Devolatilisation kinetics and pyrolytic analyses of Tectona grandis (teak)

Abstract

Devolatilisation kinetics and pyrolytic analyses were carried out on Tectona grandis (teak) using iso-conversional methods (Flynn-Wall-Ozawa and Starink) and analytical Py-GC/MS technique respectively. Proximate and elemental analyses were also performed and they showed that the ash and C contents and the HHV were 0.7%, 49.6% and 19.8MJ/kg respectively. Biomass sample was subjected to multiple heating rates (5-35K/min) in thermogravimetric experiments and kinetic parameters were evaluated from the non-isothermal TGA curves. The activation energy (E) varied between 222 and 300kJ/mol as a function of degree of conversion. Similarly, the pre-exponential frequency factor (A) varied between 9.6×10(17) and 9.55×10(24)min(-1). Analytical Py-GC/MS showed the presence of CO2, acetic acid, furan+2-butanone, levoglucosan, trans-coniferyl alcohol and lignin derivatives. The proportion of phenolic compounds identified was more than one-third with isoeugenol, acetoguaiacone, and 4-vinylguaiacol showing dominance.

Thermo-kinetic, spectroscopic study of brewer’s spent grains and characterisation of their pyrolysis products

“…The correlation coefficients obtained for the methods were fairly high, which attests to the reliability of the models [25]. Generally, the trends of the apparent activation energy for both methods and samples are fairly comparable; reaching a peak of 171.78 and 187.73 kJ mol respectively for Friedman's and Starink's.The apparent activation energy obtained for both methods were within the range reported for biomass residues [36,40]. For both BSG and extractive-free BSG, the average value of the apparent activation energy returned by Friedman's model was comparatively higher than Starink's; this is similar to an earlier observation made in literature [24].…”

“…(1), yields a temperature integral that is not amenable to an analytical solution. The temperature integral is often linearized through a couple of approximation techniques [36]. Starink [37] examined two of such techniques (Flynn-Wall-Ozawa and Kissinger-Akhira-Sunose) and optimized them to obtain the expression in Eq.…”

Evaluation of Wood Plastic Composites Produced from Mahogany and Teak

“…The mahogany and teak lignin contents were 23.0 and 27.8% while the ash contents were 0.9 and 3.4% respectively. These values are similar to 3.8% extractives, 25.3% lignin and 0.5% ash reported for teak by Balogun et al [22].…”

Thermogravimetric analysis of the co-combustion of eucalyptus residues and paper mill sludge

“…The Kissinger-AkahiraSunose (KAS) method and the Starink method were used in this study to calculate the apparent activation energy [16,17]. The expression of KAS method was based on the following Eq.…”