A review on recent advances in hydrogen energy, fuel cell, biofuel and fuel refining via ultrasound process intensification

Abstract

Hydrogen energy is one of the most suitable green substitutes for harmful fossil fuels and has been investigated widely. This review extensively compiles and compares various methodologies used in the production, storage and usage of hydrogen. Sonochemistry is an emerging synthesis process and intensification technique adapted for the synthesis of novel materials. It manifests acoustic cavitation phenomena caused by ultrasound where higher rates of reactions occur locally. The review discusses the effectiveness of sonochemical routes in developing fuel cell catalysts, fuel refining, biofuel production, chemical processes for hydrogen production and the physical, chemical and electrochemical hydrogen storage techniques. The operational parameters and environmental conditions used during ultrasonication also influence the production rates, which have been elucidated in detail. Hence, this review's major focus addresses sonochemical methods that can contribute to the technical challenges involved in hydrogen usage for energy.

Keywords: Biofuel; Fuel cell; Hydrogen; Production; Storage; Ultrasound.

Fig. 1

Comparison of energy storage devises based on energy density and power density , ,

Fig. 2

Block diagram of a hydrogen-based fuel cell.

Fig. 3

Schematic diagram of the sonoreactor and description of the cavitation phenomenon.

Scheme 1

Mechanism of hydrodesulfurization.

Scheme 2

Mechanism for the transformation of asphaltene to gas oil and resins.

Scheme 3

Mechanism of transesterification.