**7. References**

88 Distillation – Advances from Modeling to Applications

workers, Zhang et al., also developed a novel separation process of atmospheric-pressurized separation process which had the ability to separate the low concentration of DMC for the separation of the mixture with 12 wt.% of DMC base on the 500t/a pilot plant by the simulation model. The sensitive study and the optimization to this process had shown that the reflux ratio for the atmospheric and pressurized distillation had been 3.4 and 1.0 respectively, and 0.65, 0.93 of the distillate to feed ratio for the atmospheric and pressurized distillation. In this process, 99.5wt.% or higher concentration of methanol could be recovered, while the pressurized-atmospheric separation process could only obtained a

Atmospheric distillation Pressurized distillation

The model simulation and process design for the separation of DMC and methanol has been lettered in many literatures. Much number of the literatures had been presented on the simulation for the DMC synthesis with trans-esterification method, in addition with the detailed research on the catalytic distillation for the DMC synthesis by urea and methanol. However, the simulation work for the other DMC synthesis process had been little reported. Furthermore, the pressure-swing distillation process, the extractive distillation process and the azeotropic distillation process had been developed in the open reported simulative literatures for the product separation of DMC and methanol mixture. Among the derived separation process, the pressure swing distillation process and the extractive distillation process had been considered suitable for the product separation of DMC and methanol

Fig. 6. The schematic diagram of the pressure swing process.

mixture.

solution containing 13.3 wt.% of DMC in the recovered methanol stream.


**4** 

*México* 

**Batch Distillation: Thermodynamic Efficiency** 

The batch distillation is a separation processes that requires great amounts of energy. Due to high energy costs, the study of energy consumption is of great interest in this process (Zavala et al. 2007). According to Luyben (1990), the energy consumption increases when operation occurs in a batch manner. Determining how efficient is the heat transfer under specific conditions and to modify them in order to find how efficient the heat is used, is an

The analysis of thermodynamic efficiency in a batch distillation column has been presented by Kim and Diwekar (2000), Zavala-Loría (2004), Zavala et al. (2007), Zavala & Coronado (2008) and Zavala et al. (2011). The first work only developed expressions to calculate thermodynamic efficiency while the rest of the works developed expressions to calculate thermodynamic efficiency and have applied them to a new problem of optimal control:

For this study we used a conventional batch distillation column consisting of:

Figure 1 Shows a conventional batch column like the one used for this study.

mathematical model in Table 1. The model considers the following elements:

Mass balances resulting from the process shown in Figure 1, allow us to obtain the

**1. Introduction** 

important task.

 Reboiler Tray column Condenser Reflux drum Receiver

 Theoretical stages Total condenser Neglible pressure drop

Corresponding Author

 \*

Maximum thermodynamic efficiency.

**2. Description of the process** 

José C. Zavala-Loría\* and Asteria Narváez-García

*DES-DAIT: Facultad de Química, Cd. del Carmen, Cam.* 

*Universidad Autónoma del Carmen (UNACAR),* 

[18] Zhang Junliang, Wang Feng, Peng Weicai, Xiao Fukui, Wei Wei, Sun Yuhan. Process Simulation for Separation of Dimethyl Carbonate and Methanol Through Atmospheric-Pressurized Rectification. PETROCHEMICAL TECHNOLOGY, 2010, 39(6): 646-650
