Effect of ash – ZnO heat carrier on sulfur migration behavior during pyrolysis of coal

Autor: Xiao Li, Wei-song Li, Lin Feng, Chen-xiao Wang, Ruizhi Chu, Xiaofeng Jiang, Xianliang Meng, Ze-fu Ye, Jian-yun Yang
Rok vydání: 2022
Předmět:
Zdroj: Fuel. 308:121993
ISSN: 0016-2361
DOI: 10.1016/j.fuel.2021.121993
Popis: In this paper, the effects of ash heat carrier (AHC) and ash-ZnO heat carrier (A-ZHC) on the release and transformation of sulfur during the pyrolysis of Yuandatan (YDT) high-sulfur bituminous coal were studied. The samples were pyrolyzed in a fixed-bed reactor, the composition of sulfur in char, crystal structure of inorganic sulfur, and species of sulfur in pyrolysis gas were analyzed by XPS, XRD and GC. Compared with AHC, the A-ZHC can better inhibit sulfur migration to tar and gas during coal pyrolysis so as to obtain more pure volatile products. Both the AHC and A-ZHC promote the formation of CaS and FeS. The presence of ZnO in the A-ZHC promotes the formation of ZnS, and the interaction between ZnS and FeS can produce solid solutions (Zn,Fe)S, which further reduces the release of H2S and COS and advances the increase of sulfide sulfur content. In addition, the catalytic effect of ZnO in A-ZHC promotes the conversion of thiophene sulfur to sulfide sulfur in char at high temperature. The catalytic effect of ZnO also promotes the conversion of tar sulfur to sulfide and sulfone sulfur in char by reacting with metal-oxides and oxygen-containing groups during the secondary reaction stage.
Databáze: OpenAIRE