Browsing NTNU Open by Author "Solheim, Asbjørn"

Now showing items 1-16 of 16

    • Cathode Wear in Electrowinning of Aluminum Investigated by a Laboratory Test Cell 

      Wang, Zhaohui; Nobakhtghalati, Saeid; Støre, Anne; Solheim, Asbjørn; Tschöpe, Kati; Ratvik, Arne Petter; Grande, Tor (Journal article; Peer reviewed, 2016)
      The lifetime of an aluminum electrolysis cell is mainly determined by the cathode wear, especially for high amperage cells utilizing graphitized carbon cathodes. The cathode wear mechanisms are, however, complex and still ...

    • Effect of composition and temperature on current efficiency for aluminium electrolysis from cryolite-based molten alumina electrolytes 

      Morishige, Taiki; Haarberg, Geir Martin; Gudbrandsen, Henrik; Skybakmoen, Egil; Solheim, Asbjørn; Takenaka, Toshihide (Journal article; Peer reviewed, 2017)
      The current efficiency (CE) for aluminium electrolysis in modern cells can be as high as 96 %. The main reason for loss in current efficiency is the so-called back reaction between dissolved metal and the anode product of ...

    • Electrolyte Melt Compositions for Low Temperature Molten Carbonate Thermocell 

      Kandhasamy, Sathiyaraj; Solheim, Asbjørn; Kjelstrup, Signe; Haarberg, Geir Martin (Journal article; Peer reviewed, 2018)
      Industrial processes for the production of metals and alloys by metallurgical and electrochemical methods generate a great deal of waste heat due to irreversible losses. This waste heat may be used as a power source to ...

    • Gas electrodes with nickel based current collectors for molten carbonate electrolyte thermo-electrochemical cells 

      Kandhasamy, Sathiyaraj; Haarberg, Geir Martin; Kjelstrup, Signe; Solheim, Asbjørn (Journal article; Peer reviewed, 2019)
      Thermo-electrochemical cells with inexpensive molten carbonate electrolyte and (CO2|O2) gas electrodes allow the possible conversion of high temperature waste heat from industrial processes into electricity. The cell ...

    • Influence of electrode gas flow rate and electrolyte composition on thermoelectric power in molten carbonate thermocell 

      Kandhasamy, Sathiyaraj; Calandrino, Luca; Burheim, Odne Stokke; Solheim, Asbjørn; Kjelstrup, Signe Helene; Haarberg, Geir Martin (Journal article, 2016)
      A thermocell (thermo-electrochemical cell) is an electrochemical system with two identical electrodes placed at different temperatures in an electrolyte solution. Ion transport between the electrodes due to the temperature ...

    • Influence of Electrode Gas Flow Rate and Solid Oxide Ratio in Electrolyte on the Seebeck Coefficient of Molten Carbonate Thermocell 

      Kandhasamy, Sathiyaraj; Calandrino, Luca; Burheim, Odne Stokke; Solheim, Asbjørn; Kjelstrup, Signe; Haarberg, Geir Martin (Journal article; Peer reviewed, 2017)
      Thermocells represent a promising way to utilize heat as a power source. The aim of this work is to develop a thermocell with identical gas electrodes using molten carbonate-based electrolytes. The cell can generate power ...

    • Lab Scale Experiments on Alumina Raft Formation 

      Gylver, Sindre Engzelius; Solheim, Asbjørn; Gudbrandsen, Henrik; Follo, Åste Hegglid; Einarsrud, Kristian Etienne (Chapter, 2020)
      During feeding of alumina into a Hall-Héroult cell, rafts floating on the bath surface may be formed. In this study, rafts were created in a laboratory furnace by adding 4 g secondary alumina in industrial bath. Samples ...

    • Molten Carbonate Electrolyte Based Thermocell for High Temperature Waste Heat Recovery 

      Kandhasamy, Sathiyaraj (Doctoral theses at NTNU;2018:321, Doctoral thesis, 2019)
      Industrial processes for the production of metals and alloys by metallurgical and electrochemical methods generate a lot of waste heat due to irreversible losses. This waste heat could be used as a power source to produce ...

    • PFC evolution characteristics during aluminium and rare earth electrolysis 

      Kjos, Ole Sigmund; Solheim, Asbjørn; Aarhaug, Thor Anders; Osen, Karen Sende; Martinez, Ana Maria Cuellar; Sommerseth, Camilla; Gudbrandsen, Henrik; Støre, Anne; Gaertner, Heiko (Journal article; Peer reviewed, 2018)
      In addition to aluminium electrolysis, the electrolysis of rare earth (RE) metals from fluoride melts is a significant source of perfluorocarbon (PFC) emissions to the atmosphere. These processes have many similarities, ...

    • PFC Evolution in the Aluminium Production Process 

      Åsheim, Henrik (Doctoral theses at NTNU;2017:137, Doctoral thesis, 2017)
      Improvements in the Hall-Héroult process for electrowinning of aluminium have drastically reduced the anode effect duration, frequency and its associated perfluorocarbon (PFC) evolution, especially over the past 50 years. ...

    • A Pragmatic Model for Alumina Feeding 

      Johansen, Stein Tore; Einarsrud, Kristian Etienne; Solheim, Asbjørn; Vachaparambil, Kurian J. (Peer reviewed; Journal article, 2022)
      In this paper, we demonstrate how we can develop a coarse-grained model for the alumina distribution in an aluminium reduction cell. The model is designed to have the potential of being a part of a control system or play ...

    • A Pragmatic Model for Bath Temperature Evolution During Alumina Feeding 

      Vachaparambil, Kurian J.; Johansen, Stein Tore; Solheim, Asbjørn; Einarsrud, Kristian Etienne (Peer reviewed; Journal article, 2023)
      In this paper, we extend the pragmatic model for alumina feeding, presented in Johansen et al. Light metals 2022, to treat the associated evolution of bath temperature. The underlying idea of the framework is to reduce its ...

    • Thermal Conductivity of Molten Carbonates with Dispersed Solid Oxide from Differential Scanning Calorimetry 

      Kandhasamy, Sathiyaraj; Støre, Anne; Haarberg, Geir Martin; Kjelstrup, Signe; Solheim, Asbjørn (Journal article; Peer reviewed, 2019)
      Recently, there has been a noticeable increase in the applications of composite mixtures containing molten salt and solid oxide for thermal energy conversion and storage systems. This highlights that thermal conductivity ...

    • Thermoelectrochemical Cell with Molten Carbonate Electrolyte 

      Haarberg, Geir Martin; Kandhasamy, Sathiyaraj; Kjelstrup, Signe Helene; Solheim, Asbjørn (Journal article, 2017)
      Industrial processes for production of metals and alloys by metallurgical and electrochemical methods generate a lot of heat due to irreversible losses. The waste heat should be used to generate electricity. Commercial ...

    • Using Surplus Heat to Pre-Heat Carbon Anodes for Aluminium Electrolysis 

      Grimstad, Martin (Master thesis, 2019)
      Karbon anoder brukes opp i Hall-Héroult prosessen og må erstattes regelmessig. Når en ny anode blir plassert i aluminiumsovnen, vil badet umiddelbart fryse på undersiden av anoden og danne et fryst isolerende lag. Denne ...

    • Utilization of waste heat for pre-heating of anodes 

      Einarsrud, Kristian Etienne; Grimstad, Martin; Elstad, Kim Ronny; Solheim, Asbjørn (Peer reviewed; Journal article, 2020)
      Carbon anodes are replaced on a regular basis in Hall–Héroult cells as they are consumed by electrochemical reactions. Upon insertion of new anodes, bath will freeze locally as a result of low bath superheat and comparatively ...