Efficient Two-Step Utilization of Organic Matter in Shengli Lignite for Producing Chemicals and Supercapacitor Electrode Materials
Juan-Juan Zheng, Fang‐Jing Liu, Bingkang Sun, Yanhong Li, Bo Meng, Yanming Yu, Yun‐Peng Zhao, Jing‐Pei Cao, Xian‐Yong Wei, Yao Lu, H. Y. Lu
Abstract
Conversion of organic matter in lignite into chemicals and high-performance carbon materials is a promising approach for clean and efficient utilization of lignite. Herein, Shengli lignite (SL) is subjected to supercritical ethanolysis, followed by ultrasonic extraction with isometric carbon disulfide/acetone for separating SL into soluble organic matters (SOMs) and insoluble extraction residue (ER) with highly condensed aromatic structures. According to the analyses with gas chromatography/mass spectrometry (GC/MS) and Orbitrap MS, the SOMs were mainly composed of oxygen-containing compounds, such as arenols, aliphatic esters, and aromatic esters, which can be used as feedstock for producing value-added chemicals. The ER was used as a carbon precursor to produce three-dimensional porous carbon materials (PCMs) through precarbonization and activation with KOH using nano-ZnO as an in situ template. The prepared PCMs possessed high stability, large specific surface area, and abundant oxygen-doped carbon, showing a high specific capacitance of 300 F g –1 at 0.5 A g –1 in a three-electrode system, and the capacitance retention was 100% after 10,000 cycles of charge and discharge at 5 A g –1 in a two-electrode system.