Review of metals and binary oxides as sorbents for removing sulfur from coal-derived gases

High temperature desulfurization over nano-scale high surface area ceria for application in SOFC

“…In the present work, a deactivation model is proposed with the following assumptions: isothermal condition, pseudo-steady-state condition, first-order deactivation of the absorbent with respect to the solid surface which can be described in terms of an exponential decrease with time in its available surface, and constant activity throughout the surface of absorbent. The combined equation of mole balance and rate law for the packed bed reactor is given below: (6) The boundary conditions at inlet concentrations are At t=0 , C H2S =C H2Sin At t=t, C H 2 S =C H 2 Sout Therefore, (7) The first order exponential decay is a(t)=e k d t , substituting Eq. (6) to Eq.…”

“…The combined equation of mole balance and rate law for the packed bed reactor is given below: (6) The boundary conditions at inlet concentrations are At t=0 , C H2S =C H2Sin At t=t, C H 2 S =C H 2 Sout Therefore, (7) The first order exponential decay is a(t)=e k d t , substituting Eq. (6) to Eq. (8): (8) This equation is equivalent to the breakthrough [25].…”

“…ZnO has the most favorable thermodynamics for H 2 S removal among sorbents that have been investigated. However, despite its attractive thermodynamic properties, the reduction of ZnO and subsequent vaporization of elemental zinc create a serious problem over many cycles of sulfidation/regeneration at high temperatures [6,7]. As a result, alternate absorbents to minimize ZnO problems at high temperature ranges are needed.…”

Catalysts and Sorbents for Thermochemical Conversion of Biomass to Renewable Biofuels—Material Development Needs

“…39 Iron-, cobalt-, and copper-oxide based materials readily reduce in syngas at high temperature. 51 Metallic copper is thermodynamically less active in its reaction with H 2 S than copper oxides. In the development of sorbents targeted for coal syngas applications in the last two to three decades, the focus has been on producing high capacity, regenerable materials that are stable in high temperature, reducing environments.…”

Simultaneous removal of H{sub 2}S and NH{sub 3} in coal gasification processes. Final report

“…Cas forms readily under reducing conditions, and CaSO, forms under oxidizing conditions. The principal limitations of Ca-based sorbents are that at low temperatures, the chemical reaction is slow, and at high temperatures, sintering results in slow mass transport of reactants and products, and regeneration of the spent sorbent is difficult (Swisher and Swhwerdtfeger, 1992).…”