an official journal of: published by:
an official journal of: published by:
Editor in Chief: RAFFAELLO COSSU


  • Mariana Cruz - LEPABE, Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia,, Portugal
  • Emanuel Costa - LEPABE, Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia, Portugal
  • Manuel Fonseca Almeida - LEPABE, Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia, Portugal
  • Maria da Conceição Alvim-Ferraz - LEPABE, Departamento de Engenharia Química, Faculdade de Engenharia,, Portugal
  • Joana Maia Dias - LEPABE, Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia, Portugal

Released under CC BY-NC-ND

Copyright: © 2018 Cisa Publisher


The by-products acid oil from soapstock of vegetable oil refining and olive pomace oil were evaluated for biodiesel production. Enzymatic hydroesterification was studied to convert the acid oil ( ̴ 34 wt.% free fatty acids) into methyl esters; due to the low free fatty acid content of the fresh olive pomace oil ( ̴ 2 wt.%), alkaline transesterification was conducted. The results from the enzymatic hydrolysis (35˚C, 24 h, 200 rpm) showed a clear influence of enzyme concentration (0.1 – 5 wt.%, relative to oil) and water:oil ratio (1:0.25 and 1:0.5 w:w) towards free fatty acid production. After applying the best established conditions (3 wt.% of enzyme and 1:0.5 water: oil ratio, w:w), enzymatic esterification was performed (35˚C, 7 h, 200 rpm, 2 wt.% of enzyme and 2:1 molar ratio of methanol to acid). Hydroesterification led to a product with a methyl esters content of about 84 wt.% whereas the esterification alone allowed reaching only around 65 wt.%. The olive pomace oil was obtained from chemical extraction of fresh olive pomace ( ̴ 18 wt.% of oil). By performing direct alkaline transesterification (65˚C, 1 wt.% NaOH, 1 h and 6:1 molar ratio of methanol to oil) a product with a purity of 90 wt.% was obtained. The olive pomace storage in the air during 2 weeks led to an increase in the oil free fatty acid content of almost 2 fold showing the relevance of developing storage and conservation strategies to ensure a sustainable recovery of this by-product. Both by-products showed potential for biodiesel production.


Editorial History

  • Received: 26 Jun 2018
  • Revised: 01 Oct 2018
  • Accepted: 04 Nov 2018
  • Available online: 14 Nov 2018


Aguieiras, E. C. G., Cavalcanti-Oliveira, E. D., de Castro, A. M., Langone, M. A. P., & Freire, D. M. G. (2014). Biodiesel production from Acrocomia aculeata acid oil by (enzyme/enzyme) hydroesterification process: Use of vegetable lipase and fermented solid as low-cost biocatalysts. Fuel, 135, 315-321.
DOI 10.1016/j.fuel.2014.06.069

Atabani, A. E., Mahlia, T. M. I., Masjuki, H. H., Badruddin, I. A., Yussof, H. W., Chong, W. T., & Lee, K. T. (2013). A comparative evaluation of physical and chemical properties of biodiesel synthesized from edible and non-edible oils and study on the effect of biodiesel blending. Energy, 58, 296-304.
DOI 10.1016/

Avhad, M. R., & Marchetti, J. M. (2015). A review on recent advancement in catalytic materials for biodiesel production. Renew Sust Energ Rev, 50(Supplement C), 696-718.
DOI 10.1016/j.rser.2015.05.038

Azbar, N., Bayram, A., Filibeli, A., Muezzinoglu, A., Sengul, F., & Ozer, A. (2004). A Review of Waste Management Options in Olive Oil Production. Crit Rev Env Sci TEc, 34(3), 209-247.
DOI 10.1080/10643380490279932

Barbanera, M., Lascaro, E., Stanzione, V., Esposito, A., Altieri, R., & Bufacchi, M. (2016). Characterization of pellets from mixing olive pomace and olive tree pruning. Renew Energ, 88, 185-191.
DOI 10.1016/j.renene.2015.11.037

Baskar, G., & Aiswarya, R. (2016). Trends in catalytic production of biodiesel from various feedstocks. Renwe Sust Energ Rev, 57(Supplement C), 496-504.
DOI 10.1016/j.rser.2015.12.101

Bulotta, S., Celano, M., Massimo Lepore, S., Montalcini, T., Pujia, A., & Russo, D. (2014). Beneficial effects of the olive oil phenolic components oleuropein and hydroxytyrosol: Focus on protection against cardiovascular and metabolic diseases. J Transl Med, 12, 219-228.
DOI 10.1186/s12967-014-0219-9

Cavalcanti-Oliveira, E. D., Da Silva, P. R., Ramos, A. P., Aranda, D. A. G., & Freire, D. M. G. (2011). Study of soybean oil hydrolysis catalyzed by Thermomyces lanuginosus lipase and its application to biodiesel production via hydroesterification. Enzyme Res, 2011(1).
DOI 10.4061/2011/618692

Chanioti, S., & Tzia, C. (2017). Optimization of ultrasound-assisted extraction of oil from olive pomace using response surface technology: Oil recovery, unsaponifiable matter, total phenol content and antioxidant activity. LWT - Food Science and Technology, 79, 178-189.
DOI 10.1016/j.lwt.2017.01.029

Che, F., Sarantopoulos, I., Tsoutsos, T., & Gekas, V. (2012). Exploring a promising feedstock for biodiesel production in Mediterranean countries: A study on free fatty acid esterification of olive pomace oil. Biomass and Bioenerg, 36, 427-431.
DOI 10.1016/j.biombioe.2011.10.005

Chiplunkar, P. P., & Pratap, A. P. (2016). Utilization of sunflower acid oil for synthesis of alkyd resin. Prog Org Coat, 93, 61-67.
DOI 10.1016/j.porgcoat.2016.01.002

Costa, J. F., Almeida, M. F., Alvim-Ferraz, M. C. M., & Dias, J. M. (2013). Biodiesel production using oil from fish canning industry wastes. Energ Convers Manage, 74, 17-23.
DOI 10.1016/j.enconman.2013.04.032

Cruz, M., Pinho, S. C., Mota, R., Almeida, M. F., & Dias, J. M. (2017). Enzymatic esterification of acid oil from soapstocks obtained in vegetable oil refining: Effect of enzyme concentration. Renew Energ.
DOI 10.1016/j.renene.2017.06.053

Dias, J. M., Alvim-Ferraz, M. C. M., & Almeida, M. F. (2009). Production of biodiesel from acid waste lard. Bioresource Technol, 100(24), 6355-6361.
DOI 10.1016/j.biortech.2009.07.025

Echim, C., Verhe, R., Greyt, W. D., & Stevens, C. (2009). Production of biodiesel from side-stream refining products. Energy Environ Sci, 2, 1131-1141.
DOI 10.1039/B905925C

Foresti, M. L., Pedernera, M., Bucalá, V., & Ferreira, M. L. (2007). Multiple effects of water on solvent-free enzymatic esterifications. Enzyme Microb Tech, 41(1), 62-70.
DOI 10.1016/j.enzmictec.2006.11.023

Go, A. W., Sutanto, S., Ong, L. K., Tran-Nguyen, P. L., Ismadji, S., & Ju, Y.-H. (2016). Developments in in-situ (trans) esterification for biodiesel production: A critical review. Renewable and Sustainable Energy Reviews, 60, 284-305.
DOI 10.1016/j.rser.2016.01.070

Göğüş, F., & Maskan, M. (2006). Air drying characteristics of solid waste (pomace) of olive oil processing. J Food Eng, 72(4), 378-382.
DOI 10.1016/j.jfoodeng.2004.12.018

Haas, M. J. (2005). Improving the economics of biodiesel production through the use of low value lipids as feedstocks: vegetable oil soapstock. Fuel Process Technol, 86(10), 1087-1096.
DOI 10.1016/j.fuproc.2004.11.004

INE. (2018). Insituto Nacional de Estatistica - Statistic from Portugal. Retrieved from

Irandoust, H., Samie, A. H., Rahmani, H. R., Edriss, M. A., & Mateos, G. G. (2012). Influence of source of fat and supplementation of the diet with vitamin E and C on performance and egg quality of laying hens from forty four to fifty six weeks of age. Anim Feed Sci Tech, 177(1), 75-85.
DOI 10.1016/j.anifeedsci.2012.06.004

Kabbashi, N. A., Mohammed, N. I., Alam, M. Z., & Mirghani, M. E. S. (2015). Hydrolysis of Jatropha curcas oil for biodiesel synthesis using immobilized Candida cylindracea lipase. J Mol Catal B-Enzym, 116(Supplement C), 95-100.
DOI 10.1016/j.molcatb.2015.03.009

Knothe, G., & Razon, L. F. (2017). Biodiesel fuels. Prog Energ Combust, 58, 36-59.
DOI 10.1016/j.pecs.2016.08.001

López, I., Quintana, C. E., Ruiz, J. J., Cruz-Peragón, F., & Dorado, M. P. (2014). Effect of the use of olive–pomace oil biodiesel/diesel fuel blends in a compression ignition engine: Preliminary exergy analysis. Energ Convers Manage, 85, 227-233.
DOI 10.1016/j.enconman.2014.05.084

Machado, G. D., de Souza, T. L., Aranda, D. A. G., Pessoa, F. L. P., Castier, M., Cabral, V. F., & Cardozo-Filho, L. (2016). Computer simulation of biodiesel production by hydro-esterification. Chem Eng Process, 103, 37-45.
DOI 10.1016/j.cep.2015.10.015

Mahmudul, H. M., Hagos, F. Y., Mamat, R., Adam, A. A., Ishak, W. F. W., & Alenezi, R. (2017). Production, characterization and performance of biodiesel as an alternative fuel in diesel engines – A review. Renew Sust Energ Rev, 72(Supplement C), 497-509.
DOI 10.1016/j.rser.2017.01.001

Maurizio Servili, & Montedoro, G. (2002). Contribution of phenolic compounds to virgin olive oil quality. Eur J Lipid Sci Tech, 104, 302-613.
DOI 10.1002/1438-9312(200210)104:9/10<602::AID-EJLT602>3.0.CO;2-X

Missaoui, A., Bostyn, S., Belandria, V., Cagnon, B., Sarh, B., & Gökalp, I. (2017). Hydrothermal carbonization of dried olive pomace: Energy potential and process performances. J Anal Appl Pyrol, 128, 281-290.
DOI 10.1016/j.jaap.2017.09.022

Orozco, M. I., Priego-Capote, F., & Luque de Castro, M. D. (2011). Influence of Deep Frying on the Unsaponifiable Fraction of Vegetable Edible Oils Enriched with Natural Antioxidants. Journal of Agricultural and Food Chemistry, 59(13), 7194-7202.
DOI 10.1021/jf2015792

Park, J.-Y., Kim, D.-K., Wang, Z.-M., Lee, J.-P., Park, S.-C., & Lee, J.-S. (2008). Production of biodiesel from soapstock using an ion-exchange resin catalyst. Korean J Chem Eng, 25(6), 1350-1354.
DOI 10.1007/s11814-008-0221-0

Pérez-Bonilla, A., Frikha, M., Mirzaie, S., García, J., & Mateos, G. G. (2011). Effects of the main cereal and type of fat of the diet on productive performance and egg quality of brown-egg laying hens from 22 to 54 weeks of age. Poultry Sci, 90(12), 2801-2810.
DOI 10.3382/ps.2011-01503

Piloto-Rodríguez, R., Melo, E. A., Goyos-Pérez, L., & Verhelst, S. (2014). Conversion of by-products from the vegetable oil industry into biodiesel and its use in internal combustion engines: a review. Braz J Chem Eng, 31(2), 287-301.
DOI 10.1590/0104-6632.20140312s00002763

Rajaeifar, M. A., Akram, A., Ghobadian, B., Rafiee, S., Heijungs, R., & Tabatabaei, M. (2016). Environmental impact assessment of olive pomace oil biodiesel production and consumption: A comparative lifecycle assessment. Energy, 106, 87-102.
DOI 10.1016/

Rodrigues, R. C., & Ayub, M. A. Z. (2011). Effects of the combined use of Thermomyces lanuginosus and Rhizomucor miehei lipases for the transesterification and hydrolysis of soybean oil. Process Biochem, 46(3), 682-688.
DOI 10.1016/j.procbio.2010.11.013

Sousa, J. S. d., Cavalcanti-Oliveira, E. d. A., Aranda, D. A. G., & Freire, D. M. G. (2010). Application of lipase from the physic nut (Jatropha curcas L.) to a new hybrid (enzyme/chemical) hydroesterification process for biodiesel production. J Mol Catal B-Enzym, 65(1), 133-137.
DOI 10.1016/j.molcatb.2010.01.003

Verdugo, C., Luna, D., Posadillo, A., Sancho, E. D., Rodríguez, S., Bautista, F., Romero, A. A. (2011). Production of a new second generation biodiesel with a low cost lipase derived from Thermomyces lanuginosus: Optimization by response surface methodology. Catal Today, 167(1), 107-112.
DOI 10.1016/j.cattod.2010.12.028

Vescovi, V., Rojas, M. J., Baraldo, A., Jr., Botta, D. C., Santana, F. A. M., Costa, J. P., Tardioli, P. W. (2016). Lipase-Catalyzed Production of Biodiesel by Hydrolysis of Waste Cooking Oil Followed by Esterification of Free Fatty Acids. J Am Oil Chem Soc, 93(12), 1615-1624.
DOI 10.1007/s11746-016-2901-y

Watanabe, Y., Nagao, T., Nishida, Y., Takagi, Y., & Shimada, Y. (2007). Enzymatic Production of Fatty Acid Methyl Esters by Hydrolysis of Acid Oil Followed by Esterification. 84, 1015-1021.
DOI 10.1007/s11746-007-1143-4

Zenevicz, M. C. P., Jacques, A., Furigo, A. F., Oliveira, J. V., & de Oliveira, D. (2016). Enzymatic hydrolysis of soybean and waste cooking oils under ultrasound system. Ind Crop Prod, 80, 235-241.
DOI 10.1016/j.indcrop.2015.11.031

Živković, S. B., Veljković, M. V., Banković-Ilić, I. B., Krstić, I. M., Konstantinović, S. S., Ilić, S. B., Veljković, V. B. (2017). Technological, technical, economic, environmental, social, human health risk, toxicological and policy considerations of biodiesel production and use. Renew Sust Energ Rev, 79(Supplement C), 222-247.
DOI 10.1016/j.rser.2017.05.048