Specialized metallurgical processes – compositions for use therei – Processes – Producing or treating free metal
Reexamination Certificate
1998-10-10
2001-03-06
Andrews, Melvyn (Department: 1742)
Specialized metallurgical processes, compositions for use therei
Processes
Producing or treating free metal
C075S505000, C075S670000, C075S961000, C588S253000, C588S253000, C588S253000, C588S253000, C423S439000
Reexamination Certificate
active
06197087
ABSTRACT:
BACKGROUND
1. Field of Invention
This invention involves decomposition of halogenated organic hazardous waste materials into inorganic molecules. The wastes are pyrolized/cracked/reformed and reacted with iron oxide in a closed, heated, pressurized Direct Reduction of Iron Oxide (DRI) process.
2. Description of Prior Art
Direct Reduction of Iron oxide to iron and carburization of that iron to iron carbide has been described in Pat. Re. 32247. Methane is the hydrocarbon of choice for this process although use of related short chain hydrocarbons has been postulated.
This is a continuation in part of patent application Ser. No. 08/790,527 issued as U.S. Pat. No. 5,824,134 which teaches decomposition of organic hazardous wastes with polluting fractions selected tom a group consisting of organic phosphates, organic sulfurs, organic nitrogens, or organic mercury or tin.
Pat. U.S. No. 5,425,792 proposed producing syngas by reforming auto shredder and other industrial wastes under high heat in a rotary kiln. Pat. U.S. No. 5,244,490 proposed waste polymer materials as part of the fuel charge in iron melting blast furnaces. Both processes are done at temperatures in excess of 2000 degrees C. and not under the pressures customary in a closed pressurized DRI reactor. They vent products of decomposition to the atmosphere.
Pat. U.S. No. 4,834,792 teaches adding excess methane to DRI reactors to partially carburize sponge iron to make it less pyrophoric during handling.
German Patent 2841039 apparently teaches the test tube scale reduction of metal oxides using Trichlorofluromethane (CFCL3) reagent as a versatile, low temperature reducing agent. The present invention is for commercial scale safe disposal and reuse of halogenated organic waste materials.
OBJECTS AND ADVANTAGES
Accordingly, several objects and advantages of my invention are:
It provides a significant source of added revenue to the operators of a Direct Reduction of Iron Oxide reactor because the novel hydrocarbons used as feedstocks would normally be destined to become hazardous wastes or else their products of decomposition would be hazardous wastes for which disposal is difficult, environmentally hazardous and expensive.
Suppliers of such feedstocks would pay dearly to a DRI processor to accept and consume as feedstock organic hazardous wastes containing organic phosphorous, organic sulfurs, organic nitrogens, organic mercury, or organic tin but including halogenated hydrocarbons. These materials are difficult and expensive to incinerate or otherwise dispose of safely for polluting discharges are almost always released.
A DRI as hazardous feedstock reactor has the advantage that it would require much lower net energy and temperature than any of various hazardous waste incinerators and is closed, pressurized and therefore environmentally safer.
Carbon is not wasted up a stack as polluting CO
2
, but is incorporated and shipped with the iron as iron carbide.
The reactor is essentially a closed pressurized reactor with no polluting stack.
The reaction products are liquid water solid iron, solid iron carbide, may include free tin, free mercury and/or inorganic acid gases. Of said products, resulting water and inorganic remnants of polluting fractions which are scrubbed from the reducing carburizing atmosphere.
The catalysts that helps crack the hazardous waste molecules do not have to be decarburized as does y-zeolite catalyst in petroleum cat crackers since the carburized iron compounds functioning as cracking catalyst in the fluidized bed (or other DRI reactor) are shipped as the end product.
Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings.
SUMMARY
This process disposes of organic hazardous materials by breaking them down into carbon, hydrogen and inorganic forms of the polluting fractions of the beginning organic materials. Waste hydrocarbons with associated polluting fractions are pyrolyzed/cracked/reformed into progressively smaller carbon chains and into CH
4
, CO, CO
2
, H
2
O, H
2
and polluting fractions in the reaction zone of the fluidized bed (or other DRI reactor) containing iron oxide. The CO and H
2
are required to reduce the iron oxide and the CH
4
, and CO carburize the metallic iron. The water along with polluting fractions; possibly phosphates, sulfates, nitrates, or heavy metals such as mercury or tin but specifically including acid gases of halogens, can be continuously scrubbed from the reducing gases by limestone admixed in the iron oxide feedstock, water scrubber in water solution, or in ion scrubbers added for that purpose.
These feedstocks might otherwise be destined to be hazardous waste materials. These materials are difficult to incinerate or otherwise dispose of safely. Polluting byproducts are almost always released. However in this invention the reducing atmosphere is partially scrubbed of unwanted remnants of pyrolysis; soluble and condensed acid gases with condensed water vapor in the direct reduction water scrubbers. The reaction products in such a DRI reactor are inorganic, collectable, and safely reusable or disposable. Suppliers of such feedstocks would pay dearly to provide such hydrocarbons to a DRI processor to save disposal costs. This would add to that processors revenues and avoid the need to purchase some or all the usual methane feedstock.
REFERENCES:
patent: Re. 32247 (1986-09-01), Stevens
patent: 4834792 (1989-05-01), Becerra-Novoa
patent: 5244490 (1993-09-01), Agarwal
patent: 5425989 (1995-06-01), Bishop
patent: 5824134 (1998-10-01), Powers
patent: 2841039 (1980-04-01), None
LandOfFree
Pyrolysis of halogenated organic hazardous wastes with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pyrolysis of halogenated organic hazardous wastes with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pyrolysis of halogenated organic hazardous wastes with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2463357