https://www.mdu.se/

mdu.sePublications
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 175) Show all publications
Krayem, A., Thorin, E. & Wallin, F. (2024). Experiences from developing an open urban data portal for collaborative research and innovation. Applied Energy, 355, Article ID 122270.
Open this publication in new window or tab >>Experiences from developing an open urban data portal for collaborative research and innovation
2024 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 355, article id 122270Article in journal (Refereed) Published
Abstract [en]

The energy transition towards sustainable resources is more urgent than ever given the environmental and geopolitical challenges. Being one of the major energy users, cities need to understand their energy sector to accomplish its transition, by means of data. However, data are not easily accessible and have their own challenges. This paper presents a joint effort between researchers, city representatives and industry to provide an urban system service that supports research, accelerates urban innovation, and involves the community. An energy data portal, “NRGYHUB”, has been developed, where hourly data from thousands of energy meters are available. These meters were collected from neighborhoods in the city of Västerås, Sweden, and they measure electrical and heating energy. In addition, the data are complemented by geometrical and non-geometrical information of the buildings, as well as demographic statistics of the areas. The paper describes the process of data collection, preprocessing, and visualization, in addition to the main challenges and limitations of the project. This dataset can be used for energy use benchmarking, prediction, and analysis. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2024
Keywords
Data portal, District heating, Electricity, Open data, Urban data
National Category
Energy Systems
Identifiers
urn:nbn:se:mdh:diva-64796 (URN)10.1016/j.apenergy.2023.122270 (DOI)001111803100001 ()2-s2.0-85176313068 (Scopus ID)
Available from: 2023-11-22 Created: 2023-11-22 Last updated: 2024-02-14Bibliographically approved
Behzadi, A., Gram, A., Thorin, E. & Sadrizadeh, S. (2023). A hybrid machine learning-assisted optimization and rule-based energy monitoring of a green concept based on low-temperature heating and high-temperature cooling system. Journal of Cleaner Production, 384, Article ID 135535.
Open this publication in new window or tab >>A hybrid machine learning-assisted optimization and rule-based energy monitoring of a green concept based on low-temperature heating and high-temperature cooling system
2023 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 384, article id 135535Article in journal (Refereed) Published
Abstract [en]

This article aims to support the targeted worldwide green transition process by introducing and thoroughly analyzing a low-temperature heating and high-temperature cooling, smart building system. This concept allows for greater use of renewable energy while utilizing less input energy than conventional heating and cooling techniques. The proposed system consists of a reversible water-to-water heat pump driven by low-temperature geothermal energy. A rule-based control strategy is developed to establish an intelligent connection with the regional energy grids for peak shaving and compensating for the building's energy costs over the year. The dynamic simulation is carried out for a multi-family building complex in Stockholm, Sweden, using TRNSYS. The most favorable operating condition is determined via an artificial neural network-assisted tri-objective optimizer based on the grey wolf algorithm in MATLAB. The comparison of the proposed smart model with the conventional system in Sweden results in 332%, 203%, and 190% primary energy reduction, cost saving, and carbon dioxide emission mitigation, respectively. As indicated by the parametric results, the conflicting fluctuation between desirable and unfavorable indicators highlights the importance of multi-objective optimization. The grey wolf optimizer obtains 12% higher efficiency, 1.2 MWh lower annual bought energy, 24 $/MWh lower unit cost, and 5.1 MWh more yearly sold energy than the design condition. The scattered distribution reveals that tank volume and subcooling degree are sensitive parameters. According to the transient results, the suggested smart system can independently satisfy the building's heating, cooling, and electricity demands for more than 81% of the year, thanks to the two-way connection with the electricity and heating networks via the rule-based controller. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Geothermal, Heat pump, High-temperature cooling, Low-temperature heating, Multi-objective optimization, Smart energy system, Carbon dioxide, Cooling, Geothermal energy, Geothermal heat pumps, Global warming, Machine learning, MATLAB, Neural networks, Temperature, Gray wolves, Heat pumps, Heating temperatures, High temperature cooling, Low temperature heating, Multi-objectives optimization, Optimizers, Rule based, Smart energy systems, Multiobjective optimization
National Category
Energy Engineering Energy Systems
Identifiers
urn:nbn:se:mdh:diva-61357 (URN)10.1016/j.jclepro.2022.135535 (DOI)000905159100001 ()2-s2.0-85143676701 (Scopus ID)
Available from: 2022-12-21 Created: 2022-12-21 Last updated: 2023-01-25Bibliographically approved
Sylwan, I. & Thorin, E. (2023). Potential of sludge-derived char as a metal sorbent during primary settling of municipal wastewater. Environmental Technology & Innovation, 32, Article ID 103258.
Open this publication in new window or tab >>Potential of sludge-derived char as a metal sorbent during primary settling of municipal wastewater
2023 (English)In: Environmental Technology & Innovation, ISSN 2352-1864, Vol. 32, article id 103258Article in journal (Refereed) Published
Abstract [en]

Reuse of nutrients and water from municipal wastewater is attracting increasing attention. However, pollutants such as toxic metals should be minimised. This study investigated the potential for reducing metal concentrations in wastewater effluent and secondary sludge by introducing sludge-derived char (SDC) as a sorbent in primary settling. Batch experiments, performed in aqueous metal solution and wastewater, showed that Cu and Ni removal was significantly reduced in wastewater containing dissolved organic matter (68% and 40%, respectively), compared to metal solution (>99% and 99%, respectively). Modelling of primary settling indicated Cd and Cu removal enhancement with SDC addition (from 39%–79% and 30%–43%, respectively). Smaller effects were observed for Pb, Cr, and Zn. An increased risk of Ni concentration in primary settler effluent was identified (−53% removal). These results demonstrate the challenges of implementing SDC as a sorbent for real wastewater.

Place, publisher, year, edition, pages
Elsevier B.V., 2023
Keywords
Adsorbent, Adsorption, Biochar, Biosolids, Biosorbent, Wastewater resource recovery facility, Copper, Metal recovery, Nickel, Sorption, Wastewater reclamation, Water conservation, Biosorbents, Cu removals, Metal concentrations, Metal solutions, Municipal wastewaters, Resource recovery, Reuse, Toxic metals, Effluents
National Category
Water Treatment
Identifiers
urn:nbn:se:mdh:diva-63887 (URN)10.1016/j.eti.2023.103258 (DOI)001032248400001 ()2-s2.0-85164222835 (Scopus ID)
Available from: 2023-07-19 Created: 2023-07-19 Last updated: 2023-09-06Bibliographically approved
Sylwan, I., Bergna, D., Runtti, H., Westholm, L. J. & Thorin, E. (2023). Primary and digested sludge-derived char as a Cd sorbent: feasibility of local utilisation. Water Science and Technology, 11, 2917-2930
Open this publication in new window or tab >>Primary and digested sludge-derived char as a Cd sorbent: feasibility of local utilisation
Show others...
2023 (English)In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 11, p. 2917-2930Article in journal (Refereed) Published
Abstract [en]

Cadmium (Cd) is a highly toxic metal, occurring in municipal wastewater and stormwater as well as in wastewater from various industries. Char derived from the pyrolysis of municipal sewage sludge has the potential to be a low-cost sorption media for the removal of Cd. However, the balance between possible local char production and demand has not been assessed previously. In this study, the Cd sorption capacities of chars derived from primary (PSC) and secondary sludge (DSC), as well as the feasibility of char production for Cd sorbent purposes, and the pyrolysis energy balance were evaluated. Results showed that the sorption capacity of PSC (9.1 mg/g; 800 degrees C, 70 min) was superior to that of DSC (6.0 mg/g; 800 degrees C, 70 min), and increased with a higher pyrolysis temperature. Pyrolysis of primary sludge had a more favourable energy balance compared with the pyrolysis of digested sludge, however, when accounting for loss of biogas production the energy balance of primary sludge pyrolysis was negative. Assessment of the regional demand (V & auml;ster & aring;s, Sweden) indicated that PSC or DSC may cover the local Cd sorbent demand. However, it was estimated that large char volumes would be required, thus making the use of DSC/PSC less feasible.

Place, publisher, year, edition, pages
IWA PUBLISHING, 2023
Keywords
adsorbent, adsorption, biochar, biosolids, biosorbent, WRRF
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-65130 (URN)10.2166/wst.2023.356 (DOI)001103107800001 ()38096078 (PubMedID)2-s2.0-85179766907 (Scopus ID)
Available from: 2023-12-20 Created: 2023-12-20 Last updated: 2024-01-03Bibliographically approved
Dong, B., Hu, C., Skvaril, J., Thorin, E. & Li, H. (2023). Selecting the approach for dynamic modelling of CO2 capture in biomass/waste fired CHP plants. International Journal of Greenhouse Gas Control, 130, Article ID 104008.
Open this publication in new window or tab >>Selecting the approach for dynamic modelling of CO2 capture in biomass/waste fired CHP plants
Show others...
2023 (English)In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 130, article id 104008Article in journal (Refereed) Published
Abstract [en]

Integrating CO2 capture with biomass/waste fired combined heat and power (CHP) plants is a promising method to achieve negative emissions. However, the use of versatile biomass/waste and the dynamic operation of CHP plants result in bigger fluctuations in the properties of flue gas (FG), e.g. CO2 concentration (CO2vol%) and flowrates, and the heat that can be used for CO2 capture, when comparing with coal fired power plants. To address such a challenge, dynamic modelling is essential to accurately estimate the amount of captured CO2 and optimize the operation of CO2 capture. This paper compares three dynamic approaches commonly used in literature, namely using the ideal static model (IST) and using dynamic models without control (Dw/oC) and with control (DwC), for MEA based chemical absorption CO2 capture. The performance of approaches is assessed under the variations of key factors, including the flowrate and CO2vol% of FG, and the available heat for CO2 capture. Simulation results show clear differences. For example, when the CO2vol% drops from 15.7 % to 9.7 % (about 38 %) within 4 hours, DwC gives the highest amount of captured CO2, which is 7.3 % and 22.3 % higher than IST and Dw/oC, respectively. It is also found that the time step size has a clear impact on the CO2 capture amount, especially for DwC. Based on the results, suggestions are also provided regarding the selection of dynamic modelling approaches for different purposes of simulations.

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Bioenergy with carbon capture and storage (BECCS), Biomass/waste fired combined heat and power plants, Dynamic modelling approach, Dynamic performance, MEA based chemical absorption, Biomass, Carbon capture, Coal fired power plant, Cogeneration plants, Ethanolamines, Fossil fuel power plants, Gas plants, More electric aircraft, Bioenergies with carbon capture and storages, Bioenergy with carbon capture and storage, Biomass wastes, Biomass/waste fired combined heat and power plant, Chemical absorption, Dynamic modeling approach, Dynamics models, Static modelling, Carbon dioxide
National Category
Energy Systems
Identifiers
urn:nbn:se:mdh:diva-64753 (URN)10.1016/j.ijggc.2023.104008 (DOI)001112149200001 ()2-s2.0-85175621556 (Scopus ID)
Available from: 2023-11-15 Created: 2023-11-15 Last updated: 2023-12-20Bibliographically approved
Behzadi, A., Thorin, E., Duwig, C. & Sadrizadeh, S. (2023). Supply-demand side management of a building energy system driven by solar and biomass in Stockholm: A smart integration with minimal cost and emission. Energy Conversion and Management, 292, Article ID 117420.
Open this publication in new window or tab >>Supply-demand side management of a building energy system driven by solar and biomass in Stockholm: A smart integration with minimal cost and emission
2023 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 292, article id 117420Article in journal (Refereed) Published
Abstract [en]

As part of the transition to a sustainable future, energy-efficient buildings are needed to secure users' comfort and lower the built environment's energy footprint and associated emissions. This article presents a novel, realistic and affordable solution to minimize the footprint of smart building energy systems and enable higher renewable energy use in the building sector. For this, an intelligent system is being developed using a rule-based automation approach that considers thermal comfort, energy prices, meteorological data, and primary energy use. In order to lower the installation cost and part of the environmental footprint, batteries are not used, and the heat pump's size is decreased via component integration. Also, different renewable resources are effectively hybridized using photovoltaic thermal panels and an innovative biomass heater to increase the share of renewable energy, enhance reliability, and shave peak load. In order to secure feasibility, the suggested framework is assessed from the techno-economic and environmental standpoints for 100 residential apartments in Stockholm, Sweden. Our results show that 70.8 MWh of renewable electricity is transferred to the local grid, and the remaining 111.5 MWh is used to supply the building's needs and power the electrically-driven components. The biomass heater meets more than 65% of the space heating demand, mainly at low solar power and high electricity prices, illustrating the value of integration strategies to reduce the system's dependability on the local grid. The results further reveal that most energy purchases during the cloudy days and nights are repaid through the sale of excess renewable production during the warmer hours, with a bidirectional connection with the grid. The monthly energy cost is less than 140 $/MWh for most of the years. The cost can be held low due to the exclusion of batteries and minimizing the heat pump size. The proposed system has a low emission index of 11.9 kgCO2/MWh and can reduce carbon dioxide emissions by 70 TCO2/year compared to using the supply from the Swedish energy mix. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Biomass, Efficient Integration, PVT, Renewable hybridization, Simultaneous demand and supply adoption, Smart building, Solar, Carbon dioxide, Costs, Electric batteries, Electric loads, Energy efficiency, Energy utilization, Global warming, Integration, Intelligent buildings, Intelligent systems, Building energy systems, Demand and supply, Heat pumps, Hybridisation, Stockholm
National Category
Energy Systems
Identifiers
urn:nbn:se:mdh:diva-63977 (URN)10.1016/j.enconman.2023.117420 (DOI)001047553600001 ()2-s2.0-85165399604 (Scopus ID)
Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2023-08-30Bibliographically approved
Desideri, U., Krayem, A. & Thorin, E. (2023). The Unprecedented Natural Gas Crisis in Europe: Investigating the Causes and Consequences with a Focus on Italy. Energies, 16(16), Article ID 5954.
Open this publication in new window or tab >>The Unprecedented Natural Gas Crisis in Europe: Investigating the Causes and Consequences with a Focus on Italy
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 16, article id 5954Article in journal (Refereed) Published
Abstract [en]

The energy prices in Europe have in recent years surpassed unprecedented thresholds and varied in unexpected ways compared to previous years. This paper presents a study of the fuel markets in Italy, supplemented by insights from Sweden. Italy is heavily dependent on natural gas. The results show that natural gas demand changed only slightly in the period 2017–2022, but prices started to increase at the end of 2021. Notable spikes occurred at the beginning of the events in Ukraine, even though the baseline was already three times higher than the average price from 2017 to 2019. Distinct dynamics can be identified with the increase in demand for power generation, contrasted with a decrease in industrial natural gas demand after August 2022. The trends in coal and wood chip prices are consistent with those of natural gas, while oil prices appear to be less correlated. Additionally, events such as CO2 trading and the launch of the Fit for 55 program by the EU show some correlation with the trend in natural gas prices during 2021. Interestingly, the origin of the increase in natural gas prices during 2021–2022 cannot be simply attributed to the mismatch of supply and demand or any singular external event. This paper aims at starting a discussion on the topic by proposing some explanations.

Place, publisher, year, edition, pages
Multidisciplinary Digital Publishing Institute (MDPI), 2023
Keywords
cross-correlation analysis, natural gas price spillover, natural gas prices, natural gas supply–demand, Commerce, Costs, Natural gas, Wood products, Energy prices, Gas crisis, Natural gas demand, Natural gas price, Natural gas supply, Supply-demand, Gases
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-64182 (URN)10.3390/en16165954 (DOI)001057695100001 ()2-s2.0-85168780437 (Scopus ID)
Available from: 2023-09-06 Created: 2023-09-06 Last updated: 2023-12-04Bibliographically approved
Xie, Y., Wang, L., Li, H., Westholm, L. J., Carvalho, L., Thorin, E., . . . Skreiberg, Ø. (2022). A critical review on production, modification and utilization of biochar. Journal of Analytical and Applied Pyrolysis, 161, Article ID 105405.
Open this publication in new window or tab >>A critical review on production, modification and utilization of biochar
Show others...
2022 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 161, article id 105405Article in journal (Refereed) Published
Abstract [en]

There has been an increased interest in the production of sustainable biochar in the past years, as biochar shows versatile physicochemical properties and, can have a wide applicability in diverse fields. Comprehensive studies have been made to characterize biochar produced from various biomass materials, using different production technologies and under different process conditions. However, research is still lacking in correlating biochar properties needed for certain applications with (i) feedstock, (ii) biochar production processes and conditions and (iii) biochar upgrading and modification strategies. To produce biochar with desired properties, there is a great need to establish and clarify such correlations, which can guide the selection of feedstock, tuning and optimization of the production process and more efficient utilization of biochar. On the other hand, further elucidation of these correlations is also important for biochar-stakeholder and end-users for predicting physiochemical properties of biochar from certain feedstock and production conditions, assessing potential effects of biochar utilization and clearly address needs towards biochar critical properties. This review summarizes a wide range of literature on the impact of feedstocks and production processes and reactions conditions on the biochar properties and the most important biochar properties required for the different potential applications. Based on collected data, recommendations are provided for mapping out biochar production for different biochar applications. Knowledge gaps and perspectives for future research have also been identified regarding the characterization and production of biochar. 

Place, publisher, year, edition, pages
Elsevier B.V., 2022
Keywords
Applications, Biochar, Feedstock, Production, Properties
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-57195 (URN)10.1016/j.jaap.2021.105405 (DOI)000788825200008 ()2-s2.0-85123241918 (Scopus ID)
Available from: 2022-02-02 Created: 2022-02-02 Last updated: 2022-05-18Bibliographically approved
Sylwan, I. & Thorin, E. (2022). Sludge-derived char - potential as a heavy metal sorbent during primary settling of municipal wastewater. In: : . Paper presented at World Water Congress and Exhibition 2022, Copenhagen, Denmark, 11-15 September, 2022..
Open this publication in new window or tab >>Sludge-derived char - potential as a heavy metal sorbent during primary settling of municipal wastewater
2022 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Other Engineering and Technologies
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-61203 (URN)
Conference
World Water Congress and Exhibition 2022, Copenhagen, Denmark, 11-15 September, 2022.
Available from: 2022-12-12 Created: 2022-12-12 Last updated: 2022-12-12Bibliographically approved
Sun, Y., Dong, B., Wang, L., Li, H. & Thorin, E. (2022). Technology selection for capturing CO2 from wood pyrolysis. Energy Conversion and Management, 266, Article ID 115835.
Open this publication in new window or tab >>Technology selection for capturing CO2 from wood pyrolysis
Show others...
2022 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 266, article id 115835Article in journal (Refereed) Published
Abstract [en]

Emerging negative emission technologies (NETs) are considered as effective measures to reduce carbon dioxide emissions to achieve the climate goal set by the Paris Agreement, and bioenergy with carbon capture and storage (BECCS) is one of the most important NETs. Integrating CO2 capture with biomass pyrolysis (PyrCC) is attracting increasing interest, because biomass pyrolysis has been widely used to produce biooil to replace fossil fuel for decarbonizing the transport sector. In order to provide guidance to the selection of CO2 capture technologies, this paper evaluated the technical and economic performances of PyrCC when different CO2 capture technologies are integrated, including monoethanolamine-based chemical absorption (MEA-CA), temperature swing absorption (TSA), calcium looping (CaL), and chemical looping combustion (CLC). Generally speaking, CLC can realize the highest capture amount of CO2 with the lowest energy penalty. Meanwhile, CLC and CaL show the lowest levelized cost of CO2 (LCOC), which are around 56$/tCO(2); and on the contrary MEA-CA shows the highest one of 83 $/tCO(2). In addition, the key process parameter of pyrolysis, reaction time, has clear effects on the performance of CO2 capture as the longer reaction time leads to an increased amount of captured CO2 and reduced energy penalty. As a result, when the reaction time increases, the LCOCs of all assessed technologies decrease. Moreover, the net present value and the payback time are also estimated for different technologies. At the carbon price of 70.1$/tCO(2), MEA-CA and CLC show the longest and shortest payback time that are 5.9 years and 3.2 years respectively.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2022
Keywords
Bioenergy with carbon capture and storage (BECCS), Negative emission technologies, Pyrolysis, Economic analysis, Energy efficiency, Levelized cost of CO2
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-59570 (URN)10.1016/j.enconman.2022.115835 (DOI)000817782300002 ()2-s2.0-85131604822 (Scopus ID)
Available from: 2022-07-13 Created: 2022-07-13 Last updated: 2022-08-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3485-5440

Search in DiVA

Show all publications