Enhancement of thermochemical hydrogen production using an iron-silica magnetically stabilized porous structure

摘要

A synthesis process for creating an iron-based magnetically stabilized porous structure is described in detail. The structure is used as the reactive substrate for a two-step water splitting, hydrogen production process. The stability and reactivity of a 205 g magnetically stabilized structure operating at 873, 973, 1023 and 1073 K over eleven consecutive oxidation and reduction cycles has been investigated. Applying an external magnetic field exploits sintering and controls the geometry of the matrix of particles inside the structure in a favorable manner so that the chemical reactivity of the structure remains intact. The experimental results demonstrate that this structure yields peak hydrogen production rates of approximately 29 cm~3/(min g_Fe) at 1073 K without noticeable degradation over eleven consecutive cycles. The hydrogen production rate is considerably higher than those reported in the open literature for two-step water splitting processes. SEM images, hydrogen production rates, permeability of the bed, and the bed height confirm that the gas-solid contact area and porosity of the magnetically stabilized porous structure is sustained after consecutive cycling at high reaction temperatures.