Browsing USN Open Archive by Author "Thapa, Rajan Kumar"
Now showing items 1-20 of 32
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Aspen Plus simulation of biomass gasification for different types of biomass
Timsina, Ramesh; Thapa, Rajan Kumar; Eikeland, Marianne Sørflaten (Journal article; Peer reviewed, 2019)A steady-state Aspen Plus model was developed for biomass gasification in a fluidized bed reactor. A combination of different Aspen Plus unit operations was used to model the gasification process. The model was used to ... -
Aspen Plus Simulation of Biomass Gasification with known Reaction Kinetic
Eikeland, Marianne Sørflaten; Thapa, Rajan Kumar; Halvorsen, Britt (Conference object; Peer reviewed, 2015-11-25)The energy from biomass can be utilized through the thermochemical conversion processes of pyrolysis and gasification. The Aspen Plus simulation tool is applicable for simulation of the gasification processes. The most ... -
Circulating fluidized bed reactors – part 01: analyzing the effect of particle modelling parameters in computational particle fluid dynamic (CPFD) simulation with experimental validation
Bandara, Janitha; Thapa, Rajan Kumar; Nielsen, Henrik Kofoed; Moldestad, Britt Margrethe Emilie; Eikeland, Marianne Sørflaten (Peer reviewed; Journal article, 2019)A CPFD hydrodynamic model was developed for a circulating fluidized bed system and the simulation results were validated against experimental data based on particle circulation rate. Sensitivity of the computational mesh ... -
Computational particle fluid dynamics simulation of biomass gasification in an entrained flow gasifier
Timsina, Ramesh; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie; Eikeland, Marianne Sørflaten (Journal article; Peer reviewed, 2021)Entrained flow gasification is an established technology for coal and petroleum coke particles. The technology is being investigated extensively for biomass gasification to meet the requirement of the green energy targets. ... -
CPFD model for prediction of flow behavior in an agglomerated fluidized bed gasifier
Furuvik, Nora Cecilie Ivarsdatter; Jaiswal, Rajan; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie (Peer reviewed; Journal article, 2019)Renewable energy sources have significant potential for limiting climate change and reducing greenhouse gas emissions due to the increased global energy demand. Fluidized bed gasification of biomass is a substantial ... -
A CPFD model to investigate the influence of feeding positions in a gasification reactor
Jaiswal, Rajan; Furuvik, Nora Cecilie Ivarsdatter; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2020)The efficiency of a gasification process is directly related to the rate of biomass conversion into product gas. The rate of fuel conversion depends on the interaction of fuel with the bed material, the gasifying agent, ... -
CPFD simulation of a fixed bed gasification reactor
Thapa, Rajan Kumar; Jaiswal, Rajan; Moldestad, Britt Margrethe Emilie (Chapter; Peer reviewed, 2020)Biomass gasification is regarded as one of the most promising energy recovery technologies. The gases produced from the biomass gasification can be used for heat and power production. Alternatively, they can be used for ... -
Effect of particle size on flow behavior in fluidized beds
Timsina, Ramesh; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie; Eikeland, Marianne Sørflaten (Peer reviewed; Journal article, 2019)The fluidization behaviour depends on particle properties such as particle size, sphericity, density and the properties of the fluidizing agent. In this study, the effects of different particle sizes on fluidization behaviour ... -
Experimental and Computational study of Chemical Looping Combustion
Thapa, Rajan Kumar; Wijeratne, D. I. Erandi N.; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2018)In this paper, the fluidization properties of possible oxygen carriers in Chemical Looping Combustion (CLC) have been studied. Experiments were performed in a cold fluidized bed to study fluidization properties of particles ... -
Experimental and Computational Study of Oxygen Carriers in Chemical Looping Combustion
Thapa, Rajan Kumar; Wijeratne, D. I. Erandi N.; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2018)In this paper, the fluidization properties of possible oxygen carriers in Chemical Looping Combustion (CLC) have been studied. Experiments were performed in a cold fluidized bed to study fluidization properties of particles ... -
Experimental and computational study on the effect of ash deposition on fluid dynamic behavior in a bubbling fluidized bed gasifier
Thapa, Rajan Kumar; Thapa, Saroy; Jaiswal, Rajan; Furuvik, Nora Cecilie Ivarsdatter; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2019)The effect of ash deposition on fluid dynamic behavior in a fluidized bed gasification reactor has been studied using experimental and computational methods. The experiments were carried out using sand particles as bed ... -
Experimental and simulation studies of oxygen-blown, steam-injected, entrained flow gasification of lignin
Samani, Nastaran; Khalil, Roger Antoine; Seljeskog, Morten; Bakken, Jørn; Thapa, Rajan Kumar; Eikeland, Marianne Sørflaten (Peer reviewed; Journal article, 2024)This article presents results from experimental and simulation studies on a laboratory-scale pressurized O2-blown Entrained Flow biomass gasification Reactor (EFR) using pulverized commercial lignin pellets as feedstock. ... -
Experimental study and SEM-EDS analysis of agglomerates from gasification of biomass in fluidized beds
Furuvik, Nora Cecilie Ivarsdatter; Wang, Liang; Jaiswal, Rajan; Thapa, Rajan Kumar; Eikeland, Marianne Sørflaten; Moldestad, Britt Margrethe Emilie (Peer reviewed; Journal article, 2022)Fluidized bed gasification is an attractive conversion technology for biomass. However, processing biomass in fluidized beds suffers from ash related problems. In this work, bed agglomeration of wood pellets and grass ... -
Experiments and computational particle fluid dynamics simulations of biomass gasification in an air-blown fluidized bed gasifier
Timsina, Ramesh; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie; Eikeland, Marianne Sørflaten (Journal article; Peer reviewed, 2020)Experiments were performed in a pilot-scale bubbling fluidized bed gasification reactor with air as a fluidizing agent. Birch wood chips and sand particles were used as biomass and bed materials. Average molar product gas ... -
Image Processing and Measurement of the Bubble Properties in a Bubbling Fluidized Bed Reactor
Jaiswal, Rajan; Moldestad, Britt Margrethe Emilie; Eikeland, Marianne Sørflaten; Nielsen, Henrik Kofoed; Thapa, Rajan Kumar (Journal article; Peer reviewed, 2022)The efficiency of a fluidized bed reactor depends on the bed fluid dynamic behavior, which is significantly influenced by the bubble properties. This work investigates the bubble properties of a bubbling fluidized bed ... -
Improving gas distribution and evaporation in gas cooling tower at Norcem Brevik
Kasin, Fredrik; Larsen, Are; Andersen, Christian; Jaiswal, Rajan; Thapa, Rajan Kumar (Peer reviewed; Journal article, 2020)In this work, the effect of the geometry of a GCT (Gas Cooling Tower) on the flue gas distribution in a cooling tower in Norcem, Brevik is investigated by using CPFD (Computational Particle Fluid Dynamics) modeling and ... -
Investigation of flow behaviour in biomass gasifier using Electrical capacitance Tomography (ECT) and pressure sensors
Thapa, Rajan Kumar; Rautenbach, Christo; Halvorsen, Britt (Conference object; Peer reviewed, 2011)The particles in a biomass gasifier are mainly a mixture of wood chips, char particles and bed material. The charwood particles have a significant lower density than the bed material, and also a wider range of particle ... -
Investigation of the segregation and mixing behavior of biomass in a bubbling fluidized bed reactor using a CPFD model
Jaiswal, Rajan; Furuvik, Nora Cecilie Ivarsdatter; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2019)Segregation of biomass in a gasification reactor is an inevitable problem that can jeopardize the advantages such as uniform temperature control and proper mass circulation, and good solid-gas contacting area of the fluidized ... -
Method of identifying an operating regime in a bubbling fluidized bed gasification reactor
Jaiswal, Rajan; Furuvik, Nora Cecilie Ivarsdatter; Thapa, Rajan Kumar; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2020)This work presents a new method for identifying the bubbling regime of a fluidized bed gasification reactor. The method has been developed using experimental measurements and a computational model. Pressure drops are ... -
A new Approach for Scaling Up from a Small Cold to a Large Hot Bed for Biomass Conversion in a Bubbling Fluidized Bed Reactor
Agu, Cornelius Emeka; Thapa, Rajan Kumar; Pfeifer, Christoph; Tokheim, Lars-Andre; Moldestad, Britt Margrethe Emilie (Peer reviewed; Journal article, 2020)Bubbling fluidized beds are simple and attractive means of achieving efficient conversion of biomass if particle segregation and the associated effects are minimized. To improve the knowledge of fluidized bed reactor design, ...