An overview of catalytic conversion of vegetable oils/fats into middle distillates

Due to scarce conventional petroleum fuel, there is a need to search for alternative renewable fuel that can be adopted for use in place of fossil fuel oil. Even the ester-based biodiesel has many limitations, such as low energy content, oxidative stability etc. Renewable hydrocarbon-based diesel obtained by hydroprocessing of vegetable oils/fats (2nd generation biodiesel) is one of the alternatives that is getting attention from both academia and industry. The present paper reviews the emerging processes, catalysts and operating conditions for the catalytic conversion of vegetable oils/fats into hydrocarbon-based diesel via hydroprocessing. Hydroprocessing of vegetable oils is similar to petroleum hydroprocessing, but requires slight modification and optimization in the catalyst, as well as process parameters. The current status and future scope of the catalyst and process for hydroprocessing of vegetable oil are discussed.