نتایج جستجو برای: transesterification

تعداد نتایج: 2388  

Kambiz Tahvildari Tahereh Hajy Heidar

Due to the high price of virgin vegetable oils and the drawbacks of the homogeneous catalytic transesterification, in this work an economically profitable alternative process was proposed for biodiesel synthesis in which transesterification of the low-cost waste cooking oil (WCO) with methanol in a heterogeneous system was done. Alumina impregnated with sodium hydroxide was utilized as a solid ...

Abstract : In-situ process is one of the biodiesel production methods in which seeds are used directly in the reaction without oil extraction. The objective of this research is to optimize the biodiesel production conditions for the in-situ reaction using tomato seeds as a feed. The effects of reaction parameters such as molar ratio of oil to alcohol and catalyst to oil weight percent ratio on ...

2010
A. Brucato

Biodiesel has become more attractive recently because of its environmental benefits and the fact that it is made from renewable resources. Biodiesel is a mixture of monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats, mainly made of fatty acid glycerides. It is produced by transesterification processes in which oil or fat are reacted ...

2013
Prafulla D. Patil Veera Gnaneswar Gude Harvind K. Reddy Tapaswy Muppaneni Shuguang Deng

A comparative study of biodiesel production from waste cooking oil using sulfuric acid (Two-step) and microwaveassisted transesterification (One-step) was carried out. A two-step transesterification process was used to produce biodiesel (alkyl ester) from high free fatty acid (FFA) waste cooking oil. Microwave-assisted catalytic transesterification using BaO and KOH was evaluated for the effica...

2017
Jia-Ying Xin Li-Rui Sun Shu-Ming Chen Yan Wang Chun-Gu Xia

The synthesis of L-ascorbyl flurbiprofenate was achieved by esterification and transesterification in nonaqueous organic medium with Novozym 435 lipase as biocatalyst. The conversion was greatly influenced by the kinds of organic solvents, speed of agitation, catalyst loading amount, reaction time, and molar ratio of acyl donor to L-ascorbic acid. A series of solvents were investigated, and ter...

2017
Han Jin Praveen Kolar Steven W. Peretti Jason A. Osborne Jay J. Cheng

The objective of this research is to develop a kinetic model to describe the transesterification of soybean oil with methanol using NaOH-impregnated calcined oyster shell (Na-COS). Batch experiments were performed via a two-factor randomized complete block design using a molar ratio of methanol to oil (MR) of 6, 12, and 18 and catalyst loadings (CL) (mass of catalyst/mass of oil in %) of 2%, 4%...

Journal: :Acta microbiologica et immunologica Hungarica 2009
M L Verma W Azmi S S Kanwar

A wide range of fatty acid esters can be synthesized by esterification and transesterification reactions catalyzed by lipases in non-aqueous systems. In the present study, immobilization of a purified alkaline extra-cellular lipase of Bacillus cereus MTCC 8372 by adsorption on diatomaceous earth (celite) for synthesis of ethyl acetate via transesterification route was investigated. B. cereus li...

2003
Gabriela Alves Macedo Maria Mercedez Soberón Lozano Gláucia Maria Pastore

Short chain citronellyl esters were synthesized by a new microbial lipase from Rhizopus sp strain isolated and lipase produced at UNICAMP, Brazil. Direct esterification and transesterification reactions have been performed to produce citronellyl acetate and butyrate in a free-solvent system and with n-hexane in reaction medium. Reaction mixture for direct esterification and transesterification ...

Journal: :Bioresource technology 2015
Phuong Lan Tran-Nguyen Alchris Woo Go Suryadi Ismadji Yi-Hsu Ju

Most previous studies reported in literature on biodiesel production from sludge were performed by acid catalyzed transesterification that required long reaction time (about 24h) and high methanol loading. The objective of this study was to investigate the in situ transesterification of sludge in subcritical mixture of methanol and acetic acid. At 250°C and a solvent (85% methanol and 15% aceti...

Journal: Pollution 2017

The present study investigates the transesterification of corn oil with methanol over two oxides of MgO and ZnO at 65 ͦC and 1 atm. These two catalysts have been prepared via a conventional co-precipitation process. As for MgO, the corresponding mixed metal nitrate solution has been mixed and heated at the presence of urea. ZnO has also been synthesized by co-precipitation of metal acetate at th...

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