Sulfidation of zinc titanate and zinc oxide solids
- Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering
This paper describes the sulfidation of bulk mixed oxides of zinc and titanium of various compositions and Zn--Ti--O crystalline phases in H[sub 2]S--H[sub 2]--H[sub 2]O--N[sub 2] gas mixtures was investigated in a thermogravimetric apparatus over the temperature range of 400--800[degrees]C. Comparative sulfidation experiments with ZnO were also performed. In comparison to ZnO, the use of Zn--Ti--O solids allows raising the operating temperature for desulfurization of hot coal-derived fuel gas, e.g., by as much as 94[degrees]C for solids with (Zn/Ti)[sub atomic] = 2/3. The initial sulfidation rate of Zn--Ti--O solids with (Zn/Ti)[sub atomic] [le] 3 was approximately 1.5--2 times slower than for ZnO. Different zinc titanate phases (i.e., Zn[sub 2]TiO[sub 4], ZnTiO[sub 3], and Zn[sub 2]Ti[sub 3]O[sub 8]) had the same initial sulfidation rate. Similar activation energies (9--10 kcal/mol) were measured for ZnO and Zn--Ti--O sulfidation. No effect of H[sub 2] or H[sub 2]O was observed on the initial sulfidation rate. However, at high conversions, rates were lower with increasing H[sub 2] concentrations. Fine particles and cracks were observed in sulfided ZnO as a result of ZnO reduction and subsequent vapor-phase reaction between Zn and H[sub 2]S to form ZnS. These structural effects were largely absent in Zn--Ti--O solids.
- OSTI ID:
- 6915799
- Journal Information:
- Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 31:8; ISSN IECRED; ISSN 0888-5885
- Country of Publication:
- United States
- Language:
- English
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COAL
COAL GASIFICATION
CRACKS
CRYSTALS
DESULFURIZATION
DISPERSIONS
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
GASIFICATION
GRAVIMETRIC ANALYSIS
HOT GAS CLEANUP
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
MATERIALS
MIXTURES
NITROGEN
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PURIFICATION
QUANTITATIVE CHEMICAL ANALYSIS
SIZE
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
THERMOCHEMICAL PROCESSES
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WATER
ZINC COMPOUNDS
ZINC OXIDES