Premium
Mid‐Infrared Spectroscopy for Monitoring of Anaerobic Digestion Processes – Prospects and Challenges
Author(s) -
Eccleston Robin,
Wolf Christian,
Balsam Matthias,
Schulte Franziska,
Bongards Michael,
Rehorek Astrid
Publication year - 2016
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201500334
Subject(s) - anaerobic digestion , anaerobic exercise , spectroscopy , infrared spectroscopy , infrared , digestion (alchemy) , chemistry , biochemical engineering , materials science , analytical chemistry (journal) , engineering , environmental chemistry , methane , physics , chromatography , biology , optics , organic chemistry , physiology , quantum mechanics
To develop an online probe that is not only sufficiently robust, but also able to measure crucial process variables in biogas plants is a tough challenge. Therefore, a mid‐infrared (MIR) spectroscopic attenuated total reflection (ATR) probe and robust probe fitting were established. A fully automated probe control, calibration after probe cleaning, and analysis of the absorption spectra using machine learning were implemented in order to reduce maintenance of the probe to a minimum. The relevant wavelengths in the MIR spectrum for organic acids, total alkalinity, and ammonium nitrogen concentration were identified. Finally, intensive lab testing was carried out, followed by operation of the complete online measurement system at an industrial biogas plant. In order to improve signal strength and sensitivity, microelectronic mechanical system (MEMS)‐based Fabry‐Pérot interferometers were also investigated.