Ultrasonic longitudinal-radial transducer for algae processing in oil extraction

Abstract

Global energy consumption is increasing annually. Various energy sources have been newly discovered, while existing sources are being modified, with the intent to produce clean energy with a maximum energy-efficiency ratio (EER). In this study, we address the improvement of ultrasonic algae processing systems for oil extraction. Currently, all commercial ultrasonic systems for algae processing are longitudinal transducers. However, some modification attempts have been reported. Results show that algae have a good EER; therefore, by increasing the efficiency of processing, the EER can be increased further. The possible energy savings can be calculated by changing the main parameters such as time, power, and volume. We present a new design of an ultrasonic transducer for algae ultrasonication. This modification, based on Poisson’s effect, enlarges the affected volume and improves the quality. It is expected to increase efficiency with less energy consumption compared to the standard system. The cavitation intensity was measured in different reservoir locations for both the standard and modified systems. Both numerical simulations and experimental measurements of the mechanical and electrical properties were performed. The proposed system was found to process colony-forming species of algae with higher efficiency than the standard system, while it was less effective in processing single-cell algae than the standard. Different algae species may have sensitivities to different vibration modes; this remains to be explored in the future.