Selective catalytic reduction system and process using a pre-sulfated zirconia binder
AssigneeSiemens Energy, Inc.
InventorsAnatoly Sobolevskiy, Joseph A. Rossin
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Abstract
A selective catalytic reduction (SCR) process with a palladium catalyst for reducing NOx in a gas, using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream with a catalyst system, the catalyst system comprising (ZrO2)SO4, palladium, and a pre-sulfated zirconia binder. The inclusion of a pre-sulfated zirconia binder substantially increases the durability of a Pd-based SCR catalyst system. A system for implementing the disclosed process is further provided.
Claims18
A process for selective catalytic reduction of nitrogen oxides (NOx) in a gas stream in the presence of H2, the process comprising contacting the gas stream with a catalyst system, the catalyst system comprising (ZrO2)SO4, palladium, and a pre-sulfated zirconia binder.
A process for selective catalytic reduction of nitrogen oxides (NOx) in a gas stream using a hydrogen reducing agent, comprising:
- preparing a catalyst system on a catalytic bed, wherein the catalyst system comprises (ZrO2)SO4, palladium, and a pre-sulfated zirconia binder;
- positioning the catalytic bed in an exhaust stream of a gas turbine;
- injecting the hydrogen reducing agent into the exhaust stream upstream of the catalytic bed to a molar ratio for H2/NOx in the exhaust stream in the range of 10-100;
- injecting H2O into the exhaust stream upstream of the catalytic bed to maintain an H2O concentration in the exhaust stream of about 15-23 vol. %;
- and
- passing the exhaust stream over the catalytic bed at an operating temperature range of 70-250° C.
A system for implementing a process for selective catalytic reduction of nitrogen oxides (NOx) in an exhaust gas from a gas turbine in an integrated gasification combined cycle power plant, comprising:
- a fuel gas synthesizer that produces a fuel gas containing at least 10 vol. % H2 and at least 10 vol. % nitrogen;
- a gas turbine that burns a portion of the fuel gas, producing the exhaust gas;
- a catalytic bed installed in a flow path of the exhaust gas, the catalytic bed comprising a catalyst system comprising (ZrO2)SO4, palladium, and a pre-sulfated zirconia binder;
- a hydrogen injector that mixes a diverted portion of the fuel gas into the exhaust gas between the gas turbine and the catalytic bed;
- an H2O injector that mixes H2O into the exhaust gas between the gas turbine and the catalytic bed;
- and
- sensors and valves at control points in the system connected to a controller that maintains operational conditions in the exhaust gas at the catalytic bed, wherein the operational conditions comprise a temperature between 70-250° C., a molar ratio for H2/NOx in the range of 10-100, and H2O at a concentration of about 15-23 vol. %.
Dependencies are inferred from the claim text.