Ultrasound-assisted transesterification of soybean oil using low power and high frequency and no external heating source

Production of biodiesel from waste fish fat through ultrasound-assisted transesterification using petro-diesel as cosolvent and optimization of process parameters using response surface methodology

Biodiesel is a highly promising and viable alternative to fossil-based diesel that also addresses the urgent need for effective waste management. It can be synthesized by the chemical modification of triglycerides sourced from vegetable origin, animal fat, or algal oil. The transesterification reaction is the preferred method of producing biodiesel. However, the non-miscibility of alcohol and oil layer causes excessive utilization of alcohol, catalyst, and a substantial reacting time and temperature. In the current investigation, transesterification of waste fish oil was performed with petro-diesel as cosolvent, under the influence of ultrasound energy. The combination of both techniques is a unique and efficient way to minimize the mass transfer limitations considerably and hence reduces the parameters of the reaction. It is also a sincere effort to comply with the principles of green chemistry. The optimum reaction conditions were obtained using response surface methodology (RSM) that were as follows: molar ratio of methanol to oil 9.09:1, catalyst concentration of 0.97 wt%, cosolvent concentration of 29.1 wt%, temperature 60.1℃, and a reacting time 30 min. Under these listed conditions, 98.1% biodiesel was achievable, which was in close agreement with the expected result. In addition, the cosolvent removal step from the crude biodiesel was also eliminated as it could be employed as a blended fuel in CI engines.

Synthesis, catalysts and enhancement technologies of biodiesel from oil feedstock - A review

Biodiesel is considered as one of the most promising alternative fuels due to the depletion of fossil fuels and the need to cope with potential energy shortages in the future. This article provides a thorough analysis of biodiesel synthesis, covering a variety of topics including oil feedstock, synthesis methods, catalysts, and enhancement technologies. Different oil feedstock for the synthesis of biodiesel is compared in the review, including edible plant oil, non-edible plant oil, waste cooking oil, animal fat, microbial oil, and algae oil. In addition, different methods for the synthesis of biodiesel are discussed, including direct use, blending, thermal cracking, microemulsions, and transesterification processes, highlighting their respective advantages and disadvantages. Among them, the transesterification method is the most commonly used and a thorough examination is given of the benefits and drawbacks of utilizing enzymatic, heterogeneous, and homogeneous catalysts in this process. Moreover, this article provides an overview of emerging intensification technologies, such as ultrasonic and microwave-assisted, electrolysis, reactive distillation, and microreactors. The benefits and limitations of these emerging technologies are also reviewed. The contribution of this article is offering a thorough and detailed review of biodiesel production technologies, focusing mainly on recent advances in enhanced chemical reaction processes. This provides a resource for researchers to assess and compare the latest advancements in their investigations. It also opens up the potential for enhancing the value of oil feedstocks efficiently, contributing to the development of new energy sources.

Review of the design of power ultrasonic generator for piezoelectric transducer

The power ultrasonic generator (PUG) is the core device of power ultrasonic technology (PUT), and its performance determines the application of this technology in biomedicine, semiconductor, aerospace, and other fields. With the high demand for sensitive and accurate dynamic response in power ultrasonic applications, the design of PUG has become a hot topic in academic and industry. However, the previous reviews cannot be used as a universal technical manual for industrial applications. There are many technical difficulties in establishing a mature production system, which hinder the large-scale application of PUG for piezoelectric transducers. To enhance the performance of the dynamic matching and power control of PUG, the studies in various PUT applications have been reviewed in this article. Initially, the demand design covering the piezoelectric transducer application and parameter requirements for ultrasonic and electrical signals is overall summarized, and these parameter requirements have been recommended as the technical indicators of developing the new PUG. Then the factors affecting the power conversion circuit design are analyzed systematically to realize the foundational performance improvement of PUG. Furthermore, advantages and limitations of key control technologies have been summarized to provide some different ideas on how to realize automatic resonance tracking and adaptive power adjustment, and to optimize the power control and dynamic matching control. Finally, several research directions of PUG in the future have been prospected.