To further reduce the scale while m

To further reduce the scale while maintaining system efficiency is hardly attained by using conventional geometries and/or manufacture techniques of actual microreactors. Therefore, the development of breakthrough technologies capable to provide higher reaction rates per unit volume and, at the same time, enable downscaling is required. In a pioneering publication by Llorca et al. [3], a new turn of the screw in miniaturization of systems for hydrogen production was accomplished by using macroporous silicon structures coated with appropriate catalyst with millions of regular and parallel microchannels per square centimeter with a diameter of only ~3-4 Pm and a depth/diameter ratio of 65. A ~0.01 cm3 unit comprising >106 channels was successfully tested for ethanol steam reforming (ESR) under residence times