Main results on research and development on the hydrogen sulfide obtained In laboratory of Environmental Catalysis
- The oxide catalysts of different geometrical shape (spherical for using in fluidized bed apparatuses granulated, honeycomb monolith for fixed bed reactors) both supported and massive are developed.
- The regularities of the heterogeneous catalytic oxidation upon wide variation of the composition of initial gas mixture, hydrogen sulfide/oxygen ratio, temperature, catalysts formula and geometry are studied.
- The hydrogen sulfide conversion toward elemental sulfur is close to the 100% in temperature region 210-260oC where the same one for the propane is close to zero, thus introduction of the hydrocarbons to the initial gas mixture will not lead to the deactivation of the catalysts. This fact was proved upon field tests of the catalyst in the process of purification of natural gas containing hydrocarbons C1-C7.
Conversion of H2S to S and oxidation of C3H8 in oxidation of their mixture
- On the base of the laboratory experiments on the conversion of the hydrogen sulfide toward elemental sulfur the developed catalysts can be range in consecution as following.
Co3O4 > V2O5 > Fe = Cr > Mn > γ -Al2O3 ( T > 523 K )
V2O5 > Fe2O3 = Cr2O3> Co3O4 > Mn2O3 > γ -Al2O3 ( T < 523 K )
- Advanced multicomponent spherical catalyst containing titania, tungsten and vanadium oxides with high activity upon overstoichiomeric O2/H2
S ratio and space velocity up to 18000 h-1 is developed. The catalyst is tested in laboratory and pilot scale.
Conversion hydrogen sulfide and sulfur yield over multicomponent oxide catalyst
- By the FTIR spectroscopy of adsorbed CO it has been found that all the catalysts have both Lewis and Broensted acid sites on the surface. However the nature,
strength and number of sites are all particular for each type of catalyst.
FTIR spectra of adsorbed CO on fresh catalysts (top) and after H2S exposure
- DRS study have shown that various types of elemental sulfur: S4-S8 are formed on the catalyst surface during the reaction depending on the catalyst nature.
DRS spectra of sulfur formed during H2S interaction with studied catalysts
Possible mechanism of H2S oxidation
The mechanism of the hydrogen sulfide oxidation on the oxide catalysts in studied by optical methods (FTIR and UV-Vis DRS).
Possible mechanism of H2S oxidation
Direct decomposition of H2S in a catalytic membrane reactor
One of the promissing ways for purification of various gases from H2S and pure hydrogen production is the high-temperature heterogeneous decomposition
of hydrogen sulfide. The efficiency of the process can be increased substantially by using of an inorganic membrane reactor for simultaneous hydrogen sulfide decomposition
and hydrogen extraction.
Diagram of the Reactor for the Process of
Hydrogen Sulfide Decomposition on Membrane Catalyst
Inorganic Catalytic Membrane Composition
- Membrane support - Alumosilicate
- Top-layer - Gamma-alumina
- Catalytic material - Iron oxide
Main results on Catalytic Membrane testing
- Application of membrane catalyst leads to substantial increase of H2S conversion in comparison with spherical catalyst. The H2S conversion on membrane catalyst at 900oC achieves 70% at 900oC;
- The separation coefficients of a=3¸4 for H2 and H2S have been attained.
Process of direct catalytic oxidation of hydrogen sulfide to elemental sufur
for purification of gas streams formed upon high-sulfur crude extraction and processing
New catalysts and advanced technology for catalytic reduction of sulfur dioxide from emissions of nonferrous smelters
Catalytic Synthesis of Thiophene from Dialkyl Disulfides and n-Butane