Patent ID: 7992375

Claim:
A process for treating a cold-start engine exhaust gas stream containing hydrocarbons and other pollutants consisting of flowing said engine exhaust gas stream over 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 comprising a crystalline one-dimensional molecular sieve comprising essentially all silicon oxide and a nitrogen micropore volume of at least about 0.25 cc/gm and having, after calcination, the X-ray diffraction lines of TABLE II. TABLE II Calcined SSZ-73 Relative Integrated 2 Theta (a) d-spacing (Angstroms) Intensity (%) 8.84 10.00 VS 10.69 8.27 W 12.53 7.06 W 16.50 5.37 W 19.54 4.54 W 19.88 4.46 W 21.49 4.13 W 25.23 3.53 W 27.48 3.24 W 33.38 2.68 W (a) ±0.1.