Blar i NTNU Open på forfatter "Holmen, Anders"
-
Activation of Cobalt Foil Catalysts for CO Hydrogenation
Rytter, Erling; Aaserud, Christian; Hilmen, Anne-Mette; Bergene, Edvard; Holmen, Anders (Peer reviewed; Journal article, 2022)CO hydrogenation has been studied on cobalt foils as model catalysts for Fischer–Tropsch (FT) synthesis. The effect of pretreatment (number of calcinations and different reduction times) for cobalt foil catalysts at 220 ... -
Alumina supported cobalt catalysts for Fischer-Topsch synthesis
Shadman Far, Amir (Master thesis, 2012)Co supported on high surface area oxides such as alumina, silica and titania are the main catalysts for the Fischer-Tropsch synthesis. It has been shown that the catalytic performance of these catalysts depends on the ... -
Biopolymers assisted preparation of iron based fischer-tropsch catalysts
Harneshaug, Marit Liebe (Master thesis, 2018) -
Capturing metal-support interactions in situ during the reduction of a Re promoted Co/γ-Al2O3 catalyst
Tsakoumis, Nikolaos; Johnsen, Rune E.; van Beek, Wouter; Rønning, Magnus; Rytter, Erling; Holmen, Anders (Journal article; Peer reviewed, 2016)The reduction of a Re promoted Co/γ-Al2O3 catalyst was monitored in situ by synchrotron X-ray powder diffraction (XRPD) under H2 environment. Whole powder pattern analysis revealed a non-linear expansion of the unit cell ... -
Catalyst Deactivation During One-Step Dimethyl Ether Synthesis from Synthesis Gas
Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen (Journal article; Peer reviewed, 2017)Catalysts for direct synthesis of dimethyl ether (DME) from synthesis gas should essentially contain two functions, i.e., methanol synthesis and methanol dehydration. In the present work, the deactivation of both functions ... -
Catalytic partial oxidation of methane at moderate temperatures
Glas, Sophie Anne Amelie (Master thesis, 2013)Catalytic partial oxidation (CPO) is considered to be a promising route to produce synthesis gas from methane. In this work cobalt supported on CeO2−Al2O3 nanocomposites calcined at temperatures ranging from 1173 K to 1473 ... -
Charge-Tuned CO Activation over a χ‑Fe5C2 Fischer−Tropsch Catalyst
Chen, Bingxu; Wang, Di; Duan, Xuezhi; Liu, Wei; Li, Yefei; Qian, Gang; Yuan, Weikang; Holmen, Anders; Zhou, Xinggui; Chen, De (Journal article; Peer reviewed, 2018)We performed DFT calculations to understand CO activation over a χ-Fe5C2 Fischer–Tropsch catalyst. The χ-Fe5C2 catalyst exhibits unique CO activation behaviors, and the BEP relation is nearly valid for this system. The ... -
Deactivation of Co-Based Fischer−Tropsch Catalyst by Aerosol Deposition of Potassium Salts
Gavrilovic, Ljubisa; Brandin, Jan; Holmen, Anders; Venvik, Hilde Johnsen; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)A 20%Co/0.5%Re/γAl2O3 Fischer−Tropsch catalyst was poisoned by four potassium salts (KNO3, K2SO4, KCl, and K2CO3) using the aerosol deposition technique, depositing up to 3500 ppm K as solid particles. Standard characterization ... -
Direct dimethyl ether synthesis from synthesis gas: The influence of methanol dehydration on methanol synthesis reaction
Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen (Journal article; Peer reviewed, 2016)Direct dimethyl ether (DME) synthesis from synthesis gas is studied with regard to potential effects of methanol dehydration on methanol formation and copper-based catalyst performance. For this, the influence of the ... -
Direct Non-Oxidative Conversion of Methane to C2 Hydrocarbons, Aromatics and Hydrogen
Bodnar, Matus (Master thesis, 2017)Catalytic activity of Fe/HZSM-5 and Mo/HZSM-5 during methane dehydroaromatization was investigated. The catalysts were prepared by wet impregnation method, calcinated in air flow, tested in laboratory reactor and characterized ... -
Direct Nonoxidative Conversion of Methane to C2 Hydrocarbons, Aromatics and Hydrogen
Hovd, Benedicte (Master thesis, 2016)Natural gas contains a large quantity of methane that is valuable as a fuel source. However, it can also be converted to light olefins, but the present synthesis route includes the conversion into synthesis gas. This is ... -
Direct Synthesis of Dimethyl Ether in Microstructured Reactors: The Interactions Between Methanol Synthesis and Methanol Dehydration
Dadgar, Farbod (Doctoral thesis at NTNU;2016:179, Doctoral thesis, 2016)The growing concerns about the climate change, energy security and the diminishing oil reserves, stimulate the search for alternative energy sources and non-petroleum-based fuels. Natural gas in the short-term, and biomass ... -
Effects of Oxygen Mobility in La-Fe-Based Perovskites on the Catalytic Activity and Selectivity of Methane Oxidation
Chang, Hui; Bjørgum, Erlend; Mihai, Oana; Yang, Jie; Lein, Hilde Lea; Grande, Tor; Raaen, Steinar; Zhu, Yi-an; Holmen, Anders; Chen, De (Peer reviewed; Journal article, 2020)The mechanism and structure requirements of selective and total oxidation of methane in a chemical looping process are both experimentally and theoretically examined on La1–xSrxFeO3−δ (x = 0, 0.2, and 0.5) and La0.5Sr0.5 ... -
Effects of Potassium and Copper Promoters on Iron Fischer-Tropsch Catalysts
Hole, Nils-Olav Andersen (Master thesis, 2015)The demand for energy is an ever increasing problem in the world today. The need for more abundant energy sources to take over the role of crude oil is becoming more and more present. GTL processes (gas-to-liquid), which ... -
Evaluation of Reoxidation Thresholds for γ-Al2O3-Supported Cobalt Catalysts under Fischer - Tropsch Synthesis Conditions
Tsakoumis, Nikolaos; Walmsley, John; Rønning, Magnus; van Beek, Wouter; Rytter, Erling; Holmen, Anders (Journal article; Peer reviewed, 2017)Size-dependent phenomena at the nanoscale influence many applications, notably in the science of heterogeneous catalysis. In cobalt-based Fischer–Tropsch synthesis (FTS), the size of Co nanoparticles (NPs) dictates to a ... -
Experimental and Theoretical Studies on Water-Added Thermal Processing of Model Biosyngas for Improving Hydrogen Production and Restraining Soot Formation
Chytil, Svatopluk; Li, Chao'en; Lee, Woo Jin; Lødeng, Rune; Holmen, Anders; Blekkan, Edd Anders; Burke, Nick; Patel, Jim (Journal article; Peer reviewed, 2022)The upgrading of biosyngas to convert methane into syngas is a necessary step for hydrogen production from biomass. However, this process is highly energy-demanding. In this study, a model biosyngas containing H2, CH4, CO, ... -
Fischer-Tropsch conversion of biomass-derived synthesis gas to liquid fuels
Lillebø, Andreas Helland; Holmen, Anders; Enger, Bjørn Christian; Blekkan, Edd Anders (Journal article, 2013)Recent and ongoing research on Fischer-Tropsch catalysts for biomass conversion typically focus on the effects of impurities common in bio-derived synthesis gas, and also on the effect of different synthesis gas compositions ... -
Fischer-Tropsch synthesis – Influence of aerosol – deposited potassium salts on activity and selectivity of Co based catalysts
Gavrilović, Ljubiša (Doctoral theses at NTNU;2018:104, Doctoral thesis, 2018)The effect of potassium salts (K2SO4, KNO3, KCl, K2CO3) on cobalt based Fischer-Tropsch catalysts has been studied experimentally and theoretically. In order to better understand the deactivation effect of potassium species, ... -
Fischer-Tropsch synthesis—Investigation of the deactivation of a Co catalyst by exposure to aerosol particles of potassium salt
Gavrilovic, Ljubisa; Brandin, Jan; Holmen, Anders; Venvik, Hilde Johnsen; Myrstad, Rune; Blekkan, Edd Anders (Journal article; Peer reviewed, 2018)The influence of potassium species on a Co based Fischer-Tropsch catalyst was investigated using an aerosol deposition technique. This way of poisoning the catalyst was chosen to simulate the actual potassium behaviour ... -
Fischer–Tropsch Synthesis at High Conversions on Al2O3-Supported Co Catalysts with Different H2/CO Levels
Lillebø, Andreas Helland; Rytter, Erling; Blekkan, Edd Anders; Holmen, Anders (Journal article; Peer reviewed, 2017)Fischer-Tropsch experiments with different H2/CO ratios at high CO conversions have been carried out over an alumina-supported 20wt%Co-0.5wt%Re catalyst in a stainless steel fixed-bed reactor at 210 oC and 20 bar and with ...