A review on the prospects of sustainable biodiesel production: A global scenario with an emphasis on waste-oil biodiesel utilization

Due to the large amount of diesel fuel demands worldwide and the negative environmental and health impacts of its direct combustion, biodiesel production and consumption have been globally increasing as the best short-term substitute for mineral diesel. However, using edible and non-edible oil feedstocks for biodiesel production has led to several controversial issues including feedstock availability and cost, greenhouse gas (GHG) emission, land use changes (LUC), and fuel vs. food/feed competition. Fortunately, these problems can be effectively overcome using non-crop feedstocks. In this context, waste-oriented oils/fats have been proposed as the excellent options to produce biodiesel by overlooking the trivial collection/recycling costs. In this review article, a comprehensive collection plan followed by an elaborated integrated utilization strategy called waste oil biodiesel utilization scenario (WO-BUS) is proposed for Iran in order to achieve cost-effective and eco-friendly production/consumption of biodiesel. WO-BUS is adoptable by the countries with similar situations and infrastructures.