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Characterization methods for wood extractives
No full textVarious types of hydrophobic wood lipids, believed to behave detrimentally in papermaking , are presented, as well as different analytical methods for their chemical characterization. A determination of triglycerides, steryl esters, sterols, fatty and resin acids in spruce and beech chips (important raw materials in pulp and paper industry) was performed. A comparison of results, obtained by solid phase extraction (SPE), thin layer chromatography (TLC), gel permeation chromatography (GPS) and gas chromatography (GC) was made. Advantages and drawbacks of individual analytical techniques were established
Characterization methods for wood extractives
No full textPredstavljene so različne vrste hidrofobnih lesnih lipidov, ki so možni povzročitelji onesnaženja v papirniških sistemih, prav tako pa tudi analitske metode za njihovo karakterizacijo. Podani so rezultati določitve vsebnosti trigliceridov, sterolnih estrov, sterolov, maščobnih in smolnih kislin v smrekovih in bukovih sekancih, ki so pomembna vhodna surovina v celulozno-papirni industriji. Izdelana je primerjava različnih analitskih tehnik, in sicer ekstrakcije na trdni fazi (SPE), tankoplastne kromatografije (TLC), gelske porazdelitvene kromatografije (GPC) in plinske kromatografije (GC)navedene so njihove prednosti in pomanjkljivosti pri določanju kemične sestave in lesnih ekstraktivov.Various types of hydrophobic wood lipids, believed to behave detrimentally in papermaking , are presented, as well as different analytical methods for their chemical characterization. A determination of triglycerides, steryl esters, sterols, fatty and resin acids in spruce and beech chips (important raw materials in pulp and paper industry) was performed. A comparison of results, obtained by solid phase extraction (SPE), thin layer chromatography (TLC), gel permeation chromatography (GPS) and gas chromatography (GC) was made. Advantages and drawbacks of individual analytical techniques were established
Problems of wood extractives in papermaking
No full textPredstavljene so različne vrste lesnih ekstrativnih spojin, in sicer trigliceridi, voski, sterolni estri, steroli in višji alkoholi ter smolne in maščobne kisline, ki jih le-te lahko povzročajo pri proizvodnji papirja. Med najpomembnejše negativne učinke štejemo izločanje lepljivih oblog na strojni opremi in pojav madežev na papirju. Opisane so različne instrumentalne metode kemijske karakterizacije hidrofobnih ekstraktivov, ki jih do neke mere najdemov vseh fazah proizvodnje, in predlagane nekatere tehnološke rešitve za odpravo motenj v proizvodnji
Possibilities of full recovery of lignocellulosic biomass in the pulp and paper industry
No full textPossibilities for Chemical Conversion of Beech Wood
No full textThis article presents chemical composition of beech wood as well as various possibilities for its chemical conversion. The useful components of beech biomass are primarily cellulose fibers, xylan and lignin. Some of the most important technological procedures for wood fractionation are described, as for example hydrolysis, fermentation, pyrolysis and extraction, together with marketable products which are produced in the processes. The greatest potential for the future is ascribed to the production of nanofibrilated cellulose, which is considered to become the raw material of the future. Recent research has indicated that beech wood and bark contain high added value bioactive compounds, while seeds are extremely reach source of high quality oil. Beech wood, including waste such as bark and sawdust, represent reach raw material which might be conveniently converted to different marketable products
Possibilities for chemical conversion of beech wood
Full text linkV prispevku je predstavljena kemijska struktura bukovega lesa in različne možnosti za njegovo kemično predelavo. Uporabne komponente biomase so predvsem celulozna vlakna, ksilan in lignin. Predstavljeni so nekateri najpomembnejši postopki frakcioniranja lesa, in sicer hidroliza, fermentacija, piroliza in ekstrakcija ter tržno zanimivi produkti, ki pri tem nastajajo. V prihodnosti največji potencial pomeni pridobivanje nanofibrilirane celuloze, ki je surovina prihodnosti. Nedavne raziskave so pokazale, da bukov les in skorja vsebujeta tehnološko pomembne antioksidante, medtem ko so plodovi (žir) izredno bogat vir kakovostnega olja. Bukov les, skupaj z odpadki, kot sta skorja in žagovina, je bogat surovinski potencial, ki bi ga veljalo izkoristiti tudi kot vir tržno zanimivih komponent.This article presents chemical composition of beech wood as well as various possibilities for its chemical conversion. The useful components of beech biomass are primarily cellulose fibers, xylan and lignin. Some of the most important technological procedures for wood fractionation are described, as for example hydrolysis, fermentation, pyrolysis and extraction, together with marketable products which are produced in the processes. The greatest potential for the future is ascribed to the production of nanofibrilated cellulose, which is considered to become the raw material of the future. Recent research has indicated that beech wood and bark contain high added value bioactive compounds, while seeds are extremely reach source of high quality oil. Beech wood, including waste such as bark and sawdust, represent reach raw material which might be conveniently converted to different marketable products
Determination of extractive compounds in beech chips
No full textPredstavljena je plinsko kromatografska analiza kemijske sestave ekstraktivnih komponent v bukovih sekancih, namenjenih proizvodnji papirja. Identificirane in kvantitativno ovrednotene so posamezne skupine lesnih lipidov, in sicer proste maščobne kisline in steroli ter sterolni estri in trigliceridi. Okarakterizirani so posamezni predstavniki teh skupin, med njimi tudi spojine, ki delujejo moteče pri proizvodnji papirja.Gas chromatographic analysis of extractive compounds from beech wood chips, meant for paper production, is presented. The most important groups of wood lipids like fatty acids and sterols, as well as steryl esters and triglycerides have been identified and quantitatively evaluated. Individual representatives of these groups have been characterized, among them also substances, causing detrimental effects in paper production
Polyphenols in different larch (Larix spp.) species
No full textV članku so predstavljene različne vrste polifenolnih spojin, kot so npr. lignani, oligolignani in flavonoidi, ki jih najdemo v tkivih macesnov, to je dreves iz rodu Larix. Opisana je njihova biosinteza, kemijska struktura in lastnosti, med katerimi je poudarjen predvsem njihov antioksidativni potencial. Predstavljene so metode kvantitativne izolacije iz drevesnih tkiv in kemijske karakterizacije z uporabo sodobnih kromatografskih analiznih tehnik. Raziskave so pokazale, da so največje koncentracije lignanov in flavonoidov v grčah, vejah in skorji dreves. Najpomembnejši med flavonoidi v tkivih macesnov je taksifolin. Glavni predstavnik lignanov, ki jih bomo našli predvsem v grčah, je sekoizolaricirezinol, poleg njega pa sta zastopana tudi laricirezinol in ciklolaricirezinol. Polifenoli so ključnega pomena za obstojnost lesa, saj pomenijo učinkovito kemijsko zaščito pred različnimi okužbami. Zaradi visokih koncentracij bioaktivnih lignanov v grčah iglavcev bi slednje lahko rabile kot vir za tehnološko pridobivanje teh dragocenih komponent.Various types of polyphenolic compounds, such as lignans, oligolignans and flavonoids, which occur in different tissues of wood from the larch (Larix) genus, are presented in the article. Their biosynthesis, chemical structure and properties, including a distinctive antioxidative potential, are described. The methods of quantitative isolation from wood as well as their chemical characterization by means of sophisticated chromatographic analytical techniques are presented. It has been experimentally established that the highest concentrations of lignans and flavonoids are present in knots, branches and bark of trees. The most important flavonoid in larch tissues is taksifolin, while the predominating lignans in knots are secoisolariciresinol and less abundant lariciresinol and cycloisolariciresinol. The presence of polyphenols is crucial for wood durability, as these compounds represent efficient chemical protection of wood against biological decay. Due to high concentrations of bioactive lignans in knots of conifers, the latter represent a suitable source for technological production of valuable substances
Polyphenols in different larch (Larix spp.) species
No full textVarious types of polyphenolic compounds, such as lignans, oligolignans and flavonoids, which occur in different tissues of wood from the larch (Larix) genus, are presented in the article. Their biosynthesis, chemical structure and properties, including a distinctive antioxidative potential, are described. The methods of quantitative isolation from wood as well as their chemical characterization by means of sophisticated chromatographic analytical techniques are presented. It has been experimentally established that the highest concentrations of lignans and flavonoids are present in knots, branches and bark of trees. The most important flavonoid in larch tissues is taksifolin, while the predominating lignans in knots are secoisolariciresinol and less abundant lariciresinol and cycloisolariciresinol. The presence of polyphenols is crucial for wood durability, as these compounds represent efficient chemical protection of wood against biological decay. Due to high concentrations of bioactive lignans in knots of conifers, the latter represent a suitable source for technological production of valuable substances
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