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A real-life benchmark system comprising a Heat Exchanger Network operated as part of Crude Distillation Unit is considered. In such systems, the crude oil stream is typically split into parallel branches and the oil mass flows through the branches are kept in constant proportion, i.e., at constant split ratio, by the process control system. In this paper, linear control systems (proportional-integral-derivative controllers) are considered and the proposed control strategy is to adjust the parallel flows so that identical temperature values are maintained at the outlets from two parallel branches and consequently, the heat recovery in the network is maximized. The aim is to enhance the energy efficiency of the system and minimise greenhouse gas emissions. A mathematical model of the heat exchanger network was built and validated on the basis of real-life data recorded during operation of the crude distillation unit. Using MATLAB/Simulink, closed-loop control was simulated to enable comparative evaluation of the studied strategy of proportional-integral-derivative control and its potential to achieve energy savings in the operation of the distillation unit under fouling conditions. Compared to the strategy of constant split ratio, the proposed strategy of equal outlet temperatures from the network branches was found to increase the total heat recovery by about 1.5%. In the studied operation period, the heat-recovery increase fluctuated in the range 150–1100 kW and the average daily energy saving was estimated at 18 MWh.

Joint efforts and interdisciplinary approach are proper means to face the issue of global warming. An adequate response should be to employ state of the art scientific knowledge for the technology advancement, as well as for fostering new scientific insights. Together with resource efficiency, circular economy is getting in focus of researchers and consequently policymakers. Sustainable development is a multidisciplinary topic and interaction of energy, water and environment systems plays one of the central roles. Within the paradigm of circular economy, there is growing need for system integration where a by-product of one system can represent resource for the other. This review is dedicated to the 12th Conference on Sustainable Development of Energy, Water and Environment Sysmems, and discusses some latest developments in three main areas of sustainability themes: (i) Energy, (ii) Water and (iii) Environmental Systems. Examples of circular economy approach have been emphasized which improve economic efficiency of the whole chain and further decrease environmental burden, enabling cleaner production. Although integrative concept of energy, water and environmental systems is coming in the research focus, more effort is necessary for further integration of those systems, whereby increased complexity is going to be handled only by multidisciplinary, intersectoral scientific cooperation.

Sustainable development is a highly interdisciplinary concept that involves the interaction of various systems, such as energy, water, and environment. In 2002, the Sustainable Development of Energy, Water, and Environment Systems (SDEWES) Conferences were established to address this issue. In 2020, four SDEWES conferences were held—due to the COVID 19 pandemic, all of them as online events. SDEWES 2020 conferences created a temporally and spatially distributed forum for researchers worldwide to exchange and discuss their ideas and findings and show the sciences’ responsivity to national, regional, and global challenges. The overview of papers included in this Special Issue of SUSTAINABILITY is presented. The papers were chosen to match strategic importance fields of sustainable development: energy, water, buildings and infrastructure, and waste management and valorization.

La industria de la pintura de automoviles es una fuente de contaminacion ambiental causada por los compuestos organicos volatiles (COV) presentes en el aire de ventilacion descargado. Para contribuir a la mitigacion de este tipo de contaminacion atmosferica, Ekoinwentyka Ltd. desarrollo -desde la escala piloto hasta la escala completa- y adapto la tecnologia del biorreactor de lecho de goteo compacto (CTBB), cuyo principio de funcionamiento se basa en el flujo descendente de la fase gaseosa (aire contaminado) y la fase liquida (solucion de sales minerales) a traves de un lecho empacado en el que los microorganismos activos se inmovilizan en la biopelicula de las superficies de los elementos de empaquetado. El biorreactor a escala piloto de 0,32 m de diametro y 1,50 m de altura total tenia su lecho empacado inoculado con un consorcio de microorganismos dominado por la bacteria Pseudomonas fluorescens. Durante el programa experimental, que duro varios meses, el caudal de aire extraido del sistema de ventilacion del taller de pintura variaba entre 1,0 y 10,0 m3/h y la concentracion de entrada de COV oscilaba entre 10 y 200 ppm. Al medir la concentracion de COV en el aire purificado, se comprobo que el factor de biodegradacion de los COV oscilaba entre el 85 y el 99%. A partir de los experimentos a escala piloto, se ha desarrollado un CTBB a escala real de 2,8 m de diametro y 10 m de altura total y se ha instalado como componente adicional del sistema de ventilacion del taller de pintura. Las pruebas realizadas con caudales de gas de hasta 6.000 m3/h confirmaron un factor de biodegradacion de COV del 85-99%, lo que demuestra un resultado positivo de la adaptacion de la tecnologia CTBB a las condiciones de la industria de la pintura de automoviles.

Due to climate change concerns, various environmental stresses and social inequality among the people, the welfare of mankind is increasingly being viewed through the prism of sustainable development. Sustainable development is a highly multi-disciplinary field of research that has been extensively studied during last two decades. Therefore, from the beginning of the 21st century, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences were founded to address sustainable development issues. This Journal of Cleaner Production Special Volume (SV) is dedicated to the 10th SDEWES Conference. The SV is focused on three main fields that are of strategic importance to sustainable development: energy issues, water issues, and environmental engineering and management. The division of selected papers according to the named research fields was established following the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the SDEWES Conferences. Therefore, this Special Volume builds upon the previously generated SDEWES knowledge base.

Odors are emitted from agricultural and industrial activities, such as animal farms, rendering plants, wastewater treatment plants, waste treatment or disposal facilities, paint shops, oil refineries, pulp and paper mills, and various chemical industries. Effects of this kind of air pollution may include: impairment of the quality of the environment; interference with business activities; discomfort, harm or impairment of the safety of any person; rendering any property, plant or animal unsuitable for human use. Odor treatment technologies can be classified into three categories, namely ones employing chemical (thermal oxidation, catalytic oxidation, ozonation), physical (condensation, adsorption, absorption) and biological (using biofilters, biotrickling filters, bioscrubbers and other bioreactor types) treatment methods. An important advantage of biological treatment methods over physical and chemical technologies is that the biological processes can be conducted at moderate temperatures (10–40 °C) and atmospheric pressure. Moreover, microbial degradation processes are generally oxidative in nature and produce compounds such as carbon dioxide, water, sulfate and nitrate that are ecologically safe. Applications of biological odor treatment date back to 1950ties. Initially, simple biofilters with soil beds have been employed and later, the use of other bed materials in more advanced filter structures has been reported and more sophisticated types of filtration equipment such as biotrickling filters and bioscrubbers have been developed. On the basis of accumulated experience, some more process options and equipment types for the application of biological methods emerged in recent years. During more than 30 years covered by the present review, biological methods of odor treatment have matured to become a well-developed field of process technology. In order to provide an overview of the state of the art, process principles and characteristics including the use of various microorganisms and nutrients, variations in equipment design and application ranges of the different odor treatment technologies are outlined and compared.

Energy-saving heat recovery in an industrial heat exchanger network may by impaired by fouling build-up on heat transfer surfaces of the exchangers. During longer periods of network operation, monitoring of fouling growth based on measurement data makes it possible to schedule and perform exchanger cleaning if needed for the mitigation of adverse effects of fouling. Three different methods of measurement-aided fouling monitoring are outlined: two simple methods known from literature and a least-squares based method introduced by the authors. A case study is performed on their hypothetical application in a real-life network of shell-and-tube heat exchangers used for heat recovery in crude distillation unit. Using historical measurement data recorded during three-year continuous operation of the network, the different methods are first employed to estimate the thermal effects of fouling and then used in the simulation of attainable energy and economic savings resulting from two alternative options of cleaning interventions in the network. The least-squares based method of measurement-aided fouling monitoring is identified as best suited for the evaluation of effectiveness of cleaning interventions in heat exchanger networks.

Engineering analyses based on the results of numerical simulation enable shortening the duration and reducing the costs of the development and tests of equipment models or prototypes. As numerical modeling methods have uncertainties, experimental verification is required. In the literature, there are many examples of application of numerical modelling to the thermal processes occurring in electric motors but the experimental methods of model validation are not so well described. In this work, numerical and experimental investigations of heat conduction in the finned housing of an electric motor, and the comparison between their results are presented. 3D geometrical model of the motor rated 7.5 kW was imported to COMSOL Multiphysics software package. After defining thermophysical properties of the housing material and heat flows generated in the motor, and setting boundary conditions, a numerical model of heat conduction in the motor housing was obtained. The model allowed to calculate steady-state temperature distribution in the housing cross section. In order to validate the model, investigations of the temperature distribution were carried out using FLIR SC7600 thermovision camera. Steady-state temperature distribution on the surface of housing of the motor run in idling conditions was recorded by thermography. The obtained thermograms were found to be in satisfactory quantitative agreement with the simulated temperature distribution as the real values of temperature differences measured across the housing cross section deviated not more than 10% from the calculated ones. The research confirmed that a thermovision camera is an efficient experimental tool for the validation of numerical models of the heat transfer phenomena in the finned housing of an electric motor.

The influence of fouling build-up on the dynamic behavior of PID-controlled shell-and-tube heat exchangers was studied. A mathematical model was proposed in which heat exchanger is considered as an array of cells where the exchange of heat is modelled using lumped-parameter approach. The model was implemented employing Simulink/MATLAB software and validated using real-life data records acquired during 3 years of operation of a heat exchanger network coupled with a crude distillation unit. Using the validated dynamic model, a simulation study was carried out on selected PID-controlled exchangers operated in the mentioned network. For different periods of uninterrupted exchanger operation, that is, at different values of the thermal resistance of fouling, suitable controller tuning parameters were studied. The results proved that at changed thermal resistance of fouling, the values of tuning parameters should be changed too.

A compact trickle-bed bioreactor (CTBB) was tested for the removal of volatile organic compounds (VOCs) and hydrogen sulphide (H2S) present in the exhaust air of a wastewater treatment plant. At gas-flow rates varying between 2.0 and 30.0 m3/h and for specific pollutant loads up to 20 g/(m3·h), removal efficiencies for H2S and VOC were >95%. The CTBB was designed for a maximum H2S concentration of ∼200 ppm and removal efficiencies >97% were noticed. VOC concentrations were in the range of 25–240 ppmv and the removal efficiency was in the range of 85–99%. Possible consequences of an excessive pollutant overload and the time required for regenerating the microbial activity and reviving stable process conditions in the CTBB were also investigated. An increase in the H2S concentration from 400 to 600 ppmv for a few hours caused bioreactor poisoning; however, when original H2S concentrations were restored, stable CTBB operation was ascertained within 3 h.

Following the 2015 Paris Agreement, the main challenge for world economies nowadays is to commit themselves to long-term reforms aimed at increasing and promoting sustainable, inclusive and balanced development. An adequate response to this challenge will certainly require using the best available scientific knowledge and constant re-evaluation of the development process in light of the scientific findings. To ensure that the sciences are responsive to the emerging needs and to address sustainable development issues. This Virtual Special Issue of the Journal of Cleaner Production is dedicated to both Sustainable Development of Energy, Water and Environment Systems 2016 Conferences – 2nd South East European Sustainable Development of Energy, Water and Environment Systems Conference and 11th Sustainable Development of Energy, Water and Environment Systems Conference. The Virtual Special Issue is focused on four main fields: Energy issues, Water issues, Environmental engineering and management, and Sustainable engineering solutions and large-scale sustainability approaches. The division of selected papers follows the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the Sustainable Development of Energy, Water and Environment Systems Conference series.

Fermentative hydrogen production from molasses—a renewable by-product of beet-sugar processing—was considered. Technical and economic evaluations were performed of a stand-alone production plant employing a two-step fermentation process (dark thermophilic fermentation and photofermentation) followed by an adsorption-based upgrading of the produced hydrogen gas. Using a state-of-the-art knowledge base and a mathematical model composed of mass and energy balances, as well as economic relationships, the process was simulated and equipment data were estimated, the hydrogen cost was calculated and a sensibility analysis was carried out. Due to high capital, operating and labor costs, hydrogen production cost was estimated at a rather high level of 32.68 EUR/kg, while the energy output in produced hydrogen was determined as 68% more than the combined input of the thermal and electric energy needed for plant operation. As the room for improvement of plant performance is limited, a perspective on the cost competitiveness of large-scale hydrogen production from fossil sources is unclear.

The present work is an extension of the authors&rsquo, previous research, where changes in the dynamic behavior of heat exchangers induced by fouling build-up were studied. In the present work, the authors used the previously elaborated and validated mathematical model of transient heat exchange with the influence of thermal resistance of fouling taken into account. The behavior of specific Heat Exchanger Networks (HENs) coupled with a Crude Distillation Unit together with their control loops is simulated using Simulink/MATLAB and the influence of fouling build-up on specific indices of quality of operation is investigated. According to the presented results, the higher the number of heat exchangers in the PID control loop and the greater the number of heat exchangers interacting in the network, the smaller the influence of fouling on the control quality indices, and in the extreme case, this influence may be negligible. This might be caused by the compensation of the negative effects of fouling build-up when the heat exchangers are interacting in the HEN. Nevertheless, potential adverse effects of fouling on HEN operation can be prevented by periodic adjustments of the optimal values of PID gains.

The cement production industry worldwide is one of the largest CO2 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: CO2 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.

One of the main issues of the coming decades is to improve resource efficiencies by integrating various life supporting systems, using waste from one, as resource in other, and in exact moment when it is beneficial to all. The challenge is on the electricity, heating, cooling, transport, water, buildings, industry, forestry and agriculture systems to integrate and become more sustainable. Since the sustainable development depends more and more on the holistic approach on the integration of energy, water and environment systems, from the beginning of the 21st century, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences has been founded to cover these issues. The background of this Special Section of the Journal of Cleaner Production is therefore the Sustainable Development of Energy, Water and Environment Systems dedicated to both SDEWES 2014 Conferences - 1st South East European SDEWES Conference and 9th SDEWES Conference. The Special Section focuses on scientists, researchers, policy makers, educators, general public and practitioners in various branches of industry including the energy and water & wastewater sectors and environmental services. The purpose of this Special Section is to increase public awareness of key issues of sustainable development and to stimulate exchange of research results, practical experience and novel ideas among actors involved in investigating, planning and implementing sustainable development. The Special Section is focused upon four main fields that are of strategic importance to the sustainable development: Energy issues ; Water issues ; Environmental engineering and management ; Sustainability approaches and promotion of sustainability concepts. The division of selected papers according to the named research fields has been established by the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the SDEWES 2013 Conference. Hence, this Special Section is an extension of the previously generated SDEWES knowledge base in these four main research areas. As sustainable development is improving piecewise, so although it is necessary to see the big picture, actual technological improvement is one aspect of the technology systems. It has been shown that the sustainability can be improved by improving certain systems taking care of holistic sustainability criteria or integrating various systems in a way to improve the efficiency or resource efficiency of the combined system.