Photoacoustic spectroscopy (PAS) is an analytical technique that leverages the photoacoustic effect, where modulated light absorption by a gas sample causes localized heating, thermal expansion, and the generation of pressure waves that can be detected as sound.

In this project, PAS is applied to biogas plants, where precise measurement of gas components is essential. Traditional gas monitoring systems are often large, expensive, and complex, which limits their accessibility and scalability, particularly in industries that require continuous, real-time monitoring of gas compositions at multiple points in the production process. This work aims to overcome these challenges by developing a miniaturized, cost-effective photoacoustic sensor capable of simultaneously monitoring multiple gas components. 

To achieve this, finite element modeling (FEM) and computational fluid dynamics (CFD) methods are employed to gain insights into the design optimization of the sensor. COMSOL Multiphysics is used to simulate key components of the photoacoustic process, such as light propagation, heat generation, and sound wave detection. The simulation results, which cover the optical path of the infrared emitter, temperature distribution, and photoacoustic pressure, are presented. This simulation model offers valuable insights into sensor optimization by enabling the virtual testing of design parameters, such as cell dimensions, materials, and transducer placement, thereby reducing experimental costs and accelerating the development process.