The Role of Homogeneous Chemistry during Ignition of Propane Combustion in Pt-Catalyzed Microburners

Abstract

The aim of this work is to numerically investigate the ignition behavior of homogeneousheterogeneous (HH) combustion of propane in a Pt-catalyzed microburner to delineate the role of homogeneous chemistry during cold-start ignition. A two dimensional model with one-step homogeneous and catalytic mechanisms in a parallel-plate microburner is considered. The ignition characteristics (ignition temperature and ignition time) are explored for catalytic microreactor with and without homogeneous chemistry. We show that the catalytic reaction lights-off first, followed by the homogeneous reaction. Consequently, the homogeneous chemistry does not affect the ignition behavior of the catalytic microburner. The effect of inlet velocity, wall thermal conductivity and gap size on ignition characteristics is explored. The ignition characteristics are not affected by homogeneous chemistry even at larger gap sizes, despite the fact that the homogeneous contribution at steady state increases with increasing gap size of the microburner.

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“…Extensive experiments along with simulations have been demonstrated that the homogeneous chemistry cannot be ignored, especially at high temperatures and pressures [9e12]. The contribution of homogeneous chemistry in these HH microreactors varies with conditions and application [13,14]. In general, homogeneous combustion can be desirable or detrimental, depending on the specific application and conditions of the system [15].…”