Browsing NTNU Open by Author "Evjen, Sigvart"

Now showing items 1-15 of 15

    • Aerosol growth in CO2 absorption with MEA, modelling and comparison with experimental results 

      Svendsen, Hallvard Fjøsne; Majeed, Hammad; Knuutila, Hanna K; Hillestad, Magne; Evjen, Sigvart; Mejdell, T.; Einbu, A.; Hjarbo, Kai Wilhelm; Haugen, G.; Hoff, K.A. (Peer reviewed; Journal article, 2021)
      A new and improved aerosol model has been developed and tested against experimental data. An e-NRTL equilibrium model for MEA was extended to cover sulphuric acid containing droplets and validated against new eboulliometer ...

    • Aminoalkyl-functionalized pyridines as high cyclic capacity CO2 absorbents 

      Evjen, Sigvart; Løge, Oda Siebke; Fiksdahl, Anne; Knuutila, Hanna K (Journal article; Peer reviewed, 2019)
      Recent years have witnessed a growing academic interest in development of new CO2 capture solvents to reduce the capture costs. This study focused on nine picolylamines (three commercial and six synthesized) and one ...

    • Chemoenzymatic Synthesis of Synthons as Percursors for Enantiopure Clenbuterol and Other β2-Agonists 

      Blindheim, Fredrik Heen; Hansen, Mari Bergan; Evjen, Sigvart; Zhu, Wei; Jacobsen, Elisabeth Egholm (Journal article; Peer reviewed, 2018)
      Clenbuterol is a β2-agonist used in the veterinary treatment of asthma in several countries. The drug is listed on the World Antidoping Agency’s prohibited list due to its effect on increased protein synthesis in the body. ...

    • Degradative behavior and toxicity of alkylated imidazoles 

      Evjen, Sigvart; Åstrand, Ove Alexander Høgmoen; Gaarder, Mona; Paulsen, Ragnhild Elisabeth; Fiksdahl, Anne; Knuutila, Hanna K (Journal article; Peer reviewed, 2020)
      The thermal and oxidative degradation behavior and the corrosiveness of imidazole (Im), 2-methylimidazole (2MIm), 2-ethyl-4-methylimidazole (2E4MIm), 2,4,5-trimethylimidazole (2,4,5MIm), and 1,2,4,5-tetramethylimidazole ...

    • High-Capacity Amine-Imidazole Solvent Blends for CO2 Capture 

      Evjen, Sigvart; Fiksdahl, Anne; Knuutila, Hanna K (Journal article; Peer reviewed, 2019)
      The CO2 absorption performance of aqueous solvent blends containing four imidazoles (2-MeIm, 2-Et-4-MeIm, 2,4,5-MeIm and 1,2,4,5-MeIm) and four promoters (MEA, DEA, PZ, and MAPA) were investigated using a small-scale ...

    • Hydroxyl Functionalized Pyridinium Ionic Liquids: Experimental and Theoretical Study on Physicochemical and Electrochemical Properties 

      Kallidanthiyil Chellappan, Lethesh; Venkatraman, Vishwesh; Fiksdahl, Anne; Evjen, Sigvart (Journal article; Peer reviewed, 2019)
      Structurally modified hydroxyl functionalized pyridinium ionic liquids (ILs), liquid at room temperature, were synthesized and characterized. Alkylated N-(2-hydroxyethyl)-pyridinium ILs were prepared from alkylpyridines ...

    • In silico prediction and experimental verification of ionic liquid refractive indices 

      Venkatraman, Vishwesh; Jaganathan, Joshua Raj; Evjen, Sigvart; Kallidanthiyil Chellappan, Lethesh; Fiksdahl, Anne (Journal article; Peer reviewed, 2018)
      Ionic liquids (ILs) have seen increasing use as environmentally friendly solvents in a wide array of applications from energy to pharmaceuticals. Among the many properties of interest, the refractive index, is of considerable ...

    • New Polyalkylated Imidazoles Tailored for Carbon Dioxide Capture 

      Evjen, Sigvart; Fiksdahl, Anne; Pinto, Diego Di Domenico; Knuutila, Hanna K (Journal article; Peer reviewed, 2018)
      Aqueous polyalkylated imidazoles have gained interest as potential CO2 capture solvents due to their high oxidative stability and low vapor pressures compared to traditional amines. In this work, 21 aqueous solutions of ...

    • Novel Au(I) Catalyzed Cycloaddition Reactions of Propargyl Acetals 

      Evjen, Sigvart (Master thesis, 2015)
      The goal of this master's thesis was to investigate novel gold(I) catalyzed cycloaddition reactions of nitrones and azides with propargyl acetals. Screening of the reactions was performed by testing reagents with electron ...

    • Predicting ionic liquid melting points using machine learning 

      Venkatraman, Vishwesh; Evjen, Sigvart; Knuutila, Hanna K; Fiksdahl, Anne; Alsberg, Bjørn Kåre (Journal article; Peer reviewed, 2018)
      The melting point (Tm) of an ionic liquid (IL) is of crucial importance in many applications. The Tm can vary considerably depending on the choice of the anion and cation. This study explores the use of various machine ...

    • Rapid, comprehensive screening of ionic liquids towards sustainable applications 

      Venkatraman, Vishwesh; Evjen, Sigvart; Kallidanthiyil Chellappan, Lethesh; Raj, Jaganathan Joshua; Knuutila, Hanna K; Fiksdahl, Anne (Peer reviewed; Journal article, 2019)
      A computational screening strategy applied to 8 million synthetically diverse ionic liquids, demonstrates its value for sustainable solvent design. In contrast to previous studies which have largely focused on single ...

    • Synthesis and design of imidazole-based solvent systems for CO2 capture 

      Evjen, Sigvart (Doctoral theses at NTNU;2019:199, Doctoral thesis, 2019)
      Global oppvarming forårsaket av menneskelige klimagassutslipp er den største utfordringen verden står ovenfor. Det er et enormt behov for videreutvikling av teknologien rettet mot reduksjon av disse utslippene. Fangst av ...

    • The Ionic Liquid Property Explorer: An Extensive Library of Task-Specific Solvents 

      Venkatraman, Vishwesh; Evjen, Sigvart; Lethesh, Kallidanthiyil Chellappan (Journal article; Peer reviewed, 2019)
      Ionic liquids have a broad spectrum of applications ranging from gas separation to sensors and pharmaceuticals. Rational selection of the constituent ions is key to achieving tailor-made materials with functional properties. ...

    • The Salting-out Effect in Some Physical Absorbents for CO2 Capture 

      Wanderley, Ricardo Ramos; Evjen, Sigvart; Pinto, Diego Di Domenico; Knuutila, Hanna K (Journal article; Peer reviewed, 2018)
      The solubility of CO2 in organic solvents N-methyl-2-pyrrolidone (NMP), methanol and monoethylene glycol (MEG) at 30 °C was measured together with its heat of absorption. The salts lithium nitrate (LiNO3), lithium chloride ...

    • Viscosity, Density and Volatility of Binary Mixtures of Imidazole, 2-Methylimidazole, 2,4,5-Trimethylimidazole and 1,2,4,5-Tetramethylimidazole with Water 

      Evjen, Sigvart; Wanderley, Ricardo Ramos; Fiksdahl, Anne; Knuutila, Hanna K (Journal article; Peer reviewed, 2019)
      Experimental measurements and modeling of the density and viscosity of binary solutions of imidazole, 2-methylimidazole, 2,4,5-trimethylimidazole, and 1,2,4,5-tetramethylimidazole with water have been conducted. The ...