TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The rotary kiln includes a decomposition products gas outlet toward the higher end for egress of gaseous smaller order hydrocarbons from the tube.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The sealable outlet at the lower end preferably includes a seal gas port, to inject gas into the kiln to prevent the decomposition products leaving the kiln with the charcoal. Preferred Assembly: The pyrolytic conversion assembly comprises (a) electronic processor arranged to monitor torque required to rotate the rotary kiln and to regulate feeding of the kiln in response to the monitored torque, (b) dryer for drying the biomass and having a dryer outlet side coupled to the sealable inlet for passing dried biomass to the rotary kiln, (c) electrical generator mechanically coupled to an output shaft of the combustion engine, (d) cooler having an input side to receive charcoal from the kiln, (e) piping arranged to place the exit seal gas port of the kiln in communication with the dryer, where exhaust gas from the dryer is used to provide a low oxygen gas supply for the seal gas, or (f) radiator and compressor being inserted in the piping between the exit gas port and the dryer for processing the cooled exhaust gas before arriving at the seal. The assembly comprises combustion engine having a fuel intake arranged to fuel with hydrocarbons originating from the decomposition gas outlet of the rotary kiln. The dryer includes an exhaust gas inlet port to receive exhaust gases from the combustion engine for assisting in drying of the biomass. The electrical output connectors of the electrical generator are coupled to electrical components of the assembly, including the heating elements for powering of the components. The fuel intake of the gas engine communicates with the decomposition products gas outlet of the kiln through a condensate trap. The cooler is air cooled and includes pipe to convey warmed air from the cooler to a hopper for preheating of the biomass, the hopper is located upstream of the dryer. The dryer, kiln and cooler are declined and coupled to rotation assemblies such that solids are transported by gravity and rotation during operation of the assembly. The tube, sealable inlet, sealable outlet and heating elements of the rotary kiln are arranged to provide an operating temperature of at least 4000C at a pressure of at least 700 kPA. The sealable inlet and outlet is provided by plug screw feeders. EXAMPLE - No suitable example given.