• Energy Research

Guidelines on uncertainty assessment of biofuel measurements, including water content, and sampling, as well as inorganic and organic impurities. Also considering uncertainty from utilizing machine learning. Prepared by the following partners of the BIOMET project: CMI, IST, IMBiH, DTI, AMU, PROMETEC, PTB, CETIAT, TUBITAK www.biofmet.eu This project 19ENG09 BIOFMET has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme.

The complete data set that was the basis of the article: Stratulat, C.; Ginghina, R.E.; Bratu, A.E.; Isleyen, A.; Tunc, M.; Hafner-Vuk, K.; Frey, A.M.; Kjeldsen, H.; Vogl, J. Development- and Validation-Improved Metrological Methods for the Determination of Inorganic Impurities and Ash Content from Biofuels. Energies 2023, 16, 5221. https://doi.org/10.3390/en16135221 This work is part of the 19ENG09 BIOFMET project. This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 re-search and innovation programme.

This paper presents methodologies and equipment for SI-traceable inline measurements of water content (a critical quality parameter) in solid biofuels. Inline measurement systems for water content are commonly used at CHP plants, providing continuous real-time data. However, the accuracy of these systems is in most cases unsatisfactory, mainly because the systems are not calibrated representatively for the relevant material, and until now, calibrations traceable to the SI system have not been available. To provide reliable and accurate inline water content data, new procedures and equipment for calibrating measurement systems were developed. Two reference methods for the determination of water content were developed; one measures the airflow and dewpoint of desorbed water in the air passing a test sample, while the other uses a P2O₅-sensor. Additionally, a transfer standard based on a cavity resonance sensor was developed for fast onsite calibration of the inline sensor at the power plant. This new instrument allows for quick and accurate measurements. The transfer standard is made metrologically traceable to the primary measurement standards. The entire system was demonstrated by calibrating an inline microwave-based (MW) sensor at the CHP plant of VERDO in Randers, Denmark. Thus, a complete metrological traceability chain was established from an industrial to a primary standard.

In this study, five laboratories, namely, BRML (Romania), TUBITAK UME (Turkey), IMBIH (Bosnia and Herzegovina), BAM (Germany), and DTI (Denmark), developed and validated analytical procedures by ICP-MS, ICP-OES, MWP-AES, WD-XRF, and ID-MS for the determination of inorganic impurities in solid and liquid biofuels, established the budget of uncertainties, and developed the method for determining the amount of ash in the measurement range 0–1.2% with absolute repeatability less than 0.1% and absolute reproducibility of 0.2% (according to EN ISO 18122). In order to create homogeneous certified reference materials, improved methodologies for the measurement and characterization of solid and liquid biofuels were developed. Thus, information regarding the precision, accuracy, and bias of the method, and identifying the factors that intervened in the measurement of uncertainty were experimentally determined, supplementing the information from the existing standards in the field.

Guidelines on uncertainty assessment of biofuel measurements, including water content, and sampling, as well as inorganic and organic impurities. Also considering uncertainty from utilizing machine learning. Prepared by the following partners of the BIOMET project: CMI, IST, IMBiH, DTI, AMU, PROMETEC, PTB, CETIAT, TUBITAK www.biofmet.eu This project 19ENG09 BIOFMET has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme.