TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: In processing particulate carbonaceous feedstock, the size reduction process comprises either or both grinding and crushing the feedstock; and/or repeatedly contacting the feedstock with the hard objects. Contacting the feedstock with one or more hard objects comprises impacting with the feedstock with the objects. The objects are provided as grinding media composes of a set of separate and freely movable objects and repeatedly impacting the feedstock and comprises imparting momentum to the grinding media and causing the grinding media to impact the feedstock. The method comprises providing a vessel in which the size reduction process and the pyrolysis occur simultaneously, and feeding the feedstock to the vessel, the vessel having a volume V and an inner diameter D; providing the grinding media in the vessel and rotating the vessel; providing the grinding media in an amount to occupy 10-50% of the volume V of the vessel; rotating the vessel at a speed of 55-90% of a critical speed CS where: CS=42.3/D0.5 rpm; providing the objects as objects made of one of the following: silica, pebble, or steel; providing a steel, silica or refractory lining on the inside of the vessel; and providing a continuous feed of grinding media through the vessel. The pyrolysis comprises transferring heat from the objects to the feedstock by conduction and convection. The method comprises heating the objects prior to the objects coming into contact with the feedstock; and using waste heat from a process of heating the objects to dry the feedstock prior to coming into contact with the objects. The method also comprises heating the objects while the objects are in contact with the feedstock, where the pyrolysis comprises heating the vessel; generating heat for the pyrolysis by burning non-condensable gases and/or char produced by the pyrolysis of the feedstock; conducting pyrolysis at a temperature sufficient to cause torrefaction of the feedstock; providing limited oxygen into the vessel to enable partial combustion of the volatiles and/or char to generate heat for the pyrolysis of the feedstock; condensing organic vapor generated by the pyrolysis to form oil; condensing organic vapor generated by the pyrolysis on char generated by the pyrolysis to produce an oil/char mixture; feeding products generated by the pyrolysis of the feedstock as a fuel to a combustion or gasification system; using the combustion or gasification system as a source of heat for the pyrolysis; feeding products generated by the pyrolysis of the feedstock to a boiler or gasifier as a co-firing fuel; and conducting pyrolysis at a temperature of 350-650 degrees C. Preferred Plant: In the plant, the machine is a grinding machine or a milling machine, where the machine comprises grinding media consisting of a set of separate and freely movable objects and a vessel in which the grinding media and the feedstock come into contact with each other to effect particle size reduction of the feedstock. The machine operates by rotating the vessel to impart momentum to the grinding media and causing the grinding media to repeatedly impact the feedstock. The plant comprises providing a circulating feed of grinding media through the vessel, where the grinding media when in the vessel occupy 10-50% of the volume V of the vessel, and where the vessel is rotated a speed of 55-90% of a critical speed CS where: CS=42.3/D0.5 rpm, where D is the internal diameter of the vessel in meters. The heat source heats the grinding media prior to the grinding media contacting the feedstock, where the heat source heats the vessel. The heat source comprises a burner and a gas feed system to feed non-condensable gas from the pyrolysis of the feedstock to the burner. The plant comprises a condenser through which gases and vapors from the pyrolysis of the feedstock are drawn to condense and capture organic components of the pyrolysis vapors. The heat source is arranged to provide a pyrolysis temperature sufficient to cause torrefaction of the biomass. The plant is arranged to condense organic vapor generated by the pyrolysis on char-generated by the pyrolysis to produce an oil/char mixture. The plant is part of a combustion or gasification system having a combustor or gasifier, the plant being arranged to feed products generated by the pyrolysis of the feedstock as a fuel to the combustor or gasifier. Moreover, heat generated by the combustor or gasifier serves as a or the source of heat for the pyrolysis. The plant is arranged to feed products generated by the pyrolysis of the feedstock to a boiler or gasifier as a co-firing fuel. The plant also comprises a hopper for supplying the feedstock to the machine, the hopper being provided with an agitation mechanism capable of a combined rotational motion about an axis and linear reciprocation motion along the axis to facilitate a flow of the feedstock from the hopper to the machine. The heat source is arranged to provide a pyrolysis temperature of 350-650 degrees C.