Continuous production of H-2 at low temperature from methane decompositionover Ni-containing catalyst followed by gasification by steam of the carbon on the catalyst in two parallel reactors operated in cyclic manner
Vr. Choudhary et al., Continuous production of H-2 at low temperature from methane decompositionover Ni-containing catalyst followed by gasification by steam of the carbon on the catalyst in two parallel reactors operated in cyclic manner, J CATALYSIS, 198(1), 2001, pp. 136-141
CO-free H-2 in close to stoichiometric amounts was produced continuously at
a constant H-2 production rate by the stepwise steam reforming of methane
at low temperature (500 degreesC) in two parallel catalytic reactors operat
ed in cyclic manner. The process involved two simultaneous reactions: first
, catalytic decomposition of methane to H-2 and carbon (deposited on the ca
talyst), and second, gasification of the carbon deposited on the catalyst b
y steam to H-2 and CO2. The two reactions were carried out separately in tw
o parallel reactors (both containing the same Ni-containing catalyst), oper
ated in cyclic manner by switching a methane-containing feed and a steam-co
ntaining feed between the two reactors at a predecided interval of time. Th
e process shows best performance at an optimum value of the feed switchover
time. Among the different Ni-containing metal oxide (ZrO2, MgO, ThO2, CeO2
, UO3, B2O3 or MoO3) and zeolite [HZSM-5, H beta, HM, NaY, Ce(72)NaY, or Si
-MCM-41] catalysts, the Ni/ZrO2 and Ni/Ce(72)NaY showed promising results f
or the cyclic process. (C) 2001 Academic Press.