Void Fraction Measurement in a Two-Phase Bubble Column Reactor Using Distributed Acoustic Sensing

We present a novel use of Distributed Acoustic Sensing (DAS) to non-intrusively measure void fraction in a two-phase bubble column via Rayleigh scattering in optical fibers. This method leverages process-generated emissions of bubbly flows to detect acoustic wave movement in the reactor. Using presented algorithms the Speed of Sound (SoS) can be extracted which is further correlated to the void fraction. The proposed DAS measurements in a 150mm column show below 1% absolute deviation from a reference for void fractions up to 4%. DAS enables measurements at multiple points along the column, surpassing global or single-point methods.