Operability Analysis and Design of a Reverse-Flow Microreactor for Hydrogen Generation via Methane Partial Oxidation

Abstract

We present an operability analysis and a design of a microreactor for hydrogen generation via methane partial oxidation used in unidirectional (UD) and reverse-flow (RF) modes of operation. We show that the reverse-flow operation is more robust with respect to a wide range of changes in reaction parameters. Furthermore, we demonstrate that autothermal operation can be maintained only in the RF mode and not in the UD mode at higher hydrogen throughput or with partial deactivation of the catalyst. On the other hand, increasing the catalyst loading and using the reactor with a higher thermal diffusivity of the solid structure expands the region of stable autothermal UD operation. An analysis of model sensitivity to the kinetic parameters is also performed. On the basis of this, a rational scheme for improved catalyst placement in the RF reactor is proposed.

Interactions between reaction kinetics in ATR-reactors and transport mechanisms in functional ceramic membranes: A simulation approach

“…For example, a lot of research has been done on improving permeability and selectivity of hydrogen separation membranes [13][14][15][16][17][18] or meliorating the reactor process control [5,12,19]. However, it is possible that upon integration of these aspects into the system the optimization criteria of the components might change.…”

“…In order to ensure that the outcome of the simulation exercise remains comparable to that obtained from solving the entire equation set, in what has established itself as state of the art approach in modelling autothermal reforming [5,19], a comparison is drawn between the results obtained in the developed model and a second one based primarily on the work of Tiemersma et al [5]. This is done with focus on the membrane flux and the temperature hotspot that are of great interest in this investigation.…”

“…The DM1D has already been used and verified in many research work [5][6][7]19], it has established itself as a state-of-the-art model for autothermal reforming, consequently the suitability of the proposed model can be confirmed through a direct comparison where deviations can be quantified.…”

Modelling of a reverse-flow partial oxidation reactor for synthesis gas production from gasifier product gas

“…In order to avoid this problem, a reverse-flow reactor system has been suggested. This concept was first reported for the combustion of low calorific gases, and has been extensively studied over the years [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Several industrial applications of the technique exist, mainly as regenerative thermal oxidation, for the removal of volatile organic compounds and regenerative catalytic oxidation.…”

Numerical Analysis of Fractal Catalyst Structuring in Microreactors

“…Selective placement of catalysts that promote methane combustion, reforming, and water-gas shift reactions was proposed for periodically operated reverse-flow microreactors to improve the productivity by enhancing reaction rates in low-and hightemperature regions of the reactor. 6 Cot e et al 7 proposed using an auxiliary catalyst in addition to implementing a layered patterned strategy to alleviate the equilibrium limitation for paraffin dehydrogenation and methanol synthesis. In the past decade, catalytic microreactor technology has been proposed for chemical synthesis, chemical kinetics studies, and process development, because of the high surface:volume ratio and high heat-and mass-transfer rates.…”