tailieunhanh - Characterization and kinetics analysis of the thermal decomposition of the humic substance from hazelnut husk

A humic substance was obtained from hazelnut husk using an alkali extraction. The chemical and morphological structure of the humic matter was characterized via elemental analysis, Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance, Brunauer-Emmet-Teller (BET) analysis, scanning electron microscopy (SEM), and thermogravimetric-FTIR (TG-FTIR). In addition, thermal analysis measurements TG analysis-differential thermogravimetry/differential scanning calorimetry (TGA-DTG/ DSC) were performed under dynamic air conditions to better determine the origin, physical and chemical structure, and decomposition process of the humic matter. | Turkish Journal of Chemistry Turk J Chem 2020 44 1483-1494 http chem TÜBİTAK Research Article doi kim-2004-62 Characterization and kinetics analysis of the thermal decomposition of the humic substance from hazelnut husk 1 1 2 3 1 Fatma KARA Duygu ADIGÜZEL Ufuk ATMACA Murat ÇELİK Jale NAKTİYOK 1 Department of Chemical Engineering Engineering Faculty Atatürk University Erzurum Turkey 2 Oltu Vocational School Atatürk University Oltu Erzurum Turkey 3 Department of Chemical Faculty of Science Atatürk University Erzurum Turkey Received Accepted Published Online Final Version Abstract A humic substance was obtained from hazelnut husk using an alkali extraction. The chemical and morphological structure of the humic matter was characterized via elemental analysis Fourier transform infrared spectrometry FTIR nuclear magnetic resonance Brunauer-Emmet-Teller BET analysis scanning electron microscopy SEM and thermogravimetric-FTIR TG-FTIR . In addition thermal analysis measurements TG analysis-differential thermogravimetry differential scanning calorimetry TGA-DTG DSC were performed under dynamic air conditions to better determine the origin physical and chemical structure and decomposition process of the humic matter. The Kissinger-Akahira-Sunose KAS and Flynn-Wall-Ozawa FWO methods were used to calculate the kinetic parameters of the high-temperature decomposition process. It was observed that the activation energy values were almost constant at certain conversion and temperature intervals. In addition the structure of the humic substance at different temperatures was also investigated via FTIR analysis. It was found that the obtained humic substance had a very stable structure and decomposed at a high temperature. The stability of the humic matter can be a useful tool in the environmental quality research of soil. Key words Hazelnut husk humic substance thermal decomposition TG-DTG DSC analysis kinetic .