Experimental Investigation of Combustion Kinetics of Wood Powder and Pellet

Peng Haobin,Yunquan Li,Guohua Chen,Yuesheng Li,Fangyang Yuan

doi:10.1155/2018/5981598

Abstract

The combustion kinetic characteristics of wood powder and pellet were investigated within thermogravimetric analyser (TGA) and tube furnace system. The kinetic parameters of these two different forms of woody fuel were measured and derived by double-step-and-double-equal and isothermal method, respectively. The results showed that the combustion mechanisms of wood powder kept consistent through the whole process, while the combustion mechanisms of wood pellet differed significantly between the volatile and char combustion stages. The most probable mechanism functions of the two different forms of woody fuel were not the same due to the differences in internal heat and mass transfer properties. In addition, activation energy values varied from 92.33 kJ·mol−1 for wood powder to 71.20 kJ·mol−1 for wood pellet, while the preexponential factor value of wood powder (2.55×108 s−1) was far greater than the one of the wood pellet (78.55 s−1) by seven orders of magnitude.

Highlights

Suffering the consequences of excessive use of fossil fuel, the countries all over the world contribute more and more to renewable energy development and utilization [1,2,3]
The TG and DTG (Differential Thermal Gravity) curves of wood powder combustion are shown in Figures 1 and 2, respectively
By the kinetic analysis and results comparison of the combustion process of wood powder and pellet of the same kind of wood, the following conclusions are drawn: (1) For wood powder, the combustion mechanism of the whole combustion process was basically unchanged, and the most probable mechanism function had no obvious segmental characteristics; for wood pellet, there was a great discrepancy between volatile combustion stage and char combustion stage, respectively, described by different most probable mechanism functions

Summary

Introduction

Suffering the consequences of excessive use of fossil fuel, the countries all over the world contribute more and more to renewable energy development and utilization [1,2,3]. The annual use of wood, widely in construction, furniture manufacturing, packaging, and handicraft, is more than 400 million m3, yet the processing rate is only about 65% [6]. The remaining compounds such as leftover sawdust should be utilized vigorously to promote energy conservation and emission reduction [7, 8]. The most effective way to use the remains is to extrude them into granules with uniform shape and density and directly burn them for heating and power generation [9,10,11]

Methods

Results

Conclusion