|
“Streamer propagation in a packed bed plasma reactor for plasma catalysis applications”. Wang W, Kim H-H, Van Laer K, Bogaerts A, Chemical engineering journal 334, 2467 (2018). http://doi.org/10.1016/j.cej.2017.11.139
Abstract: A packed bed dielectric barrier discharge (DBD) is widely used for plasma catalysis applications, but the exact plasma characteristics in between the packing beads are far from understood. Therefore, we study here these plasma characteristics by means of fluid modelling and experimental observations using ICCD imaging, for packing materials with different dielectric constants. Our study reveals that a packed bed DBD reactor in dry air at atmospheric pressure may show three types of discharges, i.e. positive restrikes, filamentary microdischarges, which can also be localized between two packing beads, and surface discharges (so-called surface ionization
waves). Restrikes between the dielectric surfaces result in the formation of filamentary microdischarges, while surface charging creates electric field components parallel to the dielectric surfaces, leading to the formation of surface discharges. A transition in discharge mode occurs from surface discharges to local filamentary discharges between the packing beads when the dielectric constant of the packing rises from 5 to 1000. This may have implications for the efficiency of plasma catalytic gas treatment, because the catalyst activation may be limited by constraining the discharge to the contact points of the beads. The production of reactive species occurs most in the positive restrikes, the surface discharges and the local microdischarges in between the beads, and is less significant in the longer filamentary microdischarges. The faster streamer propagation and discharge development with higher dielectric constant of the packing beads leads to a faster production of reactive species. This study is of great interest for plasma catalysis, where packing beads with different dielectric constants are often used as supports for the catalytic materials. It allows us to better understand how different packing materials can influence the performance of packed bed plasma reactors for environmental applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 36
DOI: 10.1016/j.cej.2017.11.139
|
|
|
“The benefit of glass bead supports for efficient gas phase photocatalysis : case study of a commercial and a synthesised photocatalyst”. Verbruggen SW, Ribbens S, Tytgat T, Hauchecorne B, Smits M, Meynen V, Cool P, Martens JA, Lenaerts S, Chemical engineering journal 174, 318 (2011). http://doi.org/10.1016/J.CEJ.2011.09.038
Abstract: In the field of photocatalytic air purification, the immobilisation of catalyst particles on support surfaces without loss of photon efficiency is an important challenge. Therefore, an immobilisation method involving a one-step suspension coating of pre-synthesised photocatalysts on glass beads was applied. The various benefits are exemplified in the gas phase photodegradation of ethylene. Coating of glass beads is easy, fast, cheap and offers a more efficient alternative to bulk catalyst pellets. Furthermore, this coating procedure allows to use porous, pre-synthesised catalysts to their full potential, as the surface area and morphology of the initial powder is barely altered after coating, in strong contrast to pelletising. With this technique it became possible to study the gas phase photocatalytic activity of commercial titanium dioxide, trititanate nanotubes and mixed phase anatase/trititanate nanotubes in a packed bed reactor towards the degradation of ethylene without changing the catalyst properties. Coating of glass beads with the photocatalyst revealed the superior activity of the as-prepared nanotubes, compared to TiO2 Aerolyst® 7710 in gaseous phase.
Keywords: A1 Journal article; Engineering sciences. Technology; Laboratory of adsorption and catalysis (LADCA); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 39
DOI: 10.1016/J.CEJ.2011.09.038
|
|
|
“Thermodynamically unconstrained forced concentration cycling of methane catalytic partial oxidation over CeO2FeCralloy catalysts”. Ma Z, Perreault P, Pelegrin DC, Boffito DC, Patience GS, Chemical Engineering Journal 380, 122470 (2020). http://doi.org/10.1016/J.CEJ.2019.122470
Abstract: Converting waste associated natural gas from oil fields is uneconomic with current gas-to-liquid technology. Micro Gas-to-Liquids technology ( GtL) combines process intensification and numbering up economics to reduce capital costs to convert flared and vented natural gas to value-added synthetic fuel: Milli-second contact times in the catalytic partial oxidation of methane (CPOX) integrated with a tandem Fischer-Tropsch (FT) step meets the economic constraints together with remote process control. FeCralloy knitted fibres with high thermal conductivity and low pressure drop, resist thermal and mechanical stresses in the high pressure CPOX step. The FeCralloy catalysts are free of pre-reduction treatments. We deposited Pt and/or CeO2 over the fibre surface via solution combustion synthesis. Methane conversion was higher at ambient pressure compared to 2 MPa while the Pt/CeO2 FeCralloy was relatively inert from 0.1 MPa to 2 MPa. However, both catalysts demonstrated high activity in quasi-chemical looping partial oxidation of methane: during the reduction step while feeding methane, an on-line mass spectrometer only detected H2 while in the oxidation step it detected predominantly CO. Kinetic modeling of the oxidation-reduction cycles suggests that the reaction follows a direct mechanism to produce CO and H2 rather than an indirect mechanism that first produces CO2 and H2O followed by reforming.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 15.1
DOI: 10.1016/J.CEJ.2019.122470
|
|
|
“Tuning the turnover frequency and selectivity of photocatalytic CO2 reduction to CO and methane using platinum and palladium nanoparticles on Ti-Beta zeolites”. Blommaerts N, Hoeven N, Arenas Esteban D, Campos R, Mertens M, Borah R, Glisenti A, De Wael K, Bals S, Lenaerts S, Verbruggen SW, Cool P, Chemical Engineering Journal 410, 128234 (2021). http://doi.org/10.1016/j.cej.2020.128234
Abstract: A Ti-Beta zeolite was used in gas phase photocatalytic CO2 reduction to reduce the charge recombination rate and increase the surface area compared to P25 as commercial benchmark, reaching 607 m2 g-1. By adding Pt nanoparticles, the selectivity can be tuned toward CO, reaching a value of 92% and a turnover frequency (TOF) of 96 µmol.gcat-1.h-1, nearly an order of magnitude higher in comparison with P25. By adding Pd nanoparticles the selectivity can be shifted from CO (70% for a bare Ti-Beta zeolite), toward CH4 as the prevalent species (60%). In this way, the selectivity toward CO or CH4 can be tuned by either using Pt or Pd. The TOF values obtained in this work outperform reported state-of-the-art values in similar research. The improved activity by adding the nanoparticles was attributed to an improved charge separation efficiency, together with a plasmonic contribution of the metal nanoparticles under the applied experimental conditions.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.216
Times cited: 15
DOI: 10.1016/j.cej.2020.128234
|
|
|
“Unleashing lignin potential through the dithionite-assisted organosolv fractionation of lignocellulosic biomass”. Brienza F, Van Aelst K, Devred F, Magnin D, Tschulkow M, Nimmegeers P, Van Passel S, Sels BF, Gerin P, Debecker DP, Cybulska I, Chemical Engineering Journal 450, 138179 (2022). http://doi.org/10.1016/J.CEJ.2022.138179
Abstract: The development of biomass pretreatment approaches that, next to (hemi)cellulose valorization, aim at the conversion of lignin to chemicals is essential for the long-term success of a biorefinery. Herein, we discuss a dithionite-assisted organosolv fractionation (DAOF) of lignocellulose in n-butanol and water to produce cellulosic pulp and mono-/oligo-aromatics. The study frames the technicalities of this biorefinery process and relates them to the features of the obtained product streams. We comprehensively identify and quantify all products of interest: solid pulp (acid hydrolysis-HPLC, ATR-FTIR, XRD, SEM, enzymatic hydrolysis-HPLC), lignin derivatives (GPC, GC-MS/FID, 1H-13C HSQC NMR, ICP-AES), and carbohydrate derivatives (HPLC). These results were used for inspecting the economic feasibility of DAOF. In the best process configuration, a high yield of monophenolics was reached (~20%, based on acid insoluble lignin in birch sawdust). Various other lignocellulosic feedstocks were also explored, showing that DAOF is particularly effective on hardwood and herbaceous biomass. Overall, this study demonstrates that DAOF is a viable fractionation method for the sustainable upgrading of lignocellulosic biomass.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
Impact Factor: 15.1
DOI: 10.1016/J.CEJ.2022.138179
|
|