Studies on Kinetics of Dimethyl Carbonate Synthesis by Homogeneous Transesterification

A comprehensive kinetic study on dimethyl carbonate synthesis by transesterification of ethylene carbonate with methanol has been conducted. An alkali base metal (KOH) was used as catalyst in the synthesis of DMC and its catalytic ability was investigated in term of kinetics. The reaction orders, the activation energy and the rate constants were determined for both forward and backward reactions. The reaction is reversible and the equilibrium rate constant wasestimated to be 135.77exp(-16542.4/RT)

Optimization of Naoh Alkali Pretreatment of Oil Palm Empty Fruit Bunch for Bioethanol

Bioethanol from lignocellulosic waste as an alternative energy began to be developed. Pretreatment is an early stage of the process of lignocellulose conversion into bioethanol. Chemical pretreatment using NaOH was done by inserting 3 mm EFB and 10 % NaOH solution at the reactor in moderate temperature and 4 bars pressure. The effect of temperature and time on the pretreatment process was investigated. The variation of temperature process starts from 140, 150 and 160°C, during the time variation of the process starting from 20, 30 and 40 minutes. The highest of biomass recovery was obtained in the pretreatment process with temperature 140 oC, 20 minutes at 42.83 % (dba). The highest delignification at 160 oC temperature, 40 minutes was equal to 86.92 %. However, the optimal pretreatment conditions to produce the highest bioethanol from EFB obtained at 150 oC, 30 minutes were the biomass recovery reached 35.97 %, delignification reached 76.74 %, and ethanol yield from initial EFB reached 15,17 % (w/w)

Preparation of Mgo-ceo2 Mixed Oxide with Ionic Liquid as Catalyst for Dimethyl Carbonate Synthesis Via Transesterification

The synthesis and application of dimethyl carbonate (DMC) are achieving increasing importance due to its low toxicity and versatile reactivity. The phosgenation-route has been losing attraction recently due to the use of virulent phosgene. In transesterification process, DMC is co-generated with ethylene glycol (EG). In this study, various ionic liquids were used as template in coprecipitation methods to prepare mesoporous MgO-CeO2 mixed oxides particles. Among the ionic liquids, [Bmim][BF6] displayed the best performance in terms of activity, while [Omim][PF6] obtained the best selectivity for this reaction. The addition of IL's in the coprecipitation method increased the surface areaand pore volume of the catalysts. Meanwhile, the crystallite size of the catalysts was reduced many times. However, there is no effect of the surface areaand particle size as well on the catalytic activity of the catalyst in this reaction. The activity and selectivity of the catalyst depend on the base strength distribution. The moderate basic site is responsible for the catalytic activity, while the selectivity is more dependableon the strong basic site

An analysis on Free Convection Cooling of a 3×3 Heater Array in Rectangular Enclosure using Cu-EG-Water Nanofluid

This paper deals with the study of natural convection cooling of a discrete heater array in Cu-EG-water nanofluid filled rectangular enclosure. A 3 × 3 array of non-protruding heat sources is embedded on one of the vertical walls of the enclosure while the top horizontal and opposite vertical walls are assumed to be isothermally cold. The remaining portions in which the heaters are mounted and all other walls are insulated. The above setup is modeled into a system of partial differential equations which are solved numerically using finite volume method based on the Semi-Implicit Method for Pressure Linked Equation (SIMPLE) algorithm and power law scheme. The wide range of parameters for computation are the aspect ratio of the enclosure, the mixture proportion of Ethylene glycol-water, the solid volume fraction of the nanoparticle along with two different thermal conductivity models. It is observed that the proper choice of the computation parameters and thermal conductivity models could be able to maximize the heat transfer rate from the heater array. Also, the results obtained in this study will provide new guidelines in the field of electronic equipment cooling

Biological Pretreatment of Oil Palm Frond Fiber Using White-Rot Fungi for Enzymatic Saccharification

Oil palm frond is one type of lignocellulosic biomass abundantly and daily available in Indonesia. It contains cellulose which can be converted to glucose, and further processed to produce different kinds of value –added products. The aim of this research is to study the effects of biological pretreatment of oil palm frond (OPF) fiber using Phanerochaete chrysosporium and Trametes versicolor on the enzymatic saccharification of the biomass. The OPF fiber (40-60 mesh sizes) was inoculated with cultures of the two fungi and incubated at 27 °C for 4 weeks. The samples were taken after 1, 2, 3, and 4 weeks of incubation. Chemical components of the biomass after pretreatment were analyzed. The saccharification of the pretreated samples using cellulase and β-glucosidase was performed in a water bath shaker at 50 °C for 48 hours. The concentration of reducing sugar increased with increasing of incubation time, either in those pretreated with culture of P. chrysosporium or with T. versicolor. Pretreatment of OPF fiber using single culture of T. versicolor for 4 weeks gave the highest reducing sugar yield (12.61% of dry biomass)

Alkaline Pretreatment of Sweet Sorghum Bagasse for Bioethanol Production

Lignocellulosic material, which consist mainly of cellulose, hemicelluloses and lignin, are among the most promising renewable feedstocks for the production of energy and chemicals. The bagasse residue of sweet sorghum can be utilized as raw material for alternative energy such as bioethanol. Bioethanol production consists of pretreatment, saccharification, fermentation and purification process. The pretreatment process was of great importance to ethanol yield. In the present study, alkaline pretreatment was conducted using a steam explosion reactor at 1300C with concentrations of NaOH 6, and 10% (kg/L) for 10, and 30 min. For ethanol production separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) process were conducted with 30 FPU of Ctec2 and Htec2 enzyme and yeast of Saccharomyces cerevisiae. The results showed that maximum cellulose conversion to total glucose plus xylose were showed greatest with NaOH 10% for 30 min. The highest yield of ethanol is 96.26% and high concentration of ethanol 66.88 g/L were obtained at SSF condition during 48 h process. Using SSF process could increase yields and concentration of ethanol with less energy process. Article History: Received January 16th 2016; Received in revised form May 25th 2016; Accepted June 28th 2016; Available online How to Cite This Article: Sudiyani, Y., Triwahyuni, E., Muryanto, Burhani, D., Waluyo, J. Sulaswaty, A. and Abimanyu, H. (2016) Alkaline Pretreatment of Sweet Sorghum Bagasse for Bioethanol Production. Int. Journal of Renewable Energy Development, 5(2), 113-118. http://dx.doi.org/10.14710/ijred.5.2.113-11