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Effects of additives on the hydrogen generation of Al–H 2 O reaction at low temperature
Author(s) -
Sun Yunlan,
Sun Rong,
Zhu Baozhong,
Wu Yuxin
Publication year - 2017
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.3761
Subject(s) - activation energy , yield (engineering) , chemistry , hydrogen , order of reaction , reaction rate , transmission electron microscopy , reaction mechanism , chemical kinetics , hydrogen production , kinetics , nuclear chemistry , analytical chemistry (journal) , catalysis , materials science , reaction rate constant , nanotechnology , chromatography , organic chemistry , metallurgy , physics , quantum mechanics
Summary Water displacement method is used to study the influence of temperatures (60–80°C), additives (Na 2 CO 3 , NaCl, Na 2 CO 3 /NaCl) and concentrations on the reaction characteristics and kinetics of Al–H 2 O. Results show that the reaction rate and the hydrogen yield are enhanced with the increase of the temperature or by adding Na 2 CO 3 . The reaction rate is decreased by adding NaCl, but which has less effect on the hydrogen yield. For the mixture additive, Na 2 CO 3 plays a key role in improving the hydrogen yield and the reaction rate. The influence degree of different factors is analyzed by orthogonal method. The most obvious factor is additive, but additive concentration has a minimum influence. The solid products are collected and analyzed by X‐ray diffraction and transmission electron microscopy. Al, Al(OH) 3 and AlO(OH) are detected. The spherical particles are obviously found at the initial reaction stage. However, they change to flocs at the end of reaction. Kinetic analysis shows that the reaction mechanism of Al–H 2 O is changed by adding Na 2 CO 3 or mixture, but it is not affected by adding NaCl. Moreover, the apparent activation energy of Al–H 2 O is 74.49 kJ mol −1 , while it is only 43.03 kJ mol −1 for Al–H 2 O with 5 wt% Na 2 CO 3 addition. Copyright © 2017 John Wiley & Sons, Ltd.