Chemical Engineering Journal, Vol.178, 264-275, 2011
A dynamic membrane reactor concept for naphtha reforming, considering radial-flow patterns for both sweeping gas and reacting materials
Hydrogen will become an essential energy source in the near future. In this regard, refineries can be considered as alternative sources of hydrogen production. In the present study, a tubular membrane reactor with radial-flow patterns of the sweeping gas and the naphtha feed named RF-TMR is proposed as a novel configuration for radial-flow naphtha reformers. Radial-flow reactors are used in refineries as a remedy for high pressure drop through the catalytic packed-bed reactors which disturbs the reactor operation. The cross section area of the tubular membrane reactor is divided into some subsections. The walls of the gaps are coated by a Pd-Ag membrane layer to separate hydrogen from reaction side and enhance the hydrogen and aromatic production rates by 0.33 ton/day and 5.5 ton/day, respectively (compared with the AF-TR). The performance of this novel configuration is investigated and compared with the axial-flow conventional tubular reactor (AF-TR) and axial-flow tubular membrane reactor (AF-TMR). Set of coupled partial differential-algebraic equations are solved by the orthogonal collocation method. Owing to a slight pressure drop in the tube side of RF-TMR, smaller catalysts' particles with a negligible internal mass transfer resistance can be used to increase aromatics and hydrogen yields. This novel approach has the feasibility to be applied in the radial-flow moving bed reformers which are widely installed in refineries by licensors. (C) 2011 Elsevier B.V. All rights reserved.
Keywords:Radial-flow tubular membrane reactor;Naphtha reforming;Dynamic operation;Hydrogen separation;Octane improvement