TY - JOUR
T1 - Transformation and fate of sulphur during steam gasification of a spent tyre pyrolysis char
AU - Zhang, Juan
AU - Zhu, Mingming
AU - Jones, Isabelle
AU - Onyeka Okoye, Chiemeka
AU - Zhang, Zhezi
AU - Gao, Jian
AU - Zhang, Dongke
PY - 2022/8/1
Y1 - 2022/8/1
N2 - The transformation of sulphur (S) during steam gasification of a spent tyre pyrolysis char (STPC) was investigated by tracing the evolution of S species and their mass fractions through X-ray photoelectron spectroscopy analysis. The raw pyrolysis char and demineralised char samples were respectively reacted with steam in a vertical fixed bed reactor over a range of temperature (850, 950, 1050 °C), steam concentration (33.3, 50.0, 66.7 vol% steam in N2) and gasification time (0.5, 1, 2, 3, 4 h). The mass fraction of S in the partially gasified char increased with increasing time at 850 °C and 950 °C, but decreased at 1050 °C. However, the net amount of S retained in the gasified char relative to that in the raw STPC decreased with increasing mass loss ratio, implying that S loss was faster than carbon consumption. The dominant S species in the pyrolysis char were aliphatic sulphide and ZnS. After steam gasification, more than 80% S species in the gasified chars were in the form of organic S. The proportion of organic S increased while that of inorganic S decreased with increasing gasification time and temperature, regardless of steam concentration. Thiophene, aliphatic sulphide, sulphone and sulphoxide became the main organic S species while ZnS and sulphate were the dominant inorganic S species. Aliphatic sulphide, sulphone and sulphoxide were converted to more thermally stable thiophene. Sx released from ZnS or COS produced from CaSO4 reacted with the carbon matrix to form sulphone and sulphoxide in the gasified char.
AB - The transformation of sulphur (S) during steam gasification of a spent tyre pyrolysis char (STPC) was investigated by tracing the evolution of S species and their mass fractions through X-ray photoelectron spectroscopy analysis. The raw pyrolysis char and demineralised char samples were respectively reacted with steam in a vertical fixed bed reactor over a range of temperature (850, 950, 1050 °C), steam concentration (33.3, 50.0, 66.7 vol% steam in N2) and gasification time (0.5, 1, 2, 3, 4 h). The mass fraction of S in the partially gasified char increased with increasing time at 850 °C and 950 °C, but decreased at 1050 °C. However, the net amount of S retained in the gasified char relative to that in the raw STPC decreased with increasing mass loss ratio, implying that S loss was faster than carbon consumption. The dominant S species in the pyrolysis char were aliphatic sulphide and ZnS. After steam gasification, more than 80% S species in the gasified chars were in the form of organic S. The proportion of organic S increased while that of inorganic S decreased with increasing gasification time and temperature, regardless of steam concentration. Thiophene, aliphatic sulphide, sulphone and sulphoxide became the main organic S species while ZnS and sulphate were the dominant inorganic S species. Aliphatic sulphide, sulphone and sulphoxide were converted to more thermally stable thiophene. Sx released from ZnS or COS produced from CaSO4 reacted with the carbon matrix to form sulphone and sulphoxide in the gasified char.
KW - Pyrolysis char
KW - Spent tyres
KW - Steam gasification
KW - Sulphur transformation
UR - http://www.scopus.com/inward/record.url?scp=85127493846&partnerID=8YFLogxK
U2 - 10.1016/j.fuel.2022.124091
DO - 10.1016/j.fuel.2022.124091
M3 - Article
AN - SCOPUS:85127493846
SN - 0016-2361
VL - 321
JO - Fuel
JF - Fuel
M1 - 124091
ER -