scholarly journals Production of Sustainable Biochemicals by Means of Esterification Reaction and Heterogeneous Acid Catalysts

2021 ◽  
Vol 5 (3) ◽  
pp. 46
Author(s):  
Rosa Vitiello ◽  
Francesco Taddeo ◽  
Vincenzo Russo ◽  
Rosa Turco ◽  
Antonio Buonerba ◽  
...  

In recent years, the use of renewable raw materials for the production of chemicals has been the subject of different studies. In particular, the interest of the present study was the use of oleins, mixtures of free fatty acids (FFAs), and oleic acid to produce bio-based components for lubricants formulations and the investigation of the performance of a styrene-divinylbenzene acid resin (sPSB-SA) in the esterification reaction of fatty acids. This resin has shown good activity as a heterogeneous catalyst and high stability at elevated temperatures (180 °C). It was tested in the esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol. In particular, the esterification reactions were performed in a steel stirred batch reactor and a PBR loop reactor. Tests were conducted varying the reaction conditions, such as alcohol type, temperature, reaction time, and catalysts, both homogeneous and heterogeneous ones. From the obtained results, acid resin (both in reticulated and not-reticulated form) showed high activity in esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol and good resistance to the deactivation; thus, they can be considered promising candidates for future applications in continuous devices. Viscosity tests were performed, underlining the good properties of the obtained products as lubricant bases.

2021 ◽  
Vol 16 (4) ◽  
pp. 763-772
Author(s):  
Balqees A. Alshahidy ◽  
Ammar S. Abbas

Natural kaolin clay was used to successfully prepare 13X zeolite catalysts, which were modified by dealumination with citric acid. Acid leaching eliminates impurities and aluminum, and improves the Si/Al ratio of the zeolite framework. The X-ray diffraction (XRD) patterns of both the original and modified 13X zeolites were the same, indicating that the crystalline frameworks were not destroyed during the dealumination process. X-ray fluorescence data of the dealuminated 13X zeolite showed an improved Si/Al ratio. Also, Atomic Force Microscopy (AFM) was used for the characterization of the catalysts. The catalytic performance of the original and modified catalysts was tested in the esterification reaction of oleic acid in a batch reactor. A higher conversion of oleic acid was obtained using the modified 13X zeolite. The resulting experimental data from the esterification reactions were fitted to the heterogeneous Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model to determine the rates of reaction. The results of the reaction kinetics showed an increase in the rate of reaction velocity and a distinct decrease in the activation energy when using the modified zeolite, indicating that employing the modified catalyst will give a higher conversion over a shorter time through a reaction with less sensitivity to temperature. 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). 


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.


2011 ◽  
Vol 76 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Mihail Ionescu ◽  
Zoran Petrovic

Novel bio-based compounds containing phenols suitable for the synthesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid) as catalysts was studied. The reaction kinetics was followed by monitoring the decrease of the double bond content (iodine value) with time. In order to understand the mechanism of the reaction, phenol was alkylated with model compounds. The model compounds containing one internal double bond were 9-octadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82% oleic acid). It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid). Fatty acids with two double bonds (linoleic acid) and three double bonds (linolenic acid) lead to polymerized oils by a Diels Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with polymerized oil (30-60%), phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 %) and unreacted oil (30%). The phenolated vegetable oils are new aromatic-aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions) for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.


2010 ◽  
Vol 07 (13) ◽  
pp. 30-32
Author(s):  
Luis Alcides Brandini DE BONI ◽  
Eduardo GOLDANI

Several raw materials have been used in the biodiesel production since the implementation of the National Program of Production and Use of Biodiesel through the Brazilian Law 11.097 of January 13th 2005. The most common way used to produce this biofuel is the transesterification reaction which, among others features, requires a raw material with low acidity level. When this condition is not reached, the esterification reaction is alternatively used to convert free fatty acids into mono alkyl esters. Sulfuric acid is one of the catalysts that can be used in the esterification reaction which, therefore, can react with the alcohol generating dimethylsulfate. The aim of this technical report is to discuss the chemical reactions involved when the esterification reaction is used and the effects that this may cause, such as exposure to carcinogenic products.


2020 ◽  
Vol 18 (2) ◽  
pp. 47
Author(s):  
I Dewa Gede Arsa Putrawan ◽  
Adli Azharuddin ◽  
Dendy Adityawarman ◽  
Dicka Ar Rahim

Abstrak. Merkaptoetil karboksilat merupakan bahan baku stabiliser termal polivinil klorida atau polyvinyl chloride (PVC) berbasis timah organik. Stabiliser termal perlu ditambahkan ke dalam resin PVC sebelum diekstrusi untuk mencegah kerusakan karena pengerjaan panas. Stabiliser termal PVC dari timah organik dikenal sangat efektif, khususnya untuk aplikasi PVC kaku seperti pipa dan bingkai jendela. Penelitian ini bertujuan mengevaluasi sintesis merkaptoetil karboksilat dari asam lemak dan merkapto etanol dengan variasi sumber asam lemak yang meliputi asam lemak sawit, dedak padi dan biji kapuk. Percobaan dilakukan dalam sebuah reaktor partaian (batch) dengan asam kuat sebagai katalis. Percobaan dilakukan pada temperatur 60-80°C dan ekses merkapto etanol 10%. Kinerja sintesis dievaluasi melalui pengukuran kadar gugus merkaptan dan angka asam dalam produk serta perolehan produk. Pada rentang temperatur 60-80°C, ketiga asam lemak memberikan produk dengan kadar merkaptan pada rentang 6,4-7,8%.  Temperatur 70°C merupakan temperatur terbaik karena menghasilkan produk dengan kadar merkaptan tertinggi tanpa memadat selama penyimpanan. Pada temperatur ini, produk memiliki angka asam pada rentang 11-41 mg KOH/g dan perolehan pada rentang 70-81%. Ketiga sumber asam lemak memberikan produk dengan kadar merkaptan yang mencukupi untuk dapat digunakan sebagai bahan baku stabiliser PVC. Mempertimbangkan kualitas produk dan ketersediaan di pasaran, distilat asam lemak sawit dipandang sebagai bahan baku yang paling baik. Kata kunci: asam lemak, merkaptoetil karboksilat, polivinil klorida, stabiliser termal. Abstract. Synthesis of Mercaptoethyl Carboxylate as Raw Materials for Polyvinyl Chloride Thermal Stabilizer: Variation in Fatty Acid Source. Mercaptoethyl carboxylate is a raw material for organotin-based polyvinyl chloride (PVC) thermal stabilizer. Thermal stabilizers need to be added to the PVC resin before extruded to prevent degradation due to heat treatment. Organotin PVC stabilizers are known to be very effective, especially for rigid PVC applications such as pipes and frames. This study was aimed to evaluate the synthesis of mercaptoethyl carboxylate from fatty acids and mercaptoethanol with various sources of fatty acids including palm, rice bran and kapok seed fatty acids. The experiment was carried out in a batch reactor with a strong acid as a catalyst. The experiments were conducted at 60-80°C and 10% mercapto ethanol excess. The performance of synthesis was evaluated by measuring mercaptan and acid contents and yield. In the range of 60-80°C, all three fatty acids provided products with mercaptan levels in the range of 6.4-7.8%. A temperature of 70°C is the best temperature as it gave a product with the highest mercaptan content without solidification during storage. At this temperature, the product had acid values in the range 11-41 mg KOH/g and yields in the range of 70-81%. Considering product quality and availability in the market, palm fatty acid distillate was seen as the best raw material. Keywords: fatty acid, mercaptoethyl carboxylate, polyvinyl chloride, thermal stabilizer. Graphical Abstract


2015 ◽  
Vol 8 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Igor Oršula ◽  
Miroslav Lehocký ◽  
Pavol Steltenpohl

Abstract Design simulation of a reactor for acetylene production from calcium acetylide and its purification in the gaseous phase is presented. Simulations were performed using the program ASPEN+ which is a very flexible and useful tool for the simulation and optimization of various types of chemical technologies including gas-liquid-solid systems. The first step of the acetylene synthesis, based on coal as the raw material, is the production of calcium acetylide. This substance is obtained from coke and limestone in an electric arc furnace at elevated temperatures. Raw materials used in this process contain relatively large amounts of impurities that are converted and entrapped in the desired product of the above reaction. Some of the impurities, e.g. metallic iron or its alloys, can be separated easily. However, most of the other elements present in the form of their compounds with calcium remain a part of “technical grade” calcium acetylide. Acetylene is commercially produced by the reaction of “technical grade” calcium acetylide with water under controlled reaction conditions in an inert atmosphere. Depending on the purity of calcium acetylide used, the produced raw acetylene contains a variety of admixtures that lower its quality. As a consequence, prior to its expedition to the customer, raw acetylene should be submitted to a down-stream processing that consists of the separation of basic and acidic pollutants present in acetylene by absorption. The final processing step is adsorption and/or freezing-out of water vapor from the purified acetylene stream. Besides acetylene, the reaction of calcium acetylide with an excess of water provides aqueous calcium hydroxide. In order to commercialize this byproduct, the content of water in the mixture should be lowered to the required level. In this contribution, development of a model of calcium acetylide and acetylene production as well as the simulation of these processes in ASPEN+ are presented. Simulation results of a realistic production line model correlate very well with the actual data from the technology used in Fortischem, a.s., Novaky, Slovakia.


Author(s):  
Nikunj P Tanna ◽  
S. Mayadevi

Modeling of an esterification reaction in a batch pervaporation membrane reactor (PVMR), and an analysis of the PVMR performance under different reaction conditions for different membrane characteristics are presented. Esterification of ethyl alcohol with acetic acid was considered as the model reaction. The PVMR performance for this reaction could be represented by a 2-step series model. The PVMR performance was similar to that of the batch reactor when both the reactors were in the kinetic regime. However, the performance of the PVMR was superior to that of the batch reactor when both were in the intermediate/equilibrium regime of the reaction. In these regions, the PVMR performance was influenced/limited by the membrane flux and selectivity. The analysis showed that the membrane flux affected the PVMR performance in the intermediate region and the membrane selectivity affected the performance in the equilibrium regime. Further, the limitations introduced by a low-flux membrane could be overcome by appropriate selection of the membrane area and that due to poor selectivity could be compensated to a certain extent by adjusting the feed ratio.


1993 ◽  
Vol 47 (10) ◽  
pp. 1623-1625 ◽  
Author(s):  
Wei G. Hansen

The hydroxyl value is an indicator for the stages of esterification reaction. Instead of the wet chemistry titration method, the near-infrared (NIR) spectroscopic technique was utilized to monitor the hydroxyl values during the reaction. Because of the various raw materials and reaction conditions, the shifting of the -OH absorption band in the NIR spectra of esters was observed. The molecular structure, the reaction environment, and the state of the -OH groups are the most likely parameters responsible for the shifting of the -OH band.


2016 ◽  
Vol 709 ◽  
pp. 57-60
Author(s):  
Fei Ling Pua ◽  
Kah Thong Looi ◽  
Shamala Gowri Krishnan ◽  
Sharifah Nabihah

In recent years, attention has been drawn to produce heterogeneous catalyst to replace homogeneous catalyst in biodiesel industry. This study was focused on the synthesis of three different types of alginate based heterogeneous catalyst (Ferric-alginate, Copper-alginate, and Nickel alginate) and the effect of the catalyst on esterification of oleic acid. Morphology and elemental analysis was conducted to investigate the properties of the catalyst. The new heterogeneous catalysts were used to catalyze the esterification of oleic acid at reaction temperature of 60°C and 2 hours reaction time. Fe-alginate has achieved the highest free fatty acids (FFAs) conversation rate of 82.03%. The results and findings proved that transition metal-alginate heterogeneous catalyst has the potential and ability to esterify the free fatty acids prior biodiesel production from high free fatty acids feedstock.


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.


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