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Copyright of Proceedings of the International Conference on Renewable Electrical Power Sources - ICREPS is the property of Union of Mechanical & Electrotechnical Engineers & Technicians of Serbia (SMEITS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanocomposite based on nanocellulose/TiO2 can be applied as a catalyst in the synthesis of 5-hydroxymethylfurfural from fructose, which becomes an essential alternative in producing biofuels. Cellulose isolated from bamboo will be used to synthesis of nano-cellulose nanocomposite in this study. Bamboo is a fast-growing species and a high yield renewable resource. The inorganic nanoparticle TiO2 will also be introduced to produce an excellent property of the composite. FTIR, SEM, TEM, and HPLC are used to characterize the composite and catalytic activity. The yield of isolated cellulose from bamboo was obtained at 60,8%. The result of TiO2 synthesis was in nano-sized and anatase structures. The optimum condition of synthesis of 5-hydroxymethylfurfural from fructose was obtained at 120oC for 60 minutes. This condition involved 25 mg of fructose and 50 mg of catalyst resulting final yield of 19,6%. [ABSTRACT FROM AUTHOR]

Zeolite is an underutilized natural resource in Indonesia. Zeolite is widely used as a heavy metal adsorbent because of its anionic charge. The adsorbed metals in zeolite can be used as additional Lewis acid sites (catalyst) for chemical reactions. The use of zeolite as a catalyst is supported by its unique pore structure that can produce specific reactions. One chemical reaction that requires Lewis acid sites is the transformation of carbohydrate derivative compounds into 5-hydroxymethylfurfural (HMF). HMF is a multifunctional intermediate compound of polymers, fuels, pure chemicals, and derivatives of other organic compounds. HMF can be formed through the isomerization of glucose into fructose by Lewis acid catalysts and the dehydration of fructose into HMF by Brønsted acids. A bifunctional acid catalyst could allow a one-pot reaction. This study has 3 objectives, namely: a) impregnation of Ende-NTT natural zeolite as a fructose and glucose transformation catalyst into HMF, b) increasing the value and function of natural zeolite from Indonesia, and c) create a new utilization pathway for metal adsorbing zeolites. Ende-NTT natural zeolite was chemically activated by using alkaline activation (NaOH). Activated zeolite was converted to Na-zeolite through saturation with 2 M NaOH. Na-zeolite was then converted to H-zeolite through the ion exchange of Na+ with NH4+ ions which were continued by the process of removing NH3 through heating to obtain H-zeolite. The Lewis acid sites of H-zeolite was increased by impregnating Cu and Mn metal salts. Cr metal salt was used as a comparison in this study. The transformation of glucose and fructose into HMF was carried out by the reflux method using DMSO solvent and identified by using high-performance liquid chromatography. Rietveld analysis showed that Ende-NTT natural zeolite was a mixture of mordenite and clinoptilolite types of zeolite with a ratio of 81:19. CuOx-zeolite catalyst had a higher yield than H-zeolite in the transformation of fructose and glucose into HMF with yields at 69% and 10%, respectively. [ABSTRACT FROM AUTHOR]

To investigate the possibly carcinogenic substance occurring in soy sauce, the furan, 5-hydroxymethylfurfural (HMF) and nitrite, as well as chemical properties, such as total titratable acid, reducing sugars, ethanol, amino nitrogen and total nitrogen, analysis in sixteen commercial soy sauce from the China market were determined using chromatography-mass spectrometry method. There were considerable variations in furan, HMF and nitrite concentrations of different commercial soy sauces. The results showed that the level of furan and 5-hydroxymethylfurfural of the soy sauce studied ranges from15.36 to 119.82 μg/kg and 0.21 to 4.27 mg/kg, respectively, whereas the content of nitrite ranges from 0.04 to 0.73 mg/kg. The results indicated that the level of nitrogen and glucose may have a relationship with formation of furan, 5-HMF and nitrite in soy sauce. It was observed that soy sauce may be an important source of contamination by furan, HMF and nitrite. [ABSTRACT FROM AUTHOR]

Accumulation of waste is a global problem. The amount of waste deposited is increasing with every passing year. 8.3 billion metric tons of solid waste is produced every year. Considering this fact, it is of paramount importance to reduce waste by any means possible. One of them is to convert waste to substances with a value such as bio-resin. A bio-resin can be used to make wood composites. The importance of resin in the wood industry is that the lifespan of wood increases drastically when it is impregnated with resin. The resins commonly used in the wood composite industry are urea formaldehyde resin and phenol formaldehyde resin but such synthetic resins are harmful to the environment as they are derived petrochemically and the formaldehyde content in the resin makes such resins carcinogenic. If a bio-resin developed from organic waste is used in place of existing resins, carcinogenic content can be reduced, organic waste can be converted to value and an environmentally friendly product can be obtained. Organic waste was collected, dried and ground to powder in a ball mill. The powdered sample was sent for Fourier transform infrared spectroscopy. The cellulose detected was converted directly to hydroxymethylfurfural resin. Hydroxymethylfurfural resin was characterized by means of Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-performance liquid chromatography. The shortcoming of the developed bio-resin is that it lacks the required adhesiveness and tack. So, it must be added to urea formaldehyde resin to get Urea-Hydroxymetthylfurfural-formaldehyde resin. formaldehyde resin, where a part of the formaldehyde will be replaced by hydroxymethylfurfural. The resin was cured with ammonium chloride. The application of the synthesized resin is to make wood composites where the resin will act as a wood adhesive. The bio-resin is impregnated in a particleboard of set dimension under particular temperature and pressure conditions and the bioresin system is left for curing and the product wood composite is manufactured. [ABSTRACT FROM AUTHOR]

Carrageenan which is a renewable and abundant shows a potential as an energy feedstock. Carrageenan which can be extracted from Eucheuma cottonii can decompose to hydroxymethylfurfural (HMF) and levulinic acid (LA). This work is to study decomposition process of carrageenan to HMF and LA. Carrageenans were used and poured into microwave tube filled with sulfuric acid solution. The reactions were performed at a temperature (160-190°C), a loading concentration (0.025-0.15 g/mL) and batch times which is up to 120 min. The highest experimental HMF yield was 18.4 mol%, and LA was 29.7 mol%. The possible autocatalytic role of acetic acid (AA), formic acid (FA) and levulinic acid which were produced during the reaction, was investigated by conducting reactions in the presence of these acids. As a result, FA particularly shows a role as a catalyst. [ABSTRACT FROM AUTHOR]

The aim of this research was exhaustive to valuate the effects of 5 methods used to dehydrate of cajuput honey from Bac Lieu - Vietnam include thermal, microwave, ultrasonic wave, silicagel, vacuum processing on water content of honey. Beside that, comparing the effects on honey quality with the industrial-scale processing. The main honey quality paramenters (reducing sugar (RS), hydroxymethylfurfural (HMF), diastase number (DN), water and colour) of cajuput honey were analyzed. RS content were analyzed by DNS method, HMF under AOAC 980.23, diastase activity based on AOAC 958.09, water content according to AOAC 969.38B and colour parameters (L*, a*, b*) were established in the CIE system. The physico-chemical characteristics of fresh honey was as follows: water content 23.18%, RS 717.42 mg/g, HMF 4.24 mg/kg, DN 4.85 mg/kg, colour parameters L*a*b* 39.51-10.51-31.81. The results of the analysis showed that excepts ultrasonic wave processing (22.93%), the other methods allowed to dehydrate of cajuput honey (thermal - 18.73%, microwave - 16.87%, silicagel - 17.86%, vacuum - 17.35% and industrial-scale processing - 16.85%). [ABSTRACT FROM AUTHOR]

The effectiveness in the dehydration of sugars into 5-Hydroxymethylfurfural is related to the catalyst existence. A comprehensive synthesis of 5-Hydroxymethylfurfural from fructose, glucose and sucrose (3.73 mmol) with and without addition zeolite catalyst was performed in this study. The reactions were carried out in water-methanol solvent system for 3 hours reaction time at 180°C temperature. The catalytic results from HPLC showed that the reaction with zeolite increases the yield of 5-Hydroxymethylfurfural with 51.72%, 34.01% and 50.10% for fructose, glucose and sucrose respectively. The study suggests that zeolites promote the isomerization of glucose into fructose to occur and simultaneously catalyze the dehydration of fructose into 5-Hydroxymethylfurfural. Only slight changes on FT-IR spectra of use zeolite after the reaction was observed. Thus suggest that zeolite was a potential catalyst for catalytic reaction for the conversion of sugar into 5-Hydroxymethylfurfural. [ABSTRACT FROM AUTHOR]

In this study, sugar was extracted from the of core oil palm trunk (OPT) and undergoes methanolysis process. The objective of this research is to study the production of methyl levulinate (MLA) and hydroxymethyl furfurals (HMF) from four different parts of OPT such as inner, middle, outer and whole. After methanolysis, samples were characterized by gas chromatography mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). [ABSTRACT FROM AUTHOR]