A comprehensive review on non-edible woody oil-based biodiesel: composition, production, properties and emissions

With the continuous increase of world’s population, rapid development of industrialization and urbanization, and rapid growth of economy, the fossil fuel consumption is also increasing continuously to meet growing energy demand. The unsustainability of fossil fuels and the issues of national energy security make it very urgent to develop the appropriate and sustainable replacement for fossil fuels. Biodiesel is one of appropriate alternatives for diesel engine due to its renewable and eco-friendly nature. This greener fuel has been used in many countries across the continents in a blending range up to 20% with petrodiesel. However, the high biodiesel production cost is still a major obstacle to market acceptance. Non-edible woody oils can be considered as low-cost substitutions for traditional edible vegetable oils for biodiesel production. In order to make biodiesel into reality in much wider scope, a growing number of relevant researches focused on: (1) evaluating the biodiesel properties; (2) optimizing the production process; and (3) assessing the environmental impact. This article reviews these three aspects in order to reflect the research status and development potential of non-edible woody oil-based biodiesel.