scholarly journals MODIFICAÇÃO QUÍMICA DO POLIPROPILENO ATRAVÉS DA INTRODUÇÃO DE GRUPOS SULFÔNICOS PARA APLICAÇÃO COMO CATALISADOR EM REAÇÕES DE ESTERIFICAÇÃO

Química Nova ◽  
2020 ◽  
Author(s):  
Bárbara Aud ◽  
Giovani Lourenço ◽  
Lynicker Dourado ◽  
Rosana Assunção

CHEMICAL MODIFICATION OF POLYPROPYLENE THROUGH THE INTRODUCTION OF SULPHONIC GROUPS FOR APPLICATION AS CATALYST IN ESTERIFICATION REACTIONS. In this work, the chemical modification of pristine polypropylene was carried out through sulfonation reactions with concentrated sulfuric acid (PPS1) and fuming sulfuric acid (PPS2), for production of heterogeneous catalysts used in esterification reactions. Fourier transform infrared spectroscopy, elemental analysis, degree of substitution and ion exchange capacity showed that both sulfonation agents were effective to promote the functionalization of polypropylene, with the fuming sulfuric acid capable of promoting a greater chemical modification. The materials catalytic activity in esterification reaction of oleic acid with methanol was evaluated at 100 ºC, methanol: oleic acid molar ratio of 78:1 and with 5 wt% of catalyst (referred to oleic acid weight). It was observed that reaction catalyzed by PPS1 converted 68.02% of oleic acid to methyl oleate in 3 hours of reaction, while PPS2 reached 86.47% conversion in five hours, showing even greater catalytic efficiency than the commercial ion exchange resin, Amberlyst 15. Therefore, the conditions employed for the sulfonation of polypropylene were satisfactory to produce materials with acid characteristics necessary to catalyze the esterification reaction of oleic acid with methanol.

2018 ◽  
Vol 156 ◽  
pp. 03002
Author(s):  
Iwan Ridwan ◽  
Mukhtar Ghazali ◽  
Adi Kusmayadi ◽  
Resza Diwansyah Putra ◽  
Nina Marlina ◽  
...  

The oleic acid solubility in methanol is low due to two phase separation, and this causes a slow reaction time in biodiesel production. Tetrahydrofuran as co-solvent can decrease the interfacial surface tension between methanol and oleic acid. The objective of this study was to investigate the effect of co-solvent, methanol to oleic acid molar ratio, catalyst amount, and temperature of the reaction to the free fatty acid conversion. Oleic acid esterification was conducted by mixing oleic acid, methanol, tetrahydrofuran and Amberlyst 15 as a solid acid catalyst in a batch reactor. The Amberlyst 15 used had an exchange capacity of 2.57 meq/g. Significant free fatty acid conversion increments occur on biodiesel production using co-solvent compared without co-solvent. The highest free fatty acid conversion was obtained over methanol to the oleic acid molar ratio of 25:1, catalyst use of 10%, the co-solvent concentration of 8%, and a reaction temperature of 60°C. The highest FFA conversion was found at 28.6 %, and the steady state was reached after 60 minutes. In addition, the use of Amberlyst 15 oleic acid esterification shows an excellent performance as a solid acid catalyst. Catalytic activity was maintained after 4 times repeated use and reduced slightly in the fifth use.


2019 ◽  
Vol 65 (1) ◽  
pp. 21-27
Author(s):  
Qiuyun Zhang ◽  
Dandan Lei ◽  
Qianqian Luo ◽  
Taoli Deng ◽  
Jingsong Cheng ◽  
...  

Biodiesel was synthesized from oleic acid using Ni (II)-exchanged heteropolyacids immobilized on silica (Ni0.5H3SiW / SiO2 ) as a solid acid catalyst. Based on detailed analyses of FT-IR, XRD, TG and SEM, the structural, surface and thermal stability of Ni0.5H3SiW / SiO2 were investigated. Obtained results demonstrated that the Keggin structure was well in the immobilization process and possess a high thermal stability. Various esterification reaction conditions and reusability of catalyst were studied. High oleic acid conversion of 81.4 % was observed at a 1:22 mole ratio (oleic acid: methanol), 3 wt. % catalyst at 70 °C for 4 h. The Ni0.5H3SiW / SiO2 catalyst was reused for several times and presented relatively stable. More interestingly, the kinetic studies revealed the esterification process was compatible with the first order model, and a lower activation energy was obtained in this catalytic system.


2013 ◽  
Vol 750-752 ◽  
pp. 1231-1234 ◽  
Author(s):  
Li Xia Wang ◽  
Shu Heng Liu ◽  
Hua Yuan ◽  
Lin Lin Guo

Ion exchange resin-supported (NH4)6[MnMo9O32]8H2O with Waugh structure is used to prepare supported solid catalyst. Performance of this catalyst is researched by means of synthesis of isoamyl acetate. Optimal reaction conditions determined by orthogonal experiment are as follows: acid-alcohol molar ratio is 2.5:1, reaction time is 120 min, catalyst dosage is 0.8 g, dosage of water-carrying agent is 2.5 ml, esterification yield reaches 95.1%. This catalyst is characterized by high catalytic efficiency, easy separation and recovery, absence of environmental pollution and being reusable, etc.


2007 ◽  
Vol 1 (1) ◽  
pp. 19-30 ◽  
Author(s):  
K. Narasimharao ◽  
Adam Lee ◽  
Karen Wilson

Biodiesel is a renewable substitute fuel for petroleum diesel fuel which is made from nontoxic, biodegradable, renewable sources such as refined and used vegetable oils and animal fats. Biodiesel is produced by transesterification in which oil or fat is reacted with a monohydric alcohol in the presence of a catalyst. The process of transesterification is affected by the mode of reaction, molar ratio of alcohol to oil, type of alcohol, nature and amount of catalysts, reaction time, and temperature. Various studies have been carried out using different oils as the raw material and different alcohols (methanol, ethanol, butanol), as well as different catalysts, notably homogeneous ones such as sodium hydroxide, potassium hydroxide, sulfuric acid, and supercritical fluids or enzymes such as lipases. Recent research has focused on the application of heterogeneous catalysts to produce biodiesel, because of their environmental and economic advantages. This paper reviews the literature regarding both catalytic and noncatalytic production of biodiesel. Advantages and disadvantages of different methods and catalysts used are discussed. We also discuss the importance of developing a single catalyst for both esterification and transesterification reactions.


2021 ◽  
Vol 17 (1) ◽  
pp. 65-77
Author(s):  
Shamala Gowri Krishnan ◽  
Fei-Ling Pua ◽  
Ee-Sann Tan

Biomass, renewable, abundantly available and a good source of energy. The conversion of biomass waste into valuable products has received wide attention. In this study, an empty fruit bunch (oil palm EFB) supported magnetic acid catalyst for esterification reaction was successfully prepared via the one-step impregnation process. The new magnetic catalyst achieved a higher surface area of 188.87 m2/g with a total acidity of 2.4 mmol/g and identified iron oxide as g-Fe2O3. The magnetization value of 24.97 emu/g demonstrated that the superparamagnetic catalyst could be easily recovered and separated after the reaction using an external magnet. The catalytic performance of oil palm EFB supported magnetic acid catalyst was examined by esterification of oleic acid. Esterification process parameters were optimized via Response Surface Methodology (RSM) optimization tool with Box-Behnken design (BBD). The following optimum parameters were determined: an amount of 9 wt% catalyst, molar ratio of methanol to oleic acid of 12:1, reaction time of 2 h and reaction temperature of 60 °C with a maximum conversion of 94.91% was achieved. The catalyst can be recycled up to five cycles with minimal loss in its activity. The oil palm waste-based magnetic acid catalyst indicates its potential replacement to the existing solid catalysts that are economical and environmentally friendly for the esterification process in biofuel applications. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


Author(s):  
Enas A. Almadani ◽  
Farah Haron ◽  
Dala M Ibrahim

Clay and clay modified catalysts have been widely used to catalyze various types of organic reactions such as esterification reactions, isomerization reactions, cyclization reactions, oxidation of alcohols, dehydrogenation, epoxidation and several more. Due to its favorable properties such as low cost, thermal stability, selectivity, large surface area, ion exchange capacity, easily separated, as well as environmental friendly. This paper reviewed some recent studies on the using of clay and modified clay as catalyst for the production of esters.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Maryam Haghighi ◽  
Mehranoosh Fereidooni

In this study, ZSM-22 was synthesized using N,N-diethylaniline as a template through a hydrothermal method. The proton and various metals such as zirconium, strontium, and iron were immobilized on the surface of obtained zeolites through the ion exchange method. The catalysts were studied by Fourier-Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption isotherms, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) elemental analysis, and Temperature-Programmed Desorption of ammonia (TPD-NH3) technique for determining the number of acid sites. In the esterification reaction of oleic acid, the operating conditions such as catalyst dosage, temperature, molar ratio of methanol to oil, and reaction time were optimized and adjusted at 11 wt%, 70°C, 10 : 1, and 48 h subsequently. The maximum yield% of 48.07% was achieved in the presence of Zr-H-ZSM-22 at optimum conditions. In order to improve the efficiency of three zeolites Zr-H-ZSM-22, Fe-H-ZSM-22, and Sr-H-ZSM-22, the core-shell structures with SiO2 coating were prepared. Zr-H-ZSM-22@SiO2 was less active than Zr-H-ZSM-22 due to the SiO2 coverage of Lewis active sites.


2021 ◽  
Vol 17 (1) ◽  
pp. 16-19
Author(s):  
Yan Irawan ◽  
Ika Juliana ◽  
Emil Budianto

In this study, the synthesis of palm oil-based polymeric ester for application as a polymeric surfactant was carried out by a cationic addition polymerisation method through two steps. The initial step is a synthesis of fatty acid methyl esters oleate (FAMEO) through esterification reaction between oleic acid and methanol. The optimum conditions of the esterification reaction were carried out at a temperature of 70–80oC for 4 hours with the addition of 1wt% sulfuric acid as a catalyst. The molar ratio between oleic acid and methanol was 1:3. FAMEO was analysed using GCMS to determine the methyl ester content. The second step is the polymerisation of FAMEO. The polymerisation reaction of FAMEO was carried out at 120, 140, and 160oC with 1wt%, 3wt% and 5wt% of boron trifluoride dihydrate as a catalyst and an initiator of polymerisation reaction for 4 to 24 hours of reaction. The reaction conversion of the product was 66%. The polymeric ester was analysed H-NMR. Meanwhile, the molecular weight of that product was 1714 g/mol which analysed using GPC and the PDI was 1.12346 or equal to 1.12. It means that the polymerisation technique was controlled or living polymerisation, which indicates that the distribution type of this product was narrow monodisperse.


2021 ◽  
Vol 2 (2) ◽  
pp. 21-27
Author(s):  
Gabriel Henrique Wienhage ◽  
Eloá Suelen Ramos ◽  
Luana Marcele Chiarello ◽  
Vanderleia Botton ◽  
Vinicyus Rodolfo Wiggers

An alternative to fossil fuels is the use of triglyceride biomass for conversion to biofuel by the thermal cracking process, also known as pyrolysis. The liquid phase, called bio-oil, has physicochemical properties like petroleum-derived fuels. One of the undesirable characteristics of bio-oil is the high acidity index, due to the presence of short-chain carboxylic acids in its composition. This feature makes refining and use inviable. The objective of this work was to perform esterification reactions using bio-oil, produced from soybean oil pyrolysis already characterized, in order to reduce its acidity index. Besides that, the esterified bio-oil was submitted to different washing experiments to decrease even more the final acidity. For the esterification reaction 25 g of bio-oil was used at a temperature of 64 °C, using from 0.8 to 2.2% sulfuric acid and 0.5 to 99.5% mass ratio of methyl alcohol and bio-oil. The highest acidity index reduction after 20 min was 81.2%, the esterified bio-oil reduced from 129 to 32.4 mg KOH g-1. Esterification reaction followed by washing and neutralization can decrease even more those values and, the acidity index can reach zero.


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