Wöhrl Thomas, König Mario, Moos Ralf, Hagen Gunter
Department of Functional Materials, Zentrum für Energietechnik (ZET), University of Bayreuth, D-95440 Bayreuth, Germany.
Deutsches Biomasseforschungszentrum Gemeinnützige GmbH (DBFZ), D-04347 Leipzig, Germany.
Sensors (Basel). 2025 Sep 4;25(17):5519. doi: 10.3390/s25175519.
The emissions from biomass combustion systems have recently been the subject of increased attention. In addition to elevated concentrations of particulate matter and hydrocarbons (HCs) in the flue gas, significant levels of NO emissions occur depending on the used fuel, such as biogenic residues. In response to legal requirements, owners of medium-sized plants (≈100 kW) are now also forced to minimize these emissions by means of selective catalytic reduction systems (SCR). The implementation of a selective sensor is essential for the efficient dosing of the reducing agent, which is converted to ammonia (NH) in the flue gas. Preliminary laboratory investigations on a capacitive NH sensor based on a zeolite functional film have demonstrated a high sensitivity to ammonia with minimal cross-influences from HO and NO. Further investigations concern the application of this sensor in the real flue gas of an ordinary wood-burning stove and of combustion plants for biogenic residues with an ammonia dosage. The findings demonstrate a high degree of agreement between the NH concentration measured by the sensor and an FTIR spectrometer. Furthermore, the investigation of the long-term stability of the sensor and the poisoning effects of SO and HCl are of particular relevance to the laboratory measurements in this study, which show promising results.
生物质燃烧系统的排放问题近来受到了越来越多的关注。除了烟气中颗粒物和碳氢化合物（HCs）浓度升高外，根据所使用的燃料（如生物源残渣），还会产生大量的NO排放。为响应法律要求，中型工厂（约100千瓦）的业主现在也被迫通过选择性催化还原系统（SCR）来尽量减少这些排放。对于还原剂在烟气中转化为氨（NH₃）的有效计量而言，采用选择性传感器至关重要。基于沸石功能膜的电容式NH₃传感器的初步实验室研究表明，该传感器对氨具有高灵敏度，且受H₂O和NO的交叉影响极小。进一步的研究涉及该传感器在普通燃木炉灶以及用于生物源残渣且有氨计量的燃烧装置的实际烟气中的应用。研究结果表明，传感器测得的NH₃浓度与傅里叶变换红外光谱仪（FTIR）的测量结果高度一致。此外，本研究中对传感器长期稳定性以及SO₂和HCl中毒效应的研究与实验室测量特别相关，结果显示前景良好。
