**2.2 Intensified heat integration configurations**

The standard VRC assisted RDWC configuration (VRC-RDWC) presented in **Figure 6**, the overhead vapor has compacted to a surpassing temperature to turns into vapor the lowermost fluid, and formerly converts the saturated condensed fluid into the reboiler, and the condensed fluid must be low to the topmost pressure through the throttle valve (TV) that returning at the RDWC at the upper section. Now this method, in the isentropic compressor the less amount of saturated vapor was condensed and less amount of saturated fluid will flash into the throttle valve, so a heater was essential to preheat the overhead vapor and the flew vapor condensed totally by the use of cooler. While the compression ratio (CR) is


**Table 1.** *Operating parameters.*

**Figure 6.** *Schematic diagram of vapor recompression RDWC (VRC-RDWC).*

insignificant, the heater and cooler have been discounted due to the heat duties, then below large CR, these heat duties will convert huge and straight shrink the power effectiveness of VRC knowingly. The unused heat created by the VRC has recovered by intensifying the process of the heat integration technique between the VRC and RDWC (**Figure 5)**.

#### **3. Results and discussion**

#### **3.1 Temperature and composition profile**

The temperature difference between the overhead and the bottom product is high i.e. 98°C. Therefore, the compression ratio (CR) has been regulated to meet the heat transfer needed in VRC-RDWC structures as shown in **Figure 5**. The total number of stages used in both columns including i.e. RDC and Rectifying column (RC)) are 36. The composition profile of the RDC column is shown in **Figure 7.** As per the physical phenomena that the excess amount of reactant and products should be at the output side. Although, the full consumption of the limiting reactant. The graph shows a similar response as per the process phenomena. The temperature of the column continuously increases with the increase in the number of the stages as

**Figure 7.** *Composition profile of RDC column (heat integration and without heat integration).*

*Heat Integration of Reactive Divided Wall Distillation Column DOI: http://dx.doi.org/10.5772/intechopen.100811*

**Figure 8.**

*Temperature profile of RDC column (heat integration and without heat integration).*


#### **Table 2.**

*Results of heat integrated RDWC (2 column).*

shown in **Figure 8.** The maximum has risen the temperature is 85°C but with the implementation of the heat integration technique, the temperature is decreasing at about 65°C. There are no changes in composition profile by the use of heat integration technique as shown in **Figure 7.**

#### **3.2 Heat integration of two column RDWC**

To analyze the heat recovery in two columns design, a rigorous simulation has performed for the heat integrated simulation flowsheet. The Aspen simulation flowsheet of the RDWC is shown in **Figure 4.** Therefore, an enormous amount of condensed fluid flashed in the throttle valve (TV) from the compression ratio. The cooler with a heat duty of 0.020 kW condenses the flashed liquid. The reboiler duty of RDWC is 0.6667 kW after the Heat Integration of RDWC the reboiler duty was decreased by 0.5718 kW. However, the energy-saving of the intensified configuration technology is significant in comparison to the conventional column. The heat-integrated data of the divided wall distillation column is given in **Table 2.**

#### **4. Conclusion**

In this book chapter, Aspen Plus software is used to simulate the process of producing methyl acetate. The new technology used in this research was reactive dividing wall distillation technology. The position of methanol and acetic acid feed stream is set to be on the Reactive Distillation column (RDC) at 10 and 2 respectively. It is concluded that after the VRC-RDWC heat integration technique the reboiler duty is reduced from 0.6667 to 0.5718 kW and the condenser duty

is reduced from −1.386 to −1.358 kW in the case of two-column configuration Therefore, it is observed after the integration the heat load on the reboiler is reduced up to 14.23% and condenser duty is to reduce up to 0.020% in case of twocolumn configuration. Results also showed that all products compositions could be kept at desired purity against feed disorder.
