Phillips patents sulfur recycle retorting system
Oil shales with high sulfur content produce large quantities of hydrogen sulfide upon pyrolysis and large quantities of sulfur dioxide upon combustion of residual carbon. Converting these gaseous sulfur compounds to solids which can be disposed of in an environmentally sound manner would be desirable. Also, a portion of the carbon contained in the kerogen of the shale is generally not converted to upgraded liquid or gaseous products during the pyrolysis step. This residual carbon is typically combusted with oxygen to provide process heat. A process to provide for increased carbon recovery in the form of combustible liquid or gaseous products would be desirable. In one aspect of the invention, retort offgas containing hydrogen sulfide is circulated into contact with an absorbing solution which removes the H/sub 2/S. The absorbing solution is periodically regenerated by contact with oxygen to liberate sulfur dioxide. The sulfur dioxide is then circulated back into the reactor to form a solid reaction product which can be properly disposed of. The retort effluent gas will contain hydrogen in addition to hydrocarbons and H/sub 2/S. By selecting a zinc titanate as the absorbing solution, unsaturated compounds in the gas will become hydrogenated, thus raising the hydrogen/carbon ratio in the offgas at the same time as reducing the concentration of hydrogen sulfide. Another aspect of the invention involves absorbing hydrogen sulfide on a particulate support material. Oxygen is used to liberate SO/sub 2/, as before, which is recycled to the retort and reacts with the spent shale.
- OSTI ID:
- 6242171
- Journal Information:
- Pace Synth. Fuels Rep.; (United States), Vol. 23:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HYDROGEN SULFIDES
WASTE MANAGEMENT
OIL SHALES
RETORTING
SULFUR DIOXIDE
ABSORPTION
FLOWSHEETS
RETORTS
SPENT SHALES
SULFUR CONTENT
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMICAL REACTORS
DECOMPOSITION
DIAGRAMS
DISTILLATION EQUIPMENT
ENERGY SOURCES
EQUIPMENT
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
MANAGEMENT
MATERIALS
OXIDES
OXYGEN COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
SULFUR OXIDES
040402* - Oil Shales & Tar Sands- Surface Methods
040900 - Oil Shales & Tar Sands- Waste management