Cumene is produced by the vapour phase reaction of benzene with propylene. The fresh feeds have the following compositions:
Benzene: 99% w/w benzene, 1% w/w toluene
Propylene: 98% v/v propylene, 2% v/v propane
The vapour phase catalysed reaction takes place at 200°C and 3 MPa. The reactor will tolerate 2% toluene in the reactor efflux provided the feed to the reactor (not the process!) operates at a molar benzene:propylene ratio of 2:1.
The reactor efflux is cooled and partly condensed to 30°C and then perfectly separated into three streams: a gas stream containing the propane and two liquid streams - the product and the recycle + purge stream.
1. Draw a flow diagram and annotate the streams.
2. Calculate the rate and composition of the purge stream.
3. Add the flows of all streams to the PFD.
4. The feeds to the process are at 20°C. Calculate (not using a process simulator) the heat to be removed to maintain this optimum temperature for a cumene production of 1,500 kg/h.