Non-edible plant oils as renewable feedstocks for biodiesel production: a comprehensive review

Fossil fuels are finite resources, and their continued use poses environmental and energy security challenges. This review focuses on the potential of non-edible plant oils as renewable feedstocks for biodiesel production, emphasizing their suitability as a sustainable component of the global fuel mix. Unlike edible oils, which raise concerns related to food security, non-edible oils can be cultivated on less fertile lands, making them a more economical and environmentally friendly option for large-scale biodiesel production. This review highlights the technical challenges associated with converting non-edible oils to biodiesel, such as their high free fatty acid (FFA) content, which can affect the efficiency of conventional transesterification processes. Advances in catalytic technologies, including heterogeneous, enzymatic, and solid-based methods, are discussed as key solutions to these challenges, enabling more efficient and sustainable production processes. Furthermore, the environmental benefits of non-edible oil biodiesel, such as reducing greenhouse gas emissions and improving air quality, are explored alongside its economic contributions, including boosting rural economies through the cultivation of oil-bearing plants on marginal lands. Additionally, renewable diesel, derived from similar feedstocks, is emerging as a more efficient and scalable alternative to biodiesel, offering advantages such as better fuel stability and higher energy density. While challenges such as land availability and variability in crop yields persist, ongoing research and technological advancements hold promise for scaling up production. By addressing these challenges, non-edible oils can play a pivotal role in the transition toward cleaner, more sustainable energy systems. This review underscores the need for continued innovation and policy support to fully realize the potential of non-edible oils in advancing biodiesel as a vital component of the renewable energy landscape.