Combustion behavior and kinetics of low-lipid microalgae via thermogravimetric analysis

Abstract

h i g h l i g h t sCombustion of low-lipid microalgae C. pyrenoidosa and S. platensis were studied. Chemical functional groups present in two microalgae were investigated via FTIR. Apparent activation energies for combustion of the two microalgae were calculated. C. pyrenoidosa has a higher reactivity compared to S. platensis during combustion. a r t i c l e i n f o t r a c tThermogravimetric analysis and differential thermal analysis were employed to investigate combustion characteristics of two low-lipid microalgae, Chlorella pyrenoidosa (CP) and Spirulina platensis (SP) and isoconversional Starink approach was used to calculate the kinetic parameters in the present study. The results showed that three stages of mass loss, including dehydration, devolatilization and char oxidation, were observed during combustion of both of two low-lipid microalgae. The whole weight loss of combustion of two microalgae was both shifted to higher temperature zones with increased heating rates from 10 to 40 K/min. In the 0.1-0.9 conversion range, the apparent activation energy of CP increased first from 51.96 to 79.53 kJ/mol, then decreased to 55.59 kJ/mol. Finally, it slightly increased to 67.27 kJ/mol. In the case of SP, the apparent activation energy gradually increased from 68.51 to 91.06 kJ/mol.

An investigation of reaction pathways of hydrothermal liquefaction using Chlorella pyrenoidosa and Spirulina platensis

“…It suggests that CP is preferable to SP during the thermal degradation process as more volatile matters could be converted into target products. And it is consistent with the results of kinetic analysis of thermal-chemical conversion of CP and SP [13,16]. According to Kumar et al [17], the solid residue is mainly composed of ash and bio-char.…”

Kinetic study on thermal decomposition of toluene in a micro fluidized bed reactor

“…Table 2 illustrated that the average value of apparent activation energy (16.34 kJ/mol) for propane was lower than that of ethylene (17.59 kJ/mol), then accompanied with methane (23.27 kJ/mol) and hydrogen (69.55 kJ/mol). The reaction rate of a reaction with lower apparent activation energy is faster due to the lesser energy required to break down the chemical bonds between atoms [39]. According to Anis and Zainal [28], the formation of hydrocarbons is more favorable than that of hydrogen during conversion of toluene, which is consistent with the results in the present study.…”

Energetic, economic and environmental assessment of the pyrolysis and combustion of microalgae and their oils

“…Furthermore, several studies have shown the benefits and sustainability of the integration of microalgae pyrolysis processes within the biorefinery framework due to their capacity of integration with transesterification and fermentation processes [23][24][25]. Together with pyrolysis, microalgae combustion seems another viable technology for microalgae valorization [11,26].…”