| dc.description.abstract | ABSTRACT
Methanol Steam Reforming (MSR) with tubular packed bed reactor design was
developed for fuel cell using the different commercial catalyst Cu/ZnO/Al2O3 and
CuO/ZnO/Al2O3. Each catalyst has a different kinetic rate formula that has been validated
using experimental data. In simulation, using Cu/ZnO/Al2O3 catalyst uses Steam Reforming
(SR) and Reverse Water Gas Shifting (RWGS) reactions. Meanwhile, in simulation using
CuO/ZnO/Al2O3 uses Steam Reforming (SR), Decomposition and Water Gas Shifting (WGS)
reactions.
The calculation is carried out by a multiphysics program called COMSOL. Some of the
parameters are varied to be analyzed such as reformer inlet temperature, heating tubes inlet
temperature, steam to carbon and air heating tubes inlet velocity. Temperature distribution,
methanol (CH3OH), carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2) and steam
(H2O) mole fraction were calculated simultaneously. Finally, the performances of the MSR
using different catalyst are compared in terms of methanol conversion, CO selectivity and
mole fraction of each gases.
The results showed that the effect of reformer inlet temperature presenting high
methanol conversion until reach 100% at temperature inlet 300 ℃ for Cu/ZnO/Al2O3
catalyst. However, the increase of reformer inlet temperature also enhance of CO until
reaching 0.14%. Otherwise, it decreases CO2 mole fraction due to reverse water gas shift
reaction (RWGS) which convert CO2 to CO. Different results in the same parameter showed
for a reactor that using CuO/ZnO/Al2O3 which has achieved 100% methanol conversion at
reformer inlet temperature around 180 ℃ − 200℃ with CO mole fraction only 0.05%
because of the use of three reactions. The second parameter affects on the performance of
MSR is air heating tubes inlet velocity. The increasing air velocity inlet from 1 m/s to 6 m/s
can enhance the methanol conversion from 10% to 25 % in reformer using Cu/ZnO/Al2O3.
While, better results are obtained in another catalyst which is reached until 80% methanol
conversion. These increasing closely related to mass convection of hot air in heating tubes
that caused more heat could be distributed along reformer. This also causes effect of heating
tubes inlet temperature to be not too significant. With fixed parameter for air heating tubes
inlet velocity 0.1 m/s, the heat energy transfer cannot provide the enough heat for reforming
process. The increasing of steam to carbon from 0.7 to 1.45 can decrease the hydrogen
production due to the fuel dilution.
Keywords : Methanol Steam Reforming, Cu/ZnO/Al2O3, CuO/ZnO/Al2O3, Reverse Water
Gas Shifting, Water Gas Shifting, COMSOL | en_US |