Enzyme-catalysed production of n-butyl palmitate using ultrasound-assisted esterification of palmitic acid in a solvent-free system

Abstract

This work exhibits the implementation of ultrasound technology in solvent-free synthesis study of n-butyl palmitate using Fermase CALB™10000. Sequential experimental design study was instrumental in determining the most significant process variables. The effect of acid-alcohol molar ratio, enzyme dose, temperature, power and duty cycle on the reaction kinetics was studied. Highest conversion of ~ 96.6% was observed in 50 min at 1:1 molar ratio of palmitic acid to n-butanol, 70 °C temperature, 4% w/w enzyme loading, 40 W power, 70% duty cycle, 25 kHz frequency and 100 rpm speed of impeller. Ping-pong bisubstrate model showed the best fit with kinetic parameters, V = 21.88 M/min/g catalyst, K = 0.011 M, K = 8.74M, K = 0.014M, K = 0.00036M and SSE = 0.0000193. Ultrasound reduced the reaction time by over 70%. The enzyme was reusable for four successive cycles after which it showed decline in conversion.

Acoustic cavitation assisted lipase B catalysed synthesis of polyethylene glycol stearate in a solvent free system via esterification: synthesis and optimization

“…1% and 0.7% of catalyst. Similar trends were also obtained by Khan et al for the synthesis of cetyl oleate and n ‐butyl palmitate synthesis in the presence of ultrasound . The amount of enzyme optimized here, i.e.…”

“…Similar trends were also obtained by Khan et al for the synthesis of cetyl oleate and n-butyl palmitate synthesis in the presence of ultrasound. 22,36 The amount of enzyme optimized here, i.e. 0.5%, is equal to the amount required for the conventional reaction.…”

Novozym 435: the “perfect” lipase immobilized biocatalyst?

“…Water or glycerin accumulation on Lewatit may be partially reduced using ultrasound and molecular sieves. 44,152,[541][542][543][544][545][546][547][548][549][550] However, the moderate hydrophilicity of the support may complicate the understanding of the results and reuses of the biocatalyst.…”

Application of Response Surface Methodology for Lipase Catalyzed Synthesis of 2-Ethylhexyl Palmitate in a Solvent Free System Using Ultrasound

“…The minimum molar ratio (1:3) and duty cycle (30%) give minimum conversion (61%), while the increase in ratio to 1:5 with 50 % duty cycle produces maximum conversion (96%). Upon increasing the duty cycle to 70%, the conversion was decreased to 68%; this is attributed to the inactivation of the enzyme due to excess irradiation (Khan et al, 2018). The interactive effect between US power and enzyme loading was shown in Figure 8.…”