An experimental study on Microalgae Oil Extraction using Ultrasound-Assisted Algasonic Machine
Endrika Widyastuti1*, Ratih Dewi1, Dela Ayu Putriajati1, Ariella Melody Danny1, Joko Prasetyo2

1 Department of Food Science and Biotechnology, Faculty of Agroindustrial Technology, Universitas Brawijaya Malang Indonesia
2 Department of agricultural and biosystem engineering, Faculty of Agroindustrial Technology, Universitas Brawijaya Malang Indonesia

*email Corresponding author: endrika_w[at]ub.ac.id

Abstract

The increasing fuel consumption has led to a crisis in renewable energy sources. To address the depletion of fuel and rising prices, an alternative energy source to fossil fuels, namely biodiesel, is essential. One potential source of oil-producing energy is microalgae, which serves as a raw material for third-generation biodiesel. To extract oil from microalgae, an effective, environmentally friendly, and energy-efficient method is required. One of the most effective methods for microalgae oil extraction is the ultrasound method. The high pressure generated by ultrasonic waves damages and breaks the cell walls of microalgae, allowing the contained oil to be released. However, it has been observed that the widely used ultrasound method still incurs significant costs.
To address this issue, a creative innovation has been developed in the form of a microalgae oil-producing extraction machine. This machine is equipped with a 40 kHz ultrasound transducer, a heater, and an automatic control panel. In the machine testing results, the total energy consumption was approximately Rp1,000.00 per process. The instrumentation of this machine is capable of producing a microalgae oil yield from Chlorella vulgaris strain of 19.25% over a 3-hour period, with a relatively low Free Fatty Acid (FFA) content of 3.24%, making it suitable for biodiesel production. Similarly, the microalgae oil yield from Nannochloropsis oculata strain was 23.07% over 3 hours, with a low FFA content of 1.79%, indicating its suitability for biodiesel conversion. Consequently, the overall testing revealed that Nannochloropsis oculata, extracted over a 3-hour period, represents the most promising microalgae type and extraction time for potential biodiesel conversion.

Keywords: Microalgae, Ultrasound, Extraction, Oil

Topic: Renewable energy and biorefinery