CA2553812A1

CA2553812A1 - Hydroxide scrubbing with fugitive gas recovery and nitrous oxide acidification with electrolytic retrieval of nitrogen dioxide gas, with hydroxide recycling subsystem

Info

Publication number: CA2553812A1
Application number: CA 2553812
Authority: CA
Inventors: Viva M. Cundliffe
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-06-27
Filing date: 2006-06-27
Publication date: 2007-12-27

Abstract

In a two-phase system of particulate removal from flue gases, a polishing step embodies a hydroxide ion scrubbing tower with catchment systems for mercury oxides, sulphuric acid, nitric acid and carbonic acid in relatively small amounts.
Filtration and fractional distillation will separate these species and will be recycled, reused or inerted and safely land filled. The second phase follows with a full-scale oxidation of the nitrous oxide gas left with carbon dioxide; the target is to oxidize with hydroxide ions to capture all the nitrogen in nitric acid form. Once this is achieved, the nitric acid is placed in large tanks and subjected to electrolytic technique. Because the carbon dioxide gas can escape from this scrubbing, it is separated dried and compressed. The nitric acid tank comprises a sealed covering and as the electricity is applied, the anode will produce oxygen, the cathode will produce both hydrogen and nitrogen dioxide gas. Each electrode is managed so that permeable membranes for hydrogen and oxygen gases are used downstream from a fume distillation column. The fume distillation columns will ensure product gas purity, including carbon dioxide gas. The fumes of nitric acid are then retained back to the main tanks until the molecules are electrolytically treated and the oxygen and hydrogen are captured and reformed into hydroxide ions, using a gas torch blending system and an electronic charging technique.
Hydroxide production then becomes integral to this process. The carbon dioxide gas is thus made fully separate from all other compounds and made ready for dry thermal reforming in order to harvest and recycle carbon fuel.

Description

Description This invention relates to the systematic treatment of nitrogen oxide in preparation for removing it completely from the flue gases of the coal, chemical and metallurgical industries. This removal overcomes the barrier of sequestering carbon dioxide gas for recycling it as a fuel.

Pure hydroxide ions are synthesized and used to scrub small impurities from the gas stream in the first phase, leaving nitrous oxide and carbon dioxide to be dealt with. An acid handling technique is employed by a series of devices, which separate the small amount oi sulphur. mercurv oxides. other oxides. nitric acid and carbonic acids.

The second phase is the use of hydroxide ions to aggressively capture nitrous oxide, converting it to nitrogen dioxide and fully to nitric acid, HNO3. This is the normal and rapid outcome of this reaction. Instead of then having to deal with a large surplus of nitric acid, it is then subjected to electrolysis. The electrolytic reduction of both hydrogen and oxygen using the appropriate anodes and cathodes in conjunction with gas separation and de-fuming columns for nitric acid fumes are established. lhis acid reiiactorv system will emplov distillation columns to remove the acidic fumes and selective membranes above or downstream to the de-fuming columns will separate the remaining three gases.

N02 gas is vented safely to the atmosphere, and oxygen and hydrogen gases escape through their respective membranes to be recycled back into the hydroxide or other system.

This technology process will afford a 100% pure remaining stream of C02, which has also been subjected to fume removal. The gas will be dehydrated as needed, and coinpressed for application in a carbon dioxide furnace, that renders carbon dioxide a feedstock for recycling carbon as a fuel.

Claims

1) This embodiment includes a device to wet scrub impurities known as "fugitive gases" in a flue gas downstream from sulphur dioxide removal, and filter and distil them, then using a hydroxide wet scrub, remove all the nitrogen in the form of nitric acid and capture it into a tank where it is electrolytically reduced to gases, hydrogen, nitrogen dioxide, and oxygen.

2) As in claim 1, the impurity removal will involve a dilute solution of hydroxide ions in water in a tower device where the flue gas passes through and contact between the hydroxide and impurities from coal gasification, or other process in chemical or metallurgical plants that can be oxidized and remove these impurities to the stage that only nitrous oxides and carbon dioxide are left.

3) As in claims 1 and 2, the remaining products are then subjected to a nucleophilic chemical oxidation using hydroxide ions in a wet spraying tower system to the concentration and speed needed to remove all the nitrogen by forming it into nitric acid.

4) As in claim. 3, the formed nitric acid is conveyed to an electrolytic tank, where large membrane electrolytic plates at either side are placed on the walls or surfaces of the acid and the spaces above each electrode are separated hermetically from communicating with each other but the body of acid communicates.

5) As in claims 3 and 4, the working electrodes conducting a charge across the nitric acid begin giving off hydrogen and nitrogen dioxide at the cathode and oxygen at the anode, thus the gases are handled by selective separation membranes once the acid fumes are captured by packed columns.

6) As in claims 1,2, 3, 4, and 5 the packed columns will be operating a lower temperatures and will distil out of the gas stream, all of the nitric acid and retain it back to the main tank, other nitric acid from upstream scrubbing will also be treated here.

7) As in claim 6, the acid-free gases hydrogen and nitrogen dioxide will form on stream, and all of the hydrogen will be removed through a selective permeable membrane system, leaving behind nitrogen dioxide, which is vented, to the atmosphere.

8) As in claim 5,6, and 7, the anode of the system will produce oxygen, which will be purified by packed column and then removed through an oxygen permeable membrane.

9) As in claims 5, 6, 7 and 8 a containment and conveyance of the hydrogen and oxygen gases to additional processing a recycling such as being re-formed back into hydroxide via a gas torch technology, and electrically charged back into hydroxide ions.

10) As in claims 2, 3, 4, 5, 6, 7, 8, 9, the devices and techniques are to attain the formation of NOx species into nitrogen dioxide for venting and effect the full capture of carbon dioxide gas for utilization in a reduction furnace already embodied in another patent.