scholarly journals Production of biodiesel by esterification and transesterification from waste cooking oils

Author(s):  
Elsy Arenas ◽  
Aidin Urribarrí ◽  
John Sánchez ◽  
Marisela Rincón ◽  
Karina Martínez ◽  
...  

Large quantities of used vegetable oils (AVUs) are generated annually, as a result of food preparation, which can cause contamination of waters and soils, if they are not disposed of properly, but in turn have great potential in the production of biodiesel. In this work, the AVU collected from fast food establishments were subjected to an esterification pretreatment, varying the reaction conditions, molar ratio, catalyst concentration and time, to decrease the content of free fatty acids generated in the frying processes; after an alkaline transesterification. The initial acidity of the AVUs (10,08 ± 0,22 %) was found to drop below 1 % during esterification at 60 °C and 100 rpm, with RMAVU:MeOH of 1: 7 and HCl concentration of 0.3 % v/v, with a conversion of free fatty acids (FFA) to methyl esters of 94.48 and 98.61 % for reaction times of 4 and 6 hours, respectively. The previously esterified AVUs were subjected to a transesterification process with KOH as a catalyst in the presence of methanol, at 60 °C and 100 rpm, finding that the biodiesel produced was a mixture composed of the methyl esters of linoleic acids (57 %), palmitic (14 %), oleic (22 %), stearic (4 %) and elaidic (3 %). The highest concentration of methyl esters (93,797 ± 0.685 g.L-1) was obtained when using the esterified AVU during 6 hours of reaction. FTIR spectra confirmed the conversion of fatty acids to methyl esters, so this product could be used as a biofuel.

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 410 ◽  
Author(s):  
Maria Enrica Di Pietro ◽  
Alberto Mannu ◽  
Andrea Mele

The identification and quantification of free fatty acids (FFA) in edible and non-edible vegetable oils, including waste cooking oils, is a crucial index to assess their quality and drives their use in different application fields. NMR spectroscopy represents an alternative tool to conventional methods for the determination of FFA content, providing us with interesting advantages. Here the approaches reported in the literature based on 1H, 13C and 31P NMR are illustrated and compared, highlighting the pros and cons of the suggested strategies.


Author(s):  
Vijaya Lakshmi Ch ◽  
Uday Bhaskar R.V.S ◽  
Viswanath Kotra ◽  
Satyavathi Bankupalli

Biodiesel from clean oils is comparatively easier than production from crude and non-edible oils. To achieve maximum yield of biodiesel, a two stage process is adopted in which non-edible oils are used as feed-stock: an acid catalyzed esterification of free fatty acids followed by base catalyzed transesterification. Presence of water formed during esterification reaction is detrimental to a viable transesterification process. In the present work, an alternate method for removal of water by in situ hydrolysis reaction of methyl acetate is introduced. The dehydration using methyl acetate during esterification has yielded good results as the soap formed during transesterification was minimal. The results indicated high conversion of triglycerides to methyl ester for lower oil to methanol ratio and at a lower temperature. For 1:3 molar ratio of oil to methanol, the conversion obtained was less than 90 percent and is equivalent to conversions with higher alcohol ratios during esterification in the absence of methyl acetate. These results are indicative of the fact that use of methyl acetate reduces the alcohol to oil ratio without affecting the conversions. Moreover, higher conversions are possible at lower temperatures in the presence of methyl acetate. It is further observed that the oils that are subjected to free fatty acid conversions in the presence of methyl acetate record very little soap formation during the transesterification reactions, thereby resulting in higher grade of biodiesel.


Fuel ◽  
2008 ◽  
Vol 87 (10-11) ◽  
pp. 1789-1798 ◽  
Author(s):  
Nalan Özbay ◽  
Nuray Oktar ◽  
N. Alper Tapan

2013 ◽  
Vol 2 (6) ◽  
pp. 97 ◽  
Author(s):  
Juan Antonio Noriega-Rodriguez ◽  
Esther Carrillo-Perez ◽  
Nohemi Gamez-Meza ◽  
Luis A. Medina-Juarez ◽  
Ramiro Baeza-Jimenez ◽  
...  

<p>In the present work, direct enzyme-catalyzed esterification of n-3 polyunsaturated fatty acids (n-3 PUFA) isolated from sardine oil was optimized to obtain structured acyglycerols. A n-3 PUFA concentrate was prepared by urea crystallization of refined sardine oil and esterification was carried out mixing free fatty acids and glycerol at different molar ratios (<em>M</em> = 0.48, 1.5, 3.0, 4.5 and 5.52 mol/mol), using an immobilized lipase preparation from <em>Candida antarctica</em> (NV-435) at different temperatures (<em>T</em> = 38, 45, 55, 65 and 72 °C) and reaction times (<em>t</em> = 0.7, 2.75, 5.75, 8.75 and 10.8 h) in a rotatable central composition design. The degree of esterification was determined by analysis of the acylglycerides produced, using liquid chromatography (HPLC-ELSD). Optimization by response surface methodology (RSM) showed that in order to obtain higher esterification levels of n-3 PUFA to glycerol (99.5%), a molar ratio of 1.3 mol n-3 PUFA/mol glycerol, time 8.3 h and temperature 38 °C, are required. However, results of this work show that it is possible to drive the reaction to any determined product (MAG, DAG or TAG) by modifying the reaction conditions.</p>


Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4306
Author(s):  
S. Ozkan ◽  
J. F. Puna ◽  
J. F. Gomes ◽  
T. Cabrita ◽  
J. V. Palmeira ◽  
...  

In this experimental work, calcium from natural seafood wastes was used as a heterogeneous catalyst separately or in a blend of “shell mix” for producing biodiesel. Several chemical reaction runs were conducted at varied reaction times ranging from 30 min to 8 h, at 60 °C, with a mass content of 5% (Wcat./Woil) and a methanol/oil molar ratio of 12. After the purification process, the biodiesel with fatty acid methyl ester (FAME) weight content measured was higher than 99%, which indicated that it was a pure biodiesel. This work also showed that the inorganic solid waste shell mixture used as the heterogeneous catalyst can be reused three times and the reused mixture still resulted in a FAME content higher than 99%. After 40 different transesterification reactions were performed using liquid (waste cooking oils) and solid (calcium seafood shells) wastes for producing biodiesel, under the specific conditions stated above, we found a successful, innovative, and promising way to produce biodiesel. In addition, blends prepared with jet fuel A1 and biodiesel were recorded with no invalid results after certain tests, at 25 °C. In this case, except for the 10% blend, the added biodiesel had no significant effect on the viscosity (fluidity) of the biojet fuel.


2012 ◽  
Vol 581-582 ◽  
pp. 133-137
Author(s):  
Hong Wang ◽  
Yan Lin Sun ◽  
Li Zhang

Abstract: This paper is focused on the preparation of biodiesel from crude rubber seed oil with high free fatty acids (FFA) content. The rubber seeds were collected in Xishuangbanna, Yunnan province. Two-step synthesis was selected to obtain the product, that is, acid catalyzed esterification was carried out first to decrease the FFA content, then methyl esters of fatty acids can be formed by alkaline transesterification. The reaction conditions of alkaline transesterification were investigated. The results show that the optimum technique is to carry out the reaction at 60°C for 1.5h, with the methanol-to-oil molar ratio 6:1, the catalyst amount 1.0% (g NaOH/ g oil). The yield can reach 75%. GC analysis shows the content of methyl esters of fatty acids is 82.29%. Some properties of biodiesel prepared are also presented.


Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 832 ◽  
Author(s):  
Juan Francisco García Martín ◽  
Javier Carrión Ruiz ◽  
Miguel Torres García ◽  
Chao-Hui Feng ◽  
Paloma Álvarez Mateos

Companies in the field of the collection and treatment of waste cooking oils (WCO) for subsequent biodiesel production usually have to cope with high acidity oils, which cannot be directly transformed into fatty acid methyl esters due to soap production. Since glycerine is the main byproduct of biodiesel production, these high acidity oils could be esterified with the glycerine surplus to transform the free fatty acids (FFA) into triglycerides before performing the transesterification. In this work, commercial glycerol was esterified with commercial fatty acids and commercial fatty acid/lampante olive oil mixtures over tin (II) chloride. In the first set of experiments, the esterification of linoleic acid with glycerol excess from 20 to 80% molar over the stoichiometric was performed. From 20% glycerol excess, there was no improvement in FFA reduction. Using 20% glycerol excess, the performance of a biochar obtained from heavy metal-contaminated plant roots was compared to that of SnCl2. Then, the effect of the initial FFA content was assessed using different oleic acid/lampante olive oil mixtures. The results illustrated that glycerolysis was impeded at initial FFA contents lower than 10%. Finally, the glycerolysis of a WCO with 9.94% FFA was assayed, without success.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2298 ◽  
Author(s):  
Ming-Chien Hsiao ◽  
Jui-Yang Kuo ◽  
Pei-Hsuan Hsieh ◽  
Shuhn-Shyurng Hou

Biodiesel is an environmentally friendly and sustainable fuel. However, the high price of the biodiesel produced from pure vegetable oil contributes to making it uncompetitive in the market. If we can make low cost oils such as waste cooking oil and high-acid-value oil available as resources, the cost of biodiesel production will be reduced significantly. However, these low cost oils cannot be used to produce biodiesel directly because they usually contain a large amount of free fatty acids. They have to undergo a preparatory procedure to lower the acid value to a specific value. The purpose of this study was to lower the amount of free fatty acids in waste cooking oils by blending high- and low-value oils at different ratios and to reduce the transesterification reaction time using a high speed homogenizer, which has the potential to easily enlarge the capacity scale. We used a high-acid-value oil to low-acid-value oil volume ratio of 4:6 as a control. A high conversion rate (97.1%) was achieved under the optimal reaction conditions: methanol-to-oil molar ratio, 9:1; amount of catalyst (CH3ONa) used, 0.75 wt %; reaction temperature, 65 °C; rotation speed, 8000 rpm; and reaction time, 8 min.


Author(s):  
SUNNY SONI ◽  
MADHU AGARWAL

Biodiesel is a renewable liquid fuel made from natural, renewable biological sources such as edible and non edible oils. Over the last years, biodiesel has gained more market due to its benefits and because it appears as the natural substitute for diesel. Reasons for growing interest in biodiesel include its potential for reducing noxious emissions, potential contributions to rural economic development, as an additional demand center for agricultural commodities, and as a way to reduce reliance on foreign oil. Biodiesel was prepared from soybean oil by transesterification with methanol in the presence of cement clinker. Cement clinker was examined as a catalyst for a conversion of soybean oil to fatty acid methyl esters (FAMEs). It can be a promising heterogeneous catalyst for the production of biodiesel fuels from soybean oil because of high activity in the conversion and no leaching in the transesterification reaction. The reaction conditions were optimized. A study for optimizing the reaction parameters such as the reaction temperature, and reaction time, was carried out. The catalyst cement clinker composition was characterized by XRF. The results demonstrate that the cement clinker shows high catalytic performance & it was found that the yield of biodiesel can reach as high as 84.52% after 1 h reaction at 65°C, with a 6:1 molar ratio of methanol to oil, 21 wt% KOH/cement clinker as catalyst.


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