IHSS&IWA26 / BRNO / CZECHIA / 23–28 August 2026 BOOK OF ABSTRACTS 278 Poster Session / Technologies and Applications Hall A P5.13 Effect of Processing Temperature on Yield and Functional Groups of Artificial Humiclike Acids Produced from Rye Straw via a Torrefaction-Based Method Patrycja Boguta1, Kamil Skic1, Adrianna Biedrzycka1, Piotr Bulak1 1 Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4 str., 20-290 Lublin, Poland, email: k.skic@ipan.lublin.pl Humic acids constitute one of the most valuable components of soil, playing a crucial role in the uptake of micro- and macronutrients by plants, the immobilization of heavy metals, serving as an energy source for microorganisms, improving water retention, and maintaining proper soil aggregate structure [1]. In recent years, the rapid development of the global economy has significantly increased the demand for humic substances, including humic acids, thereby stimulating the search for alternative methods for producing their artificial counterparts (humic-like substances) [2]. The aim of this study was to evaluate the yield and functional group composition of artificial humic acids (AHAs) obtained through a catalyticthermal biomass conversion process. Rye straw biomass was purified, dried, and ground using a set of laboratory mills. The prepared substrate was then subjected to torrefaction at temperatures ranging from 200 to 300 °C in the presence of Fe-based catalysts, followed by oxidation, extraction, and fractionation procedures commonly used for the isolation of humic acids from soils. Process efficiency was determined gravimetrically after drying the obtained AHAs in a laboratory oven at 105 °C. The qualitative assessment of functional groups was carried out based on the results of Fourier-transform infrared spectroscopy (FTIR). Measurements were performed on AHA preparations in the form of thin pressed pellets containing 1 mg of sample, dried at 105 °C and homogenized with 200 mg of KBr. Spectra were recorded using a Tensor 27 FTIR spectrometer (Bruker Optics, Germany) in the spectral range of 400–4000 cm⁻¹, with a resolution of 2 cm⁻¹ and 256 scans. Data were processed using OPUS software (Bruker Optics, Germany). The yield of AHA production in the catalytic–thermal process depended primarily on the temperature of the torrefaction process. This parameter increased with temperature, but the above changes were particularly evident at lower temperatures. An increase in temperature also influenced the functional groups of the
RkJQdWJsaXNoZXIy NDA4Mjc=