Abstract: Batch mode supply of feedstock in non-combustive gasification systems and methods are described. In accordance with an aspect, a feedstock material is injected into a vessel at atmospheric pressure, atmosphere from the feedstock material in the vessel is purged, the purging includes evacuating the vessel, and in response to the pressure level in the vessel being below a predetermined value, injecting synthesis gas generated in a non-combustive gasification system, the vessel is pressurized to a reference pressure greater than an operating pressure of a gasification chamber, a portion of the feedstock material is supplied to an accumulation chamber, further feedstock material is injected into the gasification chamber, and atmospheric pressure in the collection vessel is recovered.