Records |
Author |
Nunez Manzano, M.; Gonzalez Quiroga, A.; Perreault, P.; Madanikashani, S.; Vandewalle, L.A.; Marin, G.B.; Heynderickx, G.J.; Van Geem, K.M. |
Title |
Biomass fast pyrolysis in an innovative gas-solid vortex reactor : experimental proof of concept |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Analytical And Applied Pyrolysis |
Abbreviated Journal |
J Anal Appl Pyrol |
Volume |
156 |
Issue |
|
Pages |
105165-12 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
Abstract |
Biomass fast pyrolysis has been considered one of the best alternatives for the thermal conversion of biomass into bio-oil. This work introduces a new reactor technology for biomass fast pyrolysis, the Gas-Solid Vortex Reactor (GSVR), to obtain high bio-oil yields. The GSVR was designed to decrease the residence time of the pyrolysis vapors; thus, the secondary cracking reactions are reduced, to enhance the segregation of the char and the unreacted biomass and to improve the heat transfer rate. Biomass fast pyrolysis experiments have been carried out for the first time in a Gas-Solid Vortex Reactor (GSVR) at 773 K, using softwood (pine) and hardwood (poplar) as feedstock. Char yields as low as 10 wt. % in the GSVR were comparable to those reported for the same feedstocks processed in conventional fluidized bed reactors. The yields of non-condensable gases in the range of 15–17 wt. % were significantly lower than those reported for other commonly used biomass fast pyrolysis reactors. Two-dimensional gas chromatography (GC × GC) revealed noticeable differences at the molecular level between the bio-oils from the GSVR and bio-oils from other reactors. The aromatics in the pine bio-oil consist almost entirely (85 wt. %) of guaiacols. For poplar bio-oils no predominant group of aromatics was found, but phenolics, syringols, and catechols were the most pronounced. The experimental results highlight the advantages of the GSVR for biomass pyrolysis, reaching stable operation in around 60 s, removing the formed char selectively during operation, and enabling fast entrainment of pyrolysis vapors. Results indicate a great potential for increasing yield and selectivity towards guaiacols in softwood (e.g., pine) bio-oil. Likewise, decreasing pyrolysis temperature could increase the yield of guaiacols and syringols in hardwood (e.g., poplar) bio-oil. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000663091200002 |
Publication Date |
2021-04-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0165-2370 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.471 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.471 |
Call Number |
UA @ admin @ c:irua:178743 |
Serial |
7562 |
Permanent link to this record |
|
|
|
Author |
Ahmadkhani, S.; Alihosseini, M.; Ghasemi, S.; Ahmadabadi, I.; Hassani, N.; Peeters, F.M.; Neek-Amal, M. |
Title |
Multiband flattening and linear Dirac band structure in graphene with impurities |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
|
Volume |
107 |
Issue |
7 |
Pages |
075401-75408 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Flat bands in the energy spectrum have attracted a lot of attention in recent years because of their unique properties and promising applications. Special arrangement of impurities on monolayer graphene are proposed to generate multiflat bands in the electronic band structure. In addition to the single midgap states in the spectrum of graphene with low hydrogen density, we found closely spaced bands around the Fermi level with increasing impurity density, which are similar to discrete lines in the spectrum of quantum dots, as well as the unusual Landau-level energy spectrum of graphene in the presence of a strong magnetic field. The presence of flat bands crucially depends on whether or not there are odd or even electrons of H(F) atoms bound to graphene. Interestingly, we found that a fully hydrogenated (fluoridated) of a hexagon of graphene sheet with six hydrogen (fluorine) atoms sitting on top and bottom in consecutive order exhibits Dirac cones in the electronic band structure with a 20% smaller Fermi velocity as compared to the pristine graphene. Functionalizing graphene introduces various C-C bond lengths resulting in nonuniform strains. Such a nonuniform strain may induce a giant pseudomagnetic field in the system, resulting in quantum Hall effect. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000994364500006 |
Publication Date |
2023-02-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:197431 |
Serial |
8822 |
Permanent link to this record |