Sustainability analysis and retrofitting of energy efficient distillation columns sequence

Distillation continues to be the most important separation technique in the chemical process industry. Recently, a new energy efficient distillation columns sequence methodology that is able to improve the energy efficiency of the existing separation systems without having major modifications has been developed. However, the developed methodology only considered the energy savings without taking into consideration the sustainability criteria. Therefore, the aim of this study was to extend the energy efficient distillation column sequence methodology by taking into account the sustainability analysis as well as the retrofitting analysis in designing sustainable sequence for distillation columns system in an easier, efficient, and systematic way. Accordingly, the methodology was divided into four hierarchical stages. The analysis of energy consumption in distillation columns sequences was simulated within Aspen HYSYS simulation environment while the sustainability index was analysed using a developed Excel-based sustainability evaluator. The capability of the proposed methodology in designing sustainable and retrofit energy efficient distillation columns sequence was tested using Aromatic Mixtures (AM) separation process, Hydrocarbon Mixtures (HM) separation process, and Natural Gas Liquids (NGLs) separation process. The results obtained shown that the proposed methodology is able to reduce energy consumption to 12 % as well as 13 % reduction in overall sustainability index for the AM separation process. Besides that, 38 % of energy reduction and 32 % of the overall sustainability index reduction was achieved in overall for HM case studies. Furthermore, overall NGLs case study shows a reduction in energy consumption up to 21 % as well as 22 % of overall sustainability index. Thus, the developed methodology is capable of operating the separation process with less energy requirement and also gives better sustainability performance in an easy, practical, and systematic manner

Energy efficient distillation columns analysis for aromatic separation process

Distillation operations became a major concern within energy savings challenge, which it becomes a primary target of energy saving efforts in industrially developed countries. However, there is still one problem, which is how do we improve the energy efficiency of the existing distillation columns systems by without having major modifications. Recently, a new energy efficient distillation columns methodology that will able to improve energy efficiency of the existing separation systems without having major modifications has been developed. Therefore, the objective of this paper is to present new improvement of existing methodology by designing an optimal sequence of energy efficient distillation columns using driving force method. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence energy analysis, ii) optimal sequence determination, iii) optimal sequence energy analysis, and iv) energy comparison and economic analysis. In the first stage, a simple and reliable short-cut method is used to simulate a base (existing) sequence. The energy consumption of the base sequence is calculated and taken as a reference for the next stage. In the second stage, an optimal sequence is determined by using driving force method. All individual driving force curves is plotted and the optimal sequence is determined based on the plotted driving force curves. Then, by using a short-cut method, the new optimal sequence is simulated and the new energy consumption is calculated in the third stage. Lastly, in the fourth stage, the energy consumption for both sequences (base and optimal) is compared. The capability of this methodology is tested in designing an optimal synthesis of energy efficient distillation columns sequence of aromatics separation unit. The existing aromatics separation unit consists of six compounds (Methylcyclopentane (MCP), Benzene, Methylcyclohexane (MCH), Toluene, m-Xylene and o-Xylene) with five direct sequence distillation columns is simulated using a simple and reliable short-cut method and rigorous within Aspen HYSYS® simulation environment. The energy and economic analysis is performed and shows that the optimal sequence determined by the driving force method has better energy reduction with total of 6.78% energy savings and return of investment of 3.10 with payback period of 4 months. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better economic cost for aromatic separation unit

Sustainable energy efficient distillation columns sequence design of aromatic separation unit

Distillation operations became a major concern within sustainability challenge, which it becomes a primary target of energy saving efforts in industrially developed countries. However, there is still one problem, which is how do we improve the energy efficiency of the existing distillation columns systems by considering the sustainability criteria without having major modifications. Recently, a new energy efficient distillation columns methodology that will able to improve energy efficiency of the existing separation systems without having major modifications has been developed. However, this developed methodology was only considered the energy savings without taking into consideration the sustainability criteria. Therefore, the objective of this paper is to present new improvement of existing methodology by including a sustainability analysis to design an optimal sequence of energy efficient distillation columns. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence sustainability analysis, ii) optimal sequence determination, iii) optimal sequence sustainability analysis, and iv) sustainability comparison. In the first stage, a simple and reliable short-cut method is used to simulate a base (existing) sequence. The sustainability index of the base sequence is calculated and taken as a reference for the next stage. In the second stage, an optimal sequence is determined by using driving force method. All individual driving force curves is plotted and the optimal sequence is determined based on the plotted driving force curves. Then, by using a short-cut method, the new optimal sequence is simulated and the new sustainability index is calculated in the third stage. Lastly, in the fourth stage, the sustainability index for both sequences (base and optimal) is compared. The capability of this methodology is tested in designing an optimal sustainable energy efficient distillation columns sequence of aromatics separation unit. The existing aromatics separation unit consists of six compounds (Methylcyclopentane (MCP), Benzene, Methylcyclohexane (MCH), Toluene, m-Xylene and o-Xylene) with five direct sequence distillation columns is simulated using a simple and reliable short-cut method and rigorous within Aspen HYSYS simulation environment. The energy and sustainability analysis is performed and shows that the optimal sequence determined by the driving force method has better energy reduction with total of 6.78 % energy savings and 0.16 % sustainability reduction compared to existing sequence with. In addition, the economic analysis shows that the return of investment of 3.10 with payback period of 4 months. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better sustainability index for aromatic separation unit

Sustainable design improvement for direct-indirect sequence of aromatic separation process

Distillation operations became a major concern within sustainability challenge, which it becomes a primary target of energy saving efforts in industrially developed countries. However, there is still one problem, which is how do we improve the energy efficiency of the existing distillation columns systems by considering the sustainability criteria without having major modifications. Recently, a new energy efficient distillation columns methodology that will able to improve energy efficiency of the existing separation systems without having major modifications has been developed. After all, this developed methodology was only considered the energy savings without taking into consideration the sustainability criteria

Optimal synthesis of energy efficient distillation columns sequence for hydrocarbon mixture separation process

The objective of this paper is to present the study of the optimal synthesis of energy efficient distillation columns (EEDCs) sequence of hydrocarbon mixture separation process by using driving force method. In order to perform the study and analysis, the EEDCs sequence methodology is developed. Accordingly, the methodology consists of four hierarchical steps; Step 1: Existing Sequence Energy Analysis, Step 2: Optimal Sequence Determination, Step 3: Optimal Sequence Energy Analysis, and Step 4: Energy Comparison. The capability of this methodology is tested in designing minimum energy distillation column sequence for hydrocarbon mixture separation process. The results show that the maximum of 18% energy reduction was able to achieve by changing the sequence suggested by the driving force method. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for hydrocarbon mixture separation process in an easy, practical and systematic manner

Design of sustainable energy efficient distillation columns (Sustain-EEDCS) sequence

A new energy efficient distillation columns methodology that will able to improve the energy efficiency of the existing separation systems without having major modifications has been developed. However, this developed methodology was only considered the energy savings without taking into consideration the sustainability criteria. Therefore, the objective of this paper is to present new improvement of the existing methodology by including the sustainability analysis to design an optimal sequence of energy efficient distillation columns. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence sustainability analysis, ii) optimal sequence determination, iii) optimal sequence sustainability analysis, and iv) sustainability comparison. The capability of this methodology is tested in designing an optimal sustainable energy efficient distillation columns sequence of hydrocarbon mixtures (HM) and Natural Gas Liquids (NGLs) separation processes. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better sustainability index reduction for both separation units

Sustainable energy efficient distillation columns sequence design of hydrocarbon mixtures separation unit

Distillation operations became a major concern within sustainability challenge, which it becomes a primary target of energy saving efforts in industrially developed countries. However, there is still one problem, which is how do we improve the energy efficiency of the existing distillation columns systems by considering the sustainability criteria without having major modifications. Recently, a new energy efficient distillation columns methodology that will able to improve energy efficiency of the existing separation systems without having major modifications has been developed. However, this developed methodology was only considered the energy savings without taking into consideration the sustainability criteria. Therefore, the objective of this paper is to present new improvement of existing methodology by including a sustainability analysis to design an optimal sequence of energy efficient distillation columns. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence sustainability analysis, ii) optimal sequence determination, iii) optimal sequence sustainability analysis, and iv) sustainability comparison. In the first stage, a simple and reliable short-cut method is used to simulate a base (existing) sequence. The sustainability index of the base sequence is calculated and taken as a reference for the next stage. In the second stage, an optimal sequence is determined by using driving force method. All individual driving force curves is plotted and the optimal sequence is determined based on the plotted driving force curves. Then, by using a short-cut method, the new optimal sequence is simulated and the new sustainability index is calculated in the third stage. Lastly, in the fourth stage, the sustainability index for both sequences (base and optimal) is compared. The capability of this methodology is tested in designing an optimal sustainable energy efficient distillation columns sequence of hydrocarbon mixtures separation unit. The existing hydrocarbon mixtures separation unit consists of eleven compounds (propane, i-butane, n-butane, i-pentane, n-pentane, n-hexane, benzene, cyclohexane, n-heptane, toluene, and n-decane) with ten indirect sequence distillation columns is simulated using a simple and reliable short-cut method and rigorous within Aspen HYSYS® simulation environment. The energy and sustainability analysis is performed and shows that the optimal sequence determined by the driving force method has better energy reduction with total of 4.64 % energy savings and sustainability reduction of 4.78 % based on existing sequence. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better sustainability index for hydrocarbon mixtures separation unit

Minimum energy distillation columns sequence for aromatics separation process

The objective of this paper is to present the study of the optimal synthesis of energy efficient distillation columns (EEDCs) sequence of aromatics separation process by using driving force method. In order to perform the study and analysis, the EEDCs sequence methodology is developed. Accordingly, the methodology consists of four hierarchical steps; Step 1: Existing Sequence Energy Analysis, Step 2: Optimal Sequence Determination, Step 3: Optimal Sequence Energy Analysis, and Step 4: Energy Comparison. The capability of this methodology is tested in designing minimum energy distillation column sequence for aromatics separation process. The results show that the maximum of 7.0% energy reduction was able to achieve by changing the sequence suggested by the driving force method. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for aromatics separation process in an easy, practical and systematic manner

Design of sustainable energy efficient distillation columns (Sustain-EEDCS) sequence

A new energy efficient distillation columns methodology that will able to improve the energy efficiency of the existing separation systems without having major modifications has been developed. However, this developed methodology was only considered the energy savings without taking into consideration the sustainability criteria. Therefore, the objective of this paper is to present new improvement of the existing methodology by including the sustainability analysis to design an optimal sequence of energy efficient distillation columns. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence sustainability analysis, ii) optimal sequence determination, iii) optimal sequence sustainability analysis, and iv) sustainability comparison. The capability of this methodology is tested in designing an optimal sustainable energy efficient distillation columns sequence of hydrocarbon mixtures (HM) and Natural Gas Liquids (NGLs) separation processes. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better sustainability index reduction for both separation units

Energy improvement for NGLs direct-indirect sequence fractionation unit

The objective of this paper is to present the study and analysis of the energy saving improvement for the natural gas liquids (NGLs) direct-indirect sequence fractionation unit by using driving force method. To perform the study and analysis, the energy efficient NGLs fractionation sequence methodology has been developed. Accordingly, the methodology consists of four hierarchical steps; Step 1: Existing Sequence Energy Analysis, Step 2: Optimal Sequence Determination, Step 3: Optimal Sequence Energy Analysis, and Step 4: Energy Comparison. The capability of this methodology is tested in designing energy efficient distillation column sequence for NGLs fractionation process, which consists of nine compounds (methane, ethane, propane, i-butane, n-butane, i-pentane, n-pentane, n-hexane, n-heptane) with eight direct-indirect sequence of distillation columns. The results show that the maximum of 6.44 % energy reduction is able to achieve using sequence changes suggested by the driving force method. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for NGLs fractionation process. All of this findings show that the methodology is able to design minimum energy distillation column sequence for NGLs fractionation process in an easy, practical and systematic manner