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The Hydrodeoxygenation of Glycerol over NiMoS x : Catalyst Stability and Activity at Hydropyrolysis Conditions
Author(s) -
Anderson Anthony D.,
Lanci Michael P.,
Buchanan J. Scott,
Dumesic James A.,
Huber George W.
Publication year - 2021
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.202001289
Subject(s) - deoxygenation , hydrodeoxygenation , catalysis , chemistry , oxygenate , glycerol , reactivity (psychology) , organic chemistry , methanol , inorganic chemistry , selectivity , medicine , alternative medicine , pathology
Catalytic activity tests were run to elucidate the chemistry and catalyst stability for the hydrodeoxygenation of glycerol and other aliphatic oxygenates over a NiMoS x /Al 2 O 3 catalyst at different pretreatments at hydropyrolysis conditions in a continuous flow reactor. Reactivity metrics were developed to quantify and compare the reactivity of NiMo for deoxygenation, hydrogenation, and C−C cleavage. Activity experiments showed sulfided NiMo and reduced NiMo catalysts had similar deoxygenation and hydrogenation activity for glycerol HDO at 400 °C and 270 psig H 2 with the NiMoS x catalyst showing higher C−C cleavage activity. Without a sulfur co‐feed, both the NiMoS x and NiMoO x catalysts lost >40 % deoxygenation activity over 30 h time on stream. With a 2100 ppm H 2 S co‐feed the NiMoS x catalyst showed a 12 times decrease in the deactivation rate for deoxygenation and 6 time decrease in the deactivation rate for hydrogenation. The main products at high conversion were propylene, propane, ethylene, methane, CO, methanol, ethanol, and 1‐propanol. At low conversion, the major products were unsaturated allyl alcohol, acrolein, hydroxyacetone, and acetaldehyde. With no H 2 S co‐feed at short contact times, there was a significant amount of carbon loss possibly due to condensation reactions, while at 2100 ppm H 2 S in the feed, the carbon balance was 102.4 %. Temperature programmed oxidation of the spent NiMoS x catalysts after 30 h of glycerol HDO without an H 2 S co‐feed showed that one of the causes of deactivation was coking.