Browsing USN Open Archive by Author "Tokheim, Lars-André"
Now showing items 1-20 of 35
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Assessment of mercury emission at Norcem's cement kiln by use of 203 Hg tracer
Eriksen, Dag Øistein; Tokheim, Lars-André; Eriksen, T.A.; Meyer, Julien; Qvenild, Carsten (Conference report, 2005)In manufacture of cement clinker, mercury (Hg) is introduced in the cement kiln system via the fuels and as constituents in the raw materials, i.e. limestone, iron ore, etc. The permissible emission of Hg to air is very ... -
Assessment of sulphur emission at Norcem's cement kiln by use of 35S-tracer
Eriksen, Dag Øistein; Tokheim, Lars-André; Eriksen, T.A.; Martini, V.; Qvenild, Carsten (Conference report, 2001)Although sulphur is not a major reacting species in making cement clinker, it is introduced as a pollutant in both the energy carrier (oil, coke, coal, household waste) and in the reactants (chalk, silica). Due to the ... -
Behaviour of biomass particles in a bubbling fluidized bed: A comparison between wood pellets and wood chips
Agu, Cornelius Emeka; Tokheim, Lars-André; Pfeifer, Christoph; Moldestad, Britt Margrethe Emilie (Peer reviewed; Journal article, 2019)For successful operation and design of a bubbling fluidized bed reactor handling a specific biomass, in-depth knowledge about the bed behaviour is paramount. This study compares the behaviour of a bed of sand containing ... -
Burning chamber installation for increased use of alternative fuels at Norcem Brevik, Norway
Tokheim, Lars-André (Conference report, 2006) -
Carbon dioxide emission reduction by increased utilization of waste-derived fuels in the cement industry
Tokheim, Lars-André; Brevik, Per (Conference report, 2007)Considerable reductions in Norway's emissions of greenhouse gases like CO2 are required to meet the commitments of the Kyoto Protocol. CO2 emissions from cement clinker production originate from decarbonation of limestone ... -
CFD Study of Particle Flow Patterns in a Rotating Cylinder Applying OpenFOAM and Fluent
Dissanayake, Susantha; Karunarathne, Sumudu S.; Lundberg, Joachim; Tokheim, Lars-André (Journal article; Peer reviewed, 2017)A rotating cylinder (RC) is a common type of reactor used in the industry, the most typical example being a cement kiln. The particle flow pattern inside such a unit is necessary for the mass and energy transfer, and this ... -
Combined calcination and CO2 capture in cement clinker production by use of electrical energy
Tokheim, Lars-André; Mathisen, Anette; Øi, Lars Erik; Jayarathna, Chameera K.; Eldrup, Nils Henrik; Gautestad, Tor (Chapter, 2019)The technical feasibility of electrifying the calcination process in a precalciner cement kiln system was assessed by studying different electrification concepts. Resistance-based heating was selected as it equires no CO2 ... -
Comparison of the influence of drag models in CFD simulation of particle mixing and segregation in a rotating cylinder
Karunarathne, Sumudu S.; Tokheim, Lars-André (Journal article; Peer reviewed, 2017)CFD modelling was used to simulate particle segregation in a transverse plane of a rotating cylinder under different particle-particle drag models. The Eulerian method was used to model the dense particulate phases in the ... -
Detailed One-Dimensional Model for Steam-Biomass Gasification in a Bubbling Fluidized Bed
Agu, Cornelius Emeka; Pfeifer, Christoph; Eikeland, Marianne Sørflaten; Tokheim, Lars-André; Moldestad, Britt Margrethe Emilie (Peer reviewed; Journal article, 2019)A one-dimensional unsteady state model is developed for simulation of biomass gasification in a bubbling fluidized bed. The proposed model accounts for the effect of hydrodynamic behavior of the fluidized bed by incorporating ... -
Determination of biomass fraction for partly renewable solid fuels.
Ariyaratne, W. K. Hiromi; Melaaen, Morten Christian; Tokheim, Lars-André (Journal article; Peer reviewed, 2014-04-29)Biomass-based waste fuels are used in many industrial applications since combustion of biomass gives no net emissions of carbon dioxide. Some waste fuels, e.g. RDF (refuse derived fuels), contain not only biomass, but also ... -
Determination of fossil fraction of refuse derived fuel by the selective dissolution method in calorific value basis: Development of simplified method.
Ariyaratne, W. K. Hiromi; Asgautsen, Øyvind; Melaaen, Morten Christian; Eine, Kristin; Tokheim, Lars-André (Journal article; Peer reviewed, 2012)Determination of net CO2 emissions from combustion of Refuse Derived Fuel (RDF) is not straight forward due to the heterogeneous nature of the fuel. The fossil fraction of the fuel is an essential parameter for the ... -
Determination of onset of bubbling and slugging in a fluidized bed using a dual-plane electric capacitance tomography system
Agu, Cornelius Emeka; Tokheim, Lars-André; Eikeland, Marianne Sørflaten; Halvorsen, Britt (Journal article; Peer reviewed, 2017)For a successful application of fluidized beds in chemical reactions and solids circulation, the boundary of regime of operation such as bubbling and slugging regimes, needs to be clearly defined. This study provides a ... -
Effect of alternative fuel properties on NOx reduction
Axelsen, Ernst Petter; Tokheim, Lars-André; Bjerketvedt, Dag (Conference report, 2002)Today we see a substantial increase in the use of alternative fuels in the cement industry. The prospect of reduction in fuel costs and the environmental benefits of waste to energy conversion are the driving forces. For ... -
Energy recovery from wastes : experience with solid alternative fuels combustion in a precalciner cement kiln
Tokheim, Lars-André; Gautestad, Tor; Axelsen, Ernst Petter; Bjerketvedt, Dag (Conference report, 2001)Today virtually all cement clinker burning processes take place in rotary kilns. A mixture of calcareous and argilaceous materials is heated to a temperature of about 1450 °C. In this process decarbonation followed by ... -
Er elbilen et bærekraftig alternativ til fossilbilen?
Tokheim, Lars-André; Høidalen, Øivind; Fuglaas, Geir (Report, 2021)De globale klimagassutslippene må reduseres til nær null i løpet av de nærmeste tre tiårene om vi skal unngå dramatiske endringer av klimaet. Transportsektoren, herunder personbilen, står for en betydelig del av ... -
Experimental Study and CFD Modelling of Minimum Fluidization Velocity for Geldart A, B and D Particles
Amarasinghe, Widuramina Sameendranath; Jayarathna, Chameera K.; Ahangama, Bovinda S; Tokheim, Lars-André; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2017)The aim of this study is to determine minimum fluidization velocity of three different particles which represent different Geldart classification groups and to compare the results with computational results. The experiments ... -
Experimental study of thermal and catalytic pyrolysis of plastic waste components
Anene, Azubuike Francis; Fredriksen, Siw Bodil; Sætre, Kai Arne; Tokheim, Lars-André (Journal article; Peer reviewed, 2018)Thermal and catalytic pyrolysis of virgin low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and mixtures of LDPE/PP were carried out in a 200 mL laboratory scale batch reactor at 460 °C ... -
Gas-to-gas heat exchanger for heat utilization in hot CO2 from an electrically heated calcination process
Jacob, Ron (Master thesis, 2019)Thesis was done with the objective of evaluating a gas to gas heat exchanger which will be used to recover heat from hot calciner exit gas from an electrically heated calcination process. Shell and tube heat exchanger ... -
Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture
Arachchige, Udara Sampath P.; Kawan, Dinsesh; Tokheim, Lars-André; Melaaen, Morten Christian (Journal article; Peer reviewed, 2014)The present study is focused on the effect of the specific thermal energy demand and the false air factor on carbon capture applied to cement kiln exhaust gases. The carbon capture process model was developed and implemented ... -
Improved Models for Predicting Bubble Velocity, Bubble Frequency and Bed Expansion in a Bubbling Fluidized Bed
Agu, Cornelius Emeka; Tokheim, Lars-André; Eikeland, Marianne Sørflaten; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2018)An efficient design and operational control of a fluidized bed reactor relies on accurate prediction of bubble properties. This paper employs measurement of bed void fraction in determining the bubble velocity in a given ...