Method for reducing emissions from two-stroke engines

• US 5,819,529 A
• Filed: 07/09/1997
• Issued: 10/13/1998
• Est. Priority Date: 10/07/1994
• Status: Expired due to Term

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Peter-Hoblyn, Jeremy D.
• Primary Examiner(s): Denion, Thomas E.
• Application Number:
  US08/890,145
• Time in Patent Office: 461 Days
• Field of Search: 60/295, 60/274
• US Class Current: 60/274
• CPC Class Codes: C10L 1/143 mixtures of organic macromolecular compounds with organic non-macromolecular compounds
• CPC Class Codes: C10L 1/1616 fractions, e.g. lubricants, solvents, naphta, bitumen, tars, terpentine
• CPC Class Codes: C10L 1/1633 homo- or copolymers obtained by reactions only involving carbon-to carbon unsaturated bonds
• CPC Class Codes: C10L 1/1641 from compounds containing aliphatic monomers
• CPC Class Codes: C10L 1/1691 petroleum waxes, mineral waxes; paraffines; alkylation products; Friedel-Crafts condensation products; petroleum resins; modified waxes (oxidised)
• CPC Class Codes: C10L 1/1814 Chelates
• CPC Class Codes: C10L 1/1832 mono-hydroxy C10L1/1802, C10L1/1805, C10L1/1808, C10L1/1811, C10L1/1814, C10L1/1817, C10L1/1828 take precedence
• CPC Class Codes: C10L 1/1852 Ethers; Acetals; Ketals; Orthoesters
• CPC Class Codes: C10L 1/1883 polycarboxylic acid
• CPC Class Codes: C10L 1/1905 of di- or polycarboxylic acids
• CPC Class Codes: C10L 1/191 of di- or polyhydroxyalcohols
• CPC Class Codes: C10L 1/1985 polyethers, e.g. di- polygylcols and derivatives; ethers - esters
• CPC Class Codes: C10L 1/201 aliphatic bond
• CPC Class Codes: C10L 1/207 containing halogen with or without hydrogen
• CPC Class Codes: C10L 1/2412 sulfur bond to an aromatic radical
• CPC Class Codes: C10L 1/2633 phosphorus bond to oxygen (no P. C. bond)
• CPC Class Codes: C10L 1/28 containing silicon
• CPC Class Codes: C10L 1/301 derived from metals
• CPC Class Codes: C10L 1/305 organo-metallic compounds (containing a metal to carbon bond)
• CPC Class Codes: C10L 1/306 organo Pb compounds
• CPC Class Codes: C10L 10/02 : for reducing smoke development
• CPC Class Codes: C10M 159/18 : Complexes with metals
• CPC Class Codes: C10M 2201/065 : Sulfides; Selenides; Tellurides
• CPC Class Codes: C10M 2227/08 : having metal-to-carbon bonds
• CPC Class Codes: C10N 2010/14 : Group 7
• CPC Class Codes: C10N 2010/16 : Groups 8, 9, or 10
• CPC Class Codes: C10N 2040/26 : Two-strokes or two-cycle engines
• CPC Class Codes: F01M 3/00 : Lubrication specially adapted for engines with crankcase compression of fuel-air mixture or for other engines in which lubricant is contained in fuel, combustion air, or fuel-air mixture separating lubricant from air or fuel-air mixture before entry into cylinder F01M11/08
• CPC Class Codes: F02B 1/04 : with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 2075/025 : two
• CPC Class Codes: F02B 47/00 : Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
• CPC Class Codes: F02B 51/02 : involving catalysts
• CPC Class Codes: F05C 2201/0427 : Platinum group, e.g. Pt, Ir
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

The effectiveness is prolonged for catalytic oxidizers to reduce emissions of both HC and CO from two-stroke gasoline engines. A compound of a platinum group metal is added to the cylinder of the engine, to make it available as an active oxidation catalyst by combustion of the fuel. Preferably, the platinum group metal compound is added with the lubricating oil, but can be added to the fuel or through a separate injection.

Claims

1. A method for operating a two-stroke gasoline engine equipped with a catalytic oxidizer to simultaneously reduce both HC and CO while maintaining catalytic efficiency over long periods of operation, comprising:

adding a platinum group metal compound selected from the group consisting of coordination compounds, acetylacetonates, dibenzylidene acetonates and tetramine soaps to the cylinder of the two-stroke gasoline engine equipped with a catalytic oxidizer capable of reducing at least HC and CO levels in the exhaust from the engine, the platinum group metal compound being added to the cylinder in an amount sufficient to provide from about 0.1 to about 1.0 milligram of platinum group metal for each liter of fuel comprising gasoline, the amount being effective to maintain the efficiency of the catalytic oxidizer over extended periods of time;

igniting the fuel in the cylinder in the presence of the platinum group metal compound to release the platinum group metal as an active oxidation catalyst and produce an exhaust gas rich in unburned hydrocarbons and containing the platinum group metal catalyst; and

passing the exhaust gas containing the platinum group metal catalyst through an exhaust duct and through the catalytic oxidizer, whereby the catalytic oxidizer is maintained at greater than 65% of its original efficiency after 6000 km of operation.

2. A method according to claim 1 wherein the catalytic oxidizer is maintained at greater than 80% of its original efficiency after 6000 km of operation.

3. A method according to claim 1 wherein the platinum group metal compound is added to the fuel prior to introducing it into the combustion chamber.

4. A method according to claim 3 wherein the platinum group metal compound is added in an amount effective to provide a concentration of the metal in the fuel of from about 0.15 to about 0.75 milligrams per liter of fuel.

5. A method according to claim 1 wherein the platinum group metal compound is added to the lubricating oil prior to introducing it into the combustion chamber.

6. A method according to claim 1 wherein the platinum group metal compound is added to the combustion chamber through a separate injection.