NANO BUBBLE CAVITATION FOR ENHANCED LIQUID AND GASEOUS FUEL PRODUCTION FROM BIOMASS

Abstract

The remarkable physicochemical characteristics of nanobubble technology, such as its nanoscale size, long-term stability, high specific surface area, strong zeta potential, and superior gas-liquid mass transfer efficiency, have made it a promising development in biomass conversion. Nanobubbles can stay in aqueous systems for long periods of time, allowing for improved interaction with chemical and biological processes, in contrast to traditional bubbles that rise and fall quickly. Along with a critical assessment of the main methods used to create nanobubbles, including electrolysis, cavitation, ultrasonication, membrane techniques, and fluidic oscillations, this review offers a thorough overview of nanobubble fundamentals, classification, stability mechanisms, and important physicochemical properties. The importance of nanobubbles in enhancing the production of liquid biofuels from lignocellulosic feedstocks and microalgae, and of gaseous biofuels (biogas and hydrogen), as well as in biomass pretreatment, is given special attention. Higher methane yields, better digestive kinetics, and higher algal productivity are the outcomes of nanobubble-assisted procedures that improve hydrolysis, microbial activity, enzymatic efficiency and gas solubility. The adaptability of nanobubble systems is illustrated through applications in fuel combustion, increased oil recovery, anaerobic digestion and algal bioreactors. Critical analysis is also given to the scale constraints, techno-economic difficulties, and sustainability issues related to energy-intensive production techniques. Overall, this review identifies important research gaps and future directions required for large-scale industrial implementation while highlighting nanobubble technology as a revolutionary tool for sustainable biofuel generation and biomass valorisation.