Production of Hydrogen by Steam Reforming of Methanol Over …
407
2 Materials and Methods
NiO/SiO 2 nanocomposite was prepared by sol–gel technique using nickel nitrate
hexahydrate [Ni (NO 3 ) 2 , 6H 2 O, Merck] as precursor and tetra ethyl orthosilicate
(TEOS, Merck) as silica matrix-forming agent with ethanol (absolute, 99%, Merck)
solution. A certain amount of TEOS and ethanol solution was stirred using magnetic
stirrer at room temperature. Nickel nitrate with intended Ni loading (5, 7, 10, 12.5,
15 wt% in the catalyst) dissolved in the aqueous ethanol solution was added slowly to
the silica sol with constant stirring. The final solution was stirred at room temperature
for about 5–6 h and allowed to age for 1 week. The obtained gel was dried in hot
air oven at 110 °C for 24 h to remove water and other volatile compounds. Then the
dried gel was calcined at 400 °C.
To prepare alumina-supported NiO/SiO 2 catalyst, alumina (SISCO), NiO–SiO 2 ,
and bentonite powder (as binder, Merck) was mixed in an appropriate proportion and
then the mixture was transformed into extrudates. The extrudates are finally dried in
hot air oven at 110 °C. The catalysts were prepared with different Ni loadings of 5,
7, 10, 12.5, and 15 wt%.
2.1 Experimental Procedure
Steam reforming reaction was carried out in a fixed bed tubular reactor (10 mm inner
diameter) placed inside a cylindrical furnace. The reactor was loaded with catalyst
mixed with inert particles, so that the bed height was maintained at 60 mm. The
remainder of the reactor was filled with inert ceramic material. The catalyst was
reduced as well as activated by heating at 550 °C with the flow of hydrogen for 4 h.
The thermocouple inserted into the thermowell of reactor recorded the catalyst bed
temperature. After catalyst activation, the reaction temperature was fixed at a desired
temperature and catalytic steam reforming reaction was performed at atmospheric
pressure by introducing the flow of methanol–water mixture. The feed mixture was
vaporized through the preheater before entering reactor inlet. The reactor outlet
stream was passed through a condenser for separation of condensable components
in the gas–liquid separator.
The product gas stream flow rate was measured using a wet gas meter. The gas
mixture was periodically sent to gas–liquid chromatography (Model: Chemito GC
1000 DPR) for analysis using thermal conductivity detector (TCD) with packed.
Nitrogen was used as carrier gas.
407
2 Materials and Methods
NiO/SiO 2 nanocomposite was prepared by sol–gel technique using nickel nitrate
hexahydrate [Ni (NO 3 ) 2 , 6H 2 O, Merck] as precursor and tetra ethyl orthosilicate
(TEOS, Merck) as silica matrix-forming agent with ethanol (absolute, 99%, Merck)
solution. A certain amount of TEOS and ethanol solution was stirred using magnetic
stirrer at room temperature. Nickel nitrate with intended Ni loading (5, 7, 10, 12.5,
15 wt% in the catalyst) dissolved in the aqueous ethanol solution was added slowly to
the silica sol with constant stirring. The final solution was stirred at room temperature
for about 5–6 h and allowed to age for 1 week. The obtained gel was dried in hot
air oven at 110 °C for 24 h to remove water and other volatile compounds. Then the
dried gel was calcined at 400 °C.
To prepare alumina-supported NiO/SiO 2 catalyst, alumina (SISCO), NiO–SiO 2 ,
and bentonite powder (as binder, Merck) was mixed in an appropriate proportion and
then the mixture was transformed into extrudates. The extrudates are finally dried in
hot air oven at 110 °C. The catalysts were prepared with different Ni loadings of 5,
7, 10, 12.5, and 15 wt%.
2.1 Experimental Procedure
Steam reforming reaction was carried out in a fixed bed tubular reactor (10 mm inner
diameter) placed inside a cylindrical furnace. The reactor was loaded with catalyst
mixed with inert particles, so that the bed height was maintained at 60 mm. The
remainder of the reactor was filled with inert ceramic material. The catalyst was
reduced as well as activated by heating at 550 °C with the flow of hydrogen for 4 h.
The thermocouple inserted into the thermowell of reactor recorded the catalyst bed
temperature. After catalyst activation, the reaction temperature was fixed at a desired
temperature and catalytic steam reforming reaction was performed at atmospheric
pressure by introducing the flow of methanol–water mixture. The feed mixture was
vaporized through the preheater before entering reactor inlet. The reactor outlet
stream was passed through a condenser for separation of condensable components
in the gas–liquid separator.
The product gas stream flow rate was measured using a wet gas meter. The gas
mixture was periodically sent to gas–liquid chromatography (Model: Chemito GC
1000 DPR) for analysis using thermal conductivity detector (TCD) with packed.
Nitrogen was used as carrier gas.