Track: Industry Practices and Solutions

Abstract

Pyrolysis has been used for thousands of years to extract fuel from carbonaceous materials and throughout the development phases of this technology, the source and method of heat application has always been one of the primary focus points in the design process.  The different heating methods all have their specific advantages and disadvantages and these normally relate to their ability to impact on important parameters such as temperatures, heating rates and maintenance. Through the years of development various types of reactor configurations have tended to favour certain heating methods and in auger-type reactors the heating rate has been one of this reactor’s limitations, especially in biomass pyrolysis where high heating rates are required to optimise pyrolysis oil yields.  One of the possible heating methods for these reactors is by means of induction heating which is the method employed in the pilot plant located in BIUST’s pyrolysis laboratory.  This paper presents results of heating performance tests done in this pilot plant on an inert material with known properties (silica) at different levels of heater duty, feed rates and residence times.  The heat transfer into the material was calculated from the measured data and plotted against feed rate and residence time for different heater duties.  It was observed that the heat transfer into the material was very efficient at the design feed rates.  In order to explore the limits of efficient heat transfer, tests were performed at up to forty times the design feed rate.  Even at these rates the heat transfer into the material was still satisfactory.  It was concluded that, from a heat transfer point of view, auger-type pyrolysis reactors fitted with induction heaters as energy source have potential of having high efficiencies. This work also forms a good basis from which a mathematical model can be developed to aid in the design of such reactors using software such as MATLAB®.