Production and characterization of hybrid coal using sugar impurities extracted from pitch pine. (25th December 2018)

• Record Type: Journal Article
• Authors: Lee, Young-Joo; Namkung, Hueon; Park, Ju-Hyoung; Song, Gyu-Seob; Park, Se-Joon; Kim, Joeng-Geun; Choi, Jong-Won; Jeon, Chung-Hwan; Choi, Young-Chan
• Is Part Of: Applied thermal engineering. Volume 145(2018)
• Page Start: 174
• Page End: 183
• Publication Date: 2018-12-25
• Subjects: Sugar impurities -- Hybrid coal -- Low-rank coal -- Biomass -- Two-in-one fuel; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2018.09.024
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: We optimized the HTP based sugar extraction process from Pitch pine to show 50 wt% yield, which were 190 °C and 30 min. The sugar impurities consist of 21.8 wt% glucan, 75.9 wt% XMG and 2.3 wt% arabinan, respectively. The hybrid coal with the sugar impurities shows 5% higher heating value and 70% reduction of moisture re-adsorption. Abstract: The main concerns of coal power plants are related to high thermal efficiency and biomass utilization for the reduction of CO2 emissions. In this work, the fuel characteristics of a hybrid coal (HCK) impregnated by sugar impurities extracted from a lignocellulosic biomass were investigated. First, an optimized extraction condition for the sugar impurities was chosen among the various reaction temperatures and times using a hydrothermal pre-treatment (HTP) reactor. The extracted sugar impurities were consisted of 21.76 wt% glucan, 75.88 wt% XMG (xylan + mannan + galactan) and 2.36 wt% arabinan at the optimized reaction condition (190 °C and 30 min). 5 wt% sugar impurities based on the coal weight (dry basis) was used to prepare the HCK and the fuel characteristics were compared. According to the H/C and O/C ratios, raw coals were upgraded. In addition, the calorific value of the raw coals was enhanced by HCK production process. The HCKs had a low moisture re-adsorption rate in an excessive water immersion condition compared to the raw coals. To clarify the combustion behavior of the HCKs, thermogravimetric analysis (TGA) was carried out. The HCKs had a single-stage combustion pattern on the differential thermogravimetric (DTG) curve, even though they were composed of a coal and biomass resource. During the kinetic study of the raw coals and HCKs, a high reaction rate constant ( k ) and low activation energy ( Ea ) for the HCKs were identified compared to that of the raw coals.