Introduction to frictional pyrolysis (FP) – An alternative method for converting biomass to solid carbonaceous products

Abstract

In the biomass sector, technologies like carbonization and torrefaction have been utilized for the production of solid carbonaceous biofuels and materials. In the framework of this manuscript a novel method for production of solid carbonaceous materials is introduced and is defined from now on as frictional pyrolysis. It uses only the application of pressure and friction whereas no external heat transfer is needed for the propagation of the process. This novel method is compared with torrefaction in order to assess its potential to process corn stover which has strongly bounder water and high content of deciduous xylan. Mass balances have been implemented for both technologies. Characterization of the products has been done by means of Simultaneous Thermal Analysis and Elemental analysis. Frictionally pyrolyzed corn stover has higher recovered mass yield, higher recovered energy yield and fixed carbon content than torrefied corn stover. Although external energy is provided by means of an internal combustion engine the net energy content of the final solid yield contained 92.2% of the input energy. The differential scanning calorimetry analysis showed that under the same heating rate regime and in oxygen-rich environment, the frictionally pyrolyzed corn stover had more exothermic decomposition than the torrefied material.