“Modeling of CO2plasma: effect of uncertainties in the plasma chemistry”. Berthelot A, Bogaerts A, Plasma sources science and technology 26, 115002 (2017). http://doi.org/10.1088/1361-6595/aa8ffb
Abstract: Low-temperature plasma chemical kinetic models are particularly important to the plasma community. These models typically require dozens of inputs, especially rate coefficients. The latter are not always precisely known and it is not surprising that the error on the rate coefficient data can propagate to the model output. In this paper, we present a model that uses N = 400 different combinations of rate coefficients based on the uncertainty attributed to each rate coefficient, giving a good estimation of the uncertainty on the model output due to the rate coefficients. We demonstrate that the uncertainty varies a lot with the conditions and the type of output. Relatively low uncertainties (about 15%) are found for electron density and temperature, while the uncertainty can reach more than an order of magnitude for the population of the vibrational levels in some cases and it can rise up to 100% for the CO2 conversion. The reactions that are mostly responsible for the largest uncertainties are identified. We show that the conditions of pressure, gas temperature and power density have a great effect on the uncertainty and on which reactions lead to this uncertainty. In all the cases tested here, while the absolute values may suffer from large uncertainties, the trends observed in previous modeling work are still valid. Finally, in accordance with the work of Turner, a number of ‘good practices’ is recommended.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 16
DOI: 10.1088/1361-6595/aa8ffb
|
“Foundations of modelling of nonequilibrium low-temperature plasmas”. Alves LL, Bogaerts A, Guerra V, Turner MM, Plasma sources science and technology 27, 023002 (2018). http://doi.org/10.1088/1361-6595/aaa86d
Abstract: This work explains the need for plasma models, introduces arguments for choosing the type of model that better fits the purpose of each study, and presents the basics of the most common nonequilibrium low-temperature plasma models and the information available from each one, along with an extensive list of references for complementary in-depth reading. The paper presents the following models, organised according to the level of multi-dimensional description of the plasma: kinetic models, based on either a statistical particle-in-cell/Monte-Carlo approach or the solution to the Boltzmann equation (in the latter case, special focus is given to the description of the electron kinetics); multi-fluid models, based on the solution to the hydrodynamic equations; global (spatially-average) models, based on the solution to the particle and energy rate-balance equations for the main plasma species, usually including a very complete reaction chemistry; mesoscopic models for plasma–surface interaction, adopting either a deterministic approach or a stochastic dynamical Monte-Carlo approach. For each plasma model, the paper puts forward the physics context, introduces the fundamental equations, presents advantages and limitations, also from a numerical perspective, and illustrates its application with some examples. Whenever pertinent, the interconnection between models is also discussed, in view of multi-scale hybrid approaches.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 17
DOI: 10.1088/1361-6595/aaa86d
|
“Effect of plasma-induced surface charging on catalytic processes: application to CO2activation”. Bal KM, Huygh S, Bogaerts A, Neyts EC, Plasma sources science and technology 27, 024001 (2018). http://doi.org/10.1088/1361-6595/aaa868
Abstract: Understanding the nature and effect of the multitude of plasma–surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M=Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 19
DOI: 10.1088/1361-6595/aaa868
|
“Propagation of a plasma streamer in catalyst pores”. Zhang Q-Z, Bogaerts A, Plasma sources science and technology 27, 035009 (2018). http://doi.org/10.1088/1361-6595/aab47a
Abstract: Although plasma catalysis is gaining increasing interest for various environmental applications, the underlying mechanisms are still far from understood. For instance, it is not yet clear whether and how plasma streamers can propagate in catalyst pores, and what is the minimum pore size to make this happen. As this is crucial information to ensure good plasma-catalyst interaction, we study here the mechanism of plasma streamer propagation in a catalyst pore, by means of a twodimensional particle-in-cell/Monte Carlo collision model, for various pore diameters in the nm range to μm-range. The so-called Debye length is an important criterion for plasma penetration into catalyst pores, i.e. a plasma streamer can penetrate into pores when their diameter is larger than the Debye length. The Debye length is typically in the order of a few 100 nm up to 1 μm at the conditions under study, depending on electron density and temperature in the plasma streamer. For pores in the range of ∼50 nm, plasma can thus only penetrate to some extent and at
very short times, i.e. at the beginning of a micro-discharge, before the actual plasma streamer reaches the catalyst surface and a sheath is formed in front of the surface. We can make plasma streamers penetrate into smaller pores (down to ca. 500 nm at the conditions under study) by increasing the applied voltage, which yields a higher plasma density, and thus reduces the Debye length. Our simulations also reveal that the plasma streamers induce surface charging of the catalyst pore sidewalls, causing discharge enhancement inside the pore, depending on pore diameter and depth.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 16
DOI: 10.1088/1361-6595/aab47a
|
“Importance of surface charging during plasma streamer propagation in catalyst pores”. Zhang Q-Z, Wang W-Z, Bogaerts A, Plasma sources science and technology 27, 065009 (2018). http://doi.org/10.1088/1361-6595/aaca6d
Abstract: Plasma catalysis is gaining increasing interest, but the underlying mechanisms are far from understood. Different catalyst materials will have different chemical effects, but in addition, they might also have different dielectric constants, which will affect surface charging, and thus the plasma behavior. In this work, we demonstrate that surface charging plays an important role in the streamer propagation and discharge enhancement inside catalyst pores, and in the plasma distribution along the dielectric surface, and this role greatly depends on the dielectric constant of the material. For εr50, surface charging causes the plasma to spread along the dielectric surface and inside the pores, leading to deeper plasma streamer penetration, while for εr>50 or for metallic coatings, the discharge is more localized, due to very weak surface charging. In addition, at εr=50, the significant surface charge density near the pore entrance causes a large potential drop at the sharp pore edges, which induces a strong electric field and results in most pronounced plasma enhancement near the pore entrance.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 13
DOI: 10.1088/1361-6595/aaca6d
|
“Enhancement of plasma generation in catalyst pores with different shapes”. Zhang Y-R, Neyts EC, Bogaerts A, Plasma sources science and technology 27, 055008 (2018). http://doi.org/10.1088/1361-6595/aac0e4
Abstract: Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.302
Times cited: 11
DOI: 10.1088/1361-6595/aac0e4
|
“Three-dimensional modeling of energy transport in a gliding arc discharge in argon”. Kolev S, Bogaerts A, Plasma Sources Science &, Technology 27, 125011 (2018). http://doi.org/10.1088/1361-6595/aaf29c
Abstract: In this work we study energy transport in a gliding arc discharge with two diverging flat
electrodes in argon gas at atmospheric pressure. The discharge is ignited at the shortest electrode
gap and it is pushed downstream by a forced gas flow. The current values considered are
relatively low and therefore a non-equilibrium plasma is produced. We consider two cases, i.e.
with high and low discharge current (28 mA and 2.8mA), and a constant gas flow of 10 lmin −1 ,
with a significant turbulent component to the velocity. The study presents an analysis of the
various energy transport mechanisms responsible for the redistribution of Joule heating to the
plasma species and the moving background gas. The objective of this work is to provide a
general understanding of the role of the different energy transport mechanisms in arc formation
and sustainment, which can be used to improve existing or new discharge designs. The work is
based on a three-dimensional numerical model, combining a fluid plasma model, the shear stress
transport Reynolds averaged Navier–Stokes turbulent gas flow model, and a model for gas
thermal balance. The obtained results show that at higher current the discharge is constricted
within a thin plasma column several hundred kelvin above room temperature, while in the low-
current discharge the combination of intense convective cooling and low Joule heating prevents
discharge contraction and the plasma column evolves to a static non-moving diffusive plasma,
continuously cooled by the flowing gas. As a result, the energy transport in the two cases is
determined by different mechanisms. At higher current and a constricted plasma column, the
plasma column is cooled mainly by turbulent transport, while at low current and an unconstricted
plasma, the major cooling mechanism is energy transport due to non-turbulent gas convection. In
general, the study also demonstrates the importance of turbulent energy transport in
redistributing the Joule heating in the arc and its significant role in arc cooling and the formation
of the gas temperature profile. In general, the turbulent energy transport lowers the average gas
temperature in the arc, thus allowing additional control of thermal non-equilibrium in the
discharge.
Keywords: A1 Journal Article; gliding arc discharge, sliding arc discharge, energy transport, fluid plasma model, atmospheric pressure plasmas; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.302
DOI: 10.1088/1361-6595/aaf29c
|
“Capacitive electrical asymmetry effect in an inductively coupled plasma reactor”. Zhang Q-Z, Bogaerts A, Plasma Sources Science &, Technology 27, 105019 (2018). http://doi.org/10.1088/1361-6595/aad796
Abstract: The electrical asymmetry effect is realized by applying multiple frequency power sources
(13.56 MHz and 27.12 MHz) to a capacitively biased substrate electrode in a specific inductively
coupled plasma reactor. On the one hand, by adjusting the phase angle θ between the multiple
frequency power sources, an almost linear self-bias develops on the substrate electrode, and
consequently the ion energy can be well modulated, while the ion flux stays constant within a
large range of θ. On the other hand, the plasma density and ion flux can be significantly
modulated by tuning the inductive power supply, while only inducing a small change in the self-
bias. Independent control of self-bias/ion energy and ion flux can thus be realized in this specific
inductively coupled plasma reactor.
Keywords: A1 Journal Article; electrical asymmetry effect, inductively coupled plasma, self-bias, independent control of the ion fluxes and ion energy; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.302
Times cited: 1
DOI: 10.1088/1361-6595/aad796
|
“Plasma streamer propagation in structured catalysts”. Zhang Q-Z, Bogaerts A, Plasma Sources Science &, Technology 27, 105013 (2018). http://doi.org/10.1088/1361-6595/aae430
Abstract: Plasma catalysis is gaining increasing interest for various environmental applications. Catalytic
material can be inserted in different shapes in the plasma, e.g., as pellets, (coated) beads, but also
as honeycomb monolith and 3DFD structures, also called ‘structured catalysts’, which have high
mass and heat transfer properties. In this work, we examine the streamer discharge propagation
and the interaction between plasma and catalysts, inside the channels of such structured catalysts,
by means of a two-dimensional particle-in-cell/Monte Carlo collision model. Our results reveal
that plasma streamers behave differently in various structured catalysts. In case of a honeycomb
structure, the streamers are limited to only one channel, with low or high plasma density when
the channels are parallel or perpendicular to the electrodes, respectively. In contrast, in case of a
3DFD structure, the streamers can distribute to different channels, causing discharge
enhancement due to surface charging on the dielectric walls of the structured catalyst, and
especially giving rise to a broader plasma distribution. The latter should be beneficial for plasma
catalysis applications, as it allows a larger catalyst surface area to be exposed to the plasma.
Keywords: A1 Journal Article; plasma catalysis, streamer propagation, 3D structures, PIC/MCC; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.302
Times cited: 3
DOI: 10.1088/1361-6595/aae430
|
“Chemistry reduction of complex CO2chemical kinetics: application to a gliding arc plasma”. Sun SR, Wang HX, Bogaerts A, Plasma Sources Science &, Technology 29, 025012 (2020). http://doi.org/10.1088/1361-6595/ab540f
Abstract: A gliding arc (GA) plasma has great potential for CO2 conversion into value-added chemicals, because of its high energy efficiency. To improve the application, a 2D/3D fluid model is needed to investigate the CO2 conversion mechanisms in the actual discharge geometry. Therefore, the complex CO2 chemical kinetics description must be reduced due to the huge computational cost associated with 2D/3D models. This paper presents a chemistry reduction method for CO2 plasmas, based on the so-called directed relation graph method. Depending on the defined threshold values, some marginal species are identified. By means of a sensitivity analysis, we can further reduce the chemistry set by removing one by one the marginal species. Based on the socalled flux-sensitivity coupling, we obtain a reduced CO2 kinetics model, consisting of 36 or 15 species (depending on whether the 21 asymmetric mode vibrational states of CO2 are explicitly included or lumped into one group), which is applied to a GA discharge. The results are compared with those predicted with the full chemistry set, and very good agreement is reached. Moreover, the range of validity of the reduced CO2 chemistry set is checked, telling us that this reduced set is suitable for low power GA discharges. Finally, the time and spatial evolution of the CO2 plasma characteristics are presented, based on a 2D model with the reduced kinetics.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ab540f
|
“Zero-dimensional modeling of unpacked and packed bed dielectric barrier discharges: the role of vibrational kinetics in ammonia synthesis”. van ‘t Veer K, Reniers F, Bogaerts A, Plasma Sources Science &, Technology 29, 045020 (2020). http://doi.org/10.1088/1361-6595/ab7a8a
Abstract: We present a zero-dimensional plasma kinetics model, including both surface and gas phase kinetics, to determine the role of vibrationally excited states in plasma-catalytic ammonia synthesis. We defined a new method to systematically capture the conditions of dielectric barrier discharges (DBDs), including those found in packed bed DBDs. We included the spatial and temporal nature of such discharges by special consideration of the number of micro-discharges in the model. We introduce a parameter that assigns only a part of the plasma power to the microdischarges, to scale the model conditions from filamentary to uniform plasma. Because of the spatial and temporal behaviour of the micro-discharges, not all micro-discharges occurring in the plasma reactor during a certain gas residence time are affecting the molecules. The fraction of power considered in the model ranges from 0.005 %, for filamentary plasma, to 100 %, for uniform plasma. If vibrational excitation is included in the plasma chemistry, these different conditions, however, yield an ammonia density that is only varying within one order of magnitude. At only 0.05 % of the power put into the uniform plasma component, a model neglecting vibrational excitation clearly does not result in adequate amounts of ammonia. Thus, our new model, which accounts for the concept in which not all the power is deposited by the micro-discharges, but some part may also be distributed in between them, suggests that vibrational kinetic processes are really important in (packed bed) DBDs. Indeed, vibrational excitation takes place in both the uniform plasma between the micro-discharges and in the strong micro-discharges, and is responsible for an increased N2 dissociation rate. This is shown here for plasma-catalytic ammonia synthesis, but might also be valid for other gas conversion applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ab7a8a
|
“Multi-dimensional modelling of a magnetically stabilized gliding arc plasma in argon and CO2”. Zhang H, Zhang H, Trenchev G, Li X, Wu Y, Bogaerts A, Plasma Sources Science &, Technology 29, 045019 (2020). http://doi.org/10.1088/1361-6595/ab7cbd
Abstract: This study focuses on a magnetically stabilized gliding arc (MGA) plasma. Two fully coupled flow-plasma models (in 3D and 2D) are presented. The 3D model is applied to compare the arc dynamics of the MGA with a traditional gas-driven gliding arc. The 2D model is used for a detailed parametric study on the effect of the external magnetic field. The results show that the relative velocity between the plasma and feed gas is generated due to the Lorentz force, which can increase the plasma-treated gas fraction. The magnetic field also helps to decrease the gas temperature by enhancing heat transfer and to increase the electron number density. This work shows the potential of an external magnetic field to control the gliding arc behavior, for enhanced gas conversion at low gas flow rates.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/ab7cbd
|
“The effect of H2O on the vibrational populations of CO2in a CO2/H2O microwave plasma: a kinetic modelling investigation”. Verheyen C, Silva T, Guerra V, Bogaerts A, Plasma Sources Science &, Technology 29, 095009 (2020). http://doi.org/10.1088/1361-6595/aba1c8
Abstract: Plasma has been studied for several years to convert CO2 into value-added products. If CO2 could be converted in the presence of H2O as a cheap H-source for making syngas and oxygenates, it would mimic natural photosynthesis. However, CO2/H2O plasmas have not yet been extensively studied, not by experiments, and certainly not computationally. Therefore, we present here a kinetic modelling study to obtain a greater understanding of the vibrational kinetics of a CO2/H2O microwave plasma. For this purpose, we first created an electron impact cross section set for H2O, using a swarm-derived method. We added the new cross section set and CO2/H2O-related chemistry to a pure CO2 model. While it was expected that H2O addition mainly causes quenching of the CO2 asymmetric mode vibrational levels due to the additional CO2/H2O vibrational-translational relaxation, our model shows that the modifications in the vibrational kinetics are mainly induced by the strong electron dissociative attachment to H2O molecules, causing a reduction in electron density, and the corresponding changes in the input of energy into the CO2 vibrational levels by electron impact processes.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.8
DOI: 10.1088/1361-6595/aba1c8
|
“A review on learning effects in prospective technology assessment”. Thomassen G, Van Passel S, Dewulf J, Renewable &, Sustainable Energy Reviews 130, 109937 (2020). http://doi.org/10.1016/j.rser.2020.109937
Abstract: Global environmental problems have urged the need for developing sustainable technologies. However, new technologies that enter the market have often higher economic costs and potentially higher environmental impacts than conventional technologies. This can be explained by learning effects: a production process that is performed for the first time runs less smooth than a production process that has been in operation for years. To obtain a fair estimation of the potential of a new technology, learning effects need to be included. A review on the current literature on learning effects was conducted in order to provide guidelines on how to include learning effects in prospective technology assessment. Based on the results of this review, five recommendations have been formulated and an integration of learning effects in the structure of prospective technology assessment has been proposed. These five recommendations include the combined use of learning effects on the component level and on the end product level; the combined use of learning effects on the technical, economic and environmental level; the combined use of extrapolated values and expert estimates; the combined use of learning-by-doing and learning-by-searching effects and; a tier-based method, including quality criteria, to calculate the learning effect. These five complementary strategies could lead to a clearer perspective on the environmental impact and cost structure of the new technology and a fairer comparison base with conventional technologies, potentially resulting in a faster adoption and a shorter time-to-market for sustainable technologies.
Keywords: A1 journal article; Learning effects; Life cycle assessment; Techno-economic assessment; Prospective technology assessment; Learning-by-doing; Learning curve; Progress rate; Experience curve; Engineering Management (ENM) ;
Impact Factor: 15.9
DOI: 10.1016/j.rser.2020.109937
|
“The path to sustainable energy supply systems: Proposal of an integrative sustainability assessment framework”. Buchmayr A, Verhofstadt E, Van Ootegem L, Sanjuan Delmás D, Thomassen G, Dewulf J, Renewable &, Sustainable Energy Reviews 138, 110666 (2021). http://doi.org/10.1016/j.rser.2020.110666
Abstract: Energy supply is essential for the functioning and well-being of a society. Decision-makers are faced with the challenge to balance burdens and benefits of energy supply practices with the aim to achieve environmental, economic, and social sustainability. Literature exhibits a broad variety of sustainability assessment frameworks for energy supply technologies. However, there is no consensus on which aspects need to be covered for a comprehensive assessment of sustainability. While some aspects, such as environmental emission damage, receive predominant attention, there is a lack of coverage and adequate quantification for others. This led in the past to an unbalanced basis for decision-making.
Based on an analysis of literature, 12 impact categories were identified for the assessment of energy technologies. The analysis included the judgement of quantification approaches regarding their significance for describing the impact categories and their maturity resulting in the proposal of 12 concrete indicators. A framework is proposed to manage and integrate the assessment of single impact categories. The framework produces normalized and weighted output indicators to use in the form of a dashboard or alternatively a single sustainability index for informed decision-making.
Finally, the proposed sustainability assessment framework relies on life cycle, local impact, and supply chain risks assessment. It consists of both well-established assessment methods as well as suggestions for new indicators in order to allow a full assessment of all impact categories. It thereby goes beyond the isolated assessment of impacts and offers the basis for comparison of complete energy supply mixes.
Keywords: A1 Journal Article; Engineering Management (ENM) ;
Impact Factor: 8.05
DOI: 10.1016/j.rser.2020.110666
|
“Win-win possibilities through capacity tariffs and battery storage in microgrids”. Milis K, Peremans H, Springael J, Van Passel S, Renewable &, Sustainable Energy Reviews 113, 109238 (2019). http://doi.org/10.1016/J.RSER.2019.06.045
Abstract: This paper investigates the impact of capacity tariff design on microgrids. While the possible benefits for utilities of capacity tariffs are well researched, comparatively little work has been done investigating the effects of capacity pricing on prosumers. Through simulating a grid connected microgrid and solving the day-ahead dispatch problem for a calendar year, we show that a well-designed capacity tariff will not only smooth out demand profiles, but could also lead to less erratic charge/discharge cycles in a real-time pricing scenario, lessening battery degradation. These results show that a properly designed capacity tariff has the potential to be beneficial for both the utilities as well as the battery-owning prosumer. Furthermore, we propose a new, heuristic approach to solve the day-ahead economic dispatch problem, which we prove to be effective and efficient. Additionally, we demonstrate that our novel approach does not impose mathematical restrictions such as continuous differentiability of the objective function. We show that the proposed capacity tariff achieves the stated aim of promoting battery storage uptake and that our novel method allows for compression and shorter run times.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 1
DOI: 10.1016/J.RSER.2019.06.045
|
“A systematic review of environmental and economic impacts of smart grids”. Moretti M, Njakou Djomo S, Azadi H, May K, De Vos K, Van Passel S, Witters N, Renewable &, Sustainable Energy Reviews 68, 888 (2017). http://doi.org/10.1016/J.RSER.2016.03.039
Abstract: Smart grids (SGs) have a central role in the development of the global power sector. Cost-benefit analyses and environmental impact assessments are used to support policy on the deployment of SG systems and technologies. However, the conflicting and widely varying estimates of costs, benefits, greenhouse gas (GHG) emission reduction, and energy savings in literature leave policy makers struggling with how to advise regarding SG deployment. Identifying the causes for the wide variation of individual estimates in the literature is crucial if evaluations are to be used in decision-making. This paper (i) summarizes and compares the methodologies used for economic and environmental evaluation of SGs (ii) identifies the sources of variation in estimates across studies, and (iii) point to gap in research on economic and environmental analyses of SG systems. Seventeen studies (nine articles and eight reports published between 2000 and 2015) addressing the economic costs versus benefits, energy efficiency, and GHG emissions of SGs were systematically searched, located, selected, and reviewed. Their methods and data were subsequently extracted and analysed. The results show that no standardized method currently exists for assessing the economic and environmental impacts of SG systems. The costs varied between 0.03 and 1143 M/yr, while the benefits ranged from 0.04 to 804 M/yr, suggesting that SG systems do not result in cost savings The primary energy savings ranged from 0.03 to 0.95 MJ/kWh, whereas the GHG emission reduction ranged from 10 to 180 gCO2/kWh, depending on the country grid mix and the system boundary of the SG system considered. The findings demonstrate that although SG systems are energy efficient and reduce GHG emissions, investments in SG systems may not yield any benefits. Standardizing some methodologies and assumptions such as discount rates, time horizon and scrutinizing some key input data will result in more consistent estimates of costs and benefits, GHG emission reduction, and energy savings.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 27
DOI: 10.1016/J.RSER.2016.03.039
|
“Steering the adoption of battery storage through electricity tariff design”. Milis K, Peremans H, Van Passel S, Renewable &, Sustainable Energy Reviews 98, 125 (2018). http://doi.org/10.1016/J.RSER.2018.09.005
Abstract: The economic viability of electricity storage using batteries, under different tariff structures and system configurations, is investigated. The economic outcomes of the different combinations of tariff design and system configuration are evaluated. Based on a discussion of the relevant literature, the following tariff designs are used in the study: (i) fixed energy prices, (ii) real-time energy pricing, (iii) fixed rate capacity tariffs, and (iv) capacity dependent capacity tariffs. Next, the different simulated system configurations are outlined: (i) no battery storage, (ii) battery storage only, and (iii) battery storage and decentralized renewable energy production with PV. Our study provides insights for policy makers, showing that capacity block pricing only incentivises storage as part of an (existing) PV installation, while the combination of real time energy pricing and capacity block pricing promotes a wider adoption of battery storage.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 7
DOI: 10.1016/J.RSER.2018.09.005
|
“Social sustainability assessments in the biobased economy : towards a systemic approach”. Rafiaani P, Kuppens T, Van Dael M, Azadi H, Lebailly P, Van Passel S, Renewable &, Sustainable Energy Reviews 82, 1839 (2018). http://doi.org/10.1016/J.RSER.2017.06.118
Abstract: The majority of impact assessments for the biobased economy are primarily focused on the environmental and (techno-)economic aspects, while social aspects are rarely considered. This study proposes a modified systemic approach for a social sustainability impact assessment of the biobased economy, based on a review on the common methodologies for assessing social impacts. Accordingly, the proposed approach follows the four general iterative steps of social life cycle analysis (SLCA) as it considers all life cycle phases of the biobased economy. The systemic approach considers the potential social impacts on local communities, workers, and consumers as the main three groups of the stakeholders. The review showed that the most common social indicators for inventory analysis within the biobased economy include health and safety, food security, income, employment, land- and worker-related concerns, energy security, profitability, and gender issues. Multi-criteria decision analysis (MCDA) was also highlighted as the broadly utilized methodology for aggregating the results of impact assessments within the biobased economy. Taking a life cycle perspective, this study provides a holistic view of the full sustainability of research, design, and innovation in the biobased economy by suggesting the integration of the social aspects with techno-economic and an environmental life cycle assessment. Our proposed systemic approach makes possible to integrate the social impacts that are highly valued by the affected stakeholders into the existing sustainability models that focus only on environmental and techno-economic aspects. We discuss the steps of the proposed systemic approach in order to identify the challenges of applying them within the biobased economy. These challenges refer mainly to the definition of the functional unit and system boundaries, the selection and the analysis of social indicators (inventory analysis), the aggregation of the inventory to impact categories, and the uncertainties associated with the social sustainability evaluation. The result of this review and the proposed systemic approach serve as a foundation for industry and policy makers to gain a better insight into the importance of social sustainability impacts assessment within the biobased economy.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 28
DOI: 10.1016/J.RSER.2017.06.118
|
“A review of the sustainability of algal-based biorefineries : towards an integrated assessment framework”. Thomassen G, Van Dael M, Lemmens B, Van Passel S, Renewable &, Sustainable Energy Reviews 68, 876 (2017). http://doi.org/10.1016/J.RSER.2016.02.015
Abstract: Algal-based bioenergy products have faced multiple economic and environmental problems. To counter these problems, algal-based biorefineries have been proposed as a promising solution. Multiple environmental and economic assessments have analyzed this concept. However, a wide variation in results was reported. This study performs a review to evaluate the methodological reasons behind this variation. Based on this review, four main challenges for a sustainability assessment were identified: 1) the use of a clear framework; 2) the adaptation of the methodology to all stages of technological maturity; 3) the use of harmonized assumptions; 4) the integration of the technological process. A generic methodology, based on the integration of a techno-economic assessment methodology and a streamlined life cycle assessment was proposed. This environmental techno-economic assessment can be performed following an iterative approach during each stage of technology development. In this way, crucial technological parameters can be directly identified and evaluated during the maturation of the technology. The use of this assessment methodology can therefore act as guidance to decrease the time-to-market for innovative and sustainable technologies.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 23
DOI: 10.1016/J.RSER.2016.02.015
|
“A review of sustainability indicators for biobased chemicals”. Van Schoubroeck S, Van Dael M, Van Passel S, Malina R, Renewable &, Sustainable Energy Reviews 94, 115 (2018). http://doi.org/10.1016/J.RSER.2018.06.007
Abstract: Companies dealing with chemical products have to cope with large amounts of waste and environmental risk due to the use and production of toxic substances. Against this background, increasing attention is being paid to green chemistry and the translation of this concept into biobased chemicals. Given the multitude of economic, environmental and societal impacts that the production and use of biobased chemicals have on sustainability, assessment approaches need to be developed that allow for measurement and comparison of these impacts. To evaluate sustainability in the context of policy and decision-making, indicators are generally accepted means. However, sustainability indicators currently predominantly exist for low-value applications in the bioeconomy, like bioenergy and biofuels. In this paper, a review of the state-of-the-art sustainability indicators for biobased chemicals is conducted and a gap analysis is performed to identify indicator development needs. Based on the analysis, a clear hierarchy within the concept of sustainability is found where the environmental aspect dominates over economic and social indicators. All one-dimensional indicator-sets account for environmental impacts (50%), whereas two-dimensional sets complement the environmental issues with economic indicators (34%). Moreover, even the sets encompassing all three sustainability dimensions (16%) do not account for the dynamics and interlinkages between the environment, economy and society. Using results from the literature review, an indicator list is presented that captures all indicators currently used within sustainability assessment of biobased chemicals. Finally, a framework is proposed for future indicator selection using a stakeholder survey to obtain a prioritized list of sustainability indicators for biobased chemicals.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 17
DOI: 10.1016/J.RSER.2018.06.007
|
“Renewable energy development in rural areas of Iran”. Afsharzade N, Papzan A, Ashjaee M, Delangizan S, Van Passel S, Azadi H, Renewable &, Sustainable Energy Reviews 65, 743 (2016). http://doi.org/10.1016/J.RSER.2016.07.042
Abstract: Iran's energy system is extremely dependent on fossil fuels which, in turn, have led to problems such as fossil fuels depletion, social, economic and environmental damage and territorial imbalance. The country should therefore design a sustainable energy system based on clean energy as well as renewable energy. Accordingly, and given that Iran's rural areas suffer from the unsustainable energy system, it is necessary to integrate renewable energy into comprehensive development programs in general, and into rural development programs, specifically. This review paper answers the following questions: Why is renewable energy important for Iran at national and rural levels? How is renewable energy related to sustainable rural development? and What are the challenges in the promotion of renewable energy technologies in Iran? The paper concludes that although renewable energy has potential for development in Iran's rural areas due to environmental, social and economic advantages, it could face some infrastructural, managerial, socio-cultural and economic challenges. Accordingly, aggressive and innovative policy making is required to meet these challenges. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 41
DOI: 10.1016/J.RSER.2016.07.042
|
“The impact of policy on microgrid economics : a review”. Milis K, Peremans H, Van Passel S, Renewable &, Sustainable Energy Reviews 81, 3111 (2018). http://doi.org/10.1016/J.RSER.2017.08.091
Abstract: This paper investigates the impact of government policy on the optimal design of microgrid systems from an economic cost minimisation perspective, and provides both an overview of the current state of the art of the field, as well as highlighting possible avenues of future research. Integer programming, to select microgrid components and to economically dispatch these components, is the optimisation method of choice in the literature. Using this methodology, a broad range of policy topics is investigated: impact of carbon taxation, economic incentives and mandatory emissions reduction or mandatory minimum percentage participation of renewables in local generation. However, the impact of alternative tariff systems, such as capacity tariffs are still unexplored. Additionally, the investigated possible benefits of microgrids are confined to emissions reduction and a possible decrease in total energy procurement costs. Possible benefits such as increased security of supply, increased power quality or energy independence are not investigated yet. Under the expected policy measures the optimal design of a microgrid will be based on a CHP-unit to provide both heat and electricity, owning to the lower capital costs associated with CHP-units when compared to those associated with renewable technologies. This means that current economic analyses indicate that the adoption of renewable energy sources within microgrids is not economically rational.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
Times cited: 11
DOI: 10.1016/J.RSER.2017.08.091
|
“Power outages and bill savings : a choice experiment on residential demand response acceptability in Delhi”. Srivastava A, Van Passel S, Valkering P, Laes EJW, Renewable &, Sustainable Energy Reviews 143, 110904 (2021). http://doi.org/10.1016/J.RSER.2021.110904
Abstract: This paper conducts a discrete choice experiment among 167 households in the Delhi region in India, to study the acceptability of demand response (DR) programs among upper-income households. Attributes include rate types, rate bands, reductions in power outages, and expected monthly savings. Results indicate a preference for time-of-use pricing over real-time pricing, and a preference for three rate slabs per day over two. Respondents prioritize reductions in power outages and minimizing potential expenses, reflecting the financial sensitivity and energy poverty relative to other countries. Respondents' ages and incomes further affect the value that they attach to reductions in power outages. The paper proposes various structures of DR programs that could achieve high predicted enrollment and concludes by estimating the potential benefits of implementing such programs. Overall, the analysis indicates that a DR program could be feasible in a developing country context, particularly if it is designed keeping in mind local socio-economic considerations. This may be supported through further confirmatory research.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 8.05
DOI: 10.1016/J.RSER.2021.110904
|
“Tapping hydrogen fuel from the ocean : a review on photocatalytic, photoelectrochemical and electrolytic splitting of seawater”. Dingenen F, Verbruggen SW, Renewable &, Sustainable Energy Reviews 142, 110866 (2021). http://doi.org/10.1016/J.RSER.2021.110866
Abstract: Direct splitting of earth-abundant seawater provides an eco-friendly route for the production of clean H2, but is hampered by selectivity and stability issues. Direct seawater electrolysis is the most established technology, attaining high current densities in the order of 1–2 A cm−2. Alternatively, light-driven processes such as photocatalytic and photoelectrochemical seawater splitting are particularly promising as well, as they rely on renewable solar power. Solar-to-Hydrogen efficiencies have increased over the past decade from negligible values to about 2%. Especially the absence of large local pH changes (in the order of several tenths of a pH unit compared to up to 9 pH units for electrolysis) is a strong asset for pure photocatalysis. This may lead to less adverse side-reactions such as Cl2 and ClO− formation, (acid or base induced) corrosion and scaling. Besides, additional requirements for electrolytic cells, e.g. membranes and electricity input, are not needed in pure photocatalysis systems. In this review, the state-of-the-art technologies in light-driven seawater splitting are compared to electrochemical approaches with a focus on sustainability and stability. Promising advances are identified at the level of the catalyst as well as the process, and insight is provided in solutions crossing different fields.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 8.05
DOI: 10.1016/J.RSER.2021.110866
|
“Towards integrated sustainability assessment for energetic use of biomass : a state of the art evaluation of assessment tools”. Buytaert V, Muys B, Devriendt N, Pelkmans L, Kretzschmar JG, Samson R, Renewable and sustainable energy reviews 15, 3918 (2011). http://doi.org/10.1016/J.RSER.2011.07.036
Abstract: Biomass is expected to play an increasingly significant role in the greening of energy supply. Nevertheless, concerns are rising about the sustainability of large-scale energy crop production. Impacts must be assessed carefully before deciding whether and how this industry should be developed, and what technologies, policies and investment strategies should be pursued. There is need for a comprehensive and reliable sustainability assessment tool to evaluate the environmental, social and economic performance of biomass energy production. This paper paves the way for such a tool by analysing and comparing the performance and applicability of a selection of existing tools that are potentially useful for sustainability assessment of bioenergy systems. The selected tools are: Criteria And Indicators (C&I), Life Cycle Assessment (LCA), Environmental Impact Assessment (EIA), Cost Benefit Analysis (CBA), Exergy Analysis (EA) and System Perturbation Analysis (SPA). To evaluate the tools, a framework was constructed that consists of four evaluation levels: sustainability issues, tool attributes, model structure, area of application. The tools were then evaluated using literature data and with the help of a Delphi panel of experts. Finally, a statistical analysis was performed on the resulting data matrix to detect significant differences between tools. It becomes clear that none of the selected tools is able to perform a comprehensive sustainability assessment of bioenergy systems. Every tool has its particular advantages and disadvantages, which means that trade-offs are inevitable and a balance must be found between scientific accuracy and pragmatic decision making. A good definition of the assessment objective is therefore crucial. It seems an interesting option to create a toolbox that combines procedural parts of C&I and EIA, supplemented with calculation algorithms of LCA and CBA for respectively environmental and economic sustainability indicators. Nevertheless, this would require a more comprehensive interdisciplinary approach to align the different tool characteristics and focuses.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.RSER.2011.07.036
|
“Geospatial environmental techno-economic assessment of pretreatment technologies for bioethanol production”. Vasilakou K, Nimmegeers P, Billen P, Van Passel S, Renewable and sustainable energy reviews 187, 113743 (2023). http://doi.org/10.1016/J.RSER.2023.113743
Abstract: Second-generation biofuels, starting from lignocellulosic biomass, are considered as a renewable alternative for fossil fuels with lower environmental impact and potentially higher supply and energy security. The economic and environmental performance of second-generation bioethanol production from corn stover in the European Union (EU) is studied, starting in Belgium as base case. A comparative environmental techno-economic assessment has been conducted, with process simulations in Aspen Plus and corn stover availability data in thirteen EU countries to calculate minimum ethanol selling prices (MESP) and Greenhouse gas emissions (GHGe). In this analysis, the emphasis is on the comparison of different pretreatment technologies, namely (i) dilute acid, (ii) alkaline, (iii) steam explosion and (iv) liquid hot water. Dilute acid showed the best economic and environmental performance for the base case scenario. Within the EU, Hungary and Romania presented the lowest MESP for the steam explosion model at 0.39 and 0.43 EUR/L respectively. Poland showed the lowest GHGe, at 0.46 kg CO2eq/L for the alkaline model, mainly due to the avoided product allocation on electricity and its high carbon intensity in the electricity generation sector. The second lowest GHGe were obtained in France for the dilute acid model and are attributed to its low agricultural emissions intensity. This study identifies a location-dependence of the economic and environmental performance of pretreatment technologies, which can be extrapolated from the EU to other large regions around the world and should be taken into consideration by decision-makers.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
Impact Factor: 15.9
DOI: 10.1016/J.RSER.2023.113743
|
“Sailing through end-of-life challenges : a comprehensive review for offshore wind”. Vetters J, Thomassen G, Van Passel S, Renewable and sustainable energy reviews 199, 114486 (2024). http://doi.org/10.1016/J.RSER.2024.114486
Abstract: Over the past thirty years, European offshore wind farm development surged, yet end-of-life and decommissioning considerations were overshadowed by initial climate and energy security objectives during design and construction. As the first major projects near their final decade, numerous unanswered questions persist. Through a comprehensive literature review, this study identifies, maps, and evaluates challenges across technical, economic, environmental, social, and policy dimensions spanning five end-of-life phases: planning, dismantling, transport and logistics, waste management, and site recovery. Examining 42 publications reveals 46 distinct challenges affecting stakeholders such as the end-of-life supply chain, policy makers, and society. While 33% of the challenges manifested in the technical dimension, 48% of the challenges covered the planning phase. Notably, the economic challenge of vessel cost and availability was raised most often. Less-explored challenges underscore the importance of consideration before the end-of-life phase intensifies. The study illustrates the complex interconnection of numerous end-of-life challenges across phases, dimensions, and disciplines, emphasizing the imperative of addressing bottlenecks in a comprehensive and integrated manner. The results of this study help steering future research, while also improving awareness of challenges for stakeholders, emphasizing the need for collaborative efforts between governmental bodies and industry stakeholders to address imminent challenges through transparent guidelines, data exchange, and circular design principles. The novelty of this study lies in its holistic, multidisciplinary approach, systematic framework for identifying challenges, and critical perspective unveiling interconnectedness.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 15.9
DOI: 10.1016/J.RSER.2024.114486
|
“Influence of Bridgman process conditions on microstructure and porosity of single crystal Ni-base superalloy CMSX-4”. Matuszewski K, Matysiak H, Jaroszewicz J, de Nolf W, Kubiak K, Kurzydlowski KJ, International journal of cast metals research 27, 329 (2014). http://doi.org/10.1179/1743133614Y.0000000112
Abstract: Synchrotron radiation micro-X-ray fluorescence and micro-X-ray diffraction analysis, micro-computed tomography and transmission electron microscopy were used to investigate the microstructure of turbine blades made of a second generation nickel based superalloy CMSX-4 manufactured by investment casting process via Bridgman technique. The dependence of microstructure on process parameters, among others, on the withdrawal rate was analysed. The results set the stage for optimising the microstructure of the blades in terms of their mechanical properties.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1179/1743133614Y.0000000112
|
“Displacive-replacive phase transformation in a Ni62.5Al37.5 phase studies by HREM and microdiffraction”. Muto S, Merk N, Schryvers D, Tanner LE, Philosophical magazine: B: physics of condensed matter: electronic, optical and magnetic properties 67, 673 (1993). http://doi.org/10.1080/13642819308219316
Abstract: The structure of the metastable Ni2Al phase, which has long been a matter of controversy, has been carefully re-examined by means of high-resolution transmission electron microscopy (HREM) and electron microdiffraction. First, it is concluded that theas-quenched NixAl100-x(60 less-than-or-equal-to x less-than-or-equal-to 65) material already exhibits a partial omega-type collapse in a one-dimensional fashion which and is consistent with the anomalous dip in the phonon dispersion curve. Ni2Al precipitates are formed on annealing by thermal decomposition of the high-temperature NixAl100-xB2 phase and still retain the small omega-type shuffle. The amount of displacement in the well developed Ni2Al phase was estimated to be between 20 and 50% of the ideal omega collapse; this was determined by means of a combined technique of HREM and microdiffraction together with dynamical calculations of HREM images and diffraction intensities.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 16
DOI: 10.1080/13642819308219316
|