types of chemical processes
DESCRIPTION
Types of chemical processes. eg Quicklime Manufacture. CaCO 3 ( s ) → CaO( s ) + CO 2 ( g ). In this case the feedstock is the raw material -limestone- that needs only be crushed. In a batch process the kiln …. - PowerPoint PPT PresentationTRANSCRIPT
Types of chemical processes
eg Quicklime Manufacture
CaCO3(s) → CaO(s) + CO
2(g)
In this case the feedstock is the raw material -limestone- that needs only be crushed.
In a batch process the kiln ….
In a batch process the kiln is filled with layers of limestone and fuel....
In a batch process the kiln is filled with layers of limestone and fuel....
In a batch process the kiln is filled with layers of limestone and fuel....
....and the latter is set alight.
When the reaction is complete and the kiln cool the contents are removed ready for the next batch.
Why is this simple process not done on a large scale ?
Cost of labour to fill and empty kiln
Kiln must be allowed to cool – wasting energy
Extent of reaction may vary within the kiln.
In a continuous reactor the limestone is fed into one end of a heated rotating tube and quicklime falls out of the other.
...but rather bigger!
What are the advantages of this plant?
It may be automated so labour costs are minimised
if decomposition is incomplete it is easy to adjust the flow rate or temperature to correct this.
BUT
An expensive plant is needed dedicated to making just one product.
Continuous reactors are suitable for high tonnage production of a single product.
Batch reactors can be used to make smaller quantities of several products and can accommodate slow reactions.
Which type would be used for:
A dyestuff
Sulphuric acid
A pharmaceutical
Batch
Batch
Continuous