scholarly journals Process Simulation of the Separation of Aqueous Acetonitrile Solution by Pressure Swing Distillation

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 409 ◽  
Author(s):  
Jing Li ◽  
Keliang Wang ◽  
Minglei Lian ◽  
Zhi Li ◽  
Tingzhao Du
Keyword(s):  
Acetonitrile Solution ◽  
Optimum Process ◽  
Total Annual Cost ◽  
Heat Integration ◽  
Reflux Ratio ◽  
Water Mixture ◽  
Aqueous Acetonitrile ◽  
Design Variables ◽  
Pressure Swing ◽  
Pressure Swing Distillation

The separation of aqueous acetonitrile solution by pressure swing distillation (PSD) was simulated and optimized through Aspen Plus software. The distillation sequence of the low pressure column (LPC) and high pressure column (HPC) was determined with a phase diagram. The pressures of the two columns were set to 1 and 4 atm, respectively. Total annual cost (TAC) was considered as the objective function, and design variables, such as the tray number, the reflux ratio, and the feeding position, were optimized. The optimum process parameters were obtained. For the reduction of energy consumption, the PSD with full-heat integration was designed. The TAC of this method is lower by 32.39% of that of the PSD without heat integration. Therefore, it is more economical to separate acetonitrile and water mixture by PSD with full-heat integration, which provides technical support for the separation design of such azeotropes.

scholarly journals Comparison of the Economy and Controllability of Pressure Swing Distillation with Two Energy-Saving Modes for Separating a Binary Azeotrope Containing Lower Alcohols

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 730
Author(s):  
Lv ◽  
Li ◽  
Zhang ◽  
Huang
Keyword(s):  
Energy Saving ◽  
Simulation Analysis ◽  
Good Control ◽  
Total Annual Cost ◽  
Control Stage ◽  
Binary Azeotrope ◽  
Detailed Simulation ◽  
Pressure Swing ◽  
Pressure Swing Distillation ◽  
Selection Of

The pressure swing distillation (PSD) with two different energy-saving modes are put forward to separate a binary azeotrope containing lower alcohols: benzene/methanol. A comparison of the economy and controllability for the partial and fully heat integrated pressure swing distillation (HIPSD) is made by detailed simulation analysis. The optimal operating parameters of partial and fully HIPSD processes are obtained by minimizing total annual cost (TAC). These results show that the fully HIPSD mode saves 5.88% TAC compared with the partial HIPSD mode. Meanwhile, this paper proposes that the composition slope profile can help to select the temperature control stage (TCS), when the temperature profile in the column is rising rapidly near the bottom and the maximum of temperature slope value occurs in the bottom of the column. Several control structures are developed to check the rationality of the selection of the TCS and evaluate the industrial application. These results illustrate the composition/temperature cascade control structure for the PSD with two energy-saving modes can both get good control performances, and the purities of benzene and methanol can be brought close back to the initial value. However, the fully HIPSD mode can only handle much smaller composition disturbances (<10%) compared with the partial HIPSD mode. Therefore, the selection of energy-saving modes for the separation process should weigh economy against controllability.

scholarly journals Design simulation and economic optimization of a benzene-toluene-xylene system distillation process upon the energy cost

2020 ◽  
Vol 202 ◽  
pp. 10003
Author(s):  
S. Silviana ◽  
Febio Dalanta ◽  
Dewi Qurrota A’yuni ◽  
Lu’luatul Khoiriyah ◽  
Putri Rousan Nabila ◽  
...  
Keyword(s):  
Process Optimization ◽  
Energy Cost ◽  
Annual Cost ◽  
Total Annual Cost ◽  
Reflux Ratio ◽  
Economic Optimization ◽  
Design Variables ◽  
Engineering Strategy ◽  
Benzene Toluene ◽  
System Properties

Distillation is the most extensively used in separation process of the chemical industry. Relationships between non-linear variables, multivariable interactions, dynamic system properties, and other irregularities render the study of design simulation and process optimization an interesting challenge for process engineers. The objective of the process optimization is to produce the most economical to conduct the system. This paper discusses the process engineering strategy started from the determination method of the degree of freedom, design variables, process tools, economic parameters, and the optimization process. The distillation variable optimized in this study was limited to reflux ratio. The optimum variable was construed from the reflux ratio producing the lowest total annual cost (TAC). Furthermore, it was analyzed the energy cost as optimization parameter in the total annual cost (TAC) calculation method to obtain minimum reflux ratio in distillation unit.

Sign in / Sign up

Export Citation Format

Share Document