Molecular sieve bed/catalyst to treat automotive exhaust
This patent describes a process for treating a cold-start engine exhaust gas stream containing hydrocarbons and other pollutants. It comprises flowing the engine exhaust gas stream over a molecular sieve bed which preferentially adsorbs the hydrocarbons over water to provide a first exhaust stream, and flowing the first exhaust gas stream over a catalyst to convert any residual hydrocarbons and other pollutants contained in the first exhaust gas stream to innocuous products and provide a treated exhaust stream and discharging the treated exhaust stream into the atmosphere, the molecular sieve bed characterized in that it comprises at least one molecular sieve selected from the group consisting of molecular sieves which have: a framework Si:Al ratio of at least 2.4; are hydrothermally stable; and have a hydrocarbon selectivity ({sup {alpha}} HC-H{sub 2}O) greater than 1.
- Assignee:
- UOP, Des Plaines, IL (United States)
- Patent Number(s):
- US 5078979; A
- Application Number:
- PPN: US 7-555953
- OSTI ID:
- 5517665
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reduction of hydrocarbon losses in a molecular sieve hydrocarbon treating system
Dual converter engine exhaust system for reducing hydrocarbon emissions
Related Subjects
330700 -- Advanced Propulsion Systems-- Emission Control
54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ADSORBENTS
AUTOMOTIVE FUELS
CATALYSTS
EXHAUST GASES
FLUIDS
FUELS
GASEOUS WASTES
GASES
HYDROCARBONS
MOLECULAR SIEVES
ORGANIC COMPOUNDS
POLLUTANTS
WASTES