An apparatus and a method for producing woodfuel briquettes, pellets, compounds, composites, agglomerates, or granulates as source material for subsequent processing in injection molding or extrusion processes, includes a pressing screw with screw spirals, which rotate around a longitudinal axis and which are arranged inside a screw shell. The feed material is conveyed to the pressing screw via a feed chute located at an input side. At the end of the pressing screw, processing tools are arranged, to which the feed material is conveyed by the rotating screw spirals. In the area of the processing tools, the residual moisture in the feed material evaporates due to the heat generated during the processing procedure, and is vented as a steam flow from the apparatus through the screw shell. In order to prevent the steam flow from carrying away part of the feed material, the apparatus includes an expansion chamber, through which the escaping steam flow is channeled, and the flow-through cross section of which is such that it causes the steam flow to decelerate. As a result of the deceleration of the steam flow in the expansion chamber, the particles of the feed material that were carried off by the steam flow can be returned to the feed material.