3.4 | Chemcad Calculations
The Chemcad program was used to calculate the heat loads required for the distillation column and the energy required for pre-heating and reactor cooling. This simulation was conducted based on the conversion data obtained from the experiments. The results are given in Table 4. The data in the Table 4 were handled on the basis of 10 kg acetone. Acetone was pre-heated with stoichiometric or excess phenol and then fed into the reactor. The energy calculation was examined based on the conversion in the experimental results. Then the mixture obtained from the reactor was subjected to distillation and the heat loads required for the boiler and condenser were examined. Preliminary trials have shown that the change in the number of trays does not substantially change the amount of energy required for the condenser and the reboiler. This brings up the results of the following; the difference between the boiling points of phenol and BPA is too high, therefore effect of the number of trays to be low. It was observed that the amount of energy consumed in the condenser and reboiler increased with the increase in reflux rates while the number of trays was constant. However, the separation time was reduced but this did not decrease significantly. The amount and duration of energy required for the separation to be realized was determined by simulation. All experiments were carried out for a column with 5 trays and reflux rate of 0.25. A total of 95476 kJ of energy is required as a result of the batch experiment with a phenol-acetone feed at a molar ratio of 10:1, and 16671 kJ of energy is required in a 2:1 molar ratio. Increase in the amount of phenol appears to increase the amount of energy in the boiler about 6 times. Again, the energy requirement in the condenser is about 9 times higher It is seen that 4 times more energy is needed for pre-heating and about 1.5 times more energy is required for reactor cooling.
Table 4. Energy requirements obtained by Chemcad simulation
program.