1. Gas-phase hydrodeoxygenation of guaiacol over iron-based catalysts. Effect of gases composition, iron load and supports (silica and activated carbon)
- Author
-
Dominique Petitjean, Roberto N. Olcese, Bernard Malaman, Mohammed M. Bettahar, L. Tibavizco, Anthony Dufour, Jaafar Ghanbaja, GREENER, Laboratoire Réactions et Génie des Procédés (LRGP), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
XRD ,Iron loading ,TEM observations ,Lignin pyrolysis ,Heterogeneous catalysis ,Lignin ,7. Clean energy ,01 natural sciences ,chemistry.chemical_compound ,Feed streams ,Benzene ,Selective catalysts ,Spent catalyst ,Reaction mechanism ,General Environmental Science ,Carbon yield ,Silica ,Biorefineries ,Catalyst activity ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Atmospheric pressure ,Chemicals ,Gases ,Carbides ,Methane ,Pyrolysis ,Hydrodeoxygenation ,Ssbauer spectroscopies ,medicine.drug ,Iron ,Activated carbon ,Inorganic chemistry ,Oxide ,Carbon deposites ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,010402 general chemistry ,Paramagnetism ,Catalysis ,Carbonaceous deposits ,Iron-based catalyst ,Gasphase ,Metallic compounds ,Phenols ,medicine ,Iron Particles ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Hydrotreatment ,010405 organic chemistry ,Active site ,Process Chemistry and Technology ,Benzene and Toluene ,[CHIM.CATA]Chemical Sciences/Catalysis ,Model compound ,Molybdenum oxide ,Biorefinery ,0104 chemical sciences ,Carbon dioxide ,chemistry ,13. Climate action ,Alcohols ,Deposits ,Guaiacol ,Aromatic ,Toluene - Abstract
Fe/SiO2 is shown to be a selective catalyst for guaiacol hydrodeoxygenation (HDO). Guaiacol is used as a model compound to study the conversion of lignin pyrolysis vapours into aromatics (benzene, phenols). The effect of each individual gas present in a pyrolysis gas (H2, CO, CO2, H2O, CH4) on the selectivity of a 10 wt% Fe/SiO2 catalyst is studied (673 K, atmospheric pressure, 50 mol% H2, 1/WHSV = 0.6 gcat h/ggua). The speciation of the iron phase (metallic (α-Fe), carbide (Fe5C2), oxide (Fe3O4), and super-paramagnetic) in spent catalysts is revealed by XRD and Mossbauer spectroscopy as a function of gases composition. At least 3 types of carbonaceous deposit were evidenced by TPO analysis. TEM observations showed that iron particles size is not markedly affected by the reaction and that carbon deposit mainly occurs in the vicinity of iron particles. When all the gases except methane (Guaiacol + H2 + CO + CO2 + H2O) are simultaneously in the feed stream, the conditions are still sufficiently reducing to maintain the activity of the catalyst (66% of benzene and toluene carbon yield, 7.5 gcat h/ggua). The effects of support (silica or activated carbon-AC) and iron loading (5, 10, 15 wt% Fe/SiO2) were also studied. 10 wt% Fe/AC has a higher selectivity in phenol and cresols production than Fe/SiO2. Active sites and reaction mechanisms are discussed.
- Published
- 2013
- Full Text
- View/download PDF