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This paper assesses various approaches that use captured greenhouse gases (GHG) as feedstocks for chemical synthesis. The analysis focuses mainly on the two most abundant anthropogenic GHG, such as carbon dioxide (CO2) and methane (CH4), as well, their conversion technologies to obtain methanol (MeOH), formic acid (FA) and dimethyl carbonate (DMC). These GHG conversions to chemicals technologies are compared with the conventional industrial methods based on fossil feedstocks. The essential information, such as the ranges of energy requirements, environmental footprint and economic production aspects, are summarised. According to the collected information and analysis, the conventional, non-GHG conversion methods are still more environmentally sustainable. Chemicals production technologies based on CO2, such as direct catalytic synthesis to obtain both MeOH and FA, as well as transesterification with MeOH to obtain DMC, are relatively good candidates for implementation on a large scale when a good source of co-reactants such as hydrogen, ethylene carbonate and urea will be provided. In turn, electrochemical methods to synthesise the target chemicals are less feasible due to energy consumption related to the concentration and purification stages of products being the main hotspots. Chemical synthesis based on captured CH4 is currently difficult to evaluate as too little information is available to draw a credible conclusion. However, it may be a trend in future. The limitations of GHG-based conversion for application are related to the capture and transport stages. [ABSTRACT FROM AUTHOR]

Increasing energy usage efficiency requires enhanced heat energy recuperation between process streams in the industry and civic sector with waste heat utilization. The condensation of different vapours is the process encountered in many industrial applications. Increasing the heat recuperation in this process is possible with efficient heat transfer equipment, among which a Plate Heat Exchanger (PHE) is at the leading position. A number of research works have been conducted in recent years concerning construction development and heat transfer enhancement in conditions of limited pressure drop to increase PHE performance in condensation processes. The results of studies on heat transfer and pressure drop in the two-phase condensing flow inside channels of PHE with different geometries of corrugations are discussed. In many implementations, the total pressure drop allowable for gaseous streams in heat exchangers is relatively small. The structure of two-phase flow in PHE channels of complex geometry is very different than in tubes and flat wall channels. The relative differences in approaches to enhance PHE performance in condensation processes based on its modelling, optimisation and design are analyzed. The directions and prospects for future developments are formulated, and potential savings for the economy and the environmental footprint is presented. [ABSTRACT FROM AUTHOR]

There has been plenty of research on the influence of various socio-economic and demographic data on waste generation to develop effective and targeted waste reduction measures, including energy recovery. This study evaluates the relationship between the waste generation and Circular Material Use rate, Environmental Tax Revenue, and Global Innovation Index beyond the typical socio-economic factors (e.g., gross domestic product or population). Correlation analysis is conducted on the EU-27 datasets before the development of the predictive model. The correlation strength between the factors is discussed to identify the potential rebound effect from the central driver of economic growth and development. A positive correlation and partial rebound effect are identified in the data. The waste amount ending in disposal and energy recovery treatment increases with the Circular Material Use rate, suggesting that the expected gains from Circular Material Use rate are offset by other socio-economic factors such as increasing population or gross domestic product. However, a diminishing trend is observed in the rebound effect over the years. Multiple linear regression with validation is applied to identify the best fit model for predicting waste generation. Using population, gross domestic product, Circular Material Use rate, and Environmental Tax Revenues as independent variables, a model is generated with a mean absolute percentage error of 18.65% (7% lower than the benchmark) and R 2 (coefficient of determination) of 0.995. [ABSTRACT FROM AUTHOR]

The plastics are becoming one of the most discussed topics in media and research. They have been branded sometimes as evil, which has to be replaced, in some cases at any cost. However, an equitable analysis and assessment are needed comparing all pros and cons based on environmental footprints quantification with a complete life cycle assessment. These 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 of disposal phases are also needed. This presented work tends to contribute to the discussion of what recommendations should be developed to the industry and business to minimize the environmental impacts. A novel Plastic Waste Footprint is proposed to understand the net potential impacts of plastic and to facilitate the decision making for plastic replacement. This study highlighted that plastic could be a friend if the Circular Economy (CE) is appropriately followed. Reduction (refrain, redesign/reduce, reuse, repair, refurbish, remanufacture, repurpose), recycle and recovery (no leaking into the ocean or other streams) play the decisive roles to minimize and recover the embodied energy, promoting sustainable plastic values chain. Policy to regulate/encourage manufacturers toward sustainable practice (taxation, end of life collection, an incentive of using secondary raw materials) and education (refrain, reuse, separation and recycle) on the potential users are important from not evolving the plastic from friend with high functionality to foe. [ABSTRACT FROM AUTHOR]

Summary: The sustainability of bioenergy is varying on a case‐by‐case basis. It considerably depends on the source of biomass, management practices (plantation, harvesting, conversion technologies, supply chain, etc.) as well as the assessment boundary and assumptions. This study summarises the carbon emissions footprint (CF) flow of bioenergy by considering the possible sources and system boundary, particularly on the CF of biogenic carbon and secondary effects. The assessment framework has been applied to a demonstrated case study identifying the upper limits of global warming potential of biogenic carbon emission (GWPbio) and secondary effects contribution where the bioenergy is still superior to the coal, natural gas and gasoline. The circumstances where the other energy source alternatives could have a lower CF than bioenergy are highlighted. For example, coal and natural gas are the selection (lower CF) if the bioelectricity is subjected to the GWPbio higher than 0.57‐0.74 and 0.18‐0.34. CF of bioheat is higher than the heat generated by natural gas when the GWPbio is more than 0.04‐0.40. Gasoline is the selection when the GWPbio of biofuel is higher than 0.12‐0.42. The validity of carbon neutrality assumption of bioenergy possesses a more decisive role in the overall selection of bioenergy compared to the assessed secondary effects such as soil organic carbon changes. This study emphasises the importance of a rigorous CF accounting for bioenergy to support the equitable decision making. Novelty Statement: The novel contributions of this study are:Summarising of the direct and secondary (soil organic carbon changes ‐ above and belowground, biochar application) effects in accounting the CF for a comprehensive assessment framework.Identifying the CF, integrated with biogenic and non‐biogenic accounting, of bioenergy from energy crops and waste/residual.Comparing the identified CF of bioenergy to the other energy alternatives (fossil‐based). [ABSTRACT FROM AUTHOR]

The condensation of vapours in the presence of non-condensable gas is happening in a number of industries. Its efficient realisation must be considered in optimisation of Heat Exchanger Networks (HENs) to increase efficiency of energy usage. In these processes, Plate Heat Exchanger (PHE) with enhanced heat and mass transfer can be effectively used. The method of preliminary selection of the PHE heat transfer area, plate size and corrugation geometry is proposed for the case of steam condensing from its mixture with air. The method uses the developed earlier one-dimensional mathematical model, modernized for PHE consisting from commercially produced plates. The heat transfer area of PHE is minimised by proper selection of plate sizes and geometrical characteristics of its corrugation. The optimisation variables are the corrugation angle to the main flow direction inside PHE channel, the corrugations depth and the length of plate. The case study illustrates the application of the method in case of utilisation low grade heat from exhaust gases after process of drying by superheated steam. The method is implemented as a computer program which can be included as a Dynamic Link Library module in software for HEN optimisation. • New method for estimating optimal parameters of Plate Heat Exchanger is proposed. • Method experimentally confirmed in industrial conditions for condensation process. • The effect of plate corrugations on Plate Heat Exchanger performance is analysed. • The effect of pressure drop on Plate Heat Exchanger performance is discussed. [ABSTRACT FROM AUTHOR]

Salt-hydrate based thermochemical energy storage is currently a momentous technique utilized for long-term energy storage due to the reversible gas-solid reaction under low-temperature. Among available salt candidates, LiOH·H 2 O is a promising thermochemical material owing to its high heat storage density of 1400 kJ/kg and low charging temperature. The expanded graphite (EG) is selected as a host matrix owing to its excellent thermal conductivity and abundant microstructure, which can promote the heat and mass transfer. This work focuses on the thermochemical performances of the form-stable LiOH·H 2 O/EG composite sorbents. Five samples were being synthesized with EG contents of 0, 5, 8, 12 and 15 wt%. These porous sorbents are characterized to understand the microstructure and thermophysical properties. Considering the comprehensive effect of thermal conductivity and storage density, as well as the adsorption kinetics, the 8 wt% EG-doped sample is the most favourable sorbent, which possesses the thermal conductivity of 6.92 W/(m K) and energy density of 1120 kJ/kg. The cyclability results also reveal the energy capacity of this composite maintains ∼90% of the original after ten consecutive heat charging (dehydration) and discharging (hydration), suggesting good stability. Additionally, the active energy of 2.58 × 109 s−1 and pre-exponential factor of 59.5 kJ/mol for the sorbent is derived. Finally, the thermal power of 123 W and thermal efficiency of 83.6% are achieved for the storage unit in simulation. All these results further confirmed the feasibility of the developed composite sorbent in low-grade heat storage. Image 1 • The TCMs based on LiOH·H 2 O with EG doping are developed. • The 8 wt% EG doped composite shows superior sorption property. • Over 90% of the original storage density is maintained after 10 cycles. • The active energy of 2.58×109 s−1 and pre-exponential factor of 59.5 kJ/mol are derived. • The thermal efficiency for heat charging is 83.6%. [ABSTRACT FROM AUTHOR]

The complex phenomenon of fouling when heating water solutions can significantly hamper the performance of heat exchangers. The fouling process is considered in an application for a plate heat exchanger (PHE) with enhanced heat transfer that proved to have much lower fouling tendencies than conventional shell and tube heat exchangers. To eliminate the drawbacks of the dimensional fouling model forms the dimensionless its form is developed. It is based on the equation for transport and chemical reaction fouling mechanism initially proposed for other types of fouling media. Thermo-hydraulic mathematical model of PHE under fouling conditions accounting for the distribution of local process parameters along heat transfer surface is presented. It enables to predict not only thermal performance of PHE, but also pressure losses. The mathematical model consists of the system of differential equations with the nonlinear right-hand side. Its solution is implemented with software for the personal computer. The model application is demonstrated with two practical examples. It confirms models' validity and its acceptable accuracy for practical calculations of PHE in industry and also the possibility of proposed dimensionless model application for different fouling substances with the similar types of fouling mechanism. • The dimensionless form of fouling model for water solutions heating is proposed. • Mathematical model of plate heat exchanger (PHE) in fouling conditions is presented. • The mathematical model allows to predict thermal and hydraulic performance of PHE. • The validity of models is confirmed with two examples from industry. • For different media the reaction and transport fouling model can be used in similar form. [ABSTRACT FROM AUTHOR]

Abstract Air pollution caused by energy generation and consumption is both a global as well as localised issue. It contributes to global warming along with degradation in human health, ecosystem health, local and global sustainable development. About 75% of the global GHG emissions, 66% of NO x emissions and most of the PM emissions are from energy sectors. Energy sectors have also been reported as the main contributors (90%) of SO 2 emission in China. Among various influential factors (like energy utilisation, the intensity of economic activities, climatic conditions), the terrain is one of the key elements for the formation and dispersion of air pollution. The relationship between air pollution and terrain requires to be more deeply studied. The main contributions of this review include: 1) Summarising the main sources and types of air pollutants as well as the emission characteristics of different sector groups; 2) Proposing the mechanism of air pollution terrain nexus; 3) Reviewing modelling and experiments approaches for air pollution terrain nexus simulation; 4) Highlighting the existing limitations and challenges. This review provides a better understanding of the air pollution terrain nexus. It can contribute to mitigating the air pollution problems. Highlights • Main sources and types of air pollutants have been analysed. • Emission characteristics of different sector groups have been analysed. • The mechanism of air pollution terrain nexus has been proposed. • Main approaches for air pollution terrain nexus simulation have been reviewed. • Limitations and challenges of this topic have been reviewed and highlighted. [ABSTRACT FROM AUTHOR]

Abstract Lignocellulosic waste (LW) is abundant in availability and is one of the suitable substrates for anaerobic digestion (AD). However, it is a complex solid substrate matrix that hinders the hydrolysis stage of anaerobic digestion. This study assessed various pre-treatment and post-treatments of lignocellulosic waste for anaerobic digestion benefiting from advanced P-graph and GaBi software (Thinkstep, Germany) from the perspective of cost and environmental performances (global warming potential, human toxicity, ozone depletion potential, particulate matter, photochemical oxidant creation, acidification and eutrophication potential). CaO pre-treatment (P4), H 2 S removal with membrane separation post-treatment (HSR MS) and without the composting of digestate is identified as the cost-optimal pathway. The biological (P7- Enzyme, P8- Microbial Consortium) and physical (P1- Grinding, P2- Steam Explosion, P3- Water Vapour) pre-treatments alternatives have lower environmental impacts than chemical pre-treatments (P4- CaO, P5- NaOH, P6- H 2 SO 4) however they are not part of the near cost optimal solutions. For post-treatment, the near cost optimal alternatives are H 2 S removal with organic physical scrubbing (HSR OPS) and H 2 S removal with amine scrubbing (HSR AS). HSR AS has a better performance in the overall environmental impacts followed by HSR MS and HSR OPS. In general, the suggested cost-optimal solution is still having relatively lower environmental impacts and feasible for implementation (cost effective). There is very complicated to find a universal AD solution. Different scenarios (the type of substrate, the scale, product demand, policies) have different constraints and consequently solutions. The trade-offs between cost and environment performances should be a future extension of this work. Highlights • The pre-and post-treatments of lignocellulosic waste anaerobic digestion are assessed. • The assessment is from the perspective of cost and environmental performance. • P-graph approach is applied to identify the cost optimal solution. • The cost optimal and near cost optimal solutions are considered in evaluating the environmental performance. • The feasible solutions are suggested and discussed. [ABSTRACT FROM AUTHOR]

Abstract The emergence of Pinch Analysis from more than four decades ago opened a new area of intense research development that has even accelerated in recent years. Initially, Pinch Analysis (PA) provided a systematic thermodynamic-based approach to address the need for large energy savings around the 1970s oil crises. Since inception, the Pinch Methodology (PM) has flourished considerably, finding meaningful application to a wide range of industrial, regional, and global challenges well beyond heat – it's most well-known and first application. This review represents an attempt to identify and substantiate future directions of research for the most significant implementations of Pinch Methodology. Reported applications in the literature range from Heat Integration, Total Site and Water Integration through to Emergy and even Financial Investment Planning; cutting across multiple engineering fields – Mechanical, Chemical, Process, Power, and Environmental Engineering – as well as entering the research domains of Management and Finance. Key findings of this review include: (1) the need for more awareness within the engineering and science research communities of the latest and continuing developments of the Pinch Methodology; (2) a need for complete tool sets covering targeting through to engineering design for many of the Pinch Methodology applications; and, (3) the full benefits of Pinch Methodology can only be achieved in developing design solutions with an appreciation for the most recent developments. Highlights • Pinch Analysis – more than 40 yr – systematic thermodynamic-based energy savings. • Extended – including water, power, hydrogen, supply chains, emissions, Total Sites. • Reviewed recent developments and suggested directions for future developments. • Future steps: exploiting the synergy, extend locally integrated regions. • As well as exergy, emergy, supply chains, targeting emissions and effluents. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) serves as a promising alternative for waste treatment and a potential solution to improve the energy supply security. The feasibility of AD has been proven in some of the technologically and agriculturally advanced countries. However, development is still needed for worldwide implementation, especially for AD process dealing with municipal solid waste (MSW). This paper reviews various approaches and stages in the AD of MSW, which used to optimise the biogas production and quality. The assessed stages include pre-treatment, digestion process, post-treatment as well as the waste collection and transportation. The latest approaches and integrated system to improve the AD process are also presented. The stages were assessed in a relatively quantitative manner. The range of energy requirement, carbon emission footprint and the percentage of enhancement are summarised. Thermal hydrolysis pre-treatment is identified to be less suitable for MSW (−5% to +15.4% enhancement), unless conducted in the two-phase AD system. Microwave pre-treatment shows consistent performance in elevating the biogas production of MSW, but the energy consumption (114.24–8,040 kW e h t −1 ) and carbon emission footprint (59.93–4,217.78 kg CO 2 t −1 waste) are relatively high. Chemical (∼0.43 kW e h m −3 ) and membrane-based (∼0.45 kW e h m −3 ) post-treatments are suggested to be a lower energy consumption approach for upgrading the biogas. The feasibility in terms of cost (scale up) and other environmental impacts (non-CO 2 footprint) needs to be further assessed. This study provides an overview to facilitate further development and extended implementation of AD. [ABSTRACT FROM AUTHOR]

The greenhouse gas emissions footprint and global warming potential are widely-used for environmental sustainability studies. However, environmental sustainability is far wider than carbon emissions and climate change. This review aims to highlight the importance of considering air pollutants in optimisation studies and evaluate the limitation of the current assessments for air emissions, particularly in relation to transportation. The source of air pollutants is firstly overviewed with special attention on non-stationary sources, freight and sea transportation. The type of measurement to obtain the emission data and the available optimisation models on transport mode choice selection were then summarised. The strengths and Weaknesses' have been indicated. The identified gap includes greenhouse gas and air pollutants not being evaluated simultaneously and the interaction between the different pollutants are not being adequately considered. A better assessment framework and impact categories classification are consequently required. The summarised assessment model of transportation mode choice shows that the current viewpoint on low emissions, green or environmental sustainability options refers to carbon dioxide as a part of greenhouse gas. Attention towards a better emission assessment and management has been supported in this study through critical discussion. The next step of this work is to develop a methodology to measure greenhouse gas and air pollutants simultaneously by considering the synergistic effect and the discussed limitation. It is important for minimising the potential of footprint shifting and poor decision-making. [ABSTRACT FROM AUTHOR]

A comprehensive analysis of publications on fouling in plate heat exchangers (PHEs) on heating water solutions is presented. The peculiarities of flow structure in PHE channels and differences in construction require studies specifically for this efficient type of heat exchanger. The main fouling mechanisms in these conditions are crystallisation and particulate fouling. The predominant way of fouling development in PHE is asymptotic when at some time of fouling growth, the deposition of fouling and its removal to the main flow becomes equal and fouling thermal resistance does not change with time. The data of different experimental research and industry tests show that the rate of fouling in PHE from 5 to 20 times lower than in shell and tube heat exchangers for the same duty and overall process conditions in heating water solutions. The different approaches to modelling fouling formation in PHEs are analysed. The modelling of local process parameters in channels with accounting for the geometry of corrugations on plates is extremely important for the accurate prediction of fouling formation. Among different ways of fouling mitigation in PHE, the accurate design and proper selection of plates and their arrangement is considered the most effective, while covering plates with fouling-reducing coatings has prospects in development and application. The cleaning of PHEs has to be done with the development of optimised maintenance schedules. The cleaning of plate-and-frame PHEs can be done by mechanical methods, but chemical cleaning in place (CIP) with special CIP machines is preferable where it is possible. [Display omitted] • The published results of studies on fouling of PHE in heating of water solutions are reviewed. • The fouling tendencies in PHEs are much lower than in shell-and-tube heat exchangers. • The transport-reaction model can account for the fouling deposition in PHE. • The fouling distribution along channels must be accounted for in PHE modelling and design. • The correct plates arrangement and accurate design necessary to mitigate PHE fouling. [ABSTRACT FROM AUTHOR]

This Virtual Special Issue (VSI) presents a selection of the presentation at the 24th Conference of Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES'21), which was held as a hybrid (face2face + online) conference in Brno, Czech Republic, on the 31st October to the November 3, 2021. The main features were related to the scope of Renewable and Sustainable Energy. Topics covered in this VSI also include climate and emission neutrality of energy systems, sustainable energy systems optimisation, energy recovery and integration. Topics covered in this VSI also cover circular economy, which has been identified as a viable strategy towards achieving sustainable development. It aims to decouple economic growth from resource use and waste generation. However, most technologies that promote circularity necessitate increased energy use to enhance material recovery and recycling. To ensure that the advances made in creating a more circular economy are not in conflict with mitigating climate change and achieving close to net zero emissions by 2050, a portfolio of technologies and strategies that reduce the carbon emissions intensity of the energy sector should be implemented. Climate and emission-neutral energy systems that utilise renewable energy, such as solar and geothermal power, decarbonise the energy sector's emissions. Developing more sustainable and renewable energy devices such as photovoltaic/thermal collectors, phase change materials, and solar devices, together with establishing infrastructure that supports these technologies, such as 6G wireless networks, would improve efficiency during energy generation, transmission, and use. The design and implementation of energy recovery and integration networks would reduce operational energy requirements in process industries. Finally, to maximise the benefits derived from these strategies, optimisation models which consider temporal and geographical constraints should be developed to determine their proper deployment. Sustainable development could be achieved by successfully integrating sustainable energy within a circular economy. • Recent development in Sustainable Energy Integration. • Contributions to the Circular Economy. • Editorial Dedicated to the Virtual Special Issue PRESʼ21. • Conference 24th Conference of Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction. [ABSTRACT FROM AUTHOR]

Design of the borehole thermal energy storage (BTES) is very important for the seasonal solar thermal storage system. The BTES designed based on the empirical method could lead to some unsatisfied effects in actual operations. This paper simulated the BTES operation in one year to study the effects of soil thermal conductivity, soil volume-specific heat, initial soil temperature and relative surface area of storage on energy efficiency of the BTES. The results show that energy efficiency of the BTES reaches the maximum when soil thermal conductivity is 1.8 W/(m·K). According to the results, soil thermal conductivity has more significant effects on the heat extraction per soil volume but has the most negligible impact on energy efficiency of the BTES. At the same time, relative surface area of storage is the most influential factor on energy efficiency of the BTES. Finally, a new BTES design method was proposed which is suitable for the studied parameter range. It is worth noting that the present study focuses on the continuous operation of the system and fixed buried pipe spacing, while the intermittent operation and other buried pipe spacing will be studied in future work. [ABSTRACT FROM AUTHOR]

Optimization of Heat Exchanger Networks (HEN) has received considerable attention in last decades, but a few studies on inherent safety. In this paper, risk assessment is considered simultaneously during the synthesis of HENs. As risks depend on the equipment selected, a superstructure enabling selection of direct and indirect heat transfer between hot and cold streams and different types of heat exchangers (HEs) was tested. The individual heat transfer and the overall HEN risk were analyzed. Different individual risk limits have been introduced for certain types of heat transfer, e.g. between two process streams or between utility and process streams. The sensitivity analyses were performed first, considering only toxicity as a risk, but later flammability and explosiveness were also simultaneously tested, in order to consider the most important aspects of safety. The results obtained indicate that rather significant changes in HEN designs can increase safety, while still exhibiting similar economic efficiency. [ABSTRACT FROM AUTHOR]

The results of mathematical modelling and experimental study of plate heat exchangers (PHEs) in steam-air mixture condensation are presented. The mathematical model is validated by test data for PHE in the industry and for five experimental samples with corrugation angles, 30°, 45°, and 60° and corrugation heights 5, 7.5 and 10 mm. With no limited pressure drop in PHE, its heat transfer area can be decreased up to 4 times with the plate's corrugations angle of 60°. When pressure drop on the side of condensing stream is limited, at a small mass fraction of air, PHE with corrugated plates' heat transfer area can be smaller than in PHE assembled from flat plates about 1.5 times ± 11% at channels of different corrugations geometries. For commercially produced plate-and-frame PHE, the pressure losses at channel entrance and distribution zones should be accounted. For plates with a corrugations angle of 60°, their share in total pressure drop can be from 7% up to 39.3%, while at a corrugations angle of 30°, up to 59%. The final choice of corrugation angle and height for plates designed for specific duty can be made by solving a future optimisation problem with a developed mathematical model. • Mathematical model of stem condensation from mixture with air is proposed. • Experimental validation of model for condensation in plate heat exchangers (PHEs). • The influence of corrugations geometry on process intensity is determined. • The intensification of steam condensation from its mixture with air in PHE is confirmed. [ABSTRACT FROM AUTHOR]

Development of cleaner biodiesel production related to hydrodynamic cavitation of methyl ester synthesis from sustainable waste cooking oil via alkali-catalysed transesterification is gaining importance due to considerable lower energy requirement and time. The effects of the oil to methanol molar ratio (1:4–1:7), catalyst concentration (0.5–1.25 wt %) and reaction temperature (50–65 °C) have been studied in a hydrodynamic cavitation and mechanical stirring system. Highest conversion of 98% was achieved under optimum conditions of 1:6 M ratio of oil to methanol, 1 wt % potassium hydroxide as alkali catalyst, 60 °C and 15 min reaction time. It has been observed that yield efficiency and reaction time were 833% higher and 600% shorter using hydrodynamic cavitation compared to mechanical stirring. Triglycerides conversion obeys pseudo-first order mechanism. The kinetic parameters of hydrodynamic cavitation and mechanical stirring were calculated, where the reaction rate constants were 0.238 and 0.031 min −1 , activation energies were 89.7 and 92.7 kJ/mol and the pre-exponential factors were 2.623 × 10 ​13 and 1.120 × 10 ​13 min −1 . Hydrodynamic cavitation was 1.8 fold more energy efficient and 4.6 fold lower feedstock used per produced product than mechanical stirring in biodiesel production. In conclusion, waste cooking oil methyl ester produced via hydrodynamic cavitation proved to be time saving and energy efficient compared to mechanical stirring. This makes the process more environmental friendly using hydrodynamic cavitation. [ABSTRACT FROM AUTHOR]

In the globalised world greenhouse gas (GHG) emissions and water consumption are becoming increasingly important indicators for policy and decision making. Development of footprint assessment techniques over the last decade has provided a set of tools for monitoring CO 2 emissions and water flows in the world. An overview of the virtual CO 2 emissions and virtual water flow trends in the international trade based on consumption perspective is performed in the current work. The review of the recent literature indicates that: (1) Producers and consumers are located at various places in different parts of the world, and consequently they are significant differences in virtual GHG (Greenhouse gases) emissions. (2) The US and the EU have high absolute net CO 2 imports. (3) China and some other fast developing countries as India, Brazil, and others are exporting countries and increasingly carry the load of exports of virtual GHG including CO 2 emissions and virtual water that are triggered due to consumption of the related goods in the importing countries. (4) By importing products produced with lower carbon emission intensity and less water consumption than in the domestic industry, international trade can reduce global environmental pressure. Results from analysis indicate that future actions should be focused onto two main areas: (i) To steer regions towards self-sufficiency based on more efficient processes and by combining production of surrounding countries. (ii) To develop a mechanism with shared market of virtual carbon and virtual water between trading partners regionally and internationally. [ABSTRACT FROM AUTHOR]

Biodiesel is envisaged as environmentally benign fuel due to its unique properties, such as biodegradability, renewability and non-toxicity. Its utilisation leads to the reduction of sulphur oxide and greenhouse gas emissions as it produces quite lower amounts of carbon and sulphur based gases in comparison to conventional fossil fuels. This paper is a review of the recent achievements of the cleaner intensification technologies for biodiesel production. Merits and limitations of the cleaner intensification technologies have been discussed. Mechanical stirring via transesterification is the most common and extensively utilised for biodiesel production. It involves the conversion of oil to glycerol and acid alkyl ester while employing methanol. However, this process has an inherent drawback of mass transfer resistance resulting in a lower reaction rate and higher production cost. Intensification technologies have become more attractive to overcome these aforementioned problems. In a bid to increase the cost competitiveness of biodiesel production compared to diesel fuel, process intensification has been studied for numerous biodiesel processing technologies. Many researchers have resorted to several intensification technologies namely; microwave, ultrasonic cavitation and hydrodynamic cavitation reactor to eliminate the mass transfer resistance of immiscible reactants. Once the mass transfer resistance is reduced, it may lead to a shorter reaction time and lower energy consumptions compared to mechanical stirring. Recent studies reveal that microwave and ultrasonic cavitation techniques are not yet completely feasible for biodiesel production at industrial scale. On the other hand, it was found that hydrodynamic cavitation offers a number of advantages over other intensification technologies. It shows good performance with respect to product yield, reaction time, energy consumption and product quality. Furthermore, it exhibits a sustainable mean for energy recovery from renewable oils. It was concluded that more studies are needed to extend the existing information of hydrodynamic cavitation for the design of the plate geometry with respect to the methyl ester conversion. This will help to develop a sustainable and industrially viable route for energy recovery from renewable oils. Yield efficiency in relation to the method followed the order: hydrodynamic cavitation > microwave > ultrasonic cavitation > mechanical stirring. [ABSTRACT FROM AUTHOR]

This special issue of Applied Energy contains articles developed from initial ideas related to the 10th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES) held in Dubrovnik, Croatia during September 27 - October 2, 2015. The main focus of the event is the sustainability development joining all required areas for achieving as improving the knowledge on method, policies and technologies as well as dissemination of the results. Overall, 64 extended manuscripts have been invited as candidate articles. After a thorough review procedure, 23 articles have been selected to be published. The topics attained in the focus of this Special Issue include Integration, Optimisation and Analysis of energy systems as well as dissemination of the developed methodology and results obtained. [ABSTRACT FROM AUTHOR]

Sustainable development requires measures to decrease energy consumption and to avoid any harmful impact on the environment. In recent years, a lot of research has been focused on designing energy systems by emulating the natural ones. This can be regarded as a novel way to support the transformation to sustainable energy systems. The initial step in forming energy systems of thus type, by emulating the ecosystem approach, is the development of a model for rendering the current situation. To contribute to the solution of this problem, an ecosystem model combining the analysis, optimisation and simulation modules has been developed as part of this study. The commonly used models for energy systems are good predictors of the general energy dynamics and structures. However, they can be inadequate when it comes to describing or predicting the complex phenomena within energy systems, such as the large number of parameters, the many end-users, the potential of the technologies, the assessment of the various environmental impacts and the variety of resources. With the implementation of the ecosystem model there is further expanding of the knowledge of an advanced, self-organising methodology integrated within the model’s operation by emulating the natural system dynamics. The ecosystem model could become a valuable tool for developing sustainable energy systems, and allowing the development of the most suitable and sustainable energy system based on the local availability of energy sources. [ABSTRACT FROM AUTHOR]

Energy is needed in all sectors: industrial, domestic, commercial, transportation, power generation. Fossil fuel has been the main source of energy since decades. Due to rising greenhouse gases (GHG) emissions, the energy mix in many countries are shifting towards alternative energy sources, such as renewable energy and nuclear. At the same time, energy demands should also be managed and minimised to curb the rising GHG. Transitioning towards cleaner energy supply may also take time due to economic, political, technology readiness and public acceptance reason. A faster solution is to sequestrate CO 2 especially through CO 2 capture, utilisation and storage technologies. This paper presents an overview of the Journal of Cleaner Production Special Volume for the 18th conference “Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES 2015)”. The paper discussed issues, methods and solutions to achieve cleaner energy. The review has been written from the perspective of the supply side management, demand side management or end-of pipe management. The content of the Special Volume also includes cleaner energy planning, policies and education. The Special Volume reviews various ideas and discussion from authors all over the world and also provides some directions for future studies. [ABSTRACT FROM AUTHOR]

The cement production industry worldwide is one of the largest CO 2 emitting industrial sectors. It accounts for a considerable amount of total global greenhouse gas (GHG) emissions. Due to the increasing awareness of global warming, more energy efficient cement production is increasingly being emphasized. One of the priorities is to reduce the energy demand and innovate the production process to move towards the cleaner production as: Energy efficiency improvements; Waste heat recovery; Reduction of clinker/cement ratio and use of alternative raw materials; Substitution of fossil fuels with alternative energy sources. When the GHG emissions at source opportunities are close to being exhausted, the other mitigations options should be considered such as: CO 2 capture and storage. This is however in most cases not the final solution from the point of Life cycle assessment (LCA). In recent years various mitigation measures are gaining on the importance and the cement industry is more and more shifting to cleaner production. Among the others, there are two measures, which can reduce the GHG emissions considerably: the use of alternative raw materials and alternative fuels. The challenge for the cement industry is to use alternative raw materials especially those originating from other industries where they are considered as by-products or even waste. Some of these by-products include: Bottom ash from municipal solid waste incinerators; Fly ash from coal power plants; Gypsum from the desulfurization plants used in power plants. Another important measure is the energy efficiency improvement in existing cement plants. There are various approaches for controlling and improving the energy efficiency within existing cement manufacturing units, however, mathematical modelling, simulation, optimisation and Process Integration are increasingly gaining in importance. The mathematical modelling approach uses the numerical simulations for the investigation of the thermo-chemical processes occurring inside of the manufacturing unit. The results gained are being used to enhance the efficiency of cement production. They improve the understanding of the flow characteristics and transport phenomena taking place inside the cement combustion unit. The objective of this paper is to review the current status of the cleaner cement manufacturing, the cement industry's shifting to alternative raw materials and alternative energy sources, and the modelling of the thermo-chemical processes inside the cement combustion units. Additionally, some critical issues, which up to now have not been adequately resolved, are outlined. [ABSTRACT FROM AUTHOR]

The production of hydrogen from hydrogen sulphide has a twofold goal as it can be seen as a challenging opportunity for combining hydrogen recovery with the abatement of a highly toxic pollutant. Despite the thermodynamics encourage hydrogen sulphide splitting with respect to water splitting, no hydrogen sulphide dissociation process proving a net superiority with respect to others has been exploited at large scale yet. This paper aims at surveying the most important techniques being proposed for hydrogen sulphide splitting, with a particular attention to chemical methods that seem to be promising candidates for real industrial applications. Several processes based on thermal dissociation, catalytic cracking, multistep thermochemical methods and photocatalytic splitting are compared and critically analysed pointing out merits and drawbacks having a basic role in technology transfer. The main objective of this short review consists of collecting new process trends and improvements in pre-existing strategies in matter of hydrogen sulphide dissociation during the last two decades. Some new techniques here reported are inspired to recent issues in material science and nanotechnology bringing basic innovations for a non-conventional hydrogen production from such a waste. [ABSTRACT FROM AUTHOR]

Extraction-condensing steam turbines mix cold-condensing and cogeneration activities making the respective power and fuel flows not directly observable. A flawed assessment of the flows is causing confusion and bias. A steam expansion path on a Mollier diagram reveals the design characteristics of a thermal power plant and of its embedded combined heat and power (CHP) activities. State variable data on a unit mass of steam, entering the turboset as life steam and leaving it at one of the heat extraction exhausts, provide the roster of the power-heat production possibility set of the plant. The actual production It possibilities are drawn from the roster by applying capacity data and constraints on the f heat extraction points. Design power-to-heat ratios of CHP activities are univocally idenf tified, allowing accurate assessments of cogenerated power. This information is needed for proper incentive regulation of CHP activities, pursuing maximization of CHP quality and quantity. Quality is gauged by the power-to-heat ratio, principally a design (investment) decision. Quantity is gauged by the operational amounts of recovered heat exhausts. Optimal regulatory specificity is attained through setting generic frameworks by technology, accommodating investment and operational decisions by plant owners. Our novel method is explained and applied with numerical data, also revealing the flaws in present regulations. [ABSTRACT FROM AUTHOR]

The growing disposable medical gown consumption due to the COVID-19 pandemic has driven tons of waste to landfills and posed plastic pollution. Investigating the pros and cons of biodegradable gowns over conventional counterparts can guide disposable medical gowns to be environmentally and socially sustainable. This work presents environmental and social life cycle assessments (E− and S-LCA) of biodegradable gowns to compare their environmental and social performances with conventional ones. The E-LCA evaluates the full-spectrum environmental impacts from gown production to end-of-life waste management processes, while the S-LCA assesses their associated influence on economic growth, employment, and worker welfare. The social impacts are evaluated based on the economic input-output analysis results of the economic sectors or gown life cycle stages involved in the gown value chain. Results show that biodegradable gown production poses 10.76% higher ecotoxicity than conventional alternatives contributed by pro-oxidant manufacturing. Integrating the landfill gas (LFG) capture and utilization processes into biodegradable gown waste treatment can reduce 48.81% of life cycle land use and over 5.67% of total greenhouse gas emissions. However, integrating this process in sanitary landfills to treat disinfected gown wastes can increase technical complexity, which enhances 70% of safety risks and 40% frequency of forced labor. Industrial composting biodegradable gowns can reduce over 20.5% of particulate matter formation versus sanitary landfills. Overall, fossil-based gowns possess full-spectrum environmental and social advantages over biodegradable counterparts treated by industrial composting and sanitary landfills. If improving the efficiencies of LFG capture by 85%, biogenic methane oxidation by 43%, and heat generation by 85%, biodegradable gowns can outperform conventional counterparts in reducing GHG emissions and fossil fuel use. [Display omitted] • Novel environmental and social life cycle assessments on disposable medical gowns. • Comparative LCAs between biodegradable gowns and their conventional counterparts. • Implementing landfill gas capture and utilization processes reduce worker welfare. • Biodegradable gowns are greener with a higher landfill gas capture efficiency. [ABSTRACT FROM AUTHOR]

The growing disposable medical gown consumption due to the COVID-19 pandemic has driven tons of waste to landfills and posed plastic pollution. Investigating the pros and cons of biodegradable gowns over conventional counterparts can guide disposable medical gowns to be environmentally and socially sustainable. This work presents environmental and social life cycle assessments (E− and S-LCA) of biodegradable gowns to compare their environmental and social performances with conventional ones. The E-LCA evaluates the full-spectrum environmental impacts from gown production to end-of-life waste management processes, while the S-LCA assesses their associated influence on economic growth, employment, and worker welfare. The social impacts are evaluated based on the economic input-output analysis results of the economic sectors or gown life cycle stages involved in the gown value chain. Results show that biodegradable gown production poses 10.76% higher ecotoxicity than conventional alternatives contributed by pro-oxidant manufacturing. Integrating the landfill gas (LFG) capture and utilization processes into biodegradable gown waste treatment can reduce 48.81% of life cycle land use and over 5.67% of total greenhouse gas emissions. However, integrating this process in sanitary landfills to treat disinfected gown wastes can increase technical complexity, which enhances 70% of safety risks and 40% frequency of forced labor. Industrial composting biodegradable gowns can reduce over 20.5% of particulate matter formation versus sanitary landfills. Overall, fossil-based gowns possess full-spectrum environmental and social advantages over biodegradable counterparts treated by industrial composting and sanitary landfills. If improving the efficiencies of LFG capture by 85%, biogenic methane oxidation by 43%, and heat generation by 85%, biodegradable gowns can outperform conventional counterparts in reducing GHG emissions and fossil fuel use. [Display omitted] • Novel environmental and social life cycle assessments on disposable medical gowns. • Comparative LCAs between biodegradable gowns and their conventional counterparts. • Implementing landfill gas capture and utilization processes reduce worker welfare. • Biodegradable gowns are greener with a higher landfill gas capture efficiency. [ABSTRACT FROM AUTHOR]

Heat exchanger network synthesis (HENS) is an effective tool for heat recovery in chemical and petrochemical industries. This study aims to show a method for HENS with the consideration of different shell-side flow arrangements in shell-and-tube heat exchangers. The proposed MINLP model is modified from the stage-wise superstructure model, incorporating newly developed correlations for shell-side pressure drop calculation for the helical baffle. The objective is to minimise the total annual cost (TAC) with a trade-off between the cost of different shell-side heat exchangers, utility cost, and pumping cost. The selection of baffle design is decided by the saved pumping cost and the increased area cost. The proposed model is tested from different points of view: with/without utility constraints and different statuses of the streams. Three case studies are presented and compared with the results from the literature. The proposed method with different shell-side baffles can reduce the heat transfer area and pressure drop. For fixed utility consumptions, the TAC in a case study is decreased by 8.9% with mixed baffle types. Although the unit per area cost of the helical baffle is higher than the segmental baffle, the increased investment cost could be compensated by the reduced operation cost, especially for plants with high viscosity streams and long-term cost-saving. [ABSTRACT FROM AUTHOR]

Heat exchanger network synthesis is an essential optimisation tool for Process Integration, particularly in energy-intensive industries. Proper design or retrofit of heat exchanger network can enable energy conservation, efficiency improvement, and process debottlenecking. Many earlier pieces of research have focused on the impact of the network structure and process features such as network topology, temperature intervals, continuous/batch processes, and so on. As the major device in heat exchanger networks, heat exchangers research has always been a hot topic. However, the individual heat exchanger research is different from the number of heat exchangers in a network. Various performance aspects of the heat exchangers, e.g., pressure drop, fouling, and thermal performance, could influence the whole network and the passive responses between each heat exchanger. Besides, integrating those aspects of individual heat exchangers into the network synthesis is still an open problem, especially for cases that demand simultaneous optimisations. This work presents a thorough assessment of research into those aspects in heat exchanger networks, as well as the state-of-the-art of current approaches for heat exchanger networks optimisation that take heat exchanger performance into account. The essential coupling among fouling, pressure drop and thermal design is explored, and the nexus between them and the heat exchanger network is analysed. Researchers will benefit from this overview of heat exchanger network synthesis retrofitting methods and applications. • The impact of heat exchanger performance on the heat exchanger network is discussed. • Progress of model and approach for heat exchanger network synthesis is reviewed. • Influence factors: fouling, pressure drop, thermal design and intensified heat transfer. [ABSTRACT FROM AUTHOR]

The significant issue affecting wastewater treatment is human faeces containing SARS-CoV-2. SARS-CoV-2, as a novel coronavirus, has expanded globally. While the current focus on the COVID-19 epidemic is rightly on preventing direct transmission, the risk of secondary transmission via wastewater should not be overlooked. Many researchers have demonstrated various methods and tools for preventing and declining this virus in wastewater treatment, especially for SARS-CoV-2 in human faeces. This research reports two people tested for 30 d, with written consent, at Mosa-Ebne-Jafar Hospital of Quchan, Iran, from September 1st to October 9th, 2021. The two people's conditions are the same. The Hyssop plant was used, which boosts the immune system's effectiveness and limonene, rosemary, caffeic acids and flavonoids, all biologically active compounds in this plant, cause improved breathing problems, colds, and especially for SARS-CoV-2. As a result, utilising the Hyssop plant can help in reducing SARS-CoV-2 in faeces. This plant's antioxidant properties effectively reduce SARS-CoV-2 in faeces by 30%; nevertheless, depending on the patient's condition. This plant is also beneficial for respiratory and digestive health. [Display omitted] • A novel coronavirus known as SARS-CoV-2 has spread over the world wastewater. • It is important to keep an eye out for secondary transmission via wastewater. • The significant issue affecting wastewater treatment is human faeces containing this virus. • We reported two people tested for 30 d, with written consent, at a hospital in Quchan, Iran. [ABSTRACT FROM AUTHOR]

The application of polymeric materials for the manufacture of absorbing elements of solar collectors allows efficient transformation of solar radiation into thermal energy with low material consumption and reduced cost of solar installations. The solar collector of flat plate type is investigated as part of two contours solar installation. The collector is equipped with an absorber made from polyethylene film of special grade. It is observed that the efficiency of such a collector reaches up to 0.95. It can be produced up to four times cheaper than a sun collector with aluminium metal absorbers. The empirical correlations for estimation of collector efficiency and heat flux depending on heated media flow rate are presented. These correlations, together with data for heated media temperature at the collector exit and solar unit operating time at daylight with different heat carrier flow rates, are used for the design of solar heating installations with plastic absorbing elements and their integration into heat supply systems at the industry and in the communal sector. [ABSTRACT FROM AUTHOR]

• Effect of activated sludge-activated carbon and activated sludge-algae in wastewater reuse. • Fuzzy logic based simulation in MATLAB was the right approach to optimize the treatment process. • Activated carbon is the critical parameter for low-strength wastewater treatment and advanced water treatment. • Activated sludge compared to algae adapted in wastewater treatment within the first 3–4 h. Wastewater reuse is a significant challenge around the world, especially in arid and semi-arid regions. In order to analyse wastewater reuse applications, chemical oxygen demand (COD) is an essential factor for tertiary treatment processes. The purpose of this study is to design an approach to evaluate COD removal from low-strength wastewater (COD 70 mg/L) for reuse. This algorithm involves two steps: 1) Activated carbon-activated sludge (AC-AS) and activated sludge-algae (AS-Algae) were investigated, and 2) Optimal conditions were determined through statistical analysis of data. Despite its inherent advantages and robustness, fuzzy logic is a well-recognised alternative algorithm in control applications. As a result of the AC-AS process, an 85% COD removal rate was achieved in 8 hours by combining 0.05 g/L AC and 5 mL/L AS. Under optimal experimental conditions (5 mL/L of AS and 7 mL/L of Algae), a 60% COD removal rate in 7 h was achieved for the AS-Algal process. Both the AC-AS and the AS-Algal systems were found to have 85% and 59% removal efficiencies, respectively. Experimental and predicted values of the AC-AS system and the AS-algal system showed excellent correlation, with a determination coefficient of 0.99 (AC-AS system) and 0.93 (AS-algal system). [ABSTRACT FROM AUTHOR]

Energy supply and its efficient use in production are key to ensuring the healthy functioning of the world economies. Based on that, to ensure sustainability, the supply and use of energy have to apply the principle of minimising negative environmental impacts and even improving the environment through net-regenerative development. In this context, ensuring cleaner energy is the cornerstone for cleaner production, especially for reducing the emissions of greenhouse gases and other pollutants, which are directly related to the types and loads of the energy sources used. This introductory article presents a review of the main lessons recently learned in the area of more efficient energy use, cleaner fuels and biofuels, cleaner production, CO 2 capture, optimisation and waste management. This article provides the readers with ideas and technologies that can be incorporated into real world solutions and can serve as the foundations for future research. With firm realisation of the importance of these issues, the 17th conference “Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction – PRES” was held in Prague, Czech Republic, to provide a platform for discussing ideas and devising solutions for cleaner energy supplies that are used more effectively and efficiently. This was followed by comprehensive research that resulted in several high quality scientific contributions published in the Journal of Cleaner Production. The wide topical coverage and the high quality provided excellent directions for future collaborative research of the PRES family – including process level emission minimisation, self-sufficient regions, and industrial symbiosis for optimizing usage of waste heat and waste material flows. [ABSTRACT FROM AUTHOR]

Researchers, industrial and institutional experts dealing with energy-related issues, have been working on improving the efficiency of energy sourcing, conversion and use, as well as on minimisation of Greenhouse Gas (GHG) emissions. As a major venue, dedicated to knowledge exchange and networking on these issues, the 19th Conference on Process Integration for Energy Saving and Pollution Reduction – PRES 2016, took place in Prague, during 27–31 August 2016. Following the venue, in collaboration with the Energy Journal, 15 high-quality manuscripts have been selected in the current Special Issue (SI). This article analyses the challenges tackled by the published articles within the overall area of energy saving and pollution reduction, briefly discussing their key actions and pointing to the achieved results. Four key areas can be distinguished in these research articles, relating to renewable energy sources, energy saving during conversion and use, direct CO 2 sequestration and regional supply issues. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) devices play an increasingly important role in solving the energy crisis. However, the conversion efficiency of the PV panel is small. Cooling of PV panels using phase change devices is an effective way to improve the working performance of PV panels. A phase change device with a two-level arrangement of metal-organic phase change materials (PCMs) is proposed. The PCM is filled in a metal cavity made of aluminium plates. A numerical model of the melting process of the combined PCMs is established, and the flow and heat transfer characteristics of the melting process are analysed. The results show that the temperature variation curve of the metal cavity wall close to the PV panel can be divided into three main stages according to the temperature increasing rate, i.e., the first rapidly rising stage, the slowly rising stage and the second rapidly rising stage. The temperature distribution inside the metallic cavity is more uniform compared to the temperature distribution inside the organic material cavity, and the flow in the metallic cavity is weaker, and the temperature controlling time shows a unimodal variation with the increase of gallium filling proportion in the studied ranges, and the optimal filling proportion is 56.9%. [Display omitted] • Solve the dimensionless temperature and velocity governing equations simultaneously. • Ambient and melting temperature influences different stage of temperature rising. • The flow in the metallic cavity is weaker than that in the organic cavity. • The temperature controlling ability of 2-stage heat sink is better than 1-stage. [ABSTRACT FROM AUTHOR]

This work aims to extend the previous Pinch Analysis framework to the industrial site material recycling network with site headers synthesis from single quality to multiple qualities. The analysis provides guided resources management strategy in any eco-industrial park to reduce the reliance on raw resources that are extracted from the environment. The Pinch Point(s) are first identified for the overall network using the Material Recovery Pinch Diagram for all the qualities. The guideline for the cross-plant material sources transfer is then built upon the concept of the Pinch Point(s) for all the qualities to minimise the cross-plant source transfer or a number of connections. An iterative header targeting framework is then proposed to determine the flowrates and the qualities of the headers. Two case studies, which have single and multiple qualities Total Site water recycling network, are used to demonstrate the proposed framework, comparing results obtained using direct integration and centralised headers. The single quality case results in 4.1% lower fresh resource intake compared to without cross-transfer, while the multiple qualities case could have 5.3% lower fresh resources for two and three plants scenarios. This framework provides a proper analysis of the problem, which allows users to gain insights on the effective cross-plant source transfer schemes with headers constraint by resource qualities. • Resources quality is the driving force for sustainable recycling of resources. • Guided strategies are proposed for minimal cross-plant source transfer with multiple qualities. • Real or 'pseudo' Pinch Points identification for multiple qualities are provided. • Iterative headers/mains parameters optimisation framework is provided. [ABSTRACT FROM AUTHOR]

Pressure drop is an important consideration in Total Site Heat Integration (TSHI). This is due to the typically large distances between the different plants and the flow across plant elevations and equipment, including heat exchangers. Failure to consider pressure drop during utility targeting and heat exchanger network (HEN) synthesis may, at best, lead to optimistic energy targets, and at worst, an inoperable system if the pumps or compressors cannot overcome the actual pressure drop. Most studies have addressed the pressure drop factor in terms of pumping cost, forbidden matches or allowable pressure drop constraints in the optimisation of HEN. This study looks at the implication of pressure drop in the context of a Total Site. The graphical Pinch-based TSHI methodology is extended to consider the pressure drop factor during the minimum energy requirement (MER) targeting stage. The improved methodology provides a more realistic estimation of the MER targets and valuable insights for the implementation of the TSHI design. In the case study, when pressure drop in the steam distribution networks is considered, the heating and cooling duties increase by 14.5% and 4.5%. [ABSTRACT FROM AUTHOR]

Present day energy policies are increasingly being focused towards local energy systems. Local communities may be more effective when implementing energy objectives due to the lower losses of energy during transmissions, closer contact with the end-users, and also greater support from local decision makers. Different tools, approaches and concepts are available for achieving greater energy efficiency within local energy systems. One of them is the Locally Integrated Energy Sectors (LIES) concept that provides energy integration with end-users from various sectors such as the industry, service, household, agriculture, transport and public sectors within a particular geographical area. LIES could well contribute towards lower energy consumption, novel opportunities for sustainable energy supply, decreased negative impact on the environment and consequently towards the amplification of sustainable development (SD) regarding local communities. The presented research focused on developing suitable metrics for evaluating the sustainability of LIES. These metrics are comprised of general sustainability indicators grouped into four major categories: energy, environmental, economic, and social. The applicability of the proposed metrics for LIES evaluation is illustrated by a case study of the district heating system within the Ormož municipality in Slovenia. [ABSTRACT FROM AUTHOR]

This paper describes a synthesis of Total Site in order to obtain additional energy savings by process-to-process heat integration. Enhanced Heat Integration and economically viable designs can be obtained by establishing an appropriate trade-off between the operating cost and the investment. The aim of this work was to improve the modeling of the Total Site by including proper pressure levels selection for intermediate utilities, preheating of intermediate utilities because of incomplete condensate recovery, pipeline layout design, and optimal pipe design with optimal pressure/temperature drops and optimal insulation thickness and heat losses during transportation along the pipes. Additionally, future utility prices are considered when synthesizing the Total Site as they are expected to influence the trade-off between investment and operating cost. A stochastic multi-period mixed-integer nonlinear programming model for the optimal synthesis of Total Site over its entire lifetime has been developed by including all the above-mentioned design aspects. [ABSTRACT FROM AUTHOR]

Due to the prominent advantages of high energy density and long-term energy conservation ability, salt hydrate-based gas-solid thermochemical energy storage (TCES) is a promising technology for effectively employing low-grade energy such as industrial waste heat and minimising fossil fuel-based sources depletion. As an innovative thermal energy storage technology that has drawn great attention from scholars in recent years, it still remains in the stage of a laboratory-scale investigation. This study establishes a reasonable classification of salt hydrates-based TCES systems, discusses the properties and performance regulation strategies of materials, types of reactors, applications, heat and mass transfer process, reaction mechanisms, and also provides critical comments and outlooks on this adsorption TCES technology. It is comprehensively elaborated and evaluated in the following steps. (i) The development of various thermochemical materials (TCMs), including pure salts, mixtures of salt hydrates, and composite TCMs of salt/matrix, is summarised and assessed in detail from the perspectives of thermochemical performances such as ESD and cyclability. (ii) The progress of the conceptual design of the reactor and prototype used for vapour/salt gas-solid reaction are presented and analysed. (iii) The existing theoretical models ranging from the views of microcosmic molecular dynamics to macrocosmic reaction kinetics are discussed. (iv) Additionally, the existing challenges regarding salt hydrate-based TCES technology are identified, and the prospects are also provided. This review enables researchers to timely grasp the latest advancements and thus may provide some rewarding insights for future investigations of salt hydrate-based gas-solid TCES and facilitate scholars to achieve better improvements. • Salt hydrate-based sorption technology is the potential for heat storage. • The composite thermochemical materials need to be further developed. • The optimisation includes three levels: material, reactor, and system. • Mechanism, model, and performance control strategy need to be further studied. • Challenges and prospects of this technology are identified. [ABSTRACT FROM AUTHOR]

Combating the COVID-19 pandemic has raised the demand for and disposal of personal protective equipment in the United States. This work proposes a novel waste personal protective equipment processing system that enables energy recovery through producing renewable fuels and other basic chemicals. Exergy analysis and environmental assessment through a detailed life cycle assessment approach are performed to evaluate the energy and environmental sustainability of the processing system. Given the environmental advantages in reducing 35.42% of total greenhouse gas emissions from the conventional incineration and 43.50% of total fossil fuel use from landfilling processes, the optimal number, sizes, and locations of establishing facilities within the proposed personal protective equipment processing system in New York State are then determined by an optimization-based site selection methodology, proposing to build two pre-processing facilities in New York County and Suffolk County and one integrated fast pyrolysis plant in Rockland County. Their optimal annual treatment capacities are 1,708 t/y, 8,000 t/y, and 9,028 t/y. The proposed optimal personal protective equipment processing system reduces 31.5% of total fossil fuel use and 35.04% of total greenhouse gas emissions compared to the personal protective equipment incineration process. It also avoids 41.52% and 47.64% of total natural land occupation from the personal protective equipment landfilling and incineration processes. • An efficient process design to produce renewable fuels from waste PPEs. • The proposed waste PPE processing system mitigates plastic pollution. • A novel detailed life cycle assessment to evaluate environmental performances. • Climate change and fossil fuel use reduction is realized in the processing system. • An application to treat waste PPEs in the New York State. [ABSTRACT FROM AUTHOR]

Collision between particle and wall is common in granular two-phase flow. This study is helpful to optimise flow conveying system, reduce attrition between materials and devices, and improve development of economy. The collision between a single coarse particle (3 mm in diameter) and wall in a viscous media was investigated by Hertz–Mindlin no-slip contact model based on the coupled computational fluid dynamics and discrete element method (CFD-DEM). Effects of impact velocity and viscosity of media on contact processes and contact force are studied in this research. The calculated results from the collision model are consistent with experimental data, and contact velocity and viscosity of media show significant effects on the contact force of particles. With the reduction of the dimensionless number St , the ratio of unloading time to loading time increases significantly. [ABSTRACT FROM AUTHOR]

Abstract: This contribution presents a simplified and more practical version of an objective dimensionality reduction method within multi-objective optimisation – a Representative Objectives Method. This method is based on similarities between several objectives in order to reduce the number of objectives to a minimum number of representative objectives. This method can be applied to different direct and total objectives. In this contribution the selected objectives are annual profit and total footprints. Total footprints are the sum of direct and indirect footprints where the direct footprints only consider the burdening of the environment, whilst the total footprints consider both the burdening and unburdening of the environment. This dimensionality reduction method is applied during a demonstration case study of regional supply chains regarding the evaluations of different total environmental footprints. This case study indicates that this simplified version of the Representative Objectives Method is easy to apply and enables the user to more easily understand multi-objective optimisation solutions. It represents a practical tool for performing the dimensionality reduction of criteria during the economic and environmental optimisation of different problems when considering total environmental footprints. [Copyright &y& Elsevier]

Process Integration supporting process design, integration and optimisation has been around for more than 40 years. Its development has been closely related to developing the Chemical Engineering, implementation of mathematical modelling and the application of information technology. Its development has been accelerating as the methodology has been able to provide answers and support for important issues regarding economic development--energy, water and resources better utilisation and savings. This contribution is targeted towards a short overview of recent achievements and future challenges. [ABSTRACT FROM AUTHOR]

Abstract: This contribution presents an optimisation methodology for a Heat Exchanger Network (HEN) design over its entire lifespan. Consideration of fluctuating energy prices is essential for achieving an optimal HEN design. The objective function presents a trade-off between investment and operating costs. Accounting for higher energy prices supports greater investments compared to solutions obtained with current prices. However, due to the uncertainty of utility prices' forecasts, retrofit with the extension of HEN regarding the lifespan, will usually be the future strategy. As there can be various designs featuring similar initial investments, the objective is to identify one design that will be the most suitable for effective future extensions, preferably with low sensitivity to energy price fluctuations. These observations resulted in development of a stochastic multi-period mixed-integer nonlinear programming (MINLP) model for the synthesis of HEN designs, with extensions accounting for future energy prices. The objective of this work was to maximise both the Expected Net Present Value with no risk assessment performed, and the Certainty Equivalent with risk assessment regarding future utility prices and investment. The results obtained indicate that when applying the proposed approach, a design with improved economic performance could be obtained, especially when compared with Total Annual Cost. [Copyright &y& Elsevier]

Vaccination now offers a way to resolve the COVID-19 pandemic. However, it is critical to recognise the full energy, environmental, economic and social equity (4E) impacts of the vaccination life cycle. The full 4E impacts include the design and trials, order management, material preparation, manufacturing, cold chain logistics, low-temperature storage, crowd management and end-of-life waste management. A life cycle perspective is necessary for sustainable vaccination management because a prolonged immunisation campaign for COVID-19 is likely. The impacts are geographically dispersed across sectors and regions, creating real and virtual 4E footprints that occur at different timescales. Decision-makers in industry and governments have to act, unify, resolve, and work together to implement more sustainable COVID-19 vaccination management globally and locally to minimise the 4E footprints. Potential practices include using renewable energy in production, storage, transportation and waste treatment, using better product design for packaging, using the Internet of Things (IoT) and big data analytics for better logistics, using real-time database management for better tracking of deliveries and public vaccination programmes, and using coordination platforms for more equitable vaccine access. These practices raise global challenges but suggest solutions with a 4E perspective, which could mitigate the impacts of global vaccination campaigns and prepare sustainably for future pandemics and global warming. • The vaccination has been rolled out globally with an unprecedented scale and pace. • The 4E pressures of COVID-19 vaccination mismanagement have been substantial. • The vaccination life cycle from vaccine development to waste management is emphasised. • Crucial lessons triggered by COVID-19 vaccination are summarised and discussed. • Smart technologies with big-vaccination-data analytics have promising applications. [ABSTRACT FROM AUTHOR]