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Abstract:The use of non-edible, second-generation feedstocks for the production of biodiesel has been an active area of research, due to its potential in replacing fossil diesel as well as its environmentally friendly qualities. Despite this, more needs to be done to remove the technical barriers associated with biodiesel production and usage, to increase its quality as well as to widen the choice of available feedstocks; so as to avoid over-dependence on limited sources. This paper assesses the feasibility of using a local plant, Reutealis trisperma, whose seeds contain a high percentage of oil of up to 51%, as one of the possible feedstocks. The techno-economic and sensitivity analysis of biodiesel production from Reutealis trisperma oil as well as implementation aspects and environmental effects of the biodiesel plant are discussed. Analysis indicates that the 50 kt Reutealis trisperma biodiesel production plant has a life cycle cost of approximately $710 million, yielding a payback period of 4.34 years. The unit cost of the biodiesel is calculated to be $0.69/L with the feedstock cost accounting for the bulk of the cost. The most important finding from this study is that the biodiesel from Reutealis trisperma oil can compete with fossil diesel, provided that appropriate policies of tax exemptions and subsidies can be put in place. To conclude, further studies on biodiesel production and its limitations are necessary before the use of biodiesel from Reutealis trisperma oil may be used as a fuel source to replace fossil diesel.

AbstrakBagas merupakan residu padat pada proses pengolahan tebu menjadi gula, yang sejauh ini masih belum banyak dimanfaatkan menjadi produk yang mempunyai nilai tambah (added value). Bagas yang termasuk biomassa mengandung lignoselulosa sangat dimungkinkan untuk dimanfaatkan menjadi sumber energi alternatif seperti bioetanol atau biogas. Dengan pemanfaatan sumber daya alam terbarukan dapat mengatasi krisis energi terutama sektor migas. Pada penelitian ini telah dilakukan konversi bagas menjadi etanol dengan menggunakan enzim xylanase. Perlakuan dengan enzim lainnya saat ini sedang dikerjakan di laboratorium kami mengingat hemisulosa juga mengandung polisakarida lainnya yang dapat didekomposisi oleh berbagai enzim. Hasil penelitian menunjukkan kandungan lignoselulosa pada bagas sebesar lebih kurang 52,7% selulosa, 20% hemiselulosa, dan 24,2% lignin. Hemiselulosa merupakan polisakarida yang dapat dihidrolisis oleh enzim xylanase dan kemudian akan difermentasikan oleh yeast S. Abstract Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification andFermentation by Xylanase. Bagasse is a solid residue from sugar cane process, which is not many use it for some product which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternative energy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesia could be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanase enzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, and 24,2% lignin. Xylanase enzyme and Saccharomyces cerevisiae was used to hydrolyse and fermentation in SSF process. Variation in this research use pH (4, 4,5, and 5), for increasing ethanol quantity, SSF process was done by added chloride acid (HCl) with concentration 0.5% and 1% (v/v) and also pre-treatment with white rot fungi such as Lentinus edodes (L.edodes) as long 4 weeks. The SSF process was done with 24, 48, 72, and 96 hour's incubation time for fermentation. Variation of pH 4, 4,5, and 5 can produce ethanol with concentrations 2,357 g/L, 2,451 g/L, 2,709 g/L. The added chloride acid (HCl) with concentration 0.5% and 1% (v/v) and L. edodes can increase ethanol yield, The highest ethanol concentration with added chloride acid (HCl) concentration 0.5% and 1% consecutively is 2,967 g/L, 3,249 g/L. The highest ethanol concentration with pre-treatment by L. edodes is 3,202 g/L.

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Background and Aim: The authentication of honey is important to protect industry and consumers from such adulterated honey. However, until now, there has been no guarantee of honey's authenticity, especially in Indonesia. The classification of honey is based on the bee species (spp.) that produces it. The study used honey from sting bee Apis spp. and stingless bee Tetragonula spp. based on the fact that the content off honey produced between them has differences. Authenticating honey with currently available rapid detection methods, such as 13C nuclear magnetic resonance analysis, is costly. This study aimed to develop an inexpensive, fast, precise, and accurate classification method for authenticating honey. Materials and Methods: In this study, we use attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with wavelengths ranging between 550 and 4000 cm-1 as an alternative analysis method, which is relatively less expensive. The spectra of authentic and fake honey samples were obtained using ATR-FTIR and plotted using chemometric discriminant analysis. The authentic honey samples were acquired from a local Indonesian breeder of honey bees, while the fake honey samples were made from a mixture of water, sugar, sodium bicarbonate, and authentic honey. Data were collected using Thermo Scientific's OMNIC FTIR software and processed using Thermo Scientific's TQ Analyst software. Results: Our method effectively classified the honey as authentic or fraudulent based on the FTIR spectra. To authenticate the honey, we formed two classes: Real honey and fake honey. The wavelengths that can best differentiate between these two classes correspond to four regions: 1600-1700 cm-1; 1175-1540 cm-1; 940-1175 cm-1; and 700-940 cm-1. Similarly, for classification purpose, we formed two classes: Apis spp. and Tetragonula spp. The wavelength region that can best classify the samples as belonging to the Apis spp. or Tetragonula spp. class is explicitly within the range of 1600-1700 cm-1. Conclusion: This study successfully demonstrated a method to rapidly and accurately classify and authenticate honey. ATR-FTIR is a useful tool to test the authenticity of honey. Keywords: Apis spp., attenuated total reflectance Fourier transform infrared, discriminant, spectrum, Tetragonula spp.

A rigorous kinetic model describing the stepwise triglyceride hydrolysis at the oil-water interface, based on the Ping Pong Bi Bi mechanism using suspended lipase having positional specificity, was constructed. The preference of the enzyme to cleave to the ester bonds at the edge and the center of the glycerol backbone of the substrates (tri-, di- or monoglyceride) was incorporated in the model. This model was applied to the experimental results for triolein hydrolysis using suspended Porcine pancreatic lipase (an sn-1,3 specific lipase) and Candida rugosa lipase (a non-specific lipase) in a biphasic oil-water system under various operating conditions. In order to discuss the model's advantages, other models that do not consider the positional specificity of the lipase were also applied to our experimental results. The model considering the positional specificity of the lipase gave results which fit better with the experimental data and described the effect of the initial enzyme concentration, the interfacial area, and the initial concentrations of triolein on the entire process of the stepwise triolein hydrolysis. This model also gives a good representation of the rate for cleaving the respective ester bonds of each substrate by each type of lipase.