Gasification systems and associated processes are disclosed herein. In one embodiment, a gasification process includes simultaneously supplying a carbonaceous material and steam to a gasifier, the gasifier containing a liquid volume containing at least about 10% by weight of iron oxide (FexOy where x and y are positive integers). The gasification process also includes performing a gasification reaction between the carbonaceous material and steam in the liquid volume, facilitating the gasification reaction with the iron oxide in the liquid volume, and producing a gas from the gasification reaction, the gas containing carbon monoxide (CO) and hydrogen (H2).