Measuring chemical heat production rates of biofuels by isothermal calorimetry for hazardous evaluation modelling

Abstract

Biofuels are commonly stored in large stacks that may heat up and self-ignite from microbiological and chemical heat production. This paper shows how isothermal (heat conduction) calorimetry can be used to measure heat production rates of biofuels at relatively low temperatures close to where self-heating starts to become a problem. Measurements can be made to assess how the reaction rate is a function of such factors as temperature, extent of reaction, oxygen pressure, water content and the presence of catalytic compounds. In the present paper, measurements on pellets made of wood and bark are presented together with an analysis of how the reaction rate of the bark pellets depends on the oxygen pressure. It is also shown that 1% iron or copper ions increased the reaction rate of wood pellets by a factor of three. Copyright © 2006 John Wiley & Sons, Ltd.