Experimental Study of Gaseous Sulfur Species Formation during the Steam Hydrogasification of Coal

Abstract

Steam hydrogasification is the thermochemical conversion of carbonaceous materials into synthesis gas in a steamand hydrogen-rich environment. The formation of gas-phase sulfur species during the pyrolysis and gasification of sulfurcontaining feedstocks, such as coal, presents well-known challenges. Gas-phase sulfur component formation under typical steam hydrogasification conditions was studied experimentally, and the impact of process parameters has been evaluated. The experimental results show that sulfur in the feedstock is mainly converted to hydrogen sulfide (H 2 S) during the steam hydrogasification reaction (SHR) process. Carbonyl sulfide (COS) and carbon disulfide (CS 2 ) were not observed in the gas phase. The H 2 -and steam-rich environment in the SHR process is favorable for the formation of H 2 S and suppresses COS and CS 2 formation. The H 2 S concentration in the gas phase increased consistently with increasing temperatures (700−800°C) and increasing water/coal mass ratios (0.5−3). These results are important in the development of a downstream sulfur cleanup system during SHR-based coal conversion.

Effect of H2O on the Transformation of Sulfur during Demineralized Coal Pyrolysis: Molecular Dynamics Simulation Using ReaxFF

“…However, the total amount and rate of H 2 S in the PL system increased significantly compared with that of the P system. The results showed that the introduction of H 2 O promoted the formation of H 2 S, which is consistent with the experimental results. ,,, …”

“…The results showed that the introduction of H 2 O promoted the formation of H 2 S, which is consistent with the experimental results. 8,13,19,20 3.3. Effect of H 2 O on Chemical Bonds.…”

“…From the perspective of thermodynamics, the desulfurization efficiency of coal in an inert atmosphere is not high, so sulfur is mainly contained in semicoke and tar . The steam atmosphere, as an oxidizing atmosphere, is more beneficial to the removal of sulfur in coal than inert atmosphere, especially it can remove more than 90% of inorganic sulfur in coal. , The steam added during pyrolysis or gasification also promotes the production of H 2 S gas, thereby increasing the share of sulfur in the gas and reducing the share of sulfur in the semicoke. ,,, …”

“…17,18 The steam added during pyrolysis or gasification also promotes the production of H 2 S gas, thereby increasing the share of sulfur in the gas and reducing the share of sulfur in the semicoke. 8,13,19,20 However, most of the current research on sulfur transformation during pyrolysis is based on the experimental or kinetic analysis. It is not enough to propose a detailed sulfur transformation mechanism of the pyrolysis process.…”

Performance of a 100 kW Heatpipe Reformer Operating on Lignite

“…The H 2 S content remains in the 1000–2000 ppm range during the whole campaign, which is a common order of magnitude for coal gasification. ,, COS measurement could not be performed because the H 2 O peak overlays the expected COS peak, but there are several publications that indicate a low concentration of COS in lignite-derived synthesis gas under reducing atmosphere . Thiophene concentration varied between 10 and 30 ppm, which is rather at the level of biomass gasification than other lignite-derived synthesis gas. , …”