Thermogravimetric and kinetic analysis of Spirulina wastes under nitrogen and air atmospheres

Impact of blend ratio on the co-firing of post-methanated distillery effluent solid waste and low-rank Indian coal via analysis of oxidation kinetics through TGA

An attempt has been made to study the oxidation kinetics of dried Post-Methanated Distillery Effluent (PMDE) solid waste blended with Low Rank Indian Coal (LRIC) at different blending ratios in a thermogravimetric analyzer (TGA).

TG-MS analysis and kinetic study for thermal decomposition of six representative components of municipal solid waste under steam atmosphere

Thermal decomposition of six representative components of municipal solid waste (MSW, including lignin, printing paper, cotton, rubber, polyvinyl chloride (PVC) and cabbage) was investigated by thermogravimetric-mass spectroscopy (TG-MS) under steam atmosphere. Compared with TG and derivative thermogravimetric (DTG) curves under N2 atmosphere, thermal decomposition of MSW components under steam atmosphere was divided into pyrolysis and gasification stages. In the pyrolysis stage, the shapes of TG and DTG curves under steam atmosphere were almost the same with those under N2 atmosphere. In the gasification stage, the presence of steam led to a greater mass loss because of the steam partial oxidation of char residue. The evolution profiles of H2, CH4, CO and CO2 were well consistent with DTG curves in terms of appearance of peaks and relevant stages in the whole temperature range, and the steam partial oxidation of char residue promoted the generation of more gas products in high temperature range. The multi-Gaussian distributed activation energy model (DAEM) was proved plausible to describe thermal decomposition behaviours of MSW components under steam atmosphere.

Thermo gravimetric and kinetic studies on dried solid waste of post-methanated distillery effluent under oxygen and nitrogen atmosphere

This work seeks for the possibility of using solid waste generated by drying the post-methanated distillery effluent, as fuel. TGA has been employed to analyse the kinetics of thermal degradation of the solid waste at different heating rates of 10, 20, 30, and 40°Cmin(-1) in pyrolysis and combustion modes. In combustion mode, the activation energy changes from 253.58 to 87.91kJmol(-1), corresponding to the changes in heating rates of 10°Cmin(-1) to 40°Cmin(-1), whereas, there is no significant change of activation energy in pyrolysis mode. The Arrhenius equation based kinetic model with regression analysis using LINEST function is able to predict the kinetic variables of dried solid waste in both the modes. Solid waste almost completely degrades at the end of isothermal condition in pyrolysis mode.

Pyrolysis characteristics and kinetics of aquatic biomass using thermogravimetric analyzer

The differences in pyrolysis process of three species of aquatic biomass (microalgae, macroalgae and duckweed) were investigated by thermogravimetric analysis (TGA). Three stages were observed during the pyrolysis process and the main decomposition stage could be divided further into three zones. The pyrolysis characteristics of various biomasses were different at each zone, which could be attributed to the differences in their components. A stepwise procedure based on iso-conversional and master-plots methods was used for the kinetic and mechanism analysis of the main decomposition stage. The calculation results based on the kinetic model was in good agreement with the experimental data of weight loss, and each biomass had an increasing activation energy of 118.35-156.13 kJ/mol, 171.85-186.46 kJ/mol and 258.51-268.71 kJ/mol in zone 1, 2 and 3, respectively. This study compares the pyrolysis behavior of various aquatic biomasses and provides basis for further applications of the biomass thermochemical conversion.

Pyrolytic and kinetic analysis of two coastal plant species: Artemisia annua and Chenopodium glaucum

The large amount of coastal plant species available makes them ideal candidates for energy production. In this study, thermogravimetric analysis was used to evaluate the fuel properties of two coastal plant species, and the distributed activation energy model (DAEM) was employed in kinetic analysis. The major mass loss due to devolatilization started at 154 and 162°C at the heating rate of 10°C min⁻¹ for Artemisia annua and Chenopodium glaucum, respectively. The results showed that the average activation energies of Artemisia annua and Chenopodium glaucum were 169.69 and 170.48 kJ mol⁻¹, respectively. Furthermore, the activation energy changed while the conversion rate increased, and the frequency factor k₀ decreased greatly while the activation energy decreased. The results also indicated that the devolatilization of the two coastal plant species underwent a set of first-order reactions and could be expressed by the DAEM. Additionally, a simplified mathematical model was proposed to facilitate the prediction of devolatilization curves.

Thermogravimetric and kinetic analysis of thermal decomposition characteristics of low-lipid microalgae

The thermal decomposition behavior of two microalgae, Chlorella pyrenoidosa (CP) and Spirulina platensis (SP), were investigated on a thermogravimetric analyzer under non-isothermal conditions. Iso-conversional Vyazovkin approach was used to calculate the kinetic parameters, and the universal integral method was applied to evaluate the most probable mechanisms for thermal degradation of the two feedstocks. The differential equations deduced from the models were compared with experimental data. For the range of conversion fraction investigated (20-80%), the thermal decomposition process of CP could be described by the reaction order model (F3), which can be calculated by the integral equation of G(α) = [(1 - α)(-2) - 1]/2. And the apparent activation energy was in the range of 58.85-114.5 kJ/mol. As for SP, it can be described by the reaction order model (F2), which can be calculated by the integral equation of G(α) = (1 - α)(-1) - 1, and the range of apparent activation energy was 74.35-140.1 kJ/mol.