ABSTRACT
Many studies have explored the pretreatment of lignocellulosic biomass based on oil palm empty fruit bunch (OPEFB) which is categorized as potential biomass waste for bioethanol production. Before proceeding further to obtain bioethanol, several steps such as pretreatment to increase organic constituents are needed. The ionic liquids (ILs) were commonly investigated by many researchers for lignocellulosic pretreatment because it is easy solubilization property, non-toxic, and not harmful impacts on the environment. Therefore in this study, the hypothesis and main objective were to observe the effectiveness of triethylammonium methanesulfonate ion liquid (TMS IL) in the OPEFB lignocellulose pretreatment process. Three variations were studied to obtain optimization of the pretreatment process, such as times duration, IL composition, and temperature. Based on these results, we observed the effectiveness of the time duration for OPEFB pretreatment of 20 hours. Furthermore, it was applied to determine the optimization of IL composition and temperature showing that using 91% (1:1:10) at 120°C for 20 hours has provided good performance for the OPEFB lignocellulose pretreatment process. TMS IL has exhibited the ability to reduce hemicellulose and lignin contents to 7.35% and 17.80%, whereas cellulose was increased by 54.24%. This has the opportunity to be projected to a larger scale for bioethanol production based on OPEFB lignocellulose.
Subject(s)
Ammonium Compounds/chemistry , Biomass , Ethanol/chemical synthesis , Green Chemistry Technology , Ionic Liquids/chemistry , Lignin/chemistry , Mesylates/chemistry , Palm Oil/chemistry , Solvents/chemistry , Fruit/chemistry , Refuse Disposal , Solubility , Temperature , Time FactorsABSTRACT
Research on the transformation of Oil Palm Empty Fruit Bunches (OPEFB) through pretreatment process using ionic liquid triethylammonium hydrogen sulphate (IL [TEA][HSO4]) was completed. The stages of the transformation process carried out were the synthesis of IL with the one-spot method, optimization of IL composition and pretreatment temperature, and IL recovery. The success of the IL synthesis stage was analyzed by FTIR, H-NMR and TGA. Based on the results obtained, it showed that IL [TEA][HSO4] was successfully synthesized. This was indicated by the presence of IR absorption at 1/λ = 2814.97 cm-1, 1401.07 cm-1, 1233.30 cm-1 and 847.92 cm-1 which were functional groups for NH, CH3, CN and SO2, respectively. These results were supported by H-NMR data at δ (ppm) = 1.217-1.236 (N-CH2-CH3), 3.005-3.023 (-H), 3.427-3.445 (N-H+) and 3.867 (N+H3). The TGA results showed that the melting point and decomposition temperature of the IL were 49 °C and 274.3 °C, respectively. Based on pretreatment optimization, it showed that the best IL composition for cellulose production was 85 wt%. Meanwhile, temperature optimization showed that the best temperature was 120 °C. In these two optimum conditions, the cellulose content was obtained at 45.84 wt%. Testing of IL [TEA][HSO4] recovery performance for reuse has shown promising results. During the pretreatment process, IL [TEA][HSO4] recovery effectively increased the cellulose content of OPEFB to 29.13 wt% and decreased the lignin content to 32.57%. The success of the recovery process is indicated by the increasing density properties of IL [TEA][HSO4]. This increase occurs when using a temperature of 80-100 °C. The overall conditions obtained from this work suggest that IL [TEA][HSO4] was effective during the transformation process of OPEFB into cellulose. This shows the potential of IL [TEA][HSO4] in the future in the renewable energy sector.
