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Santanu Bandyopadhyay - One of the best experts on this subject based on the ideXlab platform.
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Energy Integration of Multiple Effect Evaporators with Background Process and Appropriate Temperature Selection
Industrial & Engineering Chemistry Research, 2016Co-Authors: Prashant Sharan, Santanu BandyopadhyayAbstract:Multiple effect evaporators (MEEs) are energy intensive equipment. Often the focus is on minimizing the energy consumption of MEEs as a standalone system, rather than that of the entire plant. In this paper, process integration techniques are applied to integrate various stages of a MEE with the background process. To identify various energy conservation opportunities, the MEE is represented as a Grand Composite Curve (GCC) and integrated with the GCC of the background process. Change in utility consumption in the first effect, due to energy shift (in the GCC) between various effects, is determined in this paper. It is proved that for the minimum energy requirement all effects should be pinched. Using these mathematical results, a methodology for optimally integrating the MEE with the background process is developed. Furthermore, additional energy may be conserved by appropriately selecting effect temperatures. A methodology for appropriate selection of effect temperatures is also proposed in this paper. ...
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targeting for cogeneration potential through total site integration
Applied Thermal Engineering, 2010Co-Authors: Santanu Bandyopadhyay, James Varghese, Vikas BansalAbstract:Total site integration offers energy conservation opportunities across different individual processes and also to design as well as to optimize the central utility system. In total site integration of the overall process, indirect integration with intermediate fluids or through a central utility system are preferred as it offers greater advantages of flexibility and process control but with reduced energy conservation opportunities. To achieve the maximum possible indirect integration between processes assisted heat transfer, i.e., heat transfer outside the region between process pinch points, plays a significant role. A new concept is proposed in this paper for total site integration by generating a site level grand Composite Curve (SGCC). Proposed SGCC targets the maximum possible indirect integration as it incorporates assisted heat transfer. In this paper, a methodology is proposed to estimate the cogeneration potential at the total site level, utilizing the concept of multiple utility targeting on the SGCC. The proposed methodology to estimate the cogeneration potential is simple and linear as well as utilizes the rigorous energy balance at each steam header.
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source Composite Curve for waste reduction
Chemical Engineering Journal, 2006Co-Authors: Santanu BandyopadhyayAbstract:Abstract Waste reduction through source reduction and on-site recycling is an important aspect of pollution prevention. Techniques of process integration may be used for pollution prevention. In this paper an algorithmic procedure is presented to reduce waste generation through maximizing on-site reuse/recycling. The proposed methodology is based on the pinch principles and establishes a minimum waste generation target prior to the detailed network design. A new graphical representation called source Composite Curve, is utilized to understand the targeting philosophy. Minimum waste targeting algorithm is applied to address different problems such as water management, hydrogen management, as well as material reuse and recycling. Appropriate changes in a process or process modification can further reduce the waste generation. In this paper a methodology is presented to reduce waste generation through process modifications and it is demonstrated through an example.
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temperature enthalpy Curve for energy targeting of distillation columns
Computers & Chemical Engineering, 1998Co-Authors: Santanu Bandyopadhyay, Ranjan K Malik, Uday V ShenoyAbstract:Abstract The temperature–enthalpy ( T – H ) diagram of a distillation column at practical near-minimum thermodynamic condition (PNMTC) or the column grand Composite Curve (CGCC) is a useful representation for energy targeting studies and may be generated from a converged simulation of a base-case column design. The calculation procedure for the CGCC involves determination of the net enthalpy deficit at each stage by generating envelopes from either the condenser end (top-down approach) or the reboiler end (bottom-up approach). However, the values calculated by the two approaches differ for stages with feeds because existing procedures for CGCC generation do not consider the enthalpy balances at the feed stages. In fact, the net enthalpy deficits at feed stages calculated by both approaches are erroneous even for the simplest case of binary distillation. A feed stage correction (FSC) that rigorously considers the mass and enthalpy balance equations at feed stages is proposed in this work to resolve the discrepancy. Instead of assuming that the compositions obtained from the converged simulation for a feed stage will remain unchanged at PNMTC, the pinched compositions for the feed are determined by the intersection of the equilibrium Curve and the feed q -line. Rather than perform an additional flash calculation to establish the pinched feed compositions, a quadratic approximation is developed here for column targeting purposes by assuming the relative volatility obtained from the simulation to remain constant in the neighborhood of the feed stage. The proposed FSC ensures that the CGCC is identical whether the calculations are performed by the top-down approach or the bottom-up approach. The effect of the FSC on the targets for energy conservation by reflux modification, feed conditioning, and introduction of side reboilers/condensers is discussed. As the energy target for reflux modification is determined by the CGCC pinch which typically occurs at or close to the feed location, the significance of the FSC on the reflux modification target is highlighted through several case studies including a complex column featuring multiple feeds and consequently multiple pinch points. The CGCCs for these case studies are generated by a computer program based on the FSC and a single analytical equation for the calculation of the net enthalpy deficits that allows every stage to have a feed, liquid product, vapor product, and side exchanger. The studies show that the reflux modification targets may be erroneous in many cases, if the FSC is ignored.
Zainuddin Abdul Manan - One of the best experts on this subject based on the ideXlab platform.
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process modifications to maximise energy savings in total site heat integration
Applied Thermal Engineering, 2015Co-Authors: Kew Hong Chew, Jiří Jaromír Klemeš, Sharifah Rafidah Wan Alwi, Zainuddin Abdul MananAbstract:Abstract This paper extends the scope of the Pinch Analysis for process modifications of individual processes to total site heat integration (TSHI). The Plus–Minus principle has been adapted to enable the beneficial process modification options to be selected in order to maximise energy savings in TSHI. The Total Site Profile (TSP) is divided into three regions: (a) the region above the horizontal overlap between the Site Sink and Source Profiles, (b) the horizontal overlap region and (c) below the horizontal overlap region. The proposed methodology identifies the options to reduce utility targets in these regions using the TSP, Site Utility Composite Curves (SCC), Utility Grand Composite Curve (UGCC), modified Problem Table Algorithm (PTA), Total Site Problem Table Algorithm (TS-PTA) and some new heuristics. The identified changes on the TSP are then linked to the specific changes at the individual processes. The illustrative case study shows that the Plus–Minus principle application in the TSHI context can further improve heat recovery. The proposed spreadsheet-based methodology combines the advantages of graphical visualisation, as well as the numerical precision.
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algorithmic targeting for total site heat integration with variable energy supply demand
Applied Thermal Engineering, 2014Co-Authors: Peng Yen Liew, Jiří Jaromír Klemeš, Petar Sabev Varbanov, Sharifah Rafidah Wan Alwi, Zainuddin Abdul MananAbstract:Fluctuating renewable energy supply presents a challenge for applying energy-saving methodologies such as Process Integration. Graphical targeting procedures based on the Time Slices (TSLs) have been proposed in previous works to handle the energy supply/demand variability in TSHI. The targeting procedures for TSHI with TSLs include the construction of Composite Curves, Grand Composite Curve and Total Site Profile for each time interval. Heat Integration analysis utilising a numerical algorithm typically offers higher precision and more rapid calculations as compared to the graphical approach. This paper introduces an algorithm to efficiently perform utility targeting for a large-scale TSHI system involving renewable energy and variable energy supply/demand to include TSL. The presented tool is an extension of the Total Site Problem Table Algorithm (TS-PTA), which has been previously used for processes with steady energy supply/demand. Due to its algorithmic nature, the technique presented enables the accurate and rapid determination of the stream origins, and can be embedded into larger algorithms. Optimised heat storage facilities are used to manage the variable energy supply and demand. The Total Site Heat Storage Cascade (TS-HSC) is the core of the algorithm. The new developed tool is incorporated with the heat losses for the thermo-chemical energy storage systems. The process start-up and continuous operations are considered in the novel methodology. The tool is featured to analyse the heat excess in specific TSLs that can be cascaded to the next TSL via energy storage system during start-up and operation. The proposed tool can be also used to estimate the required heat storage capacity.
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a combined numerical and visualization tool for utility targeting and heat exchanger network retrofitting
Journal of Cleaner Production, 2012Co-Authors: Nabeel K Abbood, Zainuddin Abdul Manan, Sharifah Rafidah Wan AlwiAbstract:In synthesizing optimal heat recovery networks, Composite Curve (CC) plots and Problem Table Algorithms (PTAs) have been the most popular tools for determining the minimum energy targets, whereas Grid Diagrams (GDs) have been widely utilized for heat exchanger network (HEN) design. However, CCs are cumbersome to construct. Additionally, PTAs offer numerical advantages but little insight into the impact of process streams on pinch points and heat recovery bottlenecks. Meanwhile, GDs are separately needed to diagnose HEN pinch rule violations. This paper introduces the Grid Diagram Table (GDT) as an alternative tool for determining pinch points and utility targets as well as for the retrofitting of HEN. The GDT combines numerical and visualization advantages into a single diagram. The GDT, which is represented according to a stream interval temperature scale and is developed based on fundamental Composite Curve geometry, can provide vital information during the identification of the pinch points and energy targets of a process as well as enhance the intuitive visualization of pinch rule violations that are especially useful for the rapid and effective debottlenecking of an existing heat recovery system to maximize its thermal energy efficiency. This paper also demonstrates the application of the GDT in addressing a single-pinch problem, multiple-pinch problem and an industrial case study involving a palm oil refinery.
Jiří Jaromír Klemeš - One of the best experts on this subject based on the ideXlab platform.
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process modifications to maximise energy savings in total site heat integration
Applied Thermal Engineering, 2015Co-Authors: Kew Hong Chew, Jiří Jaromír Klemeš, Sharifah Rafidah Wan Alwi, Zainuddin Abdul MananAbstract:Abstract This paper extends the scope of the Pinch Analysis for process modifications of individual processes to total site heat integration (TSHI). The Plus–Minus principle has been adapted to enable the beneficial process modification options to be selected in order to maximise energy savings in TSHI. The Total Site Profile (TSP) is divided into three regions: (a) the region above the horizontal overlap between the Site Sink and Source Profiles, (b) the horizontal overlap region and (c) below the horizontal overlap region. The proposed methodology identifies the options to reduce utility targets in these regions using the TSP, Site Utility Composite Curves (SCC), Utility Grand Composite Curve (UGCC), modified Problem Table Algorithm (PTA), Total Site Problem Table Algorithm (TS-PTA) and some new heuristics. The identified changes on the TSP are then linked to the specific changes at the individual processes. The illustrative case study shows that the Plus–Minus principle application in the TSHI context can further improve heat recovery. The proposed spreadsheet-based methodology combines the advantages of graphical visualisation, as well as the numerical precision.
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algorithmic targeting for total site heat integration with variable energy supply demand
Applied Thermal Engineering, 2014Co-Authors: Peng Yen Liew, Jiří Jaromír Klemeš, Petar Sabev Varbanov, Sharifah Rafidah Wan Alwi, Zainuddin Abdul MananAbstract:Fluctuating renewable energy supply presents a challenge for applying energy-saving methodologies such as Process Integration. Graphical targeting procedures based on the Time Slices (TSLs) have been proposed in previous works to handle the energy supply/demand variability in TSHI. The targeting procedures for TSHI with TSLs include the construction of Composite Curves, Grand Composite Curve and Total Site Profile for each time interval. Heat Integration analysis utilising a numerical algorithm typically offers higher precision and more rapid calculations as compared to the graphical approach. This paper introduces an algorithm to efficiently perform utility targeting for a large-scale TSHI system involving renewable energy and variable energy supply/demand to include TSL. The presented tool is an extension of the Total Site Problem Table Algorithm (TS-PTA), which has been previously used for processes with steady energy supply/demand. Due to its algorithmic nature, the technique presented enables the accurate and rapid determination of the stream origins, and can be embedded into larger algorithms. Optimised heat storage facilities are used to manage the variable energy supply and demand. The Total Site Heat Storage Cascade (TS-HSC) is the core of the algorithm. The new developed tool is incorporated with the heat losses for the thermo-chemical energy storage systems. The process start-up and continuous operations are considered in the novel methodology. The tool is featured to analyse the heat excess in specific TSLs that can be cascaded to the next TSL via energy storage system during start-up and operation. The proposed tool can be also used to estimate the required heat storage capacity.
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regional renewable energy and resource planning
The Dubrovnik Conference on Sustainable Development of Energy Water and Environment Systems, 2011Co-Authors: Hon Loong Lam, Petar Sabev Varbanov, Jiří Jaromír KlemešAbstract:The exploitation of the energy potential in biomass in a specific geographical region is frequently constrained by high production costs and the amount of land required per unit of energy generated. In addition, the distributed nature of the biomass resource and its normally low energy density may result in large transportation costs. Biomass also requires large land areas to collect and process the incoming solar radiation before the energy can be harvested. Previously published works on regional energy clustering (REC) and the Regional Resources Management Composite Curve, RRMCC (in this paper shortened to RMC), have been extended in this paper to tackle simultaneously the issues of the biomass supply chain, transportation, and land use. The RMC is a tool for supporting decision making in regional resource management. It provides a complete view of energy and land availability in a region, displaying their trade-offs in a single plot. The extension presented in this work has been developed in two steps. The first step presents the Regional Energy Cascade Analysis, which estimates the energy target within regional supply chains and provides the result for energy exchange flows between zones, the quantity of energy required to be imported/exported, and the locations of the demands. In the second step, the initial results are analysed against potential measures for improving the energy and land use targets by using the RMC and a set of rules for its manipulation. The presented method provides the option to assess the priorities: either to produce and sell the surplus energy on the fuel market or use the land for other purposes such as food production. This extended approach is illustrated with a comprehensive case study demonstrating that with the RMC application it is possible to maximise the land use and to maximise the biofuel production for the requested energy demand.
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minimising carbon footprint of regional biomass supply chains
Resources Conservation and Recycling, 2010Co-Authors: Hon Loong Lam, Petar Sabev Varbanov, Jiří Jaromír KlemešAbstract:A new method for regional energy targeting and supply chain synthesis is presented. A demand-driven approach is applied to assess the feasible ways for transferring energy from renewable sources to customers in a given region. The studied region is partitioned into a number of clusters by using the developed Regional Energy Clustering (REC) algorithm. The REC targets aim at minimising the system carbon footprint (CFP). The biomass energy supply and management are targeted using new graphical representations. Regional Energy Surplus–Deficit Curves (RESDC) visualises the formation and the sizes of introduced energy clusters. Regional Resource Management Composite Curve (RRMCC) an analogy of the Process Integration approach shows the energy imbalances helping in trading-off resources management. These graphical tools provide straightforward information of how to manage the surplus resources (biomass and land use) in a region.
Xiao Feng - One of the best experts on this subject based on the ideXlab platform.
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a hybrid method for integration of heat pump assisted distillation system with intermediate reboiler condenser
2020Co-Authors: Jiaxin Yang, Xiao Feng, Minbo Yang, Yufei WangAbstract:Abstract Setting an intermediate reboiler/condenser for heat transfer with the heat pump can reduce both requirements of hot and cold utilities and the temperature lift of the heat pump. This paper proposes a hybrid method that combines rigorous process simulation and mathematical programming for targeting the optimal heat pump placement in the presence of intermediate reboiler/condenser to minimize the overall energy consumption. First, the grand Composite Curve of distillation column is determined via rigorous process simulation. A simulation model for the vapor compression heat pump is also established. Next, the column grand Composite Curve is taken as constrains for formulating a simulation-based optimization model by data interaction between Aspen HYSYS and Matlab. The model is solved using the genetic algorithm toolbox to determine the optimal placement of the heat pump. A de-heavy fractionator in the isobutene unit is studied to illustrate the applicability of the proposed method.
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targeting for conventional and property based water network with multiple resources
Industrial & Engineering Chemistry Research, 2011Co-Authors: Chun Deng, Xiao FengAbstract:Water scarcity and stringent emission legislation have been motivating process industries to emphasize water conservation. Pinch analysis has been accepted as one of the powerful approaches to locate targets of wastewater minimization. In this paper, the improve problem table (IPT) is presented to target conventional and property-based water networks with multiple resources on the basis of the Composite table algorithm (CTA) (Agrawal, V.; Shenoy, U. V. Unified conceptual approach to targeting and design of water and hydrogen networks. AIChE J.2006, 52, 1071−1082). The corresponding limiting Composite Curve and water supply line are plotted to facilitate the analyzing and understanding of basic physical insights. The minimum operating cost subject to availability of the water resources is also addressed. In addition, two strategies are proposed to handle flow rate constraints for certain resources, and the corresponding wastewater stream identification techniques are introduced successively. To illustrate ...
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on the use of graphical method to determine the targets of single contaminant regeneration recycling water systems
Chemical Engineering Science, 2007Co-Authors: Xiao Feng, Jie Bai, Xuesong ZhengAbstract:Water system integration with regeneration recycling can reduce freshwater consumption and wastewater discharge to the maximum extent. In this paper, by analyzing the limiting Composite Curve of a single-contaminant water system, a method is proposed to construct the optimal water supply line for regeneration recycling. Accordingly the targets for regeneration recycling water systems are obtained. The targets in sequence are the minimum freshwater consumption (the minimum wastewater discharge), the minimum regenerated water flowrate, and the optimal regeneration concentration. The post-regeneration concentration is taken to be fixed in the sequential targeting procedure. The interactions of these targets are analyzed, and formulas for calculating these targets are proposed. The results show that for a single-contaminant regeneration recycling water system, the minimum freshwater consumption is determined by the shape of the limiting Composite Curve below the post-regeneration concentration. The optimal regeneration concentration is defined as the minimum regeneration concentration at the minimum freshwater consumption and the corresponding minimum regenerated water flowrate. The minimum regenerated water flowrate and the optimal regeneration concentration are both related to the geometrical features of the limiting Composite Curve of the water-using system and to the post-regeneration concentration. The optimal regeneration concentration has no direct relationship with the pinch concentration.
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new graphical method for the integration of hydrogen distribution systems
Industrial & Engineering Chemistry Research, 2006Co-Authors: Zhenhui Zhao, Guilian Liu, Xiao FengAbstract:This paper presents a simple graphical method for determining the minimum hydrogen demand. In the pure hydrogen load versus flow rate diagram, the sink and source Composite Curves are constructed, and they can shift freely in every direction. Through moving the hydrogen source Composite Curve to the position at which the two Composite Curves intersect at only two points, the hydrogen pinch point of the system is identified. Furthermore, the minimum utility consumption can be determined from the diagram. This method is simple, efficient, and easy to understand. It can be used in hydrogen systems with any utility concentration.
Uday V Shenoy - One of the best experts on this subject based on the ideXlab platform.
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unified targeting algorithm for diverse process integration problems of resource conservation networks
Chemical Engineering Research & Design, 2011Co-Authors: Uday V ShenoyAbstract:Abstract A single algorithm is developed to establish minimum resource targets for diverse process integration problems including those of heat/mass exchange, water, hydrogen, carbon emission and material reuse networks. Previous algorithms such as the problem table algorithm for heat exchange networks and the Composite table algorithm for resource allocation networks are special cases of the newly proposed unified targeting algorithm (UTA). The conversion of streams to equivalent inlet–outlet (demand–source) pairs is shown to be a key basis for the unified approach. The tabular data from the UTA may be plotted to obtain the grand Composite Curve (GCC) or the limiting Composite Curve (LCC). These provide graphical representations of the net load deficit/surplus at various levels for resource targeting and pinch identification. For allocation networks with system loss/gain, the UTA with increasing level sort order yields the Deficit LCC to target the minimum resource, whereas the UTA with decreasing level sort order provides the Surplus LCC to target the minimum waste/excess. A single UTA calculation along with the use of fundamental overall system balance equations is sufficient to establish complete targets for a problem. Six practical case studies from diverse domains are presented to illustrate the detailed steps of the UTA.
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unified conceptual approach to targeting and design of water and hydrogen networks
Aiche Journal, 2006Co-Authors: Vibhor Agrawal, Uday V ShenoyAbstract:An algorithm is proposed to target the minimum freshwater for fixed flow rate (FF) problems in single-contaminant water networks. The approach is based on an extension of the limiting Composite Curve concept proposed earlier for fixed contaminant-load (FC) problems. The targeting method is elegant, noniterative, and can be applied to FF problems involving regeneration to minimize waste discharge. To design networks that achieve the minimum freshwater targets set for FF problems, an algorithm is presented based on the principle of nearest neighbors. The principle simply states that the sources to be chosen to satisfy a particular water demand must be the nearest available neighbors in terms of contaminant concentration. A significant advantage of the approach is that the same targeting concepts can be profitably used to determine the minimum makeup utility in hydrogen networks. Furthermore, hydrogen networks may be designed by the unified conceptual approach using the nearest neighbors algorithm. The hydrogen networks may then be evolved to account for the pressure constraints imposed by compressors or improved by regeneration through purification processes such as pressure-swing adsorption. © 2005 American Institute of Chemical Engineers AIChE J, 2006
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temperature enthalpy Curve for energy targeting of distillation columns
Computers & Chemical Engineering, 1998Co-Authors: Santanu Bandyopadhyay, Ranjan K Malik, Uday V ShenoyAbstract:Abstract The temperature–enthalpy ( T – H ) diagram of a distillation column at practical near-minimum thermodynamic condition (PNMTC) or the column grand Composite Curve (CGCC) is a useful representation for energy targeting studies and may be generated from a converged simulation of a base-case column design. The calculation procedure for the CGCC involves determination of the net enthalpy deficit at each stage by generating envelopes from either the condenser end (top-down approach) or the reboiler end (bottom-up approach). However, the values calculated by the two approaches differ for stages with feeds because existing procedures for CGCC generation do not consider the enthalpy balances at the feed stages. In fact, the net enthalpy deficits at feed stages calculated by both approaches are erroneous even for the simplest case of binary distillation. A feed stage correction (FSC) that rigorously considers the mass and enthalpy balance equations at feed stages is proposed in this work to resolve the discrepancy. Instead of assuming that the compositions obtained from the converged simulation for a feed stage will remain unchanged at PNMTC, the pinched compositions for the feed are determined by the intersection of the equilibrium Curve and the feed q -line. Rather than perform an additional flash calculation to establish the pinched feed compositions, a quadratic approximation is developed here for column targeting purposes by assuming the relative volatility obtained from the simulation to remain constant in the neighborhood of the feed stage. The proposed FSC ensures that the CGCC is identical whether the calculations are performed by the top-down approach or the bottom-up approach. The effect of the FSC on the targets for energy conservation by reflux modification, feed conditioning, and introduction of side reboilers/condensers is discussed. As the energy target for reflux modification is determined by the CGCC pinch which typically occurs at or close to the feed location, the significance of the FSC on the reflux modification target is highlighted through several case studies including a complex column featuring multiple feeds and consequently multiple pinch points. The CGCCs for these case studies are generated by a computer program based on the FSC and a single analytical equation for the calculation of the net enthalpy deficits that allows every stage to have a feed, liquid product, vapor product, and side exchanger. The studies show that the reflux modification targets may be erroneous in many cases, if the FSC is ignored.