Termiliselt töödeldud halli (Alnus incana) ja musta lepa (Alnus glutinosa) töötlusintensiivsuse tuvastamine keemiliste elementide põhjal
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Kuupäev
2024
Kättesaadavus
10.09.2024
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Puidu bioloogiline vastupidavus ja mahupüsivus paranevad termilisel töötlusel, kui töötlusparameetrid on piisavalt intensiivsed. Tarbijad on sunnitud lähtuma tootmisettevõtete kvaliteediklassidest, sest puuduvad sõltumatud kvaliteedikontrolli meetodid. Käesoleva magistritöö eesmärk oli uurida termilise töötluse intensiivsuse tuvastamise potentsiaali, keemiliste elementide sisalduse põhjal. Töö läbiviimiseks kasutati varasemalt töödeldud halli ja musta lepa proovikehasid. Proovidega teostati keemiliste elementide (NCHS) ning tuha- ja energiasisalduse analüüsid. Töös leiti, et süsiniku sisaldus suureneb töötluse intensiivsusega. Hapniku sisaldus, hapniku-süsiniku (O/C) ja vesiniku-süsiniku (H/C) moolide suhted vähenesid. Vesiniku ja väävli sisalduste väärtused varieerusid, kuid esines negatiivne trend. Lämmastiku sisaldus ei muutunud statistiliselt olulisel määral. Kvaliteedi indikaatornäitajateks sobisid kõige paremini süsinik, hapnik ja O/C suhe. Puidu termilise töötluse intensiivsuse uurimisel saadakse usaldusväärsed tulemused juhul, kui teada on uuritava proovi(keha) puuliik, keemiliste elementide sisaldus enne töötlemist ja töötlusmeetod. Mainitud teguritel on märkimisväärne mõju elementide sisalduse muutustele, termilisel töötlusel. Töötlus suurendas ainult halli lepa tuhasisaldust, kuid energiasisaldus tõusis töötlusintensiivsusega mõlema lepa puhul, mistõttu võib olla tegemist potentsiaalse indikaatornäitajaga. Tulevikus võiks uurida erinevaid puidu omaduste väärtuseid kombineerituna keemiliste elementide sisaldusega, et leida uusi väärtusi, mis ei varieeru liigisiseselt ja sobivad indikaatornäitajateks.
The biological durability and dimensional stability of wood improve with thermal treatment if the treatment parameters are sufficiently intense. Consumers must rely on the quality classifications of the producer, due to the absence of independent quality control methods. This master's thesis aimed to investigate the potential of detecting thermal treatment intensity based on the content of chemical elements. Previously treated samples of grey and black alder were used for the study. The samples underwent chemical element (NCHS), ash content, and heating value analyses. The study found that the carbon content increased with the intensity of the treatment. The oxygen content, oxygen-carbon (O/C) ratio, and hydrogen-carbon (H/C) ratio decreased. The values of hydrogen and sulfur contents varied, although showing a negative trend, while the nitrogen content did not change significantly. The results indicated that carbon, oxygen, and the O/C ratio were the best quality indicators. Reliable results in studying the intensity of wood thermal treatment, can only be obtained if the wood species, the chemical element content prior to treatment, and the treatment method are known. These factors significantly influence the changes in chemical element content during thermal treatment. Thermal treatment increased the ash content only in grey alder, but the energy content increased with treatment intensity in both alder species, suggesting it could be a potential indicator. Future research could explore various wood properties combined with chemical element content to identify new values, consistent within a species, as suitable quality indicators.
The biological durability and dimensional stability of wood improve with thermal treatment if the treatment parameters are sufficiently intense. Consumers must rely on the quality classifications of the producer, due to the absence of independent quality control methods. This master's thesis aimed to investigate the potential of detecting thermal treatment intensity based on the content of chemical elements. Previously treated samples of grey and black alder were used for the study. The samples underwent chemical element (NCHS), ash content, and heating value analyses. The study found that the carbon content increased with the intensity of the treatment. The oxygen content, oxygen-carbon (O/C) ratio, and hydrogen-carbon (H/C) ratio decreased. The values of hydrogen and sulfur contents varied, although showing a negative trend, while the nitrogen content did not change significantly. The results indicated that carbon, oxygen, and the O/C ratio were the best quality indicators. Reliable results in studying the intensity of wood thermal treatment, can only be obtained if the wood species, the chemical element content prior to treatment, and the treatment method are known. These factors significantly influence the changes in chemical element content during thermal treatment. Thermal treatment increased the ash content only in grey alder, but the energy content increased with treatment intensity in both alder species, suggesting it could be a potential indicator. Future research could explore various wood properties combined with chemical element content to identify new values, consistent within a species, as suitable quality indicators.
Kirjeldus
Magistritöö
Metsatööstuse õppekaval
Märksõnad
magistritööd, termiline töötlus, kvaliteeditagamine, keemiline koostis, tuhasisaldus, energiasisaldus