An Analysis of Increasing the Purity of Ethylene Production in the Ethylene Fractionation Column by the Genetic Algorithm

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Asadollah Karimi ◽  
Hadi Soltani ◽  
Aydin Hasanzadeh

AbstractDistillation columns are among the most common fractionation systems with numerous applications in petrochemical units. Hence, the optimization of these columns is a large step in reducing energy consumption and increasing process productivity. This study was, therefore, carried out as a case study of the simulation and optimization of the parameters influencing the ethylene production of the ethylene distillation column in an olefin unit. The two defined objective functions in this research were maximum mass flow of ethylene in the upstream flow of the distillation column and the minimum energy consumption in the distillation column. The optimal operating conditions for the independent variables were estimated using the NSGAII algorithm. The sensitivity analysis of the results was, thereafter, carried out and the optimization results introduced tray no. 71 as the most suitable feed location. In addition, the optimal reflux ratio and the optimal feed flow temperature were 5.26 and −18.49 °C, respectively. In this condition, the upstream ethylene flow rate and energy consumption in the unit increased by approximately 0.74 % and 0.9 % as compared to the initial conditions, respectively.

2021 ◽  
pp. 66-71
Author(s):  
NIKOLAY V. TSUGLENOK ◽  

The authors have determined the conditions for the eff ective use of modern electrifi ed circular sprinklers in the central part of Russia. Their designs are chosen depending on the agrotechnical requirements for irrigation, including the change in the diameter of the water distribution pipeline. However, when the diameter of the pipeline changes, the load on the electric drive of the support trolleys of the sprinkler changes too, which leads to a corresponding change in energy consumption. In turn, this also changes the load of the water supply pump. The paper sets the task of determining the optimal change in the diameter of pipelines according to the criterion of minimum energy consumption, taking into account a number of assumptions. The authors have analyzed the relationship between the change in the load on the electric drive of the sprinkler support trolley and the change in the diameter of one sprinkler section pipeline. It has been found that a decrease in the diameter by 27% (for example, the transition of the diameter of 219 mm to the diameter of 159 mm) leads to a decrease in the load on the electric drive by 38%. However, this also leads to an increase in the head loss in the water supply pump motor and, respectively, to an increase in the load and energy consumption by 0.8…3.8%. The eff ect is initially obvious, but the power of the electric motor of the water supply pump is 10…25 times higher than that of the electric motor of the sprinkler support trolley. Based on the similarity coeffi cients of the irrigation components (water supply and water distribution), the relationship beteween the total energy consumption and the change in the diameter of the water distribution pipeline has been obtained. By diff erentiating the obtained function, the dependence of the value of the optimal diameter for specifi c operating conditions is also obtained. Graphs of the relationship between energy consumption and the change in diameter have been determined, taking into account some restrictions: pump supply, static pressure, and the number of the sprinkler sections.


2012 ◽  
Vol 485 ◽  
pp. 229-232 ◽  
Author(s):  
Jun Li ◽  
Jun Wang ◽  
Zhan Hua Ma ◽  
Lan Yi Sun

A heterogeneous azeotropic distillation partitioned distillation column (HADPDC) for alcohol dehydration was investigated compared to a conventional heterogeneous azeotropic distillation sequence (CHADS) from environmental performance perspective by using the software Aspen Plus. HADPDC can eliminate the condenser of the second column and decrease the degree of back-mixing. The optimal design of HADPDC guaranteed the minimum energy consumption, which is related to the minimum CO2 emissions.


Complex chemical reactions and downstream processing can be performed in reactive distillation column to overcome with equilibrium limitations and to make it an economical process. An existing reactive distillation unit is costly to modify due its complex configuration and existing limitations of structure, space area, etc. Modifying an existing plant is a tedious task and more complex than a new process. Thus, to modify the existing operating conditions and input design variables it is necessary to verify by applying the same in real plant condition. This is done using revamping based on rigorous simulation and optimization in Aspen Plus process simulator. The main form of energy generator used in a distillation column is reboiler which directly affects the utilities such as cooling water, electricity and steam. Therefore, optimizing this reboiler duty to reduce energy losses is done using optimization model analysis tool of Aspen Plus. This reduction of energy demands diminishes the operating cost as per the reduction in utility cost. Now this reduction in operating cost is evaluated corresponding to the optimized reflux ratio and number of plates as obtained using sensitivity analysis tool of Aspen Plus.


Author(s):  
Hadi Abbas ◽  
Youngki Kim ◽  
Jason B. Siegel ◽  
Denise M. Rizzo

This paper presents a study of energy-efficient operation of vehicles with electrified powertrains leveraging route information, such as road grades, to adjust the speed trajectory. First, Pontryagin’s Maximum Principle (PMP) is applied to derive necessary conditions and to determine the possible operating modes. The analysis shows that only 5 modes are required to achieve minimum energy consumption; full propulsion, cruising, coasting, full regeneration, and full regeneration with conventional braking. The minimum energy consumption problem is reformulated and solved in the distance domain using Dynamic Programming to optimize speed profiles. A case study is shown for a light weight military robot including road grades. For this system, a tradeoff between energy consumption and trip time was found. The optimal cycle uses 20% less energy for the same trip duration, or could reduce the travel time by 14% with the same energy consumption compared to the baseline operation.


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