Clarissa Dalla Rosa

Optimization of Enzymatic Production of Biodiesel from Castor Oil in Organic Solvent Medium

We studied the production of fatty acid ethyl esters from castor oil using n-hexane as solvent and two commercial lipases, Novozym 435 and Lipozyme IM, as catalysts. For this purpose, a Taguchi experimental design was adopted considering the following variables: temperature (35–65°C), water (0–10 wt/wt%), and enzyme (5–20 wt/wt%) concentrations and oil-to-ethanol molar ratio (1∶3 to 1∶10). An empirical model was then built so as to assess the main and cross-variable effects on the reaction conversion and also to maximize biodiesel production for each enzyme. For the system containing Novozym 435 as tatalyst the maximum conversion obtained was 81.4% at 65°C, enzyme concentration of 20 wt/wt%, water concentration of 0 wt/wt%, and oil-to-ethanol molar ratio of 1∶10. When the catalyst was Lipozyme IM, a conversion as high as 98% was obtained at 65°C, enzyme concentration of 20 wt/wt%, water concentration of 0 wt/wt%, and oil-to-ethanol molar ratio of 1∶3.

Optimization of alkaline transesterification of soybean oil and castor oil for biodiesel production

This article reports experimental data on the production of fatty acid ethyl esters from refined and degummed soybean oil and castor oil using NaOH as catalyst. The variables investigated were temperature (30–70°C), reaction time (1–3 h), catalyst concentration (0.5–1.5 w/wt%), and oil-to-ethanol molar ratio (1:3–1:9). The effects of process variables on the reaction conversion as well as the optimum experimental conditions are presented. The results show that conversions >95% were achieved for all systems investigated. In general, an increase in reaction temperature, reaction time, and in oil-to-ethanol molar ratio led to an enhancement in reaction conversion, whereas an opposite trend was verified with respect to catalyst concentration.

Pretreatment of sugarcane bagasse using supercritical carbon dioxide combined with ultrasound to improve the enzymatic hydrolysis.

This work evaluates the pretreatment of sugarcane bagasse combining supercritical carbon dioxide (SC-CO2) and ultrasound to enhance the enzymatic hydrolysis of pretreated bagasse. In a first step the influence of process variables on the SC-CO2 pretreatment to enhance the enzymatic hydrolysis was evaluated by mean of a Plackett-Burmann design. Then, the sequential treatment combining ultrasound+SC-CO2 was evaluated. Results show that treatment using SC-CO2 increased the amount of fermentable sugar obtained of about 280% compared with the non-treated bagasse, leading to a hydrolysis efficiency (based on the amount of cellulose) as high as 74.2%. Combining ultrasound+SC-CO2 treatment increased about 16% the amount of fermentable sugar obtained by enzymatic hydrolysis in comparison with the treatment using only ultrasound. From the results presented in this work it can be concluded that the combined ultrasound+SC-CO2 treatment is an efficient and promising alternative to carry out the pretreatment of lignocellulosic feedstock at relatively low temperatures without the use of hazardous solvents.

Kinetics of Enzyme-Catalyzed Alcoholysis of Soybean Oil in n-Hexane

This work investigated the production of fatty acid ethyl esters (FAEEs) from soybean oil using n-hexane as solvent and two commercial lipases as catalysts, Novozym 435 and Lipozyme IM. A Taguchi experimental design was adopted considering the variables temperature (35-65 degrees C), addition of water (0-10 wt/wt%), enzyme (5-20 wt/wt%) concentration, and oil-to-ethanol molar ratio (1:3-1:10). It is shown that complete conversion in FAEE is achieved for some experimental conditions. The effects of process variables on reaction conversion and kinetics of the enzymatic reactions are presented for all experimental conditions investigated in the factorial design.

Fatty acid ethyl esters production using a non-commercial lipase in pressurized propane medium

The objective of this work is to investigate the production of fatty acid ethyl esters from soybean oil in compressed propane using a non-commercial lipase from Yarrowia lipolytica and two commercial ones as catalysts, Amano PS and Amano AY30. The experiments were performed in the temperature range of 35-65 °C. at 50 bar, enzyme concentration of 5 wt%, oil to ethanol molar ratio of 1:6 and 1:9, and solvent to substrates mass ratio of 2:1 and 4:1. The results indicated that low reaction conversions were generally obtained with the use of commercial and non-commercial lipases in pressurized propane medium. On the other hand, the aspects of low solvent to substrates mass ratio and mild temperature and pressure operating conditions used to produce ethyl esters justify further investigations to improve reaction yields.

Addendum to issue 1 - ENZITEC 2012Influence of ultrasound and compressed liquefied petroleum gas on xylanase activity

Abstract Xylanase treated with ultrasound showed activities about two times higher than those obtained in its absence for temperatures ranging from 39 to 47°C. In the absence of ultrasound the enzyme activity was about 4–10 times higher compared with the activities determined in the presence of ultrasound for temperatures higher than 56°C. Treatment with compressed LPG led to an increase of about 250% in the enzyme activity for a system pressure of 30 bar, 50°C and 1 h of exposure. On the other hand, it was shown that enzyme treatment combining compressed LPG and ultrasound did not improve xylanase activity under any experimental conditions tested. These results obtained here are promising for industrial application in the enzymatic hydrolysis of lignocellulose for the production of fuels and chemicals, since rapid treatment of xylanase with compressed LPG or ultrasound is a novel procedure which provided a significant increase in activity.

Immobilization of inulinase obtained by solid-state fermentation using spray-drying technology

Abstract This work focuses on the immobilization of a crude inulinase extract obtained by solid-state fermentation using spray-drying technology. Maltodextrin and arabic gum were used as immobilizing agents. The effects of inlet air temperature, maltodextrin/arabic gum ratio and mass fraction of crude enzyme extract on the activity of immobilized inulinase were assessed using a central composite rotatable design (CCRD) (23). The optimum operational conditions for the immobilization of inulinase by spray-drying was obtained at an inlet air temperature of 200°C, mass fraction of crude enzyme extract of 0.5 wt% and using only arabic gum as immobilizing agent. The immobilized enzyme had good thermostability, comparable with other inulinases obtained from different microorganisms. The method used gave good enzyme activity after immobilization and could be applied to other enzymes which have good thermal stability.

Aspergillus niger inulinase immobilized in polyurethane foam and treated in pressurized LPG: A potential catalyst for enzymatic synthesis of fructooligosaccharides

Abstract Inulinase from Aspergillus niger was immobilized in polyurethane foam (PU). Immobilized catalyst was treated in pressurized liquefied petroleum gas (LPG) system. This biocatalyst was used in the fructooligosaccharide production using sucrose as substrate in aqueous system. The main objective of this study was to evaluate the reaction yield and productivity by using polyurethane foam as a low-cost support for enzyme immobilization in an alternative processes for fructooligosaccharide production in pressurized LPG system with potential for industrial application. The total FOS concentration obtained were 31% as a result of sucrose concentration reduction, and formation of FOS long chain (GF3 and GF4) from kestose (GF2). FOS concentrations of 5%, 22%, and 3% were obtained for GF2, GF3, and GF4, respectively. The methodology suggested in this research work, enzyme immobilization in a low-cost support, and treatment in LPG, showed potential technology for fructooligosaccharide synthesis.

The role of organic solvent amount in the lipase-catalyzed biodiesel production

O objetivo desta pesquisa e reportar o papel da quantidade do solvente orgânico na producao de esteres etilicos de acidos graxos do oleo de soja. O n-hexano foi escolhido como solvente e duas lipases comerciais imobilizadas como catalisadores, Novozym 435 e Lipozyme IM. As reacoes foram conduzidas em 6 horas, variando a razao de solvente de zero a 50 (v/m), adotando para a Novozym 435: 65 oC, concentracao de enzima (E, m/m%) = 5, razao mola oleo:etanol (R) = 1:10, adicao de agua (H, m/m%) = 0, e para a Lipozyme IM: 35 oC, E = 5 m/m%, R = 1:3, H = 10 m/m%. Para a enzima Lipozyme IM, um aumento na quantidade de solvente conduz a uma maior conversao da reacao, enquanto um efeito nao significativo foi encontrado para a Novozym 435. Com 30 mL de solvente, a conversao encontrada para a Lipozyme IM foi de 88% e 15% para a Novozym 435.