Large scale Fluidised Bed Combustion (FBC) units have been employed for several years in the public electricity supply sector. The method consists of increasing the combustion air-flow inside the combustion chamber so that inert materials together with air, form an expanding, circulating and fluidized bed. The FBC allows the combustion of almost any kind of fuel making it an ideal method for using biomass. To improve the usability of the method, a bench-scale biomass flash pyrolysis reactor has been developed in order to test and improve reactor stability, performance and to investigate scale-up properties. The aim is to integrate the biomass pyrolytic conversion process in existing markets of liquid fuels and chemicals. Work was performed in all areas of the pyrolysis, including modifications, experimentation with a plasma reactor, modelling of scale-up rules, together with techno-economic, environmental and safety analysis for the method. The novel configuration used during investigations, improved the Circulating Fluidised Bed (CFB) method using the experimental modifications and techniques applied. The improved Bench Scale Unit (BSU) flash pyrolyzer will be utilized in other projects, as it has the potential to help the up-grading of pyrolysis in other systems. The models and analyses developed for this work can be used to benefit the design and scale-up development of pyrolysers.