Experimental Research on Measuring the Concentration of CO2 in Gas-Liquid Solution Based on PZT Piezoelectric-Photoacoustic Spectroscopy

Abstract

The feasibility of a scheme in which the concentration of CO2 in gas-liquid solution is directly measured based on PZT piezoelectric-photoacoustic spectroscopy was evaluated. The existing device used for the measurement of gas concentration in gas-liquid solution has several limitations, including prolonged duration, loss of gas, and high cost due to the degassing component. In this study, we developed a measuring device in order to solve the problems mentioned above. Using this device, how the intensity of the photoacoustic signal changes with the concentration of CO2 was demonstrated through experiment. The impact that variation of the laser modulation frequency has on the photoacoustic signal was also studied. Furthermore, the experimental data generated from measuring the concentration of CO2 in gas-liquid solution was verified for a wide range of concentrations. It was found that, not only can the error rate of the device be less than 7%, but the time of measurement can be within 60 s. To sum up, the scheme is highly feasible according to the experimental results, which makes measurement of the concentration of a gas in gas-liquid solution in the future more straightforward.

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“…Generally, a degassing process should be added prior to sensing, [ 149 ] the size of which is incompatible to in‐cell sensing. In a recent work, a PZT piezoelectric‐photoacoustic spectroscopy for detecting gas in liquid without degassing [ 150 ] has been proposed, shedding light on gas sensing in liquid phase.…”

“…The structure of photoacoustic cell. Reproduced according to the terms of the CC BY license [150]. Copyright 2022, the authors, published by MDPI.…”