Multi Energy Optimized Processing: The use of high intensity ultrasonics and electromagnetic radiation for biofuel production processes
Open Access
- Author:
- Kropf, Matthew Mason
- Graduate Program:
- Engineering Science and Mechanics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- March 18, 2008
- Committee Members:
- Bernhard R Tittmann, Committee Chair/Co-Chair
Dinesh Kumar Agrawal, Committee Member
Michael T Lanagan, Committee Member
Andre Louis Boehman, Committee Member - Keywords:
- microwaves
ultrasound
biofuels - Abstract:
- This work aimed to improve the understanding of the use of microwaves and ultrasound for chemical processes. Using biodiesel production as the case for study, the non-linear effects of high intensity ultrasonics, electromagnetic loss, and microwave heating were explored. Cavitation and atomization phenomena were used to describe the process of ultrasonic emulsification. Superheating and anisothermal heating phenomena were identified as the specific advantages afforded by microwave heating. High intensity ultrasonics was found to be capable of creating emulsions of biodiesel reactants with uniform dispersed phase droplets. Through optical microscopy, the ability to control the dispersed phase droplet size by altering the frequency and intensity of ultrasound was confirmed. This ultrasonic technique was investigated by measuring complex permittivity of the emulsions from 500 MHz and 5 GHz. The dielectric loss of emulsions consisting of methanol and soybean oil indicated that ultrasonic treatments could be used to alter the microwave absorption. Microwave heating tests of ultrasonically formed emulsions confirmed the permittivity results practically. The superheated boiling point of methanol and heating rate of methanol was extended to higher temperatures and rates in ultrasonically formed emulsions. Microwave heating of ultrasonically mixed emulsions was shown to result in faster transesterification relations than microwave heating of conventionally mixed emulsions. Finally, utilizing ultrasonics to optimize microwave absorption was shown capable of transesterification without catalyst.