화학공학소재연구정보센터
Energy, Vol.149, 1-10, 2018
Study of light, middle and severe torrefaction and effects of extractives and chemical compositions on torrefaction process by thermogravimetric analysis in five fast-growing plantations of Costa Rica
Light (T-light), middle (T-middle) and severe (T-severe) torrefaction processes by TGA in woody biomass were evaluated in relation to devolatilization rate (D-rate), maximum devolatilization rate (DRmax), temperature at the level of 50% weight loss (T-50), rate of weight loss at T-50 (R-50) and weight loss during torrefaction (Wloss-DT). The relationship between these parameters with cellulose, lignin and extractives content was established. The TGA and devolatilization curves showed that DRmax was of 4.16, 1.80 and 0.70%/min for, T-light T-middle and T-severe respectively. Wloss-DT in T-light ranges between 3 and 6%, between 9 and 14% in T-middle and from 11 to 16% in T-severe. G. arborea showed the highest Wloss-DT, with 29.10% for T-severe and C. Lusitania and T. grandis the lowest Wloss-DT, with 15% for T-severe. The duration of D-max was of 5 min in T-light and T-middle and 6 min in T-severe. Cellulose, lignin and carbon presented statistically significant correlations with R-50, T-50, Wloss-DT and DRmax. Ash content was correlated with Wloss-DT and DRmax in all torrefaction condition. Extractives in dichloromethane was significantly in many parameters. We conclude that the torrefaction of different woody species can be optimized as biomass feedstocks with a specific temperature and time of torrefaction. (C) 2018 Elsevier Ltd. All rights reserved.