Candlenut oil: review on oil properties and future liquid biofuel prospects

Summary The rapid depletion of diesel fuel, increasing energy demand, and environmental pollution concerns are increasing worldwide interest in the production of liquid biofuels. Biofuel (bio‐aviation and biodiesel) is a potential and plausible alternative to diesel fuel to substantially mitigate the environmental impact of future energy demand. Non‐edible crop oil is viewed as a potential feedstock for liquid biofuel production owing to the massive demand for edible oil as a food source. However, the major limitation of utilizing non‐edible crop oil for biodiesel production is the cost due to the high price of feedstocks and the limited supply of large‐scale biodiesel production. Candlenut trees can grow in harsh and arid climates due to low moisture requirements. Therefore, candlenut can be cultivated in the most unused lands, particularly in developing countries along coasts and riverbanks and in deserts and other wastelands unsuitable for edible crops. Additionally, candlenut seed contains a high amount of oil (30%‐60%). Thus, candlenut oil is a promising source for commercial biodiesel production. The present study was conducted to review the possibilities and challenges of utilizing candlenut as a potential feedstock for biodiesel production. Additionally, several important aspects related to candlenut oil processing, such as extraction technology, physicochemical properties, biodiesel production technologies, and advantages and limitations of candlenut biodiesel production are discussed.