Residual Lipids Pretreatment Towards Renewable Fuels

The growing interest in environmentally friendly and sustainable energy sources has led to the exploration of waste cooking oils (WCOs) as residual feedstocks for biofuel production under the circular economy approach. Considering that WCOs constitute a highly heterogenous and degraded feedstock, a pretreatment step is necessary to improve their quality, potentially enabling their conversion to biofuels in milder conditions. Particularly, WCOs are characterized by high acidity, moisture content, impurities, etc., highlighting the necessity for a systematic and easily manageable pretreatment method. This study explored a systematic and widely applicable three-step pretreatment process (involving neutralization, washing, and drying) for improving the quality of degraded WCOs derived from various origins. The results showed that all monitored properties of the pretreated WCOs notably improved, even in the case of highly degraded lipids. Τherefore, the explored approach is particularly efficient for pretreating lipid-based feedstocks prior to converting them to biofuel production.