Microwave-Stimulated Serpentinization of Olivine for Geological Hydrogen Production

TL;DR

Microwave irradiation significantly accelerates serpentinization of olivine at atmospheric pressure, increasing hydrogen production rate by approximately 12 times compared to conventional heating methods.

Contribution

This study presents the first experimental evidence that microwave stimulation can enhance geological hydrogen production via serpentinization.

Findings

Microwave heating increased hydrogen concentration 12-fold.

Hydrogen production rate increased from 2 ppb/s to 10 ppb/s with microwave.

Microwave stimulation likely causes rapid volumetric heating and localized thermal gradients.

Abstract

Serpentinization of ultramafic rocks is a naturally occurring mineralogical process that can generate molecular hydrogen through the oxidation of ferrous iron during water-rock reaction. Although the resource potential is large, the natural reaction is kinetically limited, and practical hydrogen recovery requires methods that can accelerate conversion without imposing an energy penalty that exceeds the value of the hydrogen produced. This short communication reports a preliminary atmospheric-pressure microwave serpentinization experiment using a water-saturated 2 g crushed olivine sample. Microwave irradiation produced a rapid increase in measured hydrogen concentration compared with conventional hot-plate heating under otherwise similar conditions. The preliminary experiment showed approximately a 12-fold increase in hydrogen concentration and an apparent rate increase from about 2 ppb s$^{-1}$ for conventional heating to about 10 ppb s$^{-1}$ during microwave exposure. These results suggest that electromagnetic stimulation can enhance serpentinization kinetics, likely through rapid volumetric heating, selective coupling to iron-bearing phases, and localized thermal gradients. The result provides an initial experimental basis for evaluating microwave stimulation as a route to accelerated geologic hydrogen production and motivates follow-on measurements using calibrated gas analysis, absorbed-power measurements, dielectric characterization, and elevated-pressure testing.