Description:
The invention identifies techniques to overcome the main bottlenecks of the current methods to produce biodiesel; the immiscibility of the two reactants (oil and alcohol), and the need to maintain the reactor temperature below the boiling point of the alcohol. As a consequence of the first bottleneck, the reaction rate is limited by the interfacial surface area between the two reactants, thus requiring large volume reactors. The second bottleneck is imposed to avoid using high-pressure (thus high cost) stirred- tank reactors. Another consequence of the low temperature reaction is a limiting equilibrium conversion (since the reactions are slightly endothermic), thus requiring two-step operations.
The current patent is based on generating high interfacial area between the oil and the alcohol. The process utilizes an ultrasonic atomizer to create micro-droplets (~50 microns in diameter) of the alcohol and mix them with the oil to create a homogeneous dispersion without relying on the reactor agitator. The dispersion is then fed into the tubular reactor. The much higher reaction rate (from the high interfacial surface area) enables one to carry out the reaction in a much smaller reactor and to employ a tubular reactor, which can be readily maintained at a higher pressure. Consequently, the reactor can be maintained at higher temperatures (say, above 120°C), thus providing higher reaction rates, beneficial equilibrium conversion.
Reference Number: D-0581
Market Applications:
• Cost-effective, continuous biodiesel fuel production
Features, Benefits & Advantages:
• Faster transesterification reaction rate, which produces biodiesel faster than current technologies
• Lower capital investments, as smaller mixing vessels can be used in continuous production
• Lower production costs, because less energy is required to produce the biodiesel
• Lower energy consumption, by using micro-droplets in the gas phase and dispersing them into the reactant mixture
• Ultrasonic atomizer generates alcohol droplets of uniform size, which speeds up fuel separation
• Tubular reaction vessel helps produce biodiesel continuously, dramatically increasing fuel yield
Intellectual Property:
A U.S. utility patent, 8,420,841, was issued on 04/16/2013.
Researchers:
Uzi Mann, Department of Chemical Engineering, Texas Tech University
Key Words:
Stirred-tank reactors, transesterification reactions, biodiesel production, tubular reaction vessel