Pyrolysis Kinetics of Physical Components of Wood and Wood-Polymers Using Isoconversion Method

Abstract

Two hardwood species, namely red oak and yellow-poplar, were separated into their bark, sapwood and heartwood components. The samples were tested for calorific value, specific gravity, proximate analysis, mineral composition, chemical composition, ultimate analysis, and thermo-chemical decomposition behavior. In addition, the thermo-chemical decomposition behaviors of cellulose, xylan, and lignin polymers were also tested. Thermo-chemical decomposition behavior was assessed using a thermo-gravimetric (TGA) system by heating the sample from 50 °C to 700 °C at the heating rates of 10, 30 and 50 °C/min under nitrogen. The activation energy was calculated for various fractional conversion values using the isoconversion method. The results showed that char yields of lignin, cellulose and xylan were 41.43%, 4.45% and 1.89%, respectively, at the end of pyrolysis. Furthermore, cellulose, xylan and lignin decomposed dramatically in the temperature range of 320 °C to 360 °C, 150 °C to 230 °C and 100 °C to 410 °C, respectively, with decomposition peaks occurring at 340 °C, 200 °C and 340 °C, respectively. In addition, the maximum activation energy for cellulose was 381 kJ/mol at 360 °C and for xylan it was 348 kJ/mol at 210 °C.

Microwave-assisted Dilute Acid Pretreatment and Enzymatic Hydrolysis of Sago Palm Bark

“…The second stage approximately started at 150 ºC and was completed at 400 ºC. At this major stage, the thermal degradation of the main component of biomass hemicellulose and cellulose can be identified as contributing to most loss of weight compared to other stages (Chen et al 2012;Jin et al 2013). The weight of untreated samples decreased from more than 90% to less than 40%.…”

“…The difference in the weight in this stage might be attributed to there being a higher lignin content in untreated sample. It was reported that the lignin thermal degradation occurred at a low rate in the temperature range of 100 °C to 700 °C with a tiny peak at 340 °C (Jin et al 2013). The DTG curves (Fig.…”

Thermogravimetric analysis in the study of solid fuels

“…Constructed apparatus allows to study thermal decomposition of solid fuels and obtained thermogravimetric curves are similar to those that can be performed on commercial thermobalances [5][6][7][8][9]. The advantage of the device is definitely lower price than of commercial solutions (approx.…”

A New Activated Carbon Prepared from Sago Palm Bark through Physiochemical Activated Process with Zinc Chloride

“…The weight loss observed at the first peak at 38 o C in DTG can be attributed to the moisture, while the two peaks observed at 260 and 350 o C are atrributed to hemicellulose and cellulose thermal degredation [43]. For liginin, no clear peaks were detected, though it might have been located at the same position as the cellullose peak, since lignin has tiny peak at 340ᵒC [44]. …”

“…There are three stages involved in the thermal decomposition of SPB: (1) the first stage at 25 to 125 o C, resulting in the loss of weight due to remove of bound and unbound water; (2) most loss in weight taking place in the second stage due to thermal degradation of the main component of biomass cellulose and hemicellulose at temperatures ranging from 150 to 400 o C [43,44]; and (3) slow weight loss in the third stage taking place at temperatures above 400 o C because of the sample's higher lignin content. Jin et al (2013) [44] reported that the thermal degradation of lignin occurred at a low rate in the range of 100 to 700ᵒC. This thermal degradation can be accompanied with a tiny peak at 340ᵒC.…”