solvents, adhesives and paint industries. •Most of the chemicals are prepared on small scale production on the batch reactor•Some of these chemical are additives, polyols, glycols, water treatment chemicals, solvents etc.
Industrial examples
•http://userpages.umbc.edu/~gferre1/fedbatch.html
•http://books.google.com.pk/books?id=pnNc496xxEMC&pg=PA246&lpg=PA246&dq=stirred+batch+reactor(sbr)&source=bl&ots=_8H6CF43OP&sig=gychH_LN8qXHnPw5pLpTk1GlIjQ&hl=en&ei=z1r2SpafMsGSkQXE9tyyAw&sa=X&oi=book_result&ct=result&resnum=10&ved=0CDQQ6AEwCQ#v=onepage&q=stirred%20batch%20reactor(sbr)&f=false
•http://www.rpi.edu/dept/chem-eng/Biotech-Environ/IMMOB/stirredt.htm
•http://en.wikipedia.org/wiki/Chemical_reactor#Semi-batch_reactor
References