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  • 1.
    Aftab, Umair
    et al.
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Tahira, Aneela
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, SE-60174, Sweden.
    Gradone, Alessandro
    CNR-IMM, Via Piero Gobetti 101, Bologna, 40129, Italy. Chemistry Department “G.Ciamician”, University of Bologna, Bologna, 40126, Italy.
    Morandi, Vittorio
    CNR-IMM, Via Piero Gobetti 101, Bologna, 40129, Italy.
    Abro, Muhammad Ishaq
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Baloch, Muhammad Moazam
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Bhatti, Adeel Liaquat
    Institute of Physics University of Sindh, Jamshoro, Sindh, 76080, Pakistan.
    Nafady, Ayman
    Department of Chemistry, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, Venezia, Mestre, 30172, Italy.
    Ibupoto, Zafar Hussain
    Dr. M.A Kazi Institute of Chemistry University of Sindh, Jamshoro, Sindh, 76080 Pakistan.
    Two step synthesis of TiO2–Co3O4 composite for efficient oxygen evolution reaction2021Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 46, nr 13, s. 9110-9122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For an active hydrogen gas generation through water dissociation, the sluggish oxygen evolution reaction (OER) kinetics due to large overpotential is a main hindrance. Herein, a simple approach is used to produce composite material based on TiO2/Co3O4 for efficient OER and overpotential is linearly reduced with increasing amount of TiO2. The scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) investigations reveal the wire like morphology of composite materials, formed by the self-assembly of nanoparticles. The titania nanoparticles were homogenously distributed on the larger Co3O4 nanoparticles. The powder x-ray diffraction revealed a tetragonal phase of TiO2 and the cubic phase of Co3O4 in the composite materials. Composite samples with increasing TiO2 content were obtained (18%, 33%, 41% and 65% wt.). Among the composites, cobalt oxide-titanium oxide with the highest TiO2 content (CT-20) possesses the lowest overpotential for OER with a Tafel slope of 60 mV dec−1 and an exchange current density of 2.98 × 10−3A/cm2. The CT-20 is highly durable for 45 h at different current densities of 10, 20 and 30 mA/cm2. Electrochemical impedance spectroscopy (EIS) confirmed the fast charge transport for the CT-20 sample, which potentially accelerated the OER kinetics. These results based on a two-step methodology for the synthesis of TiO2/Co3O4 material can be useful and interesting for various energy storage and energy conversion systems.

  • 2.
    Elsadek, Mohamed
    et al.
    SWERIM AB, Aronstorpsvagen 1, 974 37, Luleå, Sweden; Central Metallurgical Research and Development Institute (CMRDI), Cairo 12422, Egypt.
    Mousa, Elsayed
    SWERIM AB, Aronstorpsvagen 1, 974 37, Lulea, Sweden; Central Metallurgical Research and Development Institute (CMRDI), Cairo 12422, Egypt.
    Ahmed, Hesham
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi. Central Metallurgical Research and Development Institute (CMRDI), Cairo 12422, Egypt.
    Green approach to ironmaking: Briquetting and hydrogen reduction of mill scale using novel binders2024Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 62, s. 732-738Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The most prominent solutions are the establishment of a circular economy by recirculating the iron-rich residues from steelworks and the adoption of hydrogen as a clean reducing agent to mitigate fossil CO2 emission. One such residue is mill scale, which is generated during steelmaking, casting, and rolling processes. However, the fine particles and easy reoxidation of the mill scale make it difficult to be used directly in iron and steel production without proper compaction. This paper aims to demonstrate the feasibility of mill scale briquetting using organic binders to meet the requirements of hydrogen-based direct reduction. The study will investigate the influence of binder type, binder dosage, moisture content, and compaction pressure on the briquetting process and the briquettes quality. Moreover, the reducibility of optimized briquettes will be examined by hydrogen at 900 °C using a thermogravimetric analyzer coupled with a quadrupole mass spectroscopy (TGA-QMS). The optimal combination for achieving the best mechanical strength and reducibility was a briquette produced with 1% Alcotac® CB6, 1% KemPel, and 2.5% moisture content, compressed at a pressure of 125 kN.

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  • 3.
    Esmaili, Qadir
    et al.
    Faculty of Engineering, Amol University of Special Modern Technologies, Amol, Iran.
    Nimvari, Majid Eshagh
    Faculty of Engineering, Amol University of Special Modern Technologies, Amol, Iran.
    Jouybari, Nima Fallah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Chen, Yong-Song
    Advanced Institute of Manufacturing with High-tech Innovations and Department of Mechanical Engineering, National Chung Cheng University, 168 University Rd., Minhsiung Township, 62102, Chiayi, Taiwan, ROC.
    Model based water management diagnosis in polymer electrolyte membrane fuel cell2020Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 45, nr 31, s. 15618-15629Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water management diagnosis in polymer electrolyte membrane fuel cell is of great importance. The water produced in the fuel cell affects its performance and lifetime through the current distribution and the two phase flow pattern in the channel. The aim of the present study is to modify a segmented model in order to investigate a model-based water management diagnosis at different operating conditions. Simulations are conducted in three current densities: low (0.2 A/cm2), medium (0.6 A/cm2) and high (1 A/cm2), four temperatures ranged from 40 to 70, two stoichiometries (2 and 3) and four inlet humidities (25%, 50%,75% and 100%). The results show that at fully saturation inlet condition, there is a uniform local current density for all three considered current densities. Also, two-phase pressure drop and output voltage have similar trends. Hence two phase pressure drop can be considered as a suitable criterion for water management diagnosis. At inlet humidities less than 50%, non-uniformity of local current density increases that leads to reduction of output voltage, especially at high current density. Generally, for non-saturated inlet condition, two phase pressure drop and output voltage may show different trends. Therefore, two-phase pressure drop can be used only as a criterion for the formation of water and not for water management diagnosis.

  • 4.
    Gobbato, Paolo
    et al.
    Department of Mechanical Engineering, University of Padova.
    Masi, Massimo
    Department of Mechanical Engineering, University of Padova.
    Toffolo, Andrea
    Lazzaretto, Andrea
    Department of Mechanical Engineering, University of Padova.
    Numerical simulation of a hydrogen fuelled gas turbine combustor2011Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, nr 13, s. 7993-8002Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The interest for hydrogen-fuelled combustors is recently growing thanks to the development of gas turbines fed by high content hydrogen syngas. The diffusion flame combustion is a well-known and consolidated technology in the field of industrial gas turbine applications. However, few CFD analyses on commercial medium size heavy duty gas turbine fuelled with pure hydrogen are available in the literature. This paper presents a CFD simulation of the air-hydrogen reacting flow inside a diffusion flame combustor of a single shaft gas turbine. The 3D geometrical model extends from the compressor discharge to the gas turbine inlet (both liner and air plenum are included). A coarse grid and a very simplified reaction scheme are adopted to evaluate the capability of a rather basic model to predict the temperature field inside the combustor. The interest is focused on the liner wall temperatures and the turbine inlet temperature profile since they could affect the reliability of components designed for natural gas operation. Data of a full-scale experimental test are employed to validate the numerical results. The calculated thermal field is useful to explain the non-uniform distribution of the temperature measured at the turbine inlet

  • 5.
    Larsson, Mårten
    et al.
    Depart. of Chemical Engineering and Technology, KTH – Royal Institute of Technology, Sweden.
    Mohseni, Farzad
    SWECO, Sweden.
    Wallmark, Cecilia
    SWECO, Sweden.
    Grönkvist, Stefan
    Depart. of Chemical Engineering and Technology, KTH – Royal Institute of Technology, Sweden.
    Alvfors, Per
    Depart. of Chemical Engineering and Technology, KTH – Royal Institute of Technology, Sweden.
    Energy system analysis of the implications of hydrogen fuel cell vehicles in the Swedish road transport system2015Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 40, nr 35, s. 11722-11729Artikel i tidskrift (Refereegranskat)
  • 6.
    Raj, Aashna
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Larsson, I. A. Sofia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Ljung, Anna-Lena
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Forslund, Tobias
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Andersson, Robin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sundström, Joel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Lundström, T.Staffan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Evaluating hydrogen gas transport in pipelines: Current state of numerical and experimental methodologies2024Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 67, s. 136-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This review article provides a comprehensive overview of the fundamentals, modelling approaches, experimental studies, and challenges associated with hydrogen gas flow in pipelines. It elucidates key aspects of hydrogen gas flow, including density, compressibility factor, and other relevant properties crucial for understanding its behavior in pipelines. Equations of state are discussed in detail, highlighting their importance in accurately modeling hydrogen gas flow. In the subsequent sections, one-dimensional and three-dimensional modelling techniques for gas distribution networks and localized flow involving critical components are explored. Emphasis is placed on transient flow, friction losses, and leakage characteristics, shedding light on the complexities of hydrogen pipeline transportation. Experimental studies investigating hydrogen pipeline transportation dynamics are outlined, focusing on the impact of leakage on surrounding environments and safety parameters. The challenges and solutions associated with repurposing natural gas pipelines for hydrogen transport are discussed, along with the influence of pipeline material on hydrogen transportation. Identified research gaps underscore the need for further investigation into areas such as transient flow behavior, leakage mitigation strategies, and the development of advanced modelling techniques. Future perspectives address the growing demand for hydrogen as a clean energy carrier and the evolving landscape of hydrogen-based energy systems.

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  • 7.
    Sarkar, Omprakash
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Rova, Ulrika
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Christakopoulos, Paul
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Matsakas, Leonidas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Continuous biohydrogen and volatile fatty acids production from cheese whey in a tubular biofilm reactor: Substrate flow rate variations and microbial dynamics2024Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 59, s. 1305-1316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Three tubular bioreactors with a varied substrate flow rate of (2 mL/min, 5 mL/min, and 8 mL/min) were examined for 75 days. At 8 mL/min flow rate, the biohydrogen evolution was higher (3.88 mL H2/h), while its conversion efficiency was lower compared to 5 and 2 mL/min flow rate. The formation of volatile fatty acids and ammonium was also influenced by substrate flow rates. The volatile fatty acids production was slightly higher at 2 mL/min (12.74 ± 2.42 gCOD/L) and 5 mL/min (18.09 ± 2.01 gCOD/L) while, decreasing at 8 mL/min (11.85 ± 0.78 gCOD/L). Substrate flow rate significantly affected the pattern and composition of volatile fatty acids showing higher acetic acid, butyric and propionic acid production of 4.72 ± 1.46 gCOD/L (2 mL/min) 10.41 ± 0.91 gCOD/L (5 mL/min) and 1.78 ± 0.13 gCOD/L (5 mL/min). Continuous substrate input maintained the pH in the reactor due to replacement with fresh substrate, thereby controlling feedback inhibition and boosting metabolite production. Hydrogen-producing Firmicutes on the biofilm confirmed the pivotal role of the microbial community's significant contribution to converting waste to bioenergy. Overall, the present results support the use of a continuous operation mode for large-scale biohydrogen production. However, to ensure the efficacy of the system using waste or wastewater, low substrate flow rates are recommended.

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  • 8.
    Velvizhi, G.
    et al.
    CO2 Research and Green Technology Centre, Vellore Institute of Technology, Vellore, 632014, India.
    Sarkar, Omprakash
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik. Bioengineering and Environmental Sciences Lab, Department of Energy and Environmental Engineering (DEEE), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.
    Rovira-Alsina, Laura
    LEQUiA. Institute of the Environment, University of Girona, Campus Montilivi, C/Maria Aurelia Capmany, 69, E-17003, Girona, Spain.
    Puig, Sebastià
    LEQUiA. Institute of the Environment, University of Girona, Campus Montilivi, C/Maria Aurelia Capmany, 69, E-17003, Girona, Spain.
    Mohan, S. Venkata
    Bioengineering and Environmental Sciences Lab, Department of Energy and Environmental Engineering (DEEE), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.
    Conversion of carbon dioxide to value added products through anaerobic fermentation and electro fermentation: A comparative approach2022Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 47, nr 34, s. 15442-15455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Increasing carbon footprint alters the carbon balance in nature, thereby worsening global climate change. The conversion of carbon dioxide (CO2) into value-added products through biological routes is the pathway of the future because of its ecological and sustainable character. The present study evaluated the conversion of CO2 into short-chain fatty acids (SCFA)/volatile fatty acids (VFA) and methane using four experimental conditions (R1-R4). The experimental conditions are R1 was an anaerobic fermenter (AF) operated as control, R2 consisted of an AF with electrodes operated in open circuit, R3 was an AF with electrodes operated in a closed circuit with 100 Ω as load and R4 was an electro-fermentation reactor with an applied cathodic potential of −0.8 V vs. Ag/AgCl. The results were assessed in terms of production of SCFA, methane, current density and inorganic carbon reduction. Electro-fermentation (R4) setup achieved the highest production of SCFA (2050 mg/L) and methane (41.2 mL/day) compared to other reactors. R3 reported 1800 mg/L and 24 mL/day, R2 reported 1560 mg/L and 15 mL/day and R1 reported 1430 mg/L and 10 mL/day of methane and SCFA production. The study-inferred that electro-fermentation could effectively catalyse the biochemical reactions and enhance the conversion of CO2 to organic compounds in a sustainable manner.

  • 9.
    Zulfiqar, Waqas
    et al.
    Computational Materials Modeling Laboratory, Department of Physics, Government College University, Faisalabad, 38040, Faisalabad, Pakistan.
    Javed, Farrukh
    Computational Materials Modeling Laboratory, Department of Physics, Government College University, Faisalabad, 38040, Faisalabad, Pakistan; Department of Chemical Engineering, McGill University, 845 Sherbrooke St. W, Montreal, Quebec, Canada.
    Abbas, Ghulam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Larsson, J. Andreas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Alay-e-Abbas, Syed Muhammad
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Computational Materials Modeling Laboratory, Department of Physics, Government College University, Faisalabad, 38040, Faisalabad, Pakistan.
    Stabilizing the dopability of chalcogens in BaZrO3 through TiZr co-doping and its impact on the opto-electronic and photocatalytic properties: A meta-GGA level DFT study2024Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 58, s. 409-415Artikel i tidskrift (Refereegranskat)
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