Reduced-emissions combustion utilizing multiple-component metallic combustion catalyst

• US 20030148235A1
• Filed: 11/29/2002
• Published: 08/07/2003
• Est. Priority Date: 02/04/2002
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Sprague, Barry N., Valentine, James M.
• Granted Patent: US 6,948,926 B2
• Time in Patent Office: Days
• US Class Current: 431/4
• CPC Class Codes: C10L 1/10 containing additives
• CPC Class Codes: C10L 1/1241 metal carbonyls
• CPC Class Codes: C10L 1/125 water
• CPC Class Codes: C10L 1/1608 Well defined compounds, e.g. hexane, benzene
• CPC Class Codes: C10L 1/1814 Chelates
• CPC Class Codes: C10L 1/1881 carboxylic group attached to an aliphatic carbon atom
• CPC Class Codes: C10L 1/1886 naphthenic acid
• CPC Class Codes: C10L 1/1888 tall oil
• CPC Class Codes: C10L 1/2222 (cyclo)aliphatic amines; polyamines (no macromolecular substituent 30C); quaternair ammonium compounds; carbamates C10L1/221 takes precedence
• 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 10/02 for reducing smoke development
• CPC Class Codes: C10L 10/06 for facilitating soot removal
• CPC Class Codes: C10L 10/14 for improving low temperature properties
• CPC Class Codes: F01N 2430/04 by adding non-fuel substances to combustion air or fuel, e.g. additives
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F23J 7/00 Arrangement of devices for supplying chemicals to fire
• CPC Class Codes: F23K 2300/103 Mixing with other fluids
• CPC Class Codes: F23K 2900/05081 Treating the fuel with catalyst to enhance combustion
• CPC Class Codes: F23K 5/08 Preparation of fuel

Abstract

Residual fuels, as well as lighter distillate fuels, are combusted with greater efficiency by utilizing low concentrations of specific bimetallic or trimetallic fuel-borne catalysts. The catalysts reduce fouling of heat transfer surfaces by unburned carbon while limiting the amount of secondary additive ash which may itself cause overloading of particulate collector devices or emissions of toxic ultra fine particles when used in forms and quantities typically employed. By utilizing a fuel containing a fuel-soluble catalyst comprised of platinum and at least one additional metal comprising cerium and/or iron, production of pollutants of the type generated by incomplete combustion is reduced. Ultra low levels of nontoxic metal combustion catalysts are able to be employed for improved heat recovery and lower emissions of regulated pollutants.

Claims

1. A process for improving combustion of residual fuels, which are notoriously dirty in terms of soot generation, to reduce soot formation initially and/or to aid auto combustion of soot in the combustor, on the heat transfer surfaces, or in the ductwork downstream of the combustor, comprising:

adding to a residual fuel, a multi catalyst composition comprising platinum at concentrations of from only 0.0005 to less than 0.15 ppm and cerium and/or iron at total concentrations of from only 0.05 to less than 20 ppm, for at least a part of a treatment regimen.

4. A process according to any of claims 1 to 3, wherein the bimetallic and trimetallic platinum combinations provide low temperature soot oxidation with low additive feed rates and cost.

5. A process according to any of claims 1 to 3, wherein the use of the process results in soot oxidation temperatures reduced from 540-600°

C. for untreated fuels to 300°

C. for fuel treated with about 6 ppm of the bimetallic and trimetallic platinum combinations.

2. A process for improving combustion of burning light fuels, such as those categorized as distillate fuel oils, such as No. 2 fuel oil, which can result in lesser, but significant production of carbonaceous soot, to reduce soot formation initially and/or to aid auto combustion of soot in the combustor, on the heat transfer surfaces, or in the ductwork downstream of the combustor, comprising:

adding to a light fuel, a multi catalyst composition comprising platinum at concentrations of from only 0.0005 to less than 0.15 ppm and cerium and/or iron at total concentrations of from only 0.5 to less than 8 ppm.

3. A process for improving combustion of pilot fuel in a dual-fuel diesel engine, which operates principally on natural gas, comprising:

adding to a pilot fuel, a multi catalyst composition comprising platinum at concentrations of from only 0.0005 to less than 0.15 ppm and cerium and/or iron at total concentrations of from only 0.5 to less than 8 ppm

6. A process for combusting a carbonaceous fuel comprising:

mixing with fuel or combustion air a multi-component combustion catalyst comprising a platinum composition and cerium and/or iron compositions at levels reduced to as low as 0.0005 ppm for platinum and levels as low as 0.5 ppm for the cerium and iron;

and combusting fuel with air in the presence of the catalyst in a regimen of treatment that will utilize effective catalyst levels for a time and under conditions, which will achieve one or more of the noted improvements.

7. A process for combusting a carbonaceous fuel comprising:

mixing with fuel or combustion air a multi-component combustion catalyst comprising a platinum composition and cerium and/or iron compositions at levels of from about 0.0005 to 2 ppm for platinum and levels of from about 1 to 25 ppm for the cerium and iron;

combusting fuel with air in the presence of the catalyst in a regimen of treatment that will utilize effective catalyst levels for a time and under conditions, which will achieve one or more of the noted improvements;

then, for at least a period of time changing the amount of catalyst utilized by mixing with fuel or combustion air a multi-component combustion catalyst comprising a platinum composition and cerium and/or iron compositions at levels reduced to as low as 0.0005 ppm for platinum and levels as low as 0.5 ppm for the cerium and iron;

and combusting fuel with air in the presence of the catalyst in a regimen of treatment that will utilize effective catalyst levels for a time and under conditions, which will achieve one or more of the noted improvements.

8. A process for combusting a carbonaceous fuel comprising:

for at least a part of a treatment regimen utilizing higher catalyst concentrations, mixing with fuel a multi-component combustion catalyst comprising a platinum composition and cerium and/or iron compositions at levels of 0.0005 to less than 0.15 ppm for platinum and levels of 0.05 to less than 1.0 ppm for the cerium and iron; and

combusting the fuel with air in a regimen of treatment that will achieve one or more of the noted improvements.