Performance of an enzymatic packed bed reactor running on babassu oil to yield fatty ethyl esters (FAEE) in a solvent-free system

Abstract

HIGHLIGHTS The performance of packed bed reactor running on babassu oil to yield ethyl esters was assessed. Burkholderia cepacia lipase immobilized on SiO2-PVA composite was used as a catalyst. The molar ratio of babassu oil and ethanol was found as a critical parameter for attaining high yields. The transesterification reaction of babassu oil with ethanol mediated by Burkholderia cepacia lipase immobilized on SiO2-PVA composite was assessed in a packed bed reactor running in the continuous mode. Experiments were performed in a solvent-free system at 50 °C. The performance of the reactor (14 mm ×210 mm) was evaluated using babassu oil and ethanol at two molar ratios of 1:7 and 1:12, respectively, and operational limits in terms of substrate flow rate were determined. The system's performance was quantified for different flow rates corresponding to space times between 7 and 13 h. Under each condition, the impact of the space time on the ethyl esters formation, the transesterification yield and productivity were determined. The oil to ethanol molar ratio was found as a critical parameter in the conversion of babassu oil into the correspondent ethyl esters. The highest transesterification yield of 96.0 ± 0.9% and productivity of 41.1 ± 1.6 mgestergcatalystwere achieved at the oil to ethanol molar ratio of 1:12 and for space times equal or higher than 11 h. Moreover, the immobilized lipase was found stable with respect to its catalytic characteristics, exhibiting a half-life of 32 d.

Continuous enzymatic biodiesel production from coconut oil in two-stage packed-bed reactor incorporating an extracting column to remove glycerol formed as by-product

“…The immobilized derivative density was determined as 1.865 g cm -3 [7]. The substrate was prepared at molar ratio of 1:12 (oil-to-ethanol) and the system was fed at increased flow rates corresponding to space-time from 10 to 14 h. During the continuous runs, periodic samples were taken from the reactor vessel for analysis of the relevant variables, such as the ethyl esters concentrations, viscosity and density.…”

“…The theoretical ester concentrations were calculated by taking into account the coconut fatty acid composition and its initial weight mass in the substrate, and the transesterification yield (%) was defined as the ratio between the produced and theoretical esters concentrations [18,22]. The collected samples were purified according to the methodology described by Simões et al [7] and then evaporated by a rotary evaporator at 80°C to eliminate the residual ethanol. Then, the purified biodiesel samples were dried by adding sodium sulfate and absolute viscosity values determined by an LVDVII Brookfield viscometer (Brookfield Viscometers Ltd, England) at 40°C using a 1.0 mL aliquot of the sample.…”

“…This type of reactor provides greater surface area for the reaction per volume unit than a membrane reactor, is kinetically more favorable than stirred-tank reactors and protecting the enzyme particles from breaking down because of the low mechanical shear stress [5,7]. Despite such advantages, limitations can be verified in the transesterification reactions carried out in a packed-bed reactor running on a continuous basis, mainly due to the retention of glycerol formed as a by-product in the catalytic bed, which is adsorbed on the enzyme support, thus decreasing the enzyme activity [5,7,8]. The phenomenon involved in such activity loss can be attributed to the formation of a hydrophilic barrier around the enzyme, limiting the diffusion of the substrate (hydrophobic organic phase) from the enzyme [8][9][10].…”

Produção enzimática de biodiesel a partir do óleo de macaúba em reatores de leito fixo duplo estágio

“…Em estudos de síntese de biodiesel utilizando lipase microbiana de B. cepacia imobilizada em suporte híbrido foi determinado que o derivado imobilizado requer um teor máximo de 10% de água. Teores superiores a este nível direcionam a ação da lipase para reação inversa (DA RÓS et al, 2011;SIMÕES et al, 2015).…”

“…Em trabalhos anteriormente desenvolvidos envolvendo reatores enzimáticos constatou-se que é possível obter biodiesel a partir do óleo de babaçu e etanol na ausência de solventes em reator de leito fixo operando em fluxo contínuo (SIMÕES, 2011;SIMÕES et al, 2015). Entretanto, o processo necessita de um controle permanente de temperatura nas conexões para evitar solidificação do substrato em função da elevada proporção de ácidos graxos saturados (83%) presente nesta matéria-prima graxa.…”