Standalone micro-reformer for on-board hydrogen production from dimethyl ether

TL;DR

This paper introduces a scalable MEMS-based micro-reactor for on-board hydrogen production from DME, enabling portable power generation with high conversion efficiency and hydrogen yield.

Contribution

It presents the design, fabrication, and testing of a novel micro-reactor with integrated catalyst coating for efficient DME reforming in portable applications.

Findings

Achieved up to 74% DME conversion at 650°C.

Obtained 60% hydrogen selectivity during steam reforming.

Produced 4.5 mL H2 per mL DME at 600°C in a standalone device.

Abstract

Entering a new era of sustainable energy generation and consumption, new solutions for powering consumer electronics are required to tackle the limited capacity provided by the portable power sources employed nowadays. Hydrocarbon-fed micro-fuel cells represent a promising technology for this purpose, and micro-reactor technology can indeed enable their integration for portable applications. In this work, we present the design and fully scalable wafer-level fabrication of a MEMS-based catalytic micro-reactor, paving the way towards on-board hydrogen production for portable power generators. The device consists of an array of thousands of vertically-aligned micro-channels, 500 um in length and 50 um in diameter, for an overall superficial area per unit volume of 120 cm2 cm-3 and it embeds a thin-film heater for efficient reaction start-up. Functionalization of the active area was achieved by atomic layer deposition, resulting in the uniform coating of a Pt/Al2O3 heterogeneous catalyst. The temperature-dependent dimethyl ether (DME)-to-syngas conversion is tested through steam reforming (SR) and partial oxidation (POX) reactions. Here, conversion rates up to 74% and hydrogen selectivity of 60% are obtained by steam reforming at 650dC, while a specific volumetric hydrogen production of 4.5 mLH2 mL-1DME cm-3REACTOR at 600dC is obtained from DME POX in a standalone device tested by means of a 3D printed ceramic housing.