Hydrogen production by means of catalityc thermal decomposition of methane in rotary reactors

Abstract

The decomposition of the methane by means of a thermal and catalytic process

(DTC) has been widely studied previously. The process to laboratory level,

either in moving bed or fluidized bed, has been optimized, mainly with metallic

catalysts, obtaining an efficiency of hydrogen production nearby to the maximum

theoretically fixed by the thermodynamic, depending on the temperature of

reaction.

A rotary reactor designed by Inasmet-Tecnalia to carry out the process of

Catalytic Thermal Decomposition (DTC) of methane has been investigated in order

to achieve the COx-free production of hydrogen. The aim of the present work is

to study the efficiency of this type of reactor, in a pilot scale, for a continuous

production of hydrogen. A reactor such as, specifically designed, offers excellent

fluidodynamic properties for the route DTC, though the optimization of the design

in the scale that one has worked was not an object of the study.

The trials, carried out in this reactor, allow the study of the influence of operating

conditions such as the temperature reaction, the action of the different types of

catalyst in the bed, the flow of methane, and the residence times, with a view to

optimizing the parameters adjusted for the specific technology used. Likewise,

there has been studied the nature of the carbon obtained as by-product with a

view to his economic valorisation.

The results have been compared with the best published information referred to

the same process using traditional processes (fixed bed and fluidized bed). The

result demonstrates that the process is highly competitive taking into account

the methane conversion, turning out to be the most favorable for the economic

reasons, the simplification of the process, and the facility of scale-up. Equally,

the system permits continuous operation which is of special interest facing his

transfer to the industrial tissue.