Effects of total pressure and CO2 partial pressure on the physicochemical properties and reactivity of pressurized coal char produced at rapid heating rate. (1st October 2020)

• Record Type: Journal Article
• Authors: Zhang, Wenda; Sun, Shaozeng; Zhao, Yijun; Zhao, Zujie; Wang, Pengxiang; Feng, Dongdong; Li, Pengfei
• Is Part Of: Energy. Volume 208(2020)
• Publication Date: 2020-10-01
• Subjects: CO2 atmosphere -- Char physicochemical structure -- Reactivity -- Pressurized drop tube furnace; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2020.118297
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: The effects of the total pressure (0.1–1.3 MPa) and the CO2 partial pressure (0–0.45 MPa) on the physical structural properties, chemical structural properties and reactivity of Shenhua coal pressurized char at 1273 K were investigated in a pressurized drop tube furnace (PDTF). There were reverse-direction effects on char yield between total pressure and CO2 partial pressure for char preparation. Porosity characteristics were performed using an ASAP2020 instrument. It was found that same-direction increment effects on BET surface and porosity between total pressure and CO2 partial pressure for char preparation. Carbon structure and surface structure were performed by Raman and XPS methods. The results showed that both total pressure and CO2 partial pressure can promote the transformation of small aromatic structures to large aromatic structures and increase the graphitization degree of the char. With increasing total pressure and CO2 partial pressure, the unstable N-5 content decreased, while the N-6 and N-Q content increased. Highlights: Effects of CO2 partial pressure on pressurized char were investigated. Opposite effects on char yields between total pressure and CO2 concentration for char preparation. Role of char-N in thermal conversion was investigated under pressurized Ar/CO2 conditions. Chemical structure of char has greater influence on reactivity than physical structure.