Process and apparatus

Claim 1

A METHOD FOR OXIDIZING CONSTITUENTS OF EXHAUST GAS FROM AN INTERNAL COMBUSTION ENGINE, SAID GAS CONTAINING CARBON MONOXIDE, HYDROCARBON, AND NITROGEN OXIDES WHICH COMPRISES: PASSING DURING START-UP OF THE ENGINE SAID GAS AND AN EXCESS OF MOLECULAR OXYGEN TO A FIRST CATALYST, PASSING EFFLUENT GASES FROM SAID FIRST CATALYST TO A SUBSEQUENT CATALYST IN SEQUENTIAL GAS FLOW RELATIONSHIP WITH RESPECT TO SAID FIRST CATALYST, AT LEAST UNTIL SAID SUBSEQUENT CATALYST IS AT A TEMPERATURE SUFFICIENT TO PROMOTE THE OXIDATION OF CARBON MONOXIDE IN SAID EXHAUST GAS, SUBSEQUENTLY PASSING ADDED FUEL, MOLECULAR OXYGEN, AND NITROGEN OXIDES-CONTAINING EXHAUST GAS FROM THE ENGINE TO SAID FIRST CATALYST, THE FUEL BEING ADDED ONLY WHEN THE ENGINE INLET MANIFOLD IS AT AN ABSOLUTE PRESSURE OF LESS THAN ABOUT 20 INCHES OF MERCURY, THE AMOUNT OF FUEL BEING IN EXCESS OF THAT STOICHIOMETRICALLY REQUIRED TO CONSUME SAID OXYGEN BY OXIDATION OF THE FUEL AND TO REDUCE THE NITROGEN OXIDES IN SAID GAS, AND PASSING THE EFFLUENT GASES FROM SAID FIRST CATALYST AND MOLE ULAR OXYGEN TO SAID SUBSEQUENT CATALYST TO REDUCE THE CARBON MONOXIDE AND HYDROCARBON CONTENTS OF SAID GASES BY OXIDATION.

Claim 2

A METHOD FOR OXIDIZING CONSTITUENTS OF EXHAUST GAS FROM AN INTERNAL COMBUSTION ENGINE, SAID GAS CONTAINING CARBON MONOXIDE, HYDROCARBON, AND NITROGEN OXIDES WHICH COMPRISES: PASSING DURING START-UP OF THE ENGINE SAID GAS AND AN EXCESS OF MOLECULAR OXYGEN TO A FIRST CATALYST, PASSING EFFLUENT GASES FROM SAID FIRST CATALYST TO A SUBSEQUENT CATALYST IN SEQUENTIAL GAS FLOW RELATIONSHIP WITH RESPECT TO SAID FIRST CATALYST, AT LEAST UNTIL SAID SUBSEQUENT CATALYST IS AT A TEMPERATURE SUFFICIENT TO PROMOTE THE OXIDATION OF CARBON MONOXIDE IN SAID EXHAUST GAS, SUBSEQUENTLY PASSING ADDED FUEL, MOLECULAR OXYGEN, AND NITROGEN OXIDES-CONTAINING EXHAUST GAS FROM THE ENGINE TO SAID FIRST CATALYST, THE FUEL BEING ADDED ONLY WHEN THE ENGINE INLET MANIFOLD IS AT AN ABSOLUTE PRESSURE OF LESS THAN ABOUT 20 INCHES OF MERCURY, THE AMOUNT OF FUEL BEING IN EXCESS OF THAT STOICHIOMETRICALLY REQUIRED TO CONSUME SAID OXYGEN BY OXIDATION OF THE FUEL AND TO REDUCE THE NITROGEN OXIDES IN SAID GAS, AND PASSING THE EFFLUENT GASES FROM SAID FIRST CATALYST AND MOLE ULAR OXYGEN TO SAID SUBSEQUENT CATALYST TO REDUCE THE CARBON MONOXIDE AND HYDROCARBON CONTENTS OF SAID GASES BY OXIDATION.

Claim 3

A method for oxidizing constituents of exhaust gas from an internal combustion engine, said gas containing carbon monoxide, hydrocarbon, and nitrogen oxides which comprises: passing during start-up of the engine said gas, an excess of molecular oxygen and an added fuel to a first catalyst; passing effluent gases from said first catalyst to a subsequent catalyst in sequential gas flow relationship with respect to said first catalyst, at least until said subsequent catalyst is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalyst, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first catalyst and molecular oxygen to said subsequent catalyst to reduce the carbon monoxide and hydrocarbon contents of said gases by oxidation.

Claim 4

A method for oxidizing constituents of exhaust gas from an internal combustion engine, said gas containing carbon monoxide, hydrocarbon, and nitrogen oxides which comprises: passing during start-up of the engine said gas, an excess of molecular oxygen and an added fuel to a first catalyst; passing effluent gases from said first catalyst to a subsequent catalyst in sequential gas flow relationship with respect to said first catalyst, at least until said subsequent catalyst is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalyst, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first catalyst and molecular oxygen to said subsequent catalyst to reduce the carbon monoxide and hydrocarbon contents of said gases by oxidation.

Claim 5

A method for oxidizing constituents of exhaust gas from an internal combustion engine having an exhaust manifold, said gas containing carbon monoxide, hydrocarbon and nitrogen oxides, which comprises: passing during start-up of the engine said gas and an excess of molecular oxygen to a first catalytic converter vessel positioned closely-adjacent said exhaust manifold; passing effluent gases from said first catalytic converter vessel to a separate catalytic converter vessel positioned in a spaced-away gas flow relationship with respect to said first catalytic converter at least until the catalyst in said second catalytic converter is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalytic converter, the fuel being added only when the engine inlet manifold is at an absolute pressure of less than 20 inches of mercury, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first converter and an excess of molecular oxygen to said separate catalytic converter to reduce the carbon monoxide and hydrocarbon contents of said gas by oxidation.

Claim 6

A method for oxidizing constituents of exhaust gas from an internal combustion engine having an exhaust manifold, said gas containing carbon monoxide, hydrocarbon and nitrogen oxides, which comprises: passing during start-up of the engine said gas and an excess of molecular oxygen to a first catalytic converter vessel positioned closely-adjacent said exhaust manifold; passing effluent gases from said first catalytic converter vessel to a separate catalytic converter vessel positioned in a spaced-away gas flow relationship with respect to said first catalytic converter at least until the catalyst in said second catalytic converter is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalytic converter, the fuel being added only when the engine inlet manifold is at an absolute pressure of less than 20 inches of mercury, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first converter and an excess of molecular oxygen to said separate catalytic converter to reduce the carbon monoxide and hydrocarbon contents of said gas by oxidation.

Claim 7

A method for oxidizing constituents of exhaust gas from an internal combustion engine having an exhaust manifold, said gas containing carbon monoxide, hydrocarboN and nitrogen oxides, which comprises: passing during start-up of the engine said gas, an excess of molecular oxygen and an added fuel to a first catalytic converter vessel positioned closely-adjacent said exhaust manifold; passing effluent gases from said first catalytic converter vessel to a separate catalytic converter vessel positioned in a spaced-away gas flow relationship with respect to said first catalytic converter at least until the catalyst in said second catalytic converter is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalytic converter, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first converter and an excess of molecular oxygen to said separate catalytic converter to reduce the carbon monoxide and hydrocarbon contents of said gas by oxidation.

Claim 8

A method for oxidizing constituents of exhaust gas from an internal combustion engine having an exhaust manifold, said gas containing carbon monoxide, hydrocarboN and nitrogen oxides, which comprises: passing during start-up of the engine said gas, an excess of molecular oxygen and an added fuel to a first catalytic converter vessel positioned closely-adjacent said exhaust manifold; passing effluent gases from said first catalytic converter vessel to a separate catalytic converter vessel positioned in a spaced-away gas flow relationship with respect to said first catalytic converter at least until the catalyst in said second catalytic converter is at a temperature sufficient to promote the oxidation of carbon monoxide in said exhaust gas; subsequently passing added fuel, molecular oxygen, and nitrogen oxides-containing exhaust gas from the engine to said first catalytic converter, the amount of added fuel being in excess of that stoichiometrically required to consume said oxygen by oxidation of the fuel and to reduce the nitrogen oxides in said gas; and passing the effluent gases from said first converter and an excess of molecular oxygen to said separate catalytic converter to reduce the carbon monoxide and hydrocarbon contents of said gas by oxidation.