Presentation on theme: "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."— Presentation transcript:
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 ….
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 Continuous