A Magneto-Heated Ferrimagnetic Sponge for Continuous Recovery of Viscous Crude Oil.

The high viscosity and low fluidity of heavy crude oil hinder its sorption by conventional porous sorbents, so the efficient clean-up of such heavy crude oil spills is challenging. Recently, Joule heating has been emerging as a new tool to reduce the viscosity of heavy crude oil dramatically. However, this direct-contact heating approach presents a potential risk due to the high voltage applied. To develop a non-contact recovery of viscous crude oil, here, a new approach for the fabrication of a series of ferrimagnetic sponges (FMSs) with hydrophobic porous channels is reported, whose surface can be remotely heated to 120 °C within 10 s under an alternating magnetic field (f = 274 kHz, H = 30 kA m-1 ). Compared with the solar-driven superficial heating, the integral magnetic heating in FMSs can result in a higher internal temperature of the sponges because of the confinement of thermal transport in the porous channels, which contributes to a dramatic decrease in oil viscosity and a significant increase in oil flow into the pores of FMSs. Furthermore, FMSs assembled with a self-priming pump can achieve continuous recovery of viscous crude oil (33.05 g h-1 cm-2 ) via remotely magnetic heating.