Decomposition Characteristics and Kinetics of Microalgae in N2 and CO2 Atmospheres by a Thermogravimetry

Xu Qing,Ling Changming,Yu Zhaosheng,Ma Xiaoqian,Cai Zilin

doi:10.1155/2017/6160234

Xu Qing, Ling Changming + Show 3 more

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https://doi.org/10.1155/2017/6160234

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Abstract

The thermal degradation characteristics of microalgae were investigated in highly purified N2 and CO2 atmospheres by a thermogravimetric analysis (TGA) under different heating rates (10, 20, and 40°C/min). The results indicated that the total residual mass in CO2 atmosphere (16.86%) was less than in N2 atmosphere (23.12%); in addition, the kinetics of microalgae in N2 and CO2 atmospheres could be described by the pseudo bicomponent separated state model (PBSM) and pseudo-multi-component overall model (PMOM), respectively. The kinetic parameters calculated by Coats-Redfern method showed that, in CO2 atmosphere, the apparent activation energy (E) of microalgae was between 9.863 and 309.381 kJ mol−1 and the reaction order (n) was varied from 1.1 to 7. The kinetic parameters (E,n) of the second stage in CO2 atmosphere were quite similar to those in N2 atmosphere.

Highlights

Renewable and clean energy has become more and more important globally, especially with the current fuel crisis, economic crisis, and environmental pollution [1]
The powder of microalgae, C. vulgaris, was used in this study provided by Jiangmen YueJian Biotechnologies Co, Ltd. (Guangdong Province, China)
The C. vulgaris sample was dried in an oven at 105∘C for 20 h and milled and sieved with a screen of less than 200 μm in diameter

Summary

Introduction

Renewable and clean energy has become more and more important globally, especially with the current fuel crisis, economic crisis, and environmental pollution [1]. The bioenergy, as one form of renewable energy, is widely used in the third world. Its application can relax the energy crises and restrain the environmental pollution [2, 3]. Microalgae have many advantages over existing energy crops, such as faster growth rate, shorter growth time, higher biomass production, biochemicals and higher volume carbon abatement and no demand on arable land [5,6,7,8]. There is a possibility of direct generation of desired end products like bio-oil and hydrogen to be processed afterwards (like starch and biomass) [9]. Microalgae, as a source of biofuels and technological solution for CO2 fixation, are subject to intense academic and industrial research in its potential [10]

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