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Rising awareness for the environment as well as concerns over the sustainability of fossil fuels has encouraged developed and developing countries to find alternative ways to enhance the thermal efficiency of current power systems. The thermal efficiency of power plants can be increased from 30 – 40 % up to 80 – 90 % through the implementation of a trigeneration system by recovering dissipated waste heat for other purposes. The trigeneration system can be defined as a technology that can produce simultaneous power, heating, and cooling energy from the same fuel source. Trigeneration System Cascade Analysis (TriGenSCA) methodology is an optimisation approach based on Pinch Analysis that has been used to establish the guidelines or the proper size of the trigeneration system. This paper proposes a modification of TriGenSCA by considering a multi-period of energy consumption to optimise the size of the utility in the centralised trigeneration system by considering the transmission and storage of energy losses in the Total Site system. There are six steps involved including data extraction, identification of time slices, Problem Table Algorithm (PTA), Multiple Utility Problem Table Algorithm (MU PTA), Total Site Problem Table Algorithm (TS PTA), and modified TriGenSCA. The methodology has been tested on the centralised nuclear trigeneration system in a Total Site System as a case study and results shown that thermal energy needed by the Pressurized Water Reactor (PWR) trigeneration system with transmission losses is 2,427 MW whereas thermal energy needed by the PWR trigeneration system without transmission losses is 2,424 MW. The TriGenSCA with consideration of transmission and storage energy losses is useful for engineers and designers to determine the exact value of energy for trigeneration plant.

The plastic, more correctly to be addressed as polymers, are becoming a hot topic in media and also research. The plastics have been branded sometimes as an evil, which has to be replaced, in some cases at any cost. However, a coldblooded analysis and assessment are needed comparing all pros and cons based on environmental footprints quantification with full life cycle assessment. This should include assessment of possible health risks, consumed energy, released emissions and effluents, as well as consumption of raw materials, water and dealing with the wastewater. The assessment of recyclability, reprocessing and environmental burden is needed. The work tends to contribute to the discussion of what recommendations should be developed to the industry and business to minimise the environmental impacts. A Plastic Footprint has been assessed, and a novel Plastic Waste Footprint introduced.

This study aims to analyse the environmental sustainability performance, focuses on carbon emission footprint, of bioenergy (power) under different background/reference system. The considered variation includes the biogenic factor (effected by rotation year of biomass and time horizons of global warming potential), utilisation of biochar (energy or carbon sequestration) and soil carbon dynamics. The identified carbon emission footprint is compared against the existing electricity mix in EU-27. The carbon emission footprint of bioenergy is higher than the electricity mixes in Slovakia, Finland, Latvia, Austria, France, Lithuania and Sweden, at biogenic factor = 0.05 (rotation year = 1). It suggests the importance of a throughout assessment towards a sustainable bioenergy transition, as there is hardly one-size-fits-all solution and bioenergy is not necessary a solution with lower carbon emission footprint.

Heat exchanger network (HEN) synthesis is an efficient way for Heat Integration in the process industry. The non-linear nature of the problem leads the solution to easily be trapped into local optima. This work proposes a mixed-linear programming model (MILP)-based iteration method for HEN synthesis. The MILP aims to minimise the total annualised cost, including utility and investment cost. The logarithmic mean temperature difference (LMTD), heat transfer area, and the investment cost are linearised. The coefficients of the linearised equations are obtained by data regression. And they are evolved through the designed iteration algorithm. Two cases have been tested to show the effectiveness of the proposed method. Results show that the proposed method is accurate on the calculation of total annualised cost, the errors for Case 1 and 2 are 0% and 0.082% compared to the results calculated by the original equations. This provides a way to solve the HEN synthesis problem in a reasonable computational time and obtain the optimal solution.

Concerns over sustainability of fossil fuels, and increasing awareness for the environment have encouraged countries all over the world to shift from the heavy reliance on fossil fuel to renewable energy (RE) resources for electricity generation. Although implementation of RE has been on the rise, large-scale deployment of RE still remains a challenge, especially in terms of economic and technicality. This paper proposes the integration of the current energy system (centralised energy system, CEG running on mainly fossil fuels) with the new energy system (decentralised energy system, DEG). Numerical analysis is developed to solve and target the proposed multiple DEGs and CEG integrated system at its optimum design and sizing. Two existing numerical approaches in Power Pinch Analysis are applied, i.e. Power Pinch Analysis (PoPA) for a smaller scale decentralised energy systems while the net energy deficit will be satisfied in a centralised energy system via Electric System Cascade Analysis (ESCA). The designated combination of Power Pinch methodology in this study is based on an hourly scale operation of both systems. With case study of five (5) DEG(s), the analysis indicates that DEG 1 has 540 MWh for energy-related capacity and 70 MW for power-related capacity. DEG 2, 480 MWh and 70 MW, DEG 3, 480 MWh and 120 MW, DEG 4, 1,000 MWh and 150 MW, and DEG 5, 100 MWh and 90 MW. The CEG power plants should have a total capacity of 48.3 MW with energy storage of 270.6 MWh and 45.1 MW.

Transportation is one of the significant contributors of GHG and air pollutants, from both the tank to well and well to wheel cycle. This study aims to introduce a graphical approach to mapping the circumstances where the energy transition offers a lower emission. The proposed method is demonstrated by a case study of the EU condition (EU-28, Latvia and Sweden). Assessed energy sources to power transportation are electricity, compressed natural gas, liquefied natural gas, diesel and biodiesel. This approach facilitates the transport mode selection (road, rail, sea) and the understanding of how electricity mix or renewable energies influence the energy transition. The environmental oriented approach can be improved in a future study by integrating the economic perspective.

The transportation sector is one of the main contributors to air emissions, both GHG and air pollutants. There have been various assessment approaches being proposed to support decision making. However, it still remains a challenge due to its dynamic nature. There has always been still a gap between the identified strategies and the readiness for implementation. The study aims to propose a modified stagewise graphical approach (Emission Pinch Analysis) to facilitate the planning of an environmentally sustainable transportation system in meeting the defined emission targets. The steps by steps framework are presented. The non-GHG emission, entire life cycle and temporal dimension are suggested to be included in accounting environmental sustainability. Strategies considered are the modal shift, increase of average occupants, alternative fuels/energy and technologies, and weight reduction. A case study on passenger transportation is presented to demonstrate the applicability. This study presents the novel idea in utilising Pinch Analysis methodology for regional transportation planning.

This contribution provides an overview of IoT embedded in the cities, its contributions and the challenges, from the environmental perspective. Energy, which is the essential lifeline of smart cities, can be a crucial sector benefiting from IoT implementation. However, there is still a research gap on the offset/saving versus the footprint of the IT sector. The overall reduction of energy consumptions through the integration of IoT is yet to be verified. The end of life management remains an issue. Continuous research and development, as well as assessment, could bring the sustainable smart concept into its real-life implementation in the foreseeable future. The presentation stems to provide a platform for the discussion of future research directions and priorities.

Air pollution causes a variety of adverse effects on humans such as illness or even death and damages the living organisms and the natural environment. This environmental issue needs to be controlled using various application and technology to estimate the composition of multiple pollutants in the atmosphere for a specified time and location. The present study aims to develop a system for air pollution forecasting using an adaptive neuro-fuzzy inference system. This method is a type of artificial neural network that integrates both neural networks and fuzzy logic principles. The adaptive neuro-fuzzy inference system calculations include four phases including implement fuzzy system, enter parameters, start the learning process, and verify the processed data. As a sample, the concentrations of atmospheric pollutant data recorded by sensors. The adaptive neuro-fuzzy inference system method predicts four air pollution indicator levels, including carbon monoxide, sulfur dioxide, nitrogen oxides, and trioxygen. The analysis results reveal that the mean absolute error of the adaptive neuro-fuzzy inference system method results is less than 15 %.

Transportation is widely recognised as the main contributors to the air pollutants emission. However, the concern in freight mode selection is relatively low compared to that of greenhouse gas (GHGs) / CO 2 emission. This study identifies the relationship between the air pollutants and GHGs through an illustrative case of transporting goods from Shanghai to Hong Kong. The transport option with low GHGs emission did not necessary an option with low air pollutants (SO x , NO x , Particulate Matter) emission. The contradict results are also reflected in the case of water transportation. The limitation of life cycle study (transporting and distribution stage) in evaluating the environmental footprint is also discussed by using the case of the food product. The available studies are either excluding the distribution stage (by ship) or only considering the GHGs emission in assessing the environmental component. This study highlights the role of air pollutants in freight mode selection and the need for a comprehensive system boundary for a better decision-making.

The paper presents the techno-economic modelling of CO2 capture process in coal-fired power plants. An overall model is being developed to compare carbon capture and sequestration options at locations within the UK, and for studies of the sensitivity of the cost of disposal to changes in the major parameters of the most promising solutions identified. Technological options of CO2 capture have been studied and cost estimation relationships (CERs) for the chosen options calculated. Created models are related to the capital, operation and maintenance cost. A total annualised cost of plant electricity output and amount of CO2 avoided have been developed. The influence of interest rates and plant life has been analysed as well. The CERs are included as an integral part of the overall model.

Solar energy itself is generally considered as environmentally friendly, nevertheless it is still important to take into consideration the environmental impacts caused by production of thousands of solar thermal systems. In this work the standard LCA methodology has been extended to analyse the total environmental impacts of a new more efficient solar thermal system SOLARSTORE during its whole life cycle. This system is being developed by a 5th Framework EC project. The LCA results show that to produce 1 GJ energy with SOLARSTORE system will result in global warming potential of 6.3‐10 kg CO2, acidification potential of 46.6‐70 g SO2, eutrophication of 2.1‐3.1 g phosphate and photochemical oxidant of 0.99‐1.5 g C2H4. The raw material acquisition and components manufacturing processes contribute 99% to the total environmental impacts. In comparison with traditional heating systems, SOLARSTORE system provides a considerably better solution for reduction of negative environmental impacts by using solar energy more efficiently. q 2005 Elsevier Ltd. All rights reserved.

The production processes on industrial sites require large amounts of heating, cooling and power for their operation. Therefore, the optimal synthesis of utility systems is of central interest to engineers in the process industries. Recently, the problem of the global climate change has brought forward the question of reducing significantly the emissions of greenhouse gases into the atmosphere. In this paper, a new approach is presented for cost-effective de-carbonisation of new utility systems in the process industries. This is based on improved models of utility equipment components and an improved model and procedure for optimal synthesis of utility systems.

A cost estimate can have a major impact both on project profitability and influences the technical solution. This leads to a commitment of substantial amounts of money and manpower over an extended time. Various methods often provide different results. These differences can be rather significant towards the real cost of a project and selection of the right arrangements. It is therefore important to use a proper estimate that generates enough confidence to choose the right alternative. Another source of uncertainty during the economic analysis of design and retrofit projects is the future energy price value as part of operating costs. This value can significantly affect the project viability and profitability. This paper gives a summary of the most common methods used for cost estimation of heat exchange equipment in the process industry and the sources of energy price projections. It shows the relevance of the choice of the right method and the most reliable source of energy price forecast used when choosing between alternative retrofit projects or when trying to determine the viability of a retrofit project. Ten methods for heat exchanger costing procedure are considered. Oil, natural gas and electricity price projection figures published in reports of nine established analytical centres are discussed. Web sites of institutions and companies are also included.

Water is used in most process industries for a wide range of applications. Processes and systems using water today are being subjected to increasingly stringent environmental regulations on effluents and there is growing demand for fresh water. These changes have increased the need for better water management and wastewater minimisation. Water minimisation techniques can effectively reduce overall fresh water demand and the overall effluent generated. Thus, resulting in lower costs of fresh water and effluent treatment costs. Water pinch analysis embedded in wastewater minimisation techniques offers simple methods and beneficial results when applied to water using industries. This paper describes a water and wastewater minimisation study carried out for a citrus plant located in Argentina. Citrus juice processing plants utilise large quantities of fresh water. As part of this process, significant quantities of wastewater are produced when it comes into contact with the water using operations. The objective of this study is primarily based on reducing the overall fresh water consumption and wastewater produced in this plant, utilising water pinch technology.

The impact of a process system on environmental pollution has both a local and global effect. The performance of the heat exchanger network (HEN) in a plant is an important aspect of energy conservation. Pinch technology and its recent extensions offer an effective and practical method for designing the HEN for new and retrofit projects. The fluid catalytic cracking (FCC) is a dominant process in oil refineries and there has been a sustained effort to improve the efficiency and yield of the unit over the years. Nevertheless, benefits and scope for improvement can still be found. The HEN of the FCC process considered here consists of a main column and a gas concentration section. Appropriate data were extracted from the existing network, using flowsheeting simulation. The stream data consists of 23 hot and 11 cold streams and cost and economic data required for the analysis were specified. The incremental area efficiency methodology was used for the targeting stage of the design and the design was carried out using the network pinch method consisting of both a diagnosis and optimisation stage. In the diagnosis stage promising designs were generated using UMIST developed sprint software. The generated design was then optimised to trade-off capital cost and energy savings. The design options were compared and evaluated and the retrofit design suggested. The existing hot utility consumption of the process was 46.055 MW with a ΔTmin of 24°C. The area efficiency of existing design was 0.805. The targeting stage using incremental area efficiency sets the minimum approach temperature at 11.5°C, thereby establishing the scope for potential energy savings. To achieve a practical project, the number of modifications is limited. The selected retrofit design has 8.955 MW saving – 74% of the whole scope. This corresponds to 27% utility cost savings with a payback period of 1.5 years. The modifications include addition of four heat exchanger units and repiping of one existing exchanger.

This editorial provides an overview of a special issue dedicated to the 7th conference on Process Integration, Modeling and Optimization for Energy Saving and Pollution Reduction—PRES 2004. Eight papers have been selected and peer-reviewed covering various subjects of heat transfer engineering, focusing on the recent development of various features of heat transfer equipment design and optimization. This is the fourth special issue of Heat Transfer Engineering dedicated to selected contributions from PRES conferences [1, 2, 3].