Production of Biodiesel from Triglycerides in Binary Supercritical Mixtures of Carbon Dioxide and Methanol: Co-Solvent Effects


Biodiesel is a promising source of renewable energy because of its ability to be used in existing automobile engines and due to the large number renewable feedstocks that can be used in its production. The most widely used method for the creation of biodiesel involves the transesterification of triglycerides with methanol, and the process is catalyzed by a sodium hydroxide or similar base. This process has six moles of methanol fed per mole of triglyceride, and is a slow process which requires hours of reaction time and the separation of the salt catalyst afterwards. Another emerging process utilizes supercritical methanol without the catalyst to perform the transesterification reaction. This process is much quicker, only taking three to five minutes, but requires a much higher excess of methanol (approximately 42 moles per mole of triglyceride) to be fed. One possible solution to this is to partially supplement of the excess supercritical methanol with supercritical carbon dioxide. The conditions for carbon dioxide to become supercritical are not as severe as those for methanol, which can reduce some of the operating costs of the supercritical methanol production method. An experimental study was conducted using a 0.1 L Haynes® 282 reactor system with 42:1 to 13:1 methanol-to-triglyceride molar ratios, and 0 to 3 SLPM of carbon monoxide. The experiments were performed at 350 °C and at 1200 psi.

Meeting Name

2012 American Institute of Chemical Engineers (AIChE) Annual Meeting (2012: Oct. 28-Nov. 2, Pittsburgh, PA)


Chemical and Biochemical Engineering

Document Type

Article - Conference proceedings

Document Version


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© 2012 American Institute of Chemical Engineers (AIChE), All rights reserved.

Publication Date

02 Nov 2011

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