The influence of alkali and alkaline earth metal compounds on pyrolysis of peanut shell

Abstract

This article aims at studying the influence of alkali and alkaline earth species on the pyrolytic performances of peanut shell. The biomass sample was washed with 5 wt% acids (H2SO4 and HCl) and deionized water, respectively. The concentrations of metallic elements in the original and washed peanut shells were determined with inductively coupled plasma-atomic emission spectrometry. The pyrolysis experiment was performed on a thermogravimetric analyzer (TGA) at a heating rate of 10 °C/min and N2 flow rate of 100 mL/min. It can be observed that the derivative thermogravimetric (DTG) curves of demineralized peanut shell were obviously shifted to higher temperature and the char yields increased greatly. With the addition of 1 wt% or 10 wt% K2CO3 or dolomite to the original and acid-washed biomass samples, the DTG curves of the original peanut shell were shifted to low temperature and this effect was more distinct for the acid-washed peanut shell. K2CO3 displayed much greater effect than dolomite on the alteration of the pyrolysis behavior. The first-order kinetic analysis showed that the activation energy increased greatly with demineralization. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.