Ultra-fast polarity switching GC-IMS for the analysis of volatiles in biogas

authored by: Alexander Nitschke, Moritz Hitzemann, Jonas Winkelholz, Tim Kobelt, Christian Thoben, Martin Lippmann, Lennard Stolpe, Henrik Plinke, Stefan Zimmermann
Abstract: The Renewable Energy Act 2023 (§39i) requires reducing corn silage in biogas plants from 40 % to 30 % in 2026. Since corn silage yields the highest biogas per weight unit of all biogas feedstocks, this poses new challenges for biogas plant operators. However, alternative biogas feedstocks not harvested directly from the field may contain siloxanes due to the use of care products and disinfectants. The conversion of siloxanes into silicon dioxide during the combustion process seriously threatens the lifetime and efficiency of the used gas engine, even in very low concentrations. Consequently, we present a highly sensitive measurement system for monitoring biogas. Detection limits down to 0.037 mg/m³ for the tested siloxanes have been reached. Furthermore, ketones can be detected down to 0.002 mg/m³, alcohols down to 0.001 mg/m³. The device combines an ultra-fast polarity switching ion mobility spectrometer with a switching time of 12 ms and a resolving power of R_P = 70, a gas chromatographic pre-separation, and a non-dispersive infrared sensor for methane. In this context, we analyzed the biogas composition for volatile substances and siloxanes, whereby we only found the volatile substances. For demonstration, biogas was analyzed at three different stages during the gas purification process.
Organisation(s): Institute of Electrical Engineering and Measurement Technology
External Organisation(s): Jürgen-Heinrich & Annegret Plinke GbR “Plinke Biogas“
Type: Article
Journal: Renewable energy
Volume: 231
No. of pages: 9
ISSN: 0960-1481
Publication date: 09.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Renewable Energy, Sustainability and the Environment
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1016/j.renene.2024.120941 (Access: Open)