Abstract. The ionic liquid [MMIM][DMP] was synthesized from the reactants methyl imidazole [MIM] and trimethylphosphate [TMP] and verified using 1 HNMR and FTIR. Coconut coir dust was pretreated with a 1% alkaline solution. Its crystalline structure increased significantly due to the dissolution of lignin and hemicelluloses under alkaline conditions, exposing the cellulose. After NaOH and IL were employed, the XRD showed that peak (002) decreased significantly and peak (101) almost vanished. This significant decrease in crystallinity was related to the alteration of the substrate from the cellulose I structure to the cellulose II structure. The pretreated substrates were hydrolyzed to convert them to reducing sugars by pure cellulase and xylanase, and the reaction was conducted at 60°C, pH 3, for 12 or 48 hours. The yields of sugar hydrolyzed from untreated and NaOH-pretreated substrates were 0.07 and 0.12 g sugar/g lignocellulose, respectively. Pretreatment with IL or the combination of NaOH+IL resulted in yields of reducing sugars of 0.11 and 0.13 g/g, respectively. These findings showed that IL pretreatment of the high-lignin lignocellulose is a new prospect for the economical manufacture of reducing sugars and bioethanol in the coming years.

This study aims to produce reducing sugar hydrolyzed from substrate, coconut coir dust pretreated by recycled ionic liquid and its combination with alkaline. The 1H NMR and FTIR were performed to ver-ify the synthesized ionic liquid methylmethylimidazolium dimethyl phosphate ([mmim][dmp]). The structure of pretreated substrates was analyzed by XRD measurement. The used ionic liquid was recy-cled twice to re-employ for substrate pretreatment. The treated- and untreated-coconut coir dust were hydrolyzed into sugars using pure cellulase. The reaction, which called an enzymatic hydrolysis, was conducted at 60 °C, pH 3, for 48 h. The yields of sugar hydrolyzed from fresh IL-pretreated, 1R*IL-pretreated and 2R*IL-pretreated substrates were of 0.19, 0.15 and 0.15 g sugar / g cellu-lose+hemicellulose, respectively. Pretreatment with NaOH or the combination of NaOH+IL resulted in yields of reducing sugars of 0.25, 0.28 g/g, respectively. When alkaline combined with the recycled ionic liquids, NaOH+1R*IL, NaOH+2R*IL in the pretreatment, the yields of sugar were relatively similar to those obtained using alkaline followed by fresh ionic liquid. If the mixture enzymes, cellu-lase+xylanase, used to liberate sugars from fresh IL-pretreated, or recycled IL-pretreated substrates, the amount of sugar (concentration or yield) increased slightly compared to that employing a single cel-lulase. These findings showed that recycled IL pretreatment of the high-lignin lignocellulose, coconut coir dust, is a new prospect for the economical manufacture of fermentable sugars and biofuel in the coming years. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Kayu cempaka (Elmerrillia ovalis) adalah salah satu jenis tanaman kayu yang dipakai dalam pembuatan rumah adat/rumah panggung dan paling banyak dijumpai di Sulawesi Utara.  Industri pembuatan rumah ini menghasilkan limbah kayu dari proses pengergajian. Kayu memiliki komponen kimia utama yaitu selulosa, hemi-selulosa dan lignin yang mana dua komponen pertama dapat dikonversi menjadi gula dan etanol. Modifikasi struktur lignoselulosa yaitu dengan melakukan perlakuan/pretreatment lewat pemanasan dari gelombang mikro (microwave) supaya pemanasan bahan merata/homogen.  Keberhasilan modifikasi struktur selulosa dapat dilihat berdasarkan hasil karakterisasi X-RD memperlihatkan bahwa terjadi penurunan kristalinitas ketika dilakukan pretreatment dengan iradiasi gelombang mikro, untuk analisis SEM mengalami  perubahan morfologi permukaan struktur, dan untuk analisis gugus fungsi lewat analisis FT-IR  yang menunjukkan adanya gerak vibrasi.Wood ofcempaka (Elmerrillia ovalis) is one of woody plants used in making traditional house/stage house and most often found in North Sulawesi.  Home-making industry produced wood waste from sawing process. Wood has main chemical components i.e. cellulose, hemi-cellulose and lignin which the first two components can be converted into sugar and ethanol. Modification of lignocellulosic structure was by the microwave pretreatment for homogeneous heating. The successful modifications of cellulose ware analysed by X-RD showed decreasing of crystallinity; by SEM showed surface morphological changing, and by FT-IR showed vibration motion.

Sugarcane bagasse is one of lignocellulose materials that can be converted to biofuel. This work was aimed to develop new pretreatment combination methods to process sugarcane bagasse lignocellulose into biofuel (bio-hydrogen). Pretreatment of sugarcane bagasse using NaOH solution in combination with ionic liquid [DMIM]DMP enhanced the enzymatic hydrolysis significantly. After the pretreatment, the content of cellulose and hemicellulose increased by 29.31% compared to the untreated one. Cellulose and hemicelluloses were used as raw materials to produce reducing sugars, that can be converted to bio-hydrogen via fermentation. After being subjected to combined pretreatment processes, the crystalline index of sugarcane bagasse decreased significantly compared to solely NaOH pretratment. This indicates a more amorphous structure of the sugarcane bagasse, which makes it is easier to be hydrolyzed into reducing sugars. The recovery of cellulose + hemicellulose after pretreatment for 20 min and 120 °C was 92%, and the yield obtained was 0.556 g sugars/g (cellulose + hemicellulose) after 12 h and the bio-hydrogen yield was 0.46 mol H2/mol sugars consumed after 48 h fermentation. The use of recycled of ionic liquid showed similar performance compared to the use of fresh ionic liquid.

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The pretreatment of a high lignin substrate, coconut coir dust, was studied by chemical techniques (NaOH solution, ionic liquid, and NaOH followed by ionic liquid) and by a physical method (subcritical water, SCW). Following substrate pretreatment and a washing step, structural analyses were performed by scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. It was found that all substrates pretreated by chemical methods had more amorphous structures than the untreated substrate. The XRD patterns of the chemically treated substrates shifted toward higher angles by 0.50° to 1.00°. However, the XRD peak symmetry of the SCW-treated substrate did not shift, but its crystallinity index decreased. The results revealed that lignocellulose treated with NaOH followed by ionic liquid at 120 °C for 30 min showed the greatest extent of structural transformation.

Preventing the further degradation of monomeric or oligomeric sugar into by-product during biomass conversion is one of the challenges for fermentable sugar production. In this study, the performance of subcritical water (SCW) and enzymatic hydrolysis of coconut husk toward reducing sugar production was investigated using a severity factor (SF) approach. Furthermore, the optimal condition of SCW was optimized using response surface methodology (RSM), where the composition changes of lignocellulose and sugar yield as responses. From the results, at low SF of SCW, sugar yield escalated as increasing SF value. In the enzymatic hydrolysis process, the effect of SCW pressure is a significant factor enhancing sugar yield. A maximum total sugar yield was attained on the mild SF condition of 2.86. From this work, it was known that the SF approach is sufficient parameter to evaluate the SCW and enzymatic hydrolysis of coconut husk. Copyright © 2020 BCREC Group. All rights reserved

The cassava has been modified successfully by using the saline water, which was abundantly available on the planet. The biomass was submerged in saline waters that salt concentrations were altered at 0, 3.5 percent (seawater) and 10 percent (w/w) and were kept 5 days. After recovery by washing steps, the treated solids were characterized by using XRD (X-ray diffraction), FTOR (Fourier transform infra-red), and SEM (Scanning electron microscopic). The results showed that the XRD pattern of saline water pretreatment decreased significantly. The biggest decrease of X-ray intensity occurred at around 18 o. Meanwhile, the fingerprint of FTOR revealed the transmittance intensity of infra-red ray of saline water treated solid inclined for all wave constant numbers, suggesting that many hydrogen bonds were disconnected. Those findings also were enhanced by SEM pictures that showed the change of surface morphology of treated biomass. Ot was indicative that cassava structure was modified becoming more textured after employing saline water pretreatment. This work is an innovative finding to gradually substitute commercial ionic liquids that are very expensive with saline water for biomass pretreatment.