SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2015, Vol. 23 ›› Issue (11): 1851-1856.DOI: 10.1016/j.cjche.2015.08.016

• BIOTECHNOLOGY AND BIOENGINEERING • Previous Articles     Next Articles

Influences of operating conditions on biocatalytic activity and reusability of Novozym 435 for esterification of free fatty acids with short-chain alcohols: A case study of palm fatty acid distillate

Sawittree Mulalee, Pongrumpa Srisuwan, Muenduen Phisalaphong   

  1. Chemical Engineering Research Unit for Value Adding of Bioresources, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
  • Received:2014-10-07 Revised:2015-05-12 Online:2015-12-18 Published:2015-11-28
  • Contact: Muenduen Phisalaphong

Influences of operating conditions on biocatalytic activity and reusability of Novozym 435 for esterification of free fatty acids with short-chain alcohols: A case study of palm fatty acid distillate

Sawittree Mulalee, Pongrumpa Srisuwan, Muenduen Phisalaphong   

  1. Chemical Engineering Research Unit for Value Adding of Bioresources, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
  • 通讯作者: Muenduen Phisalaphong

Abstract: In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid (FFA) were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 ℃ could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols (methanol and ethanol) with FFA conversions of at least 90%. The presence of 4%-5% water in ethanol significantly affected the reusability of Novozym435. Changes in the surface morphology of Novozym435 during the esterification with various conditions were observed. Itwas revealed that the reduction in catalytic activity was related to the swelling degree of the catalyst surface. Additionally, biodiesel production fromlowcost renewable feedstocks, such as palmfatty acid distillate (PFAD) and 95% ethanolwas examined. The esterification of PFAD with 95% ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6% of its initial conversion after being used for 10 batches.

Key words: Biodiesel, Oleic acid, Novozym 435, Reusability, Palm fatty acid distillate

摘要: In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid (FFA) were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 ℃ could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols (methanol and ethanol) with FFA conversions of at least 90%. The presence of 4%-5% water in ethanol significantly affected the reusability of Novozym435. Changes in the surface morphology of Novozym435 during the esterification with various conditions were observed. Itwas revealed that the reduction in catalytic activity was related to the swelling degree of the catalyst surface. Additionally, biodiesel production fromlowcost renewable feedstocks, such as palmfatty acid distillate (PFAD) and 95% ethanolwas examined. The esterification of PFAD with 95% ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6% of its initial conversion after being used for 10 batches.

关键词: Biodiesel, Oleic acid, Novozym 435, Reusability, Palm fatty acid distillate