EPURATION D'HYDROXYDES AVEC RECUPERATION DES GAZ FUGACES ET ACIDIFICATION DE L'OXYDE DE DIAZOTE AVEC RECUPERATION ELECTROLYTIQUE DU DIOXYDE D'AZOTE, AVEC SOUS-SYSTEME DE RECYCLAGEDES HYDROXYDES

HYDROXIDE SCRUBBING WITH FUGITIVE GAS RECOVERY AND NITROUS OXIDE ACIDIFICATION WITH ELECTROLYTIC RETRIEVAL OF NITROGEN DIOXIDE GAS, WITH HYDROXIDE RECYCLING SUBSYSTEM

Abrégé anglais

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.

Revendications

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.

Description

CA 02553812 2006-09-20
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.