Supercritical transesterification of vegetable oil and ethanol: temperature and residence time effects on phase formation and water content

Supercritical transesterification has emerged as a readily available alternative for biodiesel production since no catalyst is required, thereby generating fewer waste products. In this research, the supercritical transesterification of refined vegetable oil and aqueous ethanol was carried out at temperatures 400 to 480 °C and a 12:1 ethanol to oil molar ratio, to assess the effect of temperature and residence time in the formation of a homogeneous phase, effluent appearance and increased water content derived from glycerol etherification. The results showed that water was produced at temperatures higher than 400 °C, as expected from the occurrence of glycerol etherification, and that prolonged times resulted in gas and soot formation, indicating esters decomposition. Through water mass balances, it was possible to identify the set of operation conditions in which the water formed from glycerol etherification matched with the maximum expected according to the proposed reaction scheme.

La transesterificación supercrítica se ha propuesto como una alternativa para la producción de biodiesel ya que no requiere catalizador de esta manera se generan menos residuos. En esta investigación, la transesterificación supercrítica de aceite vegetal refinado y etanol acuoso se llevó a cabo a temperaturas en el rango 400 a 480 °C y relación molar etanol a aceite de 12:1, para evaluar el efecto de la temperatura y el tiempo de residencia en la formación de una fase homogénea, apariencia del efluente e incremento del contenido de agua resultado de las reacciones de eterificación del glicerol. Los resultados mostraron que se produjo agua a temperaturas mayores a 400°C, atribuida a la eterificación del glicerol, y que tiempos de residencia prolongados resultaron en formación de gas y hollín, indicativo de reacciones de descomposición de esteres. A través de balances de masa, fue posible identificar el conjunto de condiciones de operación a las cuales el agua formada por la eterificación del glicerol coincide con el valor máximo esperado de acuerdo con el esquema de reacción propuesto.

A transesterificação supercrítica foi proposta como uma alternativa para a produção de biodiesel porque não requer catalisador e, dessa forma, gera menos resíduos. Nesta pesquisa, a transesterificação supercrítica de aceite vegetal refinado e etanol acuoso foi conduzida a temperaturas entre 400 e 480 °C e uma relação molar de etanol e aceite de 12: 1, para avaliar o efeito da temperatura e do tempo de residência na formação de uma fase homogênea, apariência do efluente e aumento do conteúdo de água resultante das reações de eterificação do glicerol. Os resultados mostraram que se produziu água a temperaturas maiores que 400°C, atribuída à eterificação do glicerol, e que os tempos de residência prolongados resultaram na formação de gás e hollín, indicativo de reações de decomposição de ésteres. Por meio de balanças de massa, foi possível identificar o conjunto de condições de operação em que a água formada pela eterificação do glicerol coincide com o valor máximo esperado de acordo com o esquema de reação proposto.

Production and Physicochemical Analysis of Glycerol Produced from the Transesterification Reaction of Locally Processed Fatty Acids

The study uses the transesterification reaction method to extract glycerol from three locally processed fatty acids namely; palm oil, palm kernel and shea butter. The glycerols extracted from the three fatty acids were subjected to physicochemical tests to determine if their properties are in conformity with the reported standard values. Results of the physical properties of the substances tested show that the values were in close agreement with the results of the standard values and the results reported impervious literatures. As such, the investigation concluded that the three fatty acids contain appreciable quantities of crude glycerol and can thus serve as a source for natural glycerol whose properties can be compared with standard glycerin products.

Determination of lipids and fatty acids in infant formula: comparison of the conventional x direct method / Lipídios e ácidos graxos em fórmula infantil: comparação de metodologias de extração convencional x direta

Lipids in food are conventionally analyzed in two stages: extraction with organic solvent and fat esterification reaction, in this case, the type of fat of each food influences the choice of extraction and esterification reagents. In the direct method, such procedures are performed in one step. This work compared the conventional extraction method and quantification of lipids and fatty acids, with a direct method in infant formula. A reference sample of infant formula conteining certified lipids and fatty acids values from the National Institute of Standards and Technology was used. The conventional method for lipid analysis used the acid hydrolysis method; for the determination of fatty acids, the fats were extracted with a mixture of ethyl ether and petroleum ether. The direct method consisted of direct trans esterification with sodium methoxide. In the analysis of fatty acids, the majority of the results showed statistically equal values (α < 0.05) for both methods. The direct method proved suitable, mainly because of reduction in analytical time and quantity of solvents (AU).

Os lipídios em alimentos são analisados, de forma convencional, em duas etapas: extração com solvente orgânico e reação de esterificação da gordura, neste caso o tipo de gordura de cada alimento influencia na escolha dos reagentes da extração e esterificação. No método direto, estes procedimentos são realizados em uma etapa única. Este trabalho comparou a metodologia convencional de extração e quantificação de lipídios e ácidos graxos, com um método direto em fórmula infantil. Foi utilizada uma amostra de referência de fórmula infantil com valores certificados para lipídios e ácidos graxos da Nacional Institute of Standards and Technology. A metodologia convencional para a análise de lipídios empregou método com hidrólise ácida; para a determinação dos ácidos graxos, a gordura foi extraída com uma mistura de éter etílico e éter de petróleo. O método direto fundamentou-se na transesterificação direta com metóxido de sódio. Na análise dos ácidos graxos, a maioria dos resultados demonstrou valores estatisticamente iguais (α < 0,05) para os dois métodos. O método direto demonstrou ser apropriado, principalmente pela diminuição do tempo de análise e quantidade de solventes (AU).

Venturi: dispositivo de cavitação hidrodinâmica para acelerar a síntese de biodiesel / Venturi: hydrodynamic cavitation device to accelerate biodiesel synthesis

RESUMO O objetivo deste trabalho foi avaliar o potencial do Venturi para a síntese de biodiesel a partir de óleo comestível residual em rota metílica. Para tanto, foi construído em escala de laboratório um aparato experimental constituído de um tanque de 5,2 L e um dispositivo Venturi projetado para produzir o fenômeno de cavitação. A produção de biodiesel foi avaliada em três diferentes pressões de entrada do Venturi: 4,4; 2,9; e 1,4 bar. Os teores de ésteres metílicos foram determinados por cromatografia gasosa. O tempo de síntese de 5,2 L de biodiesel, com o Venturi, foi de 23,2 segundos (ou 4,5 segundos por litro de biodiesel produzido), o que equivale a um único ciclo de passagem pelo sistema a pressão máxima (4,4 bar). Nessa condição, o rendimento dos teores de ésteres foi superior a 98%. Não há na literatura outro caso de síntese tão rápida como a encontrada neste trabalho. A caracterização do biodiesel mostrou que os parâmetros viscosidade cinemática, índice de acidez, ponto de entupimento a frio e massa específica estão dentro dos limites estabelecidos pela Agência Nacional de Petróleo. A comparação com outros estudos da literatura mostrou que o Venturi é superior às placas de orifício na síntese de biodiesel.

Abstract The objective of this work was to evaluate the potential of Venturi in the synthesis of biodiesel from residual edible oil in a methyl route. For this purpose, an experimental apparatus consisting of a 5.2 L tank and a Venturi device designed to produce the cavitation phenomenon was constructed in laboratory scale. Biodiesel production was evaluated at three different Venturi inlet pressures: 4.4; 2.9; and 1.4 bar. Methyl esters contents were determined by gas chromatography. Biodiesel synthesis time with the Venturi device was 23.2 seconds (or 4.5 seconds per liter of biodiesel produced), which is equivalent to a single cycle of the system at maximum pressure (4.4 bar). In this condition, the yield of the ester contents was greater than 98%. There is no other case of synthesis as fast as that found in this work. The biodiesel characterization showed that the parameters kinematic viscosity, acidity index, cold clogging point, and specific mass are within the limits established by National Agency of Petroleum Natural Gas and Biofuels (Agência Nacional de Petróleo). The use of Venturi, as a cavitation device, was shown to be more efficient in biodiesel synthesis than other devices, such as orifice plates.

Production and characterization of biodiesel obtained from transesterification of lipid from goat tallow

Aim: The present study was conducted to optimise the production of biodiesel from goat tallow by chemical and biological transesterification and to analyse the fuel characteristics of biodiesel. Methodology: Lipid from goat tallow was extracted after subjecting the tallow to ultrasonication and microwave heating. The lipid obtained was converted to biodiesel by chemical and biological transesterification processes. Results: Microwave heating of goat tallow with hexane produced 550 ml of oil whereas ultrasonication method produced 350 ml and 430 ml with Hexane and Hexane : Isopropanol (3:2) as solvent mixture, respectively. When one litre of this oil was subjected to transesterification reaction, 750 ml and 640 ml of biodiesel was produced by chemical and biological methods under optimized conditions (temperature 60oC for chemical and 35oC for biological transesterification). GC-MS analysis of transesterified oil indicated linolenic acid, pentadecanoic acid and stearic acid as major lipid components in goat tallow. Fuel properties were tested as per ASTM standards. Interpretation: The biological process (either with the enzyme or with organism), if properly designed can definitely be an advantageous as this process is cost effective and environmental friendly. Goat tallow can be a potential candidate for the production of biodiesel, an alternate to fossil fuel, which is the need of the hour.

Effect of Process Variables on the Transesterification Process of Palm Oil Sludge to Biodiesel

In this research work, the optimum process variables (catalyst, methanol to oil ratio and reaction time) for transesterification of palm oil sludge (POS) to biodiesel were studied. The transesterification process was carried by mixture of palm oil sludge, methanol and catalyst with the help of magnetic stirrer at 300 rpm and at temperature of 60ºC. The catalyst used for the process was potassium hydroxide (KOH). One-Factor-at-A-Time was used to select the possible optimum levels of process variable that gives high biodiesel yield. The study was evaluated by five levels of methanol-to-oil ratio (1:1 – 12:1), catalyst (0.1- 2%) and reaction time (30 – 150 min).The optimum process variables for transesterification of palm oil sludge (POS) to achieved maximum biodiesel yield were found to be methanol to oil molar ratio of 12:1, catalyst loading of 1.5wt% and reaction time of 30 min. At this optimum conditions the maximum biodiesel yield was 61.2%. The biodiesel produced from transesterification of palm oil sludge was characterized in order to determine the properties of the product. The density of POS is 857.0 kg/m3, kinematic viscosity of 5.38 mm2/s, flash point of 180°C, pour point of -5°C, and Acid value of 0.17 mgKOH/g. The biodiesel produced from transesterification of palm oil sludge meets the EN 14214 and ASTM 6751 standard. Thus, this study will be helpful to determine an efficient and economical procedure for biodiesel production from non-edible raw materials with high free fatty acid.

Process conditions for a rapid in situ transesterification for biodiesel production from oleaginous yeasts

BACKGROUND: Microbial oils produced by diverse microorganisms are being considered as alternative sources of triglycerides for biodiesel production. However, the standalone production of biodiesel from microorganisms is not currently economically feasible. In case of yeasts, the use of low-value nutrient sources in microbial production and the implementation of cost-efficient downstream processes could reduce costs and make microbial lipids competitive with other commodity-type oils in biodiesel production. Industrial biodiesel synthesis from oleaginous seeds is currently based on a multistep process. However, a simple process called in situ transesterification (ISTE), which takes place within the biomass without a previous lipid extraction step, is receiving increasing interest. In this work, the optimal conditions for an ISTE process to obtain biodiesel from previously selected oleaginous yeast (Rhodotorula graminis S1/S2) were defined using the response surface methodology (RSM). RESULTS: Using the RSM approach, the optimal conditions for the maximum yield with minimum reaction time included a methanol-to-biomass ratio of 60:1, 0.4 M H2SO4, and incubation at 70°C for 3 h. The optimized in situ process yield was significantly higher (123%) than that obtained with a two-step method in which fatty acids from saponifiable lipids were first extracted and then esterified with methanol. The composition of the fatty acid methyl ester mixture obtained from R. graminis S1/S2 by ISTE met Uruguayan standards for biodiesel. CONCLUSION: The characteristics achieved by the optimized method make microbial oil a potential alternative for biodiesel production from yeast at an industrial scale.

Fruit Peel from Astrocaryum aculeatum G. Mey. AS Substrate for Lipases Production by Aspergillus niger A2B1

The fruit of Astrocaryum aculeatum G. Mey. are consumed by population in the Brazil Northern resulting fruit peels. These peels are rich in lignocellulose and fat. The present study investigated peels from the Astrocaryum aculeatum G. Mey. as a substrate for lipases production by solid state bioprocess. To reach this objective: 1) we isolated fungi from peels from the fruit of Astrocaryum aculeatum G. Mey; 2) we screened the isolates for lipase production (screening in petri dish and screening in submerged bioprocess), 3) we investigated the production of lipases by using peels from Astrocaryum aculeatum G. Mey as substrate. The isolates belonged to the genera Aspergillus (16), Penicillium (3) and Fusarium (1). These strains were submitted to petri dishes and submerged fermentation for lipases production, these experiments resulted in the selection of five strains belonging to the Aspergillus genera. The lipases produced by these five strains performed enzymatic transesterification; however, the lipases from the strain Aspergillus niger A2B1 produced the highest ester content. The utilisation of fruit peel from Astrocaryum aculeatum G. Mey. as the main substrate, fruit peel from Astrocaryum aculeatum G. Mey. oil (13%), moisture (70%) and 75 h of incubation were the optimal conditions identified for the production of lipases by Aspergillus niger A2B1(17.42 U/g) in solid state bioprocess (SSB).

Esterificación transesterificación de aceites residuales para obtener biodiesel / Esterificationannd transesterification of waste oils for biodiesel obtaining

El biodiesel es un biocombustible producido a partir de grasas y aceites, y debido a las desventajas del uso de los combustibles fósiles, su producción y consumo ha aumentado en los últimos años. En este trabajo fue estudiada la esterificación por catálisis ácida y la transesterificación alcalina de aceites residuales para obtener biodiesel. Las condiciones de relación aceite-metanol (6:1 y 5:1) y concentración de catalizador fueron variadas para seleccionar las más favorables para el proceso. Los aceites usados fueron recolectados en restaurantes de la ciudad de Cartagena. Se encontró que la variable con mayor efecto en el rendimiento de la reacción fue la relación aceite-metanol, favoreciéndose para bajas concentraciones de metanol (6:1), a las cuales se obtienen rendimientos superiores al 93%. La concentración de catalizador no influyó de manera significado la eficiencia de la esterificación. El biodiesel obtenido presentó buenas características de acidez y bajo contenido de azufre. Adicionalmente, se evidenció la necesidad de un pretratamiento a los aceites y una purificación del biodiesel para lograr el cumplimiento de estándares internacionales.

Biodiesel is a biofuel produced from fats and oils and because of the disadvantages of fossil oils use, its production and consumption has increased in recent years. In this work the esterification of waste oil by acid catalysis and alkaline transesterification to obtain biodiesel was studied. The oil-methanol (6:1 and 5:1) ratio conditions and catalyst concentration were varied to select the most favorable for the process. The oils used were collected in restaurants in the city of Cartagena. It was found that the variable to greater effect on the reaction yield was the oil-methanol ratio, favoring low concentrations of methanol (6:1), from which yields higher than 93% are obtained. The catalyst concentration did not affect significantly the efficiency of esterification. The biodiesel obtained had good acidity characteristics and low sulfur content. Additionally the need for a pretreatment to oils and biodiesel purification to achieve compliance of international standards was evidenced.

Direct preparation of fatty acid methyl esters and determination of in vitro antioxidant potential of lipid from fresh Sebal causarium Seed.

Classical method of sample preparation for fatty acid analysis is a complicated, rigorous, multiple-step process that is often time-consuming. However, innovation has made it possible to obtain fatty acids esters in a single step without compromise of the quality and quantity of the products obtained. Fatty acid methyl esters (FAMEs) were obtained from Sabal causiarum seed using direct trans-esterification method. The reaction was performed in a one necked glass reactor equipped with a reflux condenser. The composition of the FAMEs obtained was analyzed using GC-FID/GC-MS. The FAMEs was also evaluated for its antioxidant potential using DPPH assay while α- tocopherol served as a standard. From the Total ion chromatogram, a total of twelve fatty acids were identified with the dominant being linoleic acid (29.83%), an essential polyunsaturated omega-6 fatty acid. Other compounds obtained in significant yield include palmitic acid (20.75 %), dodecanoic acid (12.15 %), oleic acid, an omega-9 monounsaturated fatty acid (11.51%), 11-Octadecenoic acid (5.89 %), Ceric acid (4.97) and lignoceric acid (4.56 %). The oil had higher antioxidant potential (with IC50 value 0.19 ± 0.31 mg/mL) than the standard, alpha-tocopherol (with IC50 of 0.25 ± 0.4 (mg/mL). The direct trans-esterification method enables the quick determination of the fatty acid profile of Sabal causiarum seed. It is a viable method that saves time, limit use of solvents and reduce the possibility of contaminations that is associated with classical multistage procedure. The chemical composition and high antioxidant value of the oil is a strong indication of the future economical and biological relevance of the Sabal causiarum seed oil.

Effect of microwave-assisted system on transesterification of castor oil with ethanol / Efecto de microondas en la transesterificación de aceite de higuerilla / Efeito microondas em transesterificação do óleo de rícino

A systematic study of microwave-assisted transesterification of castor oil was conducted in the presence of ethanol and of potassium hydroxide as catalyst. Effects of various reaction parameters such as reaction time, catalyst concentration, reaction temperature and ethanol-oil molar ratio were analyzed. Ethyl esters were successfully produced by microwave-assisted transesterification. The maximum yield was 80.1% at 60°C, 10:1 alcohol: oil molar ratio, 1.5% potassium hydroxide and 10 min. The results show that there was a reduction in reaction time for microwave-assisted transesterification as compared to conventional heating, yields were slightly affected by temperature from 40-70°C; this indicates a significant effect of microwaves even at low temperatures.

Se realizó un estudio sistemático del efecto de la radiación microondas en la transesterificación de aceite de higuerilla con etanol en presencia de hidróxido de potasio como catalizador. Diversos parámetros fueron analizados, entre ellos el tiempo de reacción, concentración de catalizador, temperatura y relación molar etanol-aceite. De acuerdo con los resultados, la transesterificación asistida por microondas resultó útil para la producción de etilésteres obteniéndose un rendimiento máximo de 80.1% a 60°C, una relación molar alcohol: aceite de 10:1, 1.5% de hidróxido de potasio y 10 min de reacción. Se observó una reducción en el tiempo de reacción para la transesterificación asistida por microondas comparada con el calentamiento convencional. Los resultados muestran que los rendimientos son ligeramente afectados por la temperatura en el rango 40-70°C lo que indica un efecto importante de las microondas incluso a bajas temperaturas.

O presente artigo, foi realizado um estudo sistemático da transesterificação assistida por irradiação de microondas com óleo de rícino na presença de etanol e de hidróxido de potássio como catalizador. Analisou-se os efeitos da variação alguns parâmetros da reação, tais como, tempo de reação, concentração de catalisador, temperatura de reação e proporção molar de óleo de etanol. De acordo com os resultados, os ésteres etílicos foram produzidos com êxito por transesterificação assistida por microondas, obtendo um rendimento máximo de 80.1% a 60 °C, razão molar de 10:1 álcool: óleo, 1.5% de hidróxido de potássio em 10 min. Houve uma redução no tempo de reação de transesterificação assistida por microondas, em relação ao aquecimento convencional. Os resultados mostram que os rendimentos são ligeiramente afetados pela temperatura, no intervalo de 40-70 °C, indicando um efeito significativo de microondas mesmo a baixas temperaturas.

Characterization of residual oils for biodiesel production

Background: Residual oils were characterized according to their physicochemical properties, i.e. acidity, iodine value, peroxide value and saponification number, to evaluate the degradation level and viability for biodiesel production. Results: The methyl esters of fatty acids (FAME) from samples of residual bovine, chicken and soybean oils were quantified by using four transesterification methods, using acidic and basic catalysis and, gas chromatography with flame ionization detector (GC-FID). Methods that used acidic catalysis at a lower temperature were the most efficient. Methyl biodiesel samples were synthesized by basic catalysis (KOH) for all quantified oils and the physicochemical properties of the biofuel were evaluated, i.e. viscosity, flash and fire points, density, water content, iodine and acidity numbers. Conclusions: The obtained results suggesting that it is possible to take advantage of these residues for biodiesel production as the obtained products were approved according to the rules established by the National Association of Petroleum (ANP); the bovine samples were the exception regarding moisture and acidity.

Statistical Optimization of Process Variables for Biodiesel Production from Waste Cooking Oil Using Heterogeneous Base Catalyst.

In this study, the effects of methanol-to-oil molar ratio, catalyst amount and reaction time on the transesterification of waste cooking oil (WCO) to biodiesel were investigated. Methanol with calcium oxide as a heterogeneous catalyst was used for the transesterification process at a temperature of 60oC and 3000 rpm stirring speed. Response surface methodology (RSM) with central composite rotable design (CCRD) was used at five levels of oil-to-methanol molar ratio (9:1 – 14:1), catalyst (1- 5 %) and reaction time (30 – 90 min) as independent variables and WCO biodiesel yield as dependent variable (response). A statistically significant (P < 0.0001) second-order quadratic polynomial regression model with a coefficient of determination, R (= 0.9964) was obtained for biodiesel production (using Design-Expert Statistical program (v. 6.0.8)) and verification experiment confirmed the validity of the predicted model. Numerical optimization technique based on desirability function was carried out to optimize the WCO conversion to biodiesel. The optimum combinations for transesterification to achieve a predicted maximum biodiesel yield of 94.15 percent were found to be: oil-to-methanol molar ratio, 9.14:1; catalyst amount, 3.49 % and reaction time, 60.49 min. At this optimum condition, the observed biodiesel yield was found to be 94.10 percent. In addition, the fuel properties of the produced biodiesel were in the acceptable ranges according to international standards for biodiesel specifications. The statistical analyses and the closeness of the experimental results to model predictions show the reliability of the regression model and thus, the results will be helpful in selecting an efficient and economical method for biodiesel production from cheap raw materials with high free fatty acid.

Obtención de biodiesel a partir de diferentes tipos de grasa residual de origen animal / Extractin biodieesel from different types of animal origin residual fat

Se estudian diferentes posibilidades de obtención de biodiesel a partir de residuos grasos generados en la explotación pecuaria: grasa de pollo, cerdo, y vacuna, para ello se analizan las variables relación molar alcohol/grasa animal y cantidad de catalizador, puesto que son las que más inciden en la calidad del biodiesel, al evaluar sus características y rendimientos de la reacción de transesterificación. El rendimiento en el proceso de extracción de la grasa de material de desecho de pollo es del 70,5%, y de la grasa de cerdo del 90%, por lo que se plantean como alternativas viables desde el punto de vista técnico, permitiendo la valorización de estos desechos orgánicos y aliviando la contaminación generada en este tipo de industrias. De la caracterización realizada a la grasa de pollo y cerdo se pudo establecer que ambas materias primas son de baja acidez lo cual garantiza un alto grado de transesterificación, teniendo en cuenta que tuvo un rendimiento del 96% a partir de la grasa de pollo y del 91,2% a partir de la grasa de cerdo. Del análisis cromatográfico del biodiesel sintetizado se obtuvo que el ácido graso más común fue el del ácido oleico.

Different possibilities of extracting biodiesel from fat residues generated on farm livestock: chicken, pork, and bovine fat, were studied. To do this, the variables molar ratio alcohol/animal fat and amount of catalyst are analyzed, since those are the ones which most affect the quality of biodiesel when assessing the characteristics and efficiency of the transesterification reaction. The efficiency in the poultry waste material extraction process is 70.5%, and in pork fat is 90%, reason why they are proposed as feasible alternatives from the technical standpoint, allowing the recovery of this organic waste, thus alleviating the pollution generated by this type of industry. From the characterization performed on chicken and pork fat, it has been established that this raw material has low acidity which ensures a high degree of transesterification, taking into account that it had 96% efficiency from chicken fat and 91.2% from pork fat. From the synthesized biodiesel Chromatographic analysis it was found that the most common fatty acid was oleic acid.

Caracterización de biodiesel obtenido de aceite residual de cocina / Characterization of Biodiesel obtained from waste cooking oil

Se realizó un análisis físico y químico a cada uno de los siguientes tipos de aceite: desechado proveniente de asaderos de pollo, usado de hogares y fresco adquirido en el mercado local de la ciudad de Florencia, Caquetá (Colombia). Se evaluaron los siguientes parámetros: Peso específico, índice de yodo, índice de saponificación, índice de refracción, humedad y materia volátil, punto de fusión, impurezas insolubles, índice de acidez, coeficiente específico de extinción valores k232< y k270, color y prueba de Kreiss. Igualmente se evaluaron los espectros UV-VIS de los tres tipos de aceite estudiados. Se ensayaron siete diferentes tipos de catalizadores para la reacción de transesterificación manteniendo en todos los casos la proporción de catalizador: aceite 38:190 (v/v), tiempo de reacción (2h) y temperatura de reacción (60°C). Se lograron rendimientos de biodiesel de 75.8% de aceite desechado usando KOH 1,269%p/v/MeOH 99%; 87.50% de aceite usado con KOH 0,537%p/v/MeOH 99% y 86.60% de aceite fresco usando KOH 0,457%p/v/MeOH 99%. Al biodiesel obtenido en cada caso se le determinó peso específico, índice de refracción, humedad y materia volátil, cenizas sulfatadas, carbón residual, corrosión a la lámina de cobre y perfil de ácidos grasos. En todos los casos hubo predominio de ácido palmítico, ácido oléico y ácido esteárico en los aceites usados y desechados. Del análisis por cromatografía de gases acoplada a espectrometría de masas se pudo establecer que el contenido total de ésteres metílicos de ácidos grasos es del 98,38% para el biodiesel de aceite desechado; 99,53% para el biodiesel de aceite usado y 97, 69% para el biodiesel de aceite fresco.

There was performed a physical and chemical analysis to the following types of oils: waste oil taken from chicken steakhouses, waste oil from houses and clean oil taken from the local market at Florencia, Caquetá (Colombia). There were evaluated the following parameters: specific weight, iodine value, saponification value, refractive index, moisture and volatile matter, melting point insoluble impurities acid, specific extinction coefficient k232< and k270 values, color and Kreiss test. Also, there were evaluated the UV-VIS spectra for the three types of oil studied. There were tested seven different types of catalysts for the transesterification reaction, maintaining the same ratio of catalyst for all cases: oil 38:190(v/v), reaction time (2 h) and reaction temperature (60 °C). There was achieved biodiesel yields of 75.8% discarded oil using KOH 1.269%w/v/99%MeOH; 87.50% wasted oil with KOH 0.537% w/v/99%MeOH and 86.60% fresh oil using KOH 0.457% w/v/MeOH99%. For the biodiesel obtained, in each case, was determined specific gravity, refractive index, moisture and volatile matter, sulfated ash, carbon residue, corrosion to the copper foil and fatty acid profile. In all cases, there was a predominance of palmitic, stearic and oleic acids in the waited and discarded oils. From the chromatography gases analysis with the mass spectrometry was established that the total content of fatty acid methyl esters was 98.38 % for biodiesel taken from waste oil; 99.53% for biodiesel taken from wasted oil and 97,69% for biodiesel taken from clean oil.

Glicerina semipurificada vegetal e mista na alimentação de coelhos em crescimento / Vegetal and mixed semipurified glycerin in the feeding of growing rabbits

Dois experimentos foram conduzidos com o objetivo de determinar a energia digestível da glicerina semipurificada vegetal e mista e o desempenho de coelhos em crescimento alimentados com dietas contendo os coprodutos. No ensaio de digestibilidade, foram utilizados 108 coelhos da raça Nova Zelândia Branco, com 45 dias de idade, distribuídos ao acaso em nove tratamentos (0, 4, 8, 12 e 16% de inclusão de glicerina vegetal e mista na dieta), com 12 repetições. Para o ensaio de desempenho, utilizaram-se 180 coelhos da raça Nova Zelândia Branco, dos 32 aos 70 dias de idade, distribuídos ao acaso em arranjo fatorial 2 x 4 (dois tipos de glicerina e quatro porcentagens de inclusão: 3, 6, 9 e 12%) mais uma dieta referência, com 10 repetições e dois animais por unidade experimental. Glicerinas vegetal e mista apresentaram energia digestível de 4.048 e 3.697kcal/kg MS, respectivamente. Entre 32 e 50 dias de idade dos coelhos, a dieta com 12% de glicerina mista prejudicou (P<0,05) o ganho de peso (32,14 g/dia), a conversão alimentar (3,57) e o custo por quilo de ganho de peso (R$ 2,08) em relação à dieta referência (39,42g/dia, 2,87 e R$1,69, respectivamente). Dos 32 aos 70 dias, o ganho de peso (30,11g/dia) e a conversão alimentar (3,99) dos animais que receberam 12% de glicerina mista na dieta foram piores (P<0,05) em relação aos da dieta referência (34,00g/dia e 3,65, respectivamente). Para as características de desempenho, dos 32 aos 70 dias, não foram verificadas diferenças (P>0,05) entre a inclusão de glicerina vegetal na dieta e a dieta referência, porém a maior viabilidade econômica (P<0,05) foi com 12% de inclusão (R$1,89 x R$2,15, respectivamente). A glicerina vegetal pode ser incluída em até 12% da dieta e a mista, em até 9%, diminuindo o custo de produção sem afetar o desempenho animal.

Two trials were conducted with the goal of determining the digestible energy of vegetal and mixed semi purified glycerin and the performance of growing rabbits fed with diets containing the byproducts. In the digestibility assay 108 New Zealand White rabbits, 45 days old, were used, assigned in a completely randomized design into nine treatments (0, 4, 8, 12 and 16% of glycerins inclusion), with 12 replications. The treatment with 0% of glycerin inclusion was considered the reference diet. In the performance assay, 180 New Zealand White rabbits, 32 to 70 days of age, were assigned to a completely randomized design into a 2 × 4 factorial arrangement (two types of glycerin and four percentages of inclusion: 3, 6, 9 and 12%) plus a reference diet and ten replications with two animals per experimental unit. Vegetal and mixed glycerin showed a digestible energy of 4,048 and 3,697 kcal/kg of dry matter, respectively. From 32 to 50 days of age, the diet with 12% of mixed glycerin affected (P<0.05) weight gain (32.14g/day), feed conversion (3.57) and cost per kilo of weight gain (R$2.08) in relation to the reference diet (39.42g/day, 2.87 and R$ 1.69, respectively). From 32 to 70 days, weight gain (30.11g/day) and feed conversion (3.99) of the animals fed with the diet containing 12% of mixed glycerin were worst (P<0.05) in relation to the reference diet (34.00 g/day and 3.65, respectively). Regarding characteristics of animal performance, from 32 to 70 days, no differences (P>0.05) were observed between the inclusion of vegetal glycerin in the diet and the reference diet, but better economic viability was verified (P<0.05) with the diet containing 12% of vegetal glycerin (R$1.89 x R$2.15, respectively). Vegetal glycerin can be included up to 12% in the diet and mixed up to 9%, reducing production cost without affecting animal performance.

Comparison of extraction and transesterification methods on the determination of the fatty acid contents of three Brazilian seaweed species

Seaweeds are photosynthetic organisms important to their ecosystem and constitute a source of compounds with several different applications in the pharmaceutical, cosmetic and biotechnology industries, such as triacylglycerols, which can be converted to fatty acid methyl esters that make up biodiesel, an alternative source of fuel applied in economic important areas. This study evaluates the fatty acid profiles and concentrations of three Brazilian seaweed species, Hypnea musciformis (Wulfen) J.V. Lamouroux (Rhodophya), Sargassum cymosum C. Agardh (Heterokontophyta), and Ulva lactuca L. (Chlorophyta), comparing three extraction methods (Bligh & Dyer - B&D; AOAC Official Methods - AOM; and extraction with methanol and ultrasound - EMU) and two transesterification methods (7% BF3 in methanol - BF3; and 5% HCl in methanol - HCl). The fatty acid contents of the three species of seaweeds were significantly different when extracted and transesterified by the different methods. Moreover, the best method for one species was not the same for the other species. The best extraction and transesterification methods for H. musciformis, S. cymosum and U. lactuca were, respectively, AOM-HCl, B&D-BF3 and B&D-BF3/B&D-HCl. These results point to a matrix effect and the method used for the analysis of the fatty acid content of different organisms should be selected carefully.

Recent developments in microbial oils production: a possible alternative to vegetable oils for biodiesel without competition with human food?

Since centuries vegetable oils are consumed as human food but it also finds applications in biodiesel production which is attracting more attention. But due to being in competition with food it could not be sustainable and leads the need to search for alternative. Nowdays microbes-derived oils (single cell oils) seem to be alternatives for biodiesel production due to their similar composition to that of vegetable oils. However, the cold flow properties of the biodiesel produced from microbial oils are unacceptable and have to be modified by an efficient transesterification. Glycerol which is by product of transesterification can be valorised into some more useful products so that it can also be utilised along with biodiesel to simplify the downstream processing. The review paper discusses about various potent microorganisms for biodiesel production, enzymes involved in the lipid accumulation, lipid quantification methods, catalysts used in transesterification (including enzymatic catalyst) and valorisation of glycerol.

Estudo da viabilidade técnico-científica da produção de biodiesel a partir de resíduos gordurosos / Evaluate the waste fatty acid by scientific and technical study to obtain biodiesel

Os resíduos gordurosos provenientes de caixas de gordura foram avaliados como substrato para obtenção de biodiesel, em escala laboratorial. Os resíduos foram desemulsificados, purificados e submetidos à reação química de transesterificação com catálise alcalina e esterificação com catálise ácida para a obtenção de ésteres etílicos. O produto obtido foi purificado por adsorção em coluna de sílica, e caracterizado por cromatografia gasosa com sistema de detecção de massa. Os percentuais de conversão da gordura em ésteres etílicos foram calculados com o fechamento dos balanços de massa do processo. Os produtos obtidos foram purificados com o uso de processos secundários de forma a viabilizar sua utilização como bicombustível e insumo para diversos processos industriais, respectivamente.

Waste fatty acid, from fatty boxes was evaluated as feedstock to obtain biodiesel in a laboratory scale. The residues were desemulsified, purified and used to obtain ethyl esters, through the transesterification with alkaline catalysis and esterification with acid catalysis reactions. The product was purified by adsorption in column of silica, and characterized by GLC with mass detector. Using this methodology the fatty residues was converted in the ethyl esters showed the scientific e technical validation of this propose. The conversion of fatty acids in ethylic esters was calculated by mass balances processes same for the highs degradation of the residue evaluates. To purify the biodiesel and glycerol obtained was necessary secondary processes to increase the qualities of this full and to use the glycerin in many industrial processes.

Research Progress on Biodiesel Production by Lipase Catalysis / 中国生物工程杂志

As a renewable clean energy,biodiesel has been the subject of much research in recent years owing to its excellent environmental performance.The bio-enzymatic method possesses unparalleled advantages over conventional chemical catalysis,and it would be the direction in biodiesel industrialization process.The progress and application of three biocatalytic approaches for biodiesel production including immobilized lipase,free lipase and whole-cell catalysis were summerized.Finally,the challenges of biodiesel industrialization in China are analyzed,and some effective measures are put forward.