A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract This part of the paper builds on the developments of Part 1. It starts by developing a targeting method for tray columns using detailed capital costing methods. The number of units, column diameters and tray spacings, and the distribution of units and trays will all be considered. The limitations of stages targeting are also discussed, leading to an explanation of why stages targets may be beaten, and showing how continuous contactors are more analogous to heat exchangers than stagewise contactors. A procedure for determining capital cost targets for networks of continuous contactors (usually packed columns) is then developed. Networks featuring different exchanger specifications are also dealt with. As before, capital cost targets are combined with operating cost targets to give total annual cost targets. The design of networks to meet the targets is then discussed. Systems featuring significant differences in exchanger specifications may require some deviation from ideal (vertical) driving force use. The examples presented in this part of the paper demonstrate that the targets are accurate enough for preliminary design as well as pre-design optimisation. The work in both parts of this paper reduces the amount of design work required when evaluating processes at the conceptual stage. <s> BIB001 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract In this paper two design techniques, based on mathematical programming, for the synthesis of mass exchange networks (MENs) are compared. Problems not generally dealt with in the literature, and associated with these techniques, are highlighted. A method is presented for generating several feasible initial solutions to avoid accepting poor local solutions as final designs. A method of handling the discontinuity of the Kremser equation used for determination of the number of stages is also discussed. The new method does not rely on the use of integer variables. In addition, a method of generating MINLP solutions that feature integer stage-numbers is also presented. It is shown that insight-based superstructures assuming vertical mass transfer may fail to include the optimal structure of the MEN. Solutions of several MEN synthesis example problems are presented. Advanced pinch and mathematical programming-based solutions are compared. Both simple and advanced capital costing functions are used for the estimation of the total annual cost (TAC) of the MENs. <s> BIB002 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Pinch analysis techniques have been developed for a wide range of applications ranging from process plant thermal or water integration to financial and supply chain management. This paper presents a new application of pinch analysis. A scenario is assumed wherein energy sector planning takes place with carbon emission constraints arising from an effort to reduce climate change effects. A procedure for identifying the minimum amount of zero-carbon energy resource required to achieve the overall emissions target for a country or region, given that the amount of fossil energy resources available are already known. The pinch analysis method can be used for a single overall emissions target, or for cases wherein separate sectors or geographic regions have distinct targets but share a common energy resource. For the latter case the procedure allows the allocation of the energy resources to meet both the overall emissions limit and the individual targets of the different sectors or location. Numerical examples are provided to illustrate the technique, which is intended for use as a preliminary energy sector-planning tool. <s> BIB003 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Sustainability has recently emerged as a key issue in process systems engineering (PSE). Mathematical programming techniques offer a general modeling framework for including environmental concerns in the synthesis and planning of chemical processes. In this paper, we review major contributions in process synthesis and supply chain management, highlighting the main optimization approaches that are available, including the handling of uncertainty and the multi-objective optimization of economic and environmental objectives. Finally, we discuss challenges and opportunities identified in the area. <s> BIB004 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Process Integration (PI) supporting Process Design, Integration, and Optimisation has been around from the early 1970s. PI was developed originally from Heat Integration, which remains the cornerstone for PI continuous advance. It has been closely related to the development of Chemical, Mechanical and Power Engineering supported by the extended implementation of mathematical modelling, simulation and optimisation, and by the application of information technology. Its development has accelerated over the years as its methodology has been able to provide answers and support for important issues regarding economic development — better utilisation and savings regarding energy, water, and other resources. This contribution is targeting towards providing at least a short overview of its historical development, achievements, and future challenges. <s> BIB005 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> The synthesis of mass exchange networks (MENs) is an important systematic tool for screening mass-separating agents (MSAs) and satisfying the mass transfer demands while considering process, environmental, and economic requirements. Most of the MEN research has focused on single-component problems. Much less attention has been given to the multicomponent problem. Therefore, the aim of this paper is to develop a systematic method to deal with the multicomponent MEN synthesis problem. The concept of interception is introduced to account for compatible mass transfer of the multiple components in a way that can be practically realized in mass exchange units. A mixed-integer nonlinear programming (MINLP) model is established to embed potential configurations of interest. Linearization, disjunctive programming, and relaxation are used to enhance the solvability of the optimization program, which is aimed at minimizing the total annualized cost (TAC) of the MEN. Two case studies from the literature, the recovery of copper from an etching plant and the simultaneous removal of H₂S and CO₂ from coke-oven gas (COG), are solved to illustrate the application of the proposed method. <s> BIB006 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Two key steps in reducing the energy demand of a production site are (1) technological optimization via efficient technologies increasing process efficiency and (2) system optimization via heat integration of the total production site. Heat integration solutions will be influenced by the implemented process technologies, so the evaluation of the existing technologies and analysis of potential changes is a vital basis in energy demand reduction. This article presents the new pinch analysis tool ‘SOCO’ for systematic heat integration with intelligent storage systems which can reduce thermal energy consumption and improve the design of solar process heat integration in the food industry, specifically in breweries. The application to two brewery case studies reveals the usability of the new approach for designing new heat recovery concepts and the implications of technology changes in the energy demand profile. The simulation module of SOCO identifies that the use of modern state-of-the-art technologies in brewing can enhance heat integration potential by 10–35% for different processes and allows the evaluation of storage design. WIREs Energy Environ 2014, 3:561–574. doi: 10.1002/wene.117 ::: ::: For further resources related to this article, please visit the WIREs website. ::: ::: Conflict of interest: The author has declared no conflicts of interest for this article. <s> BIB007 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Carbon capture and storage (CCS) is a key technology for the mitigation of industrial carbon dioxide (CO2) emissions. It involves the reduction of emissions from large industrial facilities (i.e., sources) by capturing the CO2 from the exhaust gases and subsequently storing it in appropriate geological storage sites (i.e., sinks) such as depleted oil and/or gas reservoirs, saline aquifers, coal seams and other similar formations. In practice, these sites may not be readily available for storage at the same time or before the sources are operating, which gives rise to a temporal aspect in the planning problem. At the same time, sources and sinks may need to be clustered geographically to minimize the need to transport CO2 over long distances. This work presents an improved pinch analysis based methodology by simultaneously considering injectivity constraint of every sink as well as time of availability of various sources and sinks. Three illustrative case studies are used to demonstrate the applicability of the proposed methodology. The first two case studies illustrate graphical and algebraic variants, while the third case studies shows an extension that involves two distinct geographical regions. <s> BIB008 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Iron and steel industry is the largest energy consuming manufacturing sector in the world. It is responsible for emitting 4–5% of the total anthropogenic CO2. Due to consistently increasing demand of iron and steel products for human needs, fossil-fuel energy use and CO2 emission will continue to grow in this industry. So there is a strong motivation to develop and implement energy-efficient and low-carbon technologies as well as carbon reduction programs for this industry. Enhancing the development and deployment of high-temperature waste heat energy recovering technologies along a desired combination of carbon capture and storage (CCS) technologies will be the effective solution to reducing CO2 emissions from iron and steel production. The aim of this paper is to provide a comprehensive overview of the worldwide carbon reduction programs and new CO2 breakthrough technologies for energy saving and carbon capture and storage in iron and steel making processes by collating updated information from a wide range of sources. Also, a discussion on the selection of the appropriate technology and their barriers and stages of development and deployment is presented. It is found that lots of factors that limit the role of using biomass in CO2 abatement, so implementation of CCS technology in coal-based integrated steel plant would be an efficient means for sustainable green iron and steel manufacturing. <s> BIB009 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Optimization of heat exchanger network is attributed to improving the process industrial energy utilization ratio. Energy consumption reduction plays an important role in the low-carbon economic development. Several synthesis approaches for heat exchanger network have been proposed and extended during the last three decades. With the evolution of the computer technology, the simultaneous synthesis method via mathematic programming attracts a great deal of attention worldwide. However, some difficulties still need to be overcome, for instance, model simplification and computational complexity. In this work, the simultaneous stage-wise synthesis model without the assumption of isothermal mixing is presented and implemented using effective initialization strategies and a novel two-level algorithm. Three case studies illustrated the better performance of the initialization strategies and two-level algorithm for heat exchanger network synthesis problems, considering non-isothermal mixing. <s> BIB010 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract Process synthesis methods have only recently been applied for the design of CO 2 capture systems. At the crux of the CO 2 capture process is a separation technology (sorbent, membrane or phase separation) applied to CO 2 /N 2 , CO 2 /H 2 or O 2 /N 2 systems. Development of novel sorbents and membranes have been identified to be an important area of research to realize cost-competitive CO 2 capture technologies. Thus, there are different capture technologies at varying levels of maturity that need to be integrated with the power plant or industrial process. Traditional optimization based approaches to process synthesis of CO 2 capture systems, while important for mature process components, have a lesser role to play in this application wheer components are still in a constant state of development. Due to the multidisciplinary nature of CO 2 capture, integrating other sciences such as process chemistry with process synthesis should be emphasized. This work will present novel approaches to process synthesis that represent a new paradigm in process synthesis. The focus of process synthesis is modified from identifying an “optimum” process, to using the framework of the discipline to provide feedback on optimum operating parameters/conditions of the novel separation processes. Motivation for visual and hybrid methodologies based on attainable region approach as opposed to the more common optimization based methods are presented. <s> BIB011 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Chilled/cooling water is a common utility widely used in office or commercial buildings for air conditioning. It is also used in various industries such as semiconductor fabrication and the food industries for process cooling. Previous studies focused on the synthesis of chilled/cooling water networks within individual plants. The establishment of an ecoindustrial park (EIP) that originates from the concept of industrial symbiosis allows individual plants to cooperate with each other so as to achieve greater water and energy recovery through interplant chilled/cooling water reuse/recycle. However, periodical circumstances such as variation of market demands and plant shutdown schedules, which are common in different business operations, have not been well considered in designing an EIP. Thus, there is a need to study explicitly the effect of such periodical operations due to the high level of connectivity within an EIP. This paper presents a design methodology to develop a robust EIP by integrating a set ... <s> BIB012 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Anaerobic digestion, a well-established technology to generate biogas from sewage sludge, is constrained by the hydrolysis (or solubilization) stage. Several pretreatments attempt to overcome this limitation, with thermal hydrolysis emerging as the technology of choice due to its techno-economic advantages. The objective of this work is to optimize the integration of this energy intensive pretreatment within the wastewater treatment plant, ensuring that the digestion performance improves in an energy-efficient way. By applying pinch analysis, a methodology to optimize energy systems, a strategy is suggested that selects a second-generation thermal hydrolysis technology designed to recover all process vapors, defines the optimum combined heat and power scheme to ensure an efficient integration and determines the minimum sludge feed concentration to guarantee energy self-sufficiency, the recovery of all waste heat and the minimization of expensive polyelectrolyte use. <s> BIB013 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract Renewable energy sources can contribute to the increasing energy demand as well as reduction of green-house gas emissions and pollutants. It is desirable to find the optimum mix between renewable and non-renewable energy sources, based on carbon emissions or cost of electricity constraints. In this paper, a Pinch Analysis based method for allocating different energy sources to different demands of a region is proposed. The proposed approach determines the cost optimum mix of various energy sources. Applicability of the method is demonstrated through an illustrative case study of Lakshadweep Islands, India. These islands are too remote to have inter-connections with the mainland and depend on imports of oil for electrical, process, and transport energy requirements. The locally available renewable energy sources can be used to solve problems of energy security, higher energy cost, and environmental pollution. Additionally, the Government of India provides a significant amount of subsidy to supply electricity in Lakshadweep Islands. The proposed method helps in reducing the burden of subsidy significantly by appropriately utilizing locally available renewable energy sources. The proposed Pinch Analysis formulation consider energy as flow, cost of energy as quality, and minimizes subsidized diesel based power generation (formulated as resource). Based on the current acceptable price of electricity, the use of renewable energy sources leads to saving in the subsidy of 317.08 × 10 6 Rs./y and reduction in emissions from diesel generator set by about 58%. The policy implications for subsidy are also discussed in this paper and therefore, the work is useful to guide policy makers. <s> BIB014 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> In a batch process, either direct or indirect heat integration may be employed. The former involves direct heat transfer from hot to cold process streams. In the latter, heat from a hot process stream is first transferred to an intermediate fluid where the heat is stored until it is finally transferred to a cold stream. Storage of product streams allows direct heat integration to be delayed, thereby providing an opportunity for energy conservation while avoiding the use of an intermediate fluid. This paper presents a new methodology for batch heat integration that involves the direct storage of product streams within the procedure to set the minimum utility targets. Application of the proposed methodology on illustrative examples demonstrates that significant energy reduction can be achieved by shifting product streams on the time scale. Potential reductions of 33.2% cold utility and 45.1% hot utility were estimated for the first example when the product stream was stored. Similarly, reductions of 3.5% cold utility and 6.5% hot utility were observed for a two-product batch plant when the cooling requirement for one of the products was shifted on time scale. <s> BIB015 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Renewable energy has a more important role to play in China’s power sector, especially at the regional level. Renewable electricity in China has made great progress on the basis of national policies. However, the promotion of renewable electricity sector at the regional level is still hampered by local issues. China needs to solve some challenging barriers related to implementation of polices for the development of renewable electricity. These barriers stem largely from availability and reliability constraints. Systematic planning techniques are needed to fully utilize abundant renewable energy resources. In this work, an improved graphical pinch analysis-based approach is presented, which considers carbon-constrained regional electricity planning and supply chain synthesis of biomass energy at the regional level in rural China. The minimum renewable energy target is identified by Carbon Emissions Pinch Analysis (CEPA). Next, a demand-driven approach is applied to synthesize the biomass supply chain network to meet the established target in a given region. A detailed case study of Laixi County in China is used to demonstrate the applicability of the proposed approach for policy-making to promote utilization of renewable electricity at the regional level. <s> BIB016 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Pinch Analysis is an established method for enhancing the sustainability of industrial processes via efficient use of various resources. It is based on the principle of target identification followed by subsequent system design aided by a problem decomposition strategy based on the Pinch Point. This approach has recently been extended to apply to a broad range of structurally analogous problems in various domains, such as financial management and carbon-constrained energy planning. In this work, a novel graphical methodology for industrial safety risk and environmental management is proposed. In this method, it is assumed that a set of risk or pollution reduction measures is available, and that each measure is characterized by its implementation cost and the degree of benefit that it delivers. These data are then used to generate a source composite curve. Targeting can then be achieved by shifting this curve relative to a pre-defined sink composite curve, which represents the locus of the plant management’s “willingness to pay,” or budget relative to benefits with respect to risk or pollutant reduction. The methodology is then demonstrated on two case studies. The first case is based on the well-known Bhopal incident, while the second case focuses on the reduction of airborne fluoride emissions from brick firing plant. <s> BIB017 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract In this work an approach is presented for the synthesis of near cost optimal heat exchanger networks with a high controllability. The presented methodology is based on a sequential approach utilizing different algorithms and mathematical models. The procedure is carried out in three steps. A genetic algorithm is used to produce a high diversity of promising structures that suffice the needs for cost reduction and controllability characteristics. For selected structures controllability evaluations are carried out, which are mainly based on relative gain array and condition number assessments. Therefore, a linear model is utilized which was further used to calculate the area adjustments and nominal bypasses for complete disturbance rejection for perfect control. As a last step simplified mathematical solution models are used to further extend insight gained for decision-making. These models are used to carry out dynamic simulations for testing the impact of different possible decentralized feedback control structure designs developed by previous methods. The application of the developed approach will be shown using an example from literature. <s> BIB018 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract This study makes use of a novel methodology for the synthesis of heat exchanger networks, which is aimed at overcoming the shortcomings associated with the use of shortcut models to represent individual exchangers in the synthesis network. The new approach entails the use of a number of correction factors to get networks which are based on the use of shortcut models, such as the mixed integer non-linear programming (MINLP) stage-wise superstructure (SWS) of Yee and Grossmann (1990) to more closely represent physically achievable heat exchangers and ensure that the MINLP network topology optimisation step of these models converge on a real design, rather than an approximated one. In this paper, the SWS formulation is used for the generation of an initial network after which its objective function is modified to include the correction factors that force its objective function towards the cost of a network whose individual exchangers are designed using methods such as Bell–Delaware and heuristics. The modified objective function includes parameters that modify the areas obtained by the shortcut based MINLP model so as to more closely represent the areas obtained by the detailed models and also includes a novel method for including the number of shells required for each exchanger duty. The correction factors account for pressure drops, F t correction factors, number of shells, TEMA considerations, and changes to the overall heat transfer co-efficient of each stream match. The methodology is applied to two examples and the solutions are comparable with other solutions obtained in literature and were shown to produce good solutions. The reason that the method is effective is because many potential networks are evaluated during the iterative procedure and the best network, based on the detailed exchanger designs, is chosen. In this way it is possible to use the detailed exchanger designs to “guide” the MINLP optimisation towards more realistic networks and also to generate many different potential networks. <s> BIB019 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract This paper suggests a new approach to design of heat storage units. The designed Heat Storage Units (HSU) should be used in repeatable processes for different Time Slices (TS) with the same pair of previously heat integrated process streams. The design of Heat Storage Units (HSU) is based on analysis of heat cascades calculated for heat process integration of selected streams with Pinch Table Algorithm (PTA). Determined surplus heat loads, the temperature difference of storage material and the physical characteristics of heat storage material were used for computation of construction characteristics and estimated cost for Heat Storage Units (HSU). Two different approaches were used, heat storage process depends on industrial process parameters related to Pinch technology as well as determination of optimal volume for heat storage design on total cost for investing in such units. The designed Heat Storage system related to Pinch technology gave different compared to the approach with minimization of total estimated costs. The final selections of Heat Storage Unit design was determined with satisfying of Pinch Technology rules. The previously analyzed case study for heat process integration of Baker‘s yeast and ethyl alcohol production plant were referent system for upgrading for Heat Storage system. The cost estimation of designed Heat Storage Units (on both proposed ways) was made, and it was compared with estimated prices for hot and cold utility that would be replaced with Heat Storage for the whole annual cycle. In this case study low profitability was found because of small heat load within Heat Storage accumulation. Systems that would accumulate much more heat energy would give profitable investment. <s> BIB020 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract The synthesis of hydrogen distribution networks has been an active area of research over the last two decades. The concept of hydrogen management based on an economic cost-driven analysis appeared late in the 1990s and was followed up by numerous insight-based and mathematical optimisation approaches in the 2000s. More recently, several superstructure-based optimisation methods have been proposed to accommodate pressure restrictions, additional equipment and other practical constraints when finding the optimal flowsheet configuration. This paper provides a state-of-the-art review of different process integration technologies adopted for the assessment of hydrogen resources in refineries and petrochemical plants, published from late in the 1990s to the present time. Both targeting and design methods are reviewed. An effective hydrogen management strategy can only be achieved by combining different insight-based approaches with detailed mathematical programming. <s> BIB021 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Energy conservation measures are an important means of reducing operating costs and greenhouse emissions. However, one of the barriers to the implementation of such projects is the limited availability of financial resources. Pinch Analysis, which was initially developed to conserve thermal energy and improve energy efficiency in industrial processes, is extended in this paper to address the problem of energy conservation project selection. A new method is developed to include financial cash flows for appropriate selection among independent projects. This study applies Financial Pinch Analysis to select multiple independent projects from a large pool of candidate projects, subject to different funding constraints. To account for the time value of money, Net Present Value is used to determine the financial feasibility of the projects against various funding options. The applicability of the proposed method considers a pool of projects with equal and unequal lives, as well as the financial risk associated with individual projects. In this study, risk is estimated by calculating the certainty equivalent cash flows of the projects. A graphical approach to obtain optimal insightful solutions is presented and demonstrated through three illustrative examples of energy conservation projects in the pulp and paper and cement industries. <s> BIB022 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Project selection is a very important decision that every firm has to take; in fact, this decision plays a major role in the prosperity of the firm. Pinch analysis, which was initially developed to conserve energy and improve energy efficiency in industrial process, is now being extended to non-conventional areas. In this paper, pinch analysis is applied to select multiple independent projects from a large pool of viable projects, subject to budget constraints. The underlying mathematical optimization problem is discussed and a graphical approach to obtain optimal insightful solutions is presented. Applicability of the proposed methodology is demonstrated through an illustrative example of energy conservation in the Indian cement industry. <s> BIB023 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract Cost-effective retrofit of heat exchanger networks (HENs) remains a significant challenge. This paper explores different methods for achieving cost-effective retrofit. The first part of this article presents a novel methodology for the application of heat transfer enhancement in HEN retrofit with a fixed network structure considering pressure drop constraints. Heat transfer enhancement is a low-cost option. However, heat transfer enhancement on its own without changes to the network structure provides a limited scope for energy reduction. The second part of this paper presents a new pinch retrofit method that identifies network structural changes sequentially to meet the retrofit target. However, the high capital cost associated with installing new heat exchangers, relocating existing exchangers, and augmenting the heat transfer area of existing heat exchangers most often leads to uneconomic retrofits. Low-cost retrofit requires few modifications. Therefore, the third part of this paper combines the new pinch retrofit method with the use of heat transfer enhancement to provide low-cost retrofit by combining the merits of both approaches. A case study highlights the benefits of the new approach. <s> BIB024 </s> A review on heat and mass integration techniques for energy and material minimization during CO2 capture <s> Application of pinch analysis and mathematical programming in CO 2 capture systems <s> Abstract Total Site Heat Integration (TSHI) targeting and optimisation methods have been well developed while few studies deal with detailed Utility Exchanger Network (UEN) design. The UEN is the network of heat exchangers that connect a site’s centralised utility system to provide the required process heating and cooling while also facilitating inter-process heat recovery, i.e. TSHI. This paper presents a new UEN design procedure based on the recently developed Unified TSHI targeting method. The Unified method applies more strict constraints on the UEN network, compared to Conventional methods, allowing series utility exchanger matches for a non-isothermal utility if the exchangers in series are from the same process. This constraint reduces the dependency of the individual processes that constitute the Total Site. In UEN design procedure based on the Unified method, calculated utility targets can be archived after UEN design and the number of exchangers reduces compared to the Conventional methods’ design procedure. Also, different Exchanger Minimum Approach Temperature in the UEN synthesis may have an influence on network design and the exchanger configuration but the identical heat recovery and utility targets are achieved after UEN design based on both design procedures. <s> BIB025
Recent studies in sustainable environmental engineering have highlighted the need to improve the efficiency, material and energy-saving potential of most CO 2 capture methodologies BIB010 BIB009 BIB020 . The amount of CO 2 emitted from industrial processes need to be minimized using the CCS techniques with minimum energy expenditure and material usage. With the application of pinch analysis in CO 2 capture systems, appropriate loads on various process streams can be identified and, as such, energy consumption and material usage during CO 2 capture can also be minimized  BIB011 BIB021 . In addition, pinch analysis can provide a target for the minimum energy consumption of the entire CO 2 capture process from the process data of a CO 2 capture operation. The energysaving potential for the process is then obtained using composite curves. The minimum energy-saving requirements set by composite curves depend on the energy and material balance of the CO 2 capture process. Adjusting the energy and material balance of the capture system makes it possible to further reduce its energy requirement BIB021 . BIB012 Pinch analysis, which is based on thermodynamic principles, provides a systematic approach for energy saving with a wide range of applications in many chemical processes BIB013  , in finance BIB022 , supply chain management BIB025 BIB023 and power sector planning BIB024 BIB025 BIB014 . The use of pinch analysis in setting energy targets and mass separating agents targets in industrial processes has attracted a lot of attention in the past BIB015  BIB007 , though not directly applied to CO 2 capture studies. In addition, it also has wide applications in both new and retrofit design situations. So far, the application of pinch technology in retrofit design is much higher than in new design applications BIB016 BIB017 . Pinch analysis approach was first reported by Tan and Foo BIB003 to address CCS planning problem, particularly for carbon capture planning. The basic concept of pinch analysis in heat integration is to match the available internal heat sources with the appropriate heat sinks to maximize energy recovery and to minimize the need for external utilities  . To maintain cost-effective mass and heat exchange networks during the design and integration of individual network in CO 2 capture systems resulting from the interaction which exists amongst the process parameters, it is essential to apply pinch analysis techniques during process integration and design BIB005 BIB008 . Apart from pinch technology, mathematical programming is another technique currently used to synthesize optimum heat and mass exchanger networks for effective energy and material minimization BIB006 BIB004 BIB001 BIB002 , but it has not been adequately tested in CO 2 capture systems. Design and synthesis of heat and mass exchanger networks give rise to discrete optimization problems, which if presented in algebraic form will result in mixed-integer optimization problems BIB018 . Mathematical programming through the use of computer programs in choosing a suitable alternative from a set of available options is a very good technique to solve the aforementioned problem BIB019 . There have been substantial advances in the application of mathematical programming methods for process synthesis in the past. The solutions of mixed-integer nonlinear programming problems as well as the rigorous global optimization of nonlinear programs have also become a reality in recent times. There have also been new trends towards logic-based formulations that can facilitate the modelling and solution of these problems. In this review, it is recognized that availability of modelling strategies that can facilitate the formulation of optimization problems have recorded tremendous progress through mathematical programming, as well as the development of several solution strategies in process synthesis. This section further suggests that the idea of mathematical programming can be used in conjunction with pinch analysis and extended to different capture methods such as membrane separation, adsorptive and absorptive CO 2 capture.