Extraction and characterization of the cellulose and lignin from the plant Miscanthus giganteus

Iz uzorka biljke Miscanthus x giganteus ekstrahirane su glavne komponente lignocelulozne biomase lignin i celuloza. Dobiveni udio celuloze je 68,51 %, a lignina 27,34 %. Zbog velikog udjela celuloze iz koje se hidrolizom i fermentacijom proizvodi bioetanol, biljka Miscanthus x giganteus je pogodna sirovina za proizvodnju biogoriva. Analiza uzorka biomase ionskom kromatografijom provedena je kako bi se odredile koncentracije K+, Na+ i Cl- koji tijekom izgaranja biomase mogu stvarati taloge, prah ili aglomerate. Dobivene mase iona K+, Na+ i Cl- po kilogramu biomase su 5287 mg, 2 mg i 674 mg. Optičkom emisijskom spektroskopijom uz induktivno spregnutu plazmu (ICP-OES) određene su koncentracije makro- i mikroelemenata u biomasi zbog njihove toksičnosti ili mogućnosti stvaranja taloga. Infracrvenom spektroskopijom (IR) i spektroskopijom nuklearne magnetske rezonancije (NMR) analizirani su uzorci lignina i celuloze u svrhu identifikacije i strukturne karakterizacije. Spektar IR snimljen je u srednjem području zračenja IR od 4000 cm1 do 400 cm1, metodom KBr pastile. Spektri 1H NMR i DOSY snimljeni u DMSO-d6. Snimljeni su i spektri u čvrstom stanju korištenjem tehnike 13C CP/MAS NMR. Dobiveni spektri uspoređeni su s onima iz literature.Main components of lignocellulosic biomass lignin and cellulose were extracted from the plant Miscanthus x giganteus. The obtained mass fraction of cellulose and lignin were 68.51 % and 27.34 %, respectively. Owing to the large mass fraction of cellulose, from which bioethanol is produced by hydrolysis and fermentation, the plant Miscanthus x giganteusis is suitable raw material for the production of biofuels. In order to determine concentration of K+, Na+ and Cl-, which may form deposits, powders or agglomerates during combustion process, ion chromatography was used. The obtained ion masses of K+, Na+, Cl- per weight of biomass kilogram were 5287 mg, 2 mg and 674 mg, respectively. By using inductively coupled plasma optical emission spectrometry (ICP-OES), concentrations of microelements and macroelements in biomass were determined, since they are toxic and may form residues. Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies were applied to identify and structurally characterized samples of lignin and cellulose. IR spectrum recorded by using KBr pellets in the middle IR region (4000 cm1 to 400 cm1) displayed vibrational modes characteristic of lignin and cellulose. 1H NMR and DOSY spectra recorded in DMSO-d6 have confirmed the presence of lignin and cellulose in the samples. Furthermore, spectra in the solid state were also recorded by using 13C CP/MAS NMR technique. All recorded spectra were compared with those reported in the literature