Dr Francisco Trujillo is a senior lecturer at the school of Chemical Engineering. He has a wide experience in designing, developing and modelling complex multiphysics system including food processing, ultrasonic processing, heat and mass transfer, multiphase hydrodynamic systems, transport of light and radiation, membranes, photocatalysis, chemical reactions, and water detoxification. In the field of ultrasonics Dr Trujillo has worked on modelling ultrasonic operations of importance for the food processing industry such as modelling the acoustic streaming generated by low-frequency-high-power horn sonoreactors. Currently Dr Trujillo is working on achieving separation of particles and liquid droplets within emulsions via high frequency ultrasound, which can find several applications of importance for food, biological, pharmaceutical, chemical and petrochemical industries.
In the area of water detoxification Dr Trujillo is currently working on Radio Frequency (RF) Plasma on water for destruction of microorganisms and chemical pollutants. Using RF alone and/or combined with ultrasound or electrolysis is a new process for complete mineralization of recalcitrant pollutants in wastewater. In the case of Ultrasonic Assisted Plasma Detoxification (UAPD) ultrasound is injected into the fluid via a horn producing cavitation bubbles, while plasma is produced via Radio Frequency electromagnetic waves. The mechanism of this technology is still unknown but is based on the synergism of acoustic cavitation bubbles that facilitate and sustain the plasma formation. The plasma produces radical species that mineralize pollutants and inactivate microorganisms.
Dr Trujillo is also working in using RF electric fields as a non-thermal processing technology for inactivation of vegetative microorganisms in foods by rupturing cellular membranes at sub-pasteurization temperatures. This is a promising technology for the preservation of heat sensitive food products as well as liquid foods with enhanced organoleptic properties due to lower temperature and treatment times.
In the area of Membranes, Dr Trujillo is developing a system that combines membranes with ultrasound for fouling control in membranes, as well as modelling the effect of vibration of hollow membranes on cake formation and concentration polarization.
Dr Trujillo has also worked on modelling the simultaneous heat and mass transfer during chilling of food products. In the area of photocalysis he has worked developing a CFD model of a bubble column photoreactor. This is a complex multiphase and multiphysics system that involves the presence of three phases: gas, liquid and solid. The model solved the Radiation Transport equation, which needed to be coupled with the hydrodynamic modelling because of light scattering produced by reflection and refraction on gas bubbles.