Study of biodiesel production from waste cooking oil by ethyl transesterification and its purification with the use of natural adsorbents

Biodiesel production from waste cooking oil (WCO) has become an economic opportunity and an environmental strategy to help address the global challenges of renewable energy production. Considering classical industrial processes for biodiesel production, adsorption and ion exchange technologies are the most commonly used alternatives for crude biodiesel purification. These methods, also known as dry cleaning methods, use an appropriate adsorbent to selectively remove certain impurities from the liquid biodiesel phase through contact with the surface of the adsorbent. Dry cleaning offers several advantages, including simple integration into an existing industrial plant, shorter purification time, lower water consumption, and lower effluent generation. In this work, the main goals are the optimization of ethylic biodiesel production from WCO, followed by the study of its purification by adsorption, applying various types of previously characterized natural adsorbents, physically and chemically activated, which were obtained from residual biomass (olive pits), with a specific focus on glycerol removal.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021).