T. Gundersen | Norwegian University of Science and Technology (original) (raw)
Papers by T. Gundersen
On-line optimization and choice of optimization variables for control of heat exchanger networks
Chemical Engineering Transactions, 2017
Heat Exchange Networks (HENs) and Mass Exchange Networks (MENs) have been widely adopted and exte... more Heat Exchange Networks (HENs) and Mass Exchange Networks (MENs) have been widely adopted and extensively studied for heat and material recovery to save energy and other resources. However, work recovery can also result in significant energy savings in for example oil refineries, petrochemical plants and cryogenic processes, such as the production of liquefied natural gas (LNG). The concept of Work Exchange Networks (WENs) was first proposed and identified as a new research topic in Process Synthesis in 1996. This research area has broadened considerably during the last 5-10 years, and it covers both flow work (material streams) and shaft work (energy streams or non-flow processes). More recently, there has also been considerable development in the combined problem of Work and Heat Exchange Networks (WHENs). Two research directions have developed for WHENs; one with a focus on work integration accounting for heat effects, and one focusing on heat integration accounting for heating an...
Chemical Engineering Transactions, 2012
Oxy-combustion is a competitive technology to enable the capture of CO2 from fossil fuel based po... more Oxy-combustion is a competitive technology to enable the capture of CO2 from fossil fuel based power plants. Cryogenic air separation is the only commercially available technology for large volume O2 production that can be applied for oxy-combustion plants. The considerable energy consumption in the air separation units is the main challenge to implement oxy-combustion technology. The compression heat in the air compression process is generally removed by cooling water. The water coolers are responsible for 17.6 % of the total exergy losses in an air separation unit. This paper investigates the possibilities of integrating the compression heat from the air separation unit with the steam cycle. The compression process of the air is studied in two cases: adiabatic (one-stage) compression and three-stage compression with interstage cooling. A decomposed methodology has been developed for studying the heat balance in the boiler feedwater heaters in the steam cycle. The Grand Composite C...
This paper presents a detailed exergy analysis of an oxy-combustion process for a supercritical p... more This paper presents a detailed exergy analysis of an oxy-combustion process for a supercritical pulverized coal power plant with CO 2 capture. The results from the exergy analysis show that the power efficiency penalty related to CO 2 capture is 10.2% points and is caused by two units: the air separation unit (ASU) and the CO 2 purification & compression unit (CPU). The composite curves are applied to study the sub-ambient heat exchangers in the ASU & CPU. The power efficiency can be improved by heat integration between the ASU & CPU. The CO 2 recovery rate is also an important factor for the net power efficiency.
International Journal of Greenhouse Gas Control, 2014
An integrated framework focusing on the energetic analysis and environmental impacts of a CO2 cap... more An integrated framework focusing on the energetic analysis and environmental impacts of a CO2 capture and storage (CCS) system is presented, in which the process simulation method and the life cycle assessment (LCA) method are integrated and applied to the CCS value chain. Three scenarios for carbon capture from post-combustion power plant-an MEA-based system, a gas separation membrane process and a hybrid membrane-cryogenic process are studied. The energy efficiency of power plant and the specific capture energy consumption for each scenario are estimated from process simulation. The environmental impacts for each scenario and the base case without CCS are assessed with LCA method. The results show that the MEA-based capture system faces the challenges of higher energy consumption, and higher environmental impact caused by solvent degradation and emissions compared to gas membrane separation processes. The hybrid membrane-cryogenic process shows a better environmental potential for CO2 capture from flue gases due to much lower power consumption and relatively lower environmental impacts.
Ullmann's Encyclopedia of Industrial Chemistry, 2013
ABSTRACT The article contains sections titled: 1.Introduction2.Process Synthesis and Design2.1.Ob... more ABSTRACT The article contains sections titled: 1.Introduction2.Process Synthesis and Design2.1.Objective of Process Synthesis and Design2.2.Generic Problem Definition2.3.Process Synthesis–Design Methods2.4.Challenges and Opportunities3.Process Integration–Energy3.1.Process Integration–Introduction to Key Concepts and Major Topics3.1.1.Design of Heat Exchanger Networks (HENs)3.1.2.Correct Heat Integration3.1.3.Use of Optimization in Process Integration3.1.4.Use of Exergy in Process Integration3.1.5.Heat Recovery in Batch Processes3.1.6.Expansions of the Pinch Concept3.1.7.Concluding Remarks and Future Directions3.2.Introduction to the Synthesis of Heat Exchanger Networks3.2.1.Problem Statement3.2.2.Minimum Utility Cost3.2.2.1.Partition of Temperature Scale3.2.2.2.Linear Programming Transshipment Model3.2.2.3.Illustration3.2.3.Minimum Number of Matches3.2.4.Derivation of Optimal HEN Structure3.2.4.1.Problem Statement3.2.4.2.HEN superstructure3.2.4.3.Mathematical Formulation of the HEN Superstructure3.2.5.Simultaneous HEN Synthesis Approach4.Process Intensification4.1.Introduction4.2.Definition of PI4.3.Process Systems Engineering (PSE) and Process Intensification (PI)4.3.1.Synthesis and Design4.3.2.Modeling and Simulation4.4.Analysis and Verification4.5.Perspective5.Reactive Distillation Processes5.1.Graphical Design Methods5.1.1.Element Balances and Equilibrium Condition5.1.2.Design of Reactive Distillation Columns5.1.2.1.Binary-Element Reactive Systems5.1.2.2.The Reactive Equilibrium Curve5.1.2.3.Constant Total Element Mass Overflow Assumption (CTEMO)5.1.2.4.The Reactive McCabe–Thiele Diagram5.1.2.5.Accounting Heat Effects: The Reactive Ponchon–Savarit Diagram5.1.3.Application Examples5.1.4.Conclusions5.2.New Applications5.2.1.Clean Fuels, Challenges and Opportunities5.2.2.Methodology5.2.3.Case Study: Production of Ultra-Clean Diesel5.2.3.1.The Reaction System (Stage 1)5.2.3.2.Model Formulation: Batch Reactive Distillation Process (Stage 2)5.2.3.3.Conceptual design of a reactive distillation column (Stage 3)5.2.3.4.Rigorous Simulation of Reactive Distillation Process (Stage 3)5.2.4.Conclusions6.Chemical Product Synthesis/Design6.1.Introduction6.2.Design, Synthesis, and Formulation6.2.1.Mathematical Formulation of the Chemical Product Design Problem6.2.2.Database Searches6.2.3.Enumeration & Generation6.2.4.Optimization6.3.Tools for Product Design6.3.1.Computer-Aided Mixture/Blend Design (CAMbD)6.3.2.Computer-Aided Molecular Design (CAMD)6.3.3.Design of Structured Chemical Products6.4.Example: Design of an Insect Repellent6.5.Conclusions and Future Directions7.Approaches to Pharmaceutical Product Design7.1.Introduction7.2.General Concepts in Pharmaceutical Product Design7.3.Design and Development of Active Pharmaceutical Ingredient7.3.1.Overview7.3.2.Ligand Screening7.3.3.Structure-Based Drug Design7.4.Pharmaceutical Formulation Design7.4.1.Overview7.4.2.Formulation Properties and Selection7.4.3.Computer-Aided Molecular Design of Excipients7.5.Example: Formulation Design to Minimize Aggregation of Protein Drugs7.5.1.Overview7.5.2.Prediction of Protein Aggregation7.5.3.Design of Excipients for the Minimization of Aggregation7.6.Conclusions and Future Directions8.Acknowledgments
Modeling, Identification and Control: A Norwegian Research Bulletin, 1983
Energy, 2012
Oxy-combustion is a competitive technology to capture CO 2. Current air separation technologies f... more Oxy-combustion is a competitive technology to capture CO 2. Current air separation technologies for high volume O 2 production are based on cryogenic distillation. When a double-column distillation cycle is applied to produce O 2 with a purity of 95 mol%, the oxygen production process is causing the largest power penalty (6.6% points) related to CO 2 capture. The actual power consumption is around 4.7 times the theoretical minimum. This paper describes a comprehensive exergy analysis of an air separation unit for producing O 2 with low purity (95 mol%) and low pressure (120 kPa). The air compression process and the distillation system cause the two largest exergy losses: 38.4% and 28.2% respectively. The power consumption in the air compressor can be reduced by 19% if the isentropic efficiency increases from 0.74 to 0.9. The total power consumption is reduced by 10% when dual reboilers are applied in the lower pressure column. The exergy losses in the condenser/reboiler exchanger is responsible for only 6.3% of the total losses, thus the power saving potential by developing new heat exchangers with smaller temperature differences is limited. The plant performance in air separation units is not expected to be significantly improved unless the flowsheet structures are improved.
Computers & Chemical Engineering, 1999
The paper discusses optimal operation of a general heat exchanger network with given structure, h... more The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A formulation of the steady state optimization problem is developed, which is easily adapted to any heat exchanger network. Using this model periodically for optimization, the operating conditions that minimize utility cost are found. Setpoints are constant from one optimization to the next, and for implementing the optimal solution special attention is paid to the selection of controlled variables such that the operation is insensitive to uncertainties (unknown disturbances and model errors). This is the idea of self-optimizing control. In addition to heat exchanger networks, the proposed method may also be applied to other processes where the optimum lies at the intersection of constraints.
Computers & Chemical Engineering, 1997
The paper discusses optimal operation of a general heat exchanger network with given structure, h... more The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A method that combines the use of steady state optimization and decentralized feedback control is proposed. A general steady state model is developed, which is easily adapted to any heat exchanger network. Using this model periodically for optimization, the operating conditions that minimize utility cost are found. Setpoints are constant from one optimization to the next, and special attention is paid to the selection of measurements such that the utility cost is minimized in the presence of disturbances and model errors. In addition to heat exchanger networks, the proposed method may also be applied to other processes where the optimum lies at the intersection of constraints.
Energy Procedia, 2012
The application of Carbon Capture and Storage (CCS) in the power industry is important for reduci... more The application of Carbon Capture and Storage (CCS) in the power industry is important for reducing man-made CO 2 emissions. This paper proposes new ways to categorize the options for mitigation of man-made CO 2 emissions and CO 2 capture. A detailed description on the ways to capture, transport and store CO 2 has been presented. The power penalties and cost can be big challenges to apply CCS to the power industry, while a lot of opportunities exist, such as value added CO 2 storage, industrial utilization of CO 2 and the development of the carbon trade market.
On-line optimization and choice of optimization variables for control of heat exchanger networks
Chemical Engineering Transactions, 2017
Heat Exchange Networks (HENs) and Mass Exchange Networks (MENs) have been widely adopted and exte... more Heat Exchange Networks (HENs) and Mass Exchange Networks (MENs) have been widely adopted and extensively studied for heat and material recovery to save energy and other resources. However, work recovery can also result in significant energy savings in for example oil refineries, petrochemical plants and cryogenic processes, such as the production of liquefied natural gas (LNG). The concept of Work Exchange Networks (WENs) was first proposed and identified as a new research topic in Process Synthesis in 1996. This research area has broadened considerably during the last 5-10 years, and it covers both flow work (material streams) and shaft work (energy streams or non-flow processes). More recently, there has also been considerable development in the combined problem of Work and Heat Exchange Networks (WHENs). Two research directions have developed for WHENs; one with a focus on work integration accounting for heat effects, and one focusing on heat integration accounting for heating an...
Chemical Engineering Transactions, 2012
Oxy-combustion is a competitive technology to enable the capture of CO2 from fossil fuel based po... more Oxy-combustion is a competitive technology to enable the capture of CO2 from fossil fuel based power plants. Cryogenic air separation is the only commercially available technology for large volume O2 production that can be applied for oxy-combustion plants. The considerable energy consumption in the air separation units is the main challenge to implement oxy-combustion technology. The compression heat in the air compression process is generally removed by cooling water. The water coolers are responsible for 17.6 % of the total exergy losses in an air separation unit. This paper investigates the possibilities of integrating the compression heat from the air separation unit with the steam cycle. The compression process of the air is studied in two cases: adiabatic (one-stage) compression and three-stage compression with interstage cooling. A decomposed methodology has been developed for studying the heat balance in the boiler feedwater heaters in the steam cycle. The Grand Composite C...
This paper presents a detailed exergy analysis of an oxy-combustion process for a supercritical p... more This paper presents a detailed exergy analysis of an oxy-combustion process for a supercritical pulverized coal power plant with CO 2 capture. The results from the exergy analysis show that the power efficiency penalty related to CO 2 capture is 10.2% points and is caused by two units: the air separation unit (ASU) and the CO 2 purification & compression unit (CPU). The composite curves are applied to study the sub-ambient heat exchangers in the ASU & CPU. The power efficiency can be improved by heat integration between the ASU & CPU. The CO 2 recovery rate is also an important factor for the net power efficiency.
International Journal of Greenhouse Gas Control, 2014
An integrated framework focusing on the energetic analysis and environmental impacts of a CO2 cap... more An integrated framework focusing on the energetic analysis and environmental impacts of a CO2 capture and storage (CCS) system is presented, in which the process simulation method and the life cycle assessment (LCA) method are integrated and applied to the CCS value chain. Three scenarios for carbon capture from post-combustion power plant-an MEA-based system, a gas separation membrane process and a hybrid membrane-cryogenic process are studied. The energy efficiency of power plant and the specific capture energy consumption for each scenario are estimated from process simulation. The environmental impacts for each scenario and the base case without CCS are assessed with LCA method. The results show that the MEA-based capture system faces the challenges of higher energy consumption, and higher environmental impact caused by solvent degradation and emissions compared to gas membrane separation processes. The hybrid membrane-cryogenic process shows a better environmental potential for CO2 capture from flue gases due to much lower power consumption and relatively lower environmental impacts.
Ullmann's Encyclopedia of Industrial Chemistry, 2013
ABSTRACT The article contains sections titled: 1.Introduction2.Process Synthesis and Design2.1.Ob... more ABSTRACT The article contains sections titled: 1.Introduction2.Process Synthesis and Design2.1.Objective of Process Synthesis and Design2.2.Generic Problem Definition2.3.Process Synthesis–Design Methods2.4.Challenges and Opportunities3.Process Integration–Energy3.1.Process Integration–Introduction to Key Concepts and Major Topics3.1.1.Design of Heat Exchanger Networks (HENs)3.1.2.Correct Heat Integration3.1.3.Use of Optimization in Process Integration3.1.4.Use of Exergy in Process Integration3.1.5.Heat Recovery in Batch Processes3.1.6.Expansions of the Pinch Concept3.1.7.Concluding Remarks and Future Directions3.2.Introduction to the Synthesis of Heat Exchanger Networks3.2.1.Problem Statement3.2.2.Minimum Utility Cost3.2.2.1.Partition of Temperature Scale3.2.2.2.Linear Programming Transshipment Model3.2.2.3.Illustration3.2.3.Minimum Number of Matches3.2.4.Derivation of Optimal HEN Structure3.2.4.1.Problem Statement3.2.4.2.HEN superstructure3.2.4.3.Mathematical Formulation of the HEN Superstructure3.2.5.Simultaneous HEN Synthesis Approach4.Process Intensification4.1.Introduction4.2.Definition of PI4.3.Process Systems Engineering (PSE) and Process Intensification (PI)4.3.1.Synthesis and Design4.3.2.Modeling and Simulation4.4.Analysis and Verification4.5.Perspective5.Reactive Distillation Processes5.1.Graphical Design Methods5.1.1.Element Balances and Equilibrium Condition5.1.2.Design of Reactive Distillation Columns5.1.2.1.Binary-Element Reactive Systems5.1.2.2.The Reactive Equilibrium Curve5.1.2.3.Constant Total Element Mass Overflow Assumption (CTEMO)5.1.2.4.The Reactive McCabe–Thiele Diagram5.1.2.5.Accounting Heat Effects: The Reactive Ponchon–Savarit Diagram5.1.3.Application Examples5.1.4.Conclusions5.2.New Applications5.2.1.Clean Fuels, Challenges and Opportunities5.2.2.Methodology5.2.3.Case Study: Production of Ultra-Clean Diesel5.2.3.1.The Reaction System (Stage 1)5.2.3.2.Model Formulation: Batch Reactive Distillation Process (Stage 2)5.2.3.3.Conceptual design of a reactive distillation column (Stage 3)5.2.3.4.Rigorous Simulation of Reactive Distillation Process (Stage 3)5.2.4.Conclusions6.Chemical Product Synthesis/Design6.1.Introduction6.2.Design, Synthesis, and Formulation6.2.1.Mathematical Formulation of the Chemical Product Design Problem6.2.2.Database Searches6.2.3.Enumeration & Generation6.2.4.Optimization6.3.Tools for Product Design6.3.1.Computer-Aided Mixture/Blend Design (CAMbD)6.3.2.Computer-Aided Molecular Design (CAMD)6.3.3.Design of Structured Chemical Products6.4.Example: Design of an Insect Repellent6.5.Conclusions and Future Directions7.Approaches to Pharmaceutical Product Design7.1.Introduction7.2.General Concepts in Pharmaceutical Product Design7.3.Design and Development of Active Pharmaceutical Ingredient7.3.1.Overview7.3.2.Ligand Screening7.3.3.Structure-Based Drug Design7.4.Pharmaceutical Formulation Design7.4.1.Overview7.4.2.Formulation Properties and Selection7.4.3.Computer-Aided Molecular Design of Excipients7.5.Example: Formulation Design to Minimize Aggregation of Protein Drugs7.5.1.Overview7.5.2.Prediction of Protein Aggregation7.5.3.Design of Excipients for the Minimization of Aggregation7.6.Conclusions and Future Directions8.Acknowledgments
Modeling, Identification and Control: A Norwegian Research Bulletin, 1983
Energy, 2012
Oxy-combustion is a competitive technology to capture CO 2. Current air separation technologies f... more Oxy-combustion is a competitive technology to capture CO 2. Current air separation technologies for high volume O 2 production are based on cryogenic distillation. When a double-column distillation cycle is applied to produce O 2 with a purity of 95 mol%, the oxygen production process is causing the largest power penalty (6.6% points) related to CO 2 capture. The actual power consumption is around 4.7 times the theoretical minimum. This paper describes a comprehensive exergy analysis of an air separation unit for producing O 2 with low purity (95 mol%) and low pressure (120 kPa). The air compression process and the distillation system cause the two largest exergy losses: 38.4% and 28.2% respectively. The power consumption in the air compressor can be reduced by 19% if the isentropic efficiency increases from 0.74 to 0.9. The total power consumption is reduced by 10% when dual reboilers are applied in the lower pressure column. The exergy losses in the condenser/reboiler exchanger is responsible for only 6.3% of the total losses, thus the power saving potential by developing new heat exchangers with smaller temperature differences is limited. The plant performance in air separation units is not expected to be significantly improved unless the flowsheet structures are improved.
Computers & Chemical Engineering, 1999
The paper discusses optimal operation of a general heat exchanger network with given structure, h... more The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A formulation of the steady state optimization problem is developed, which is easily adapted to any heat exchanger network. Using this model periodically for optimization, the operating conditions that minimize utility cost are found. Setpoints are constant from one optimization to the next, and for implementing the optimal solution special attention is paid to the selection of controlled variables such that the operation is insensitive to uncertainties (unknown disturbances and model errors). This is the idea of self-optimizing control. In addition to heat exchanger networks, the proposed method may also be applied to other processes where the optimum lies at the intersection of constraints.
Computers & Chemical Engineering, 1997
The paper discusses optimal operation of a general heat exchanger network with given structure, h... more The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A method that combines the use of steady state optimization and decentralized feedback control is proposed. A general steady state model is developed, which is easily adapted to any heat exchanger network. Using this model periodically for optimization, the operating conditions that minimize utility cost are found. Setpoints are constant from one optimization to the next, and special attention is paid to the selection of measurements such that the utility cost is minimized in the presence of disturbances and model errors. In addition to heat exchanger networks, the proposed method may also be applied to other processes where the optimum lies at the intersection of constraints.
Energy Procedia, 2012
The application of Carbon Capture and Storage (CCS) in the power industry is important for reduci... more The application of Carbon Capture and Storage (CCS) in the power industry is important for reducing man-made CO 2 emissions. This paper proposes new ways to categorize the options for mitigation of man-made CO 2 emissions and CO 2 capture. A detailed description on the ways to capture, transport and store CO 2 has been presented. The power penalties and cost can be big challenges to apply CCS to the power industry, while a lot of opportunities exist, such as value added CO 2 storage, industrial utilization of CO 2 and the development of the carbon trade market.