Article View: ca.environment
Article #6340Water, the next oil industry
From: Marc Andelman
Date: Sun, 24 Dec 1995 00:00
Date: Sun, 24 Dec 1995 00:00
498 lines
32381 bytes
32381 bytes
I am looking for a sizeable investment of some
millions of dollars to ensure commercialization of the following patented
water purification technology , called a flow through capacitor.
This is a simple technology that is roughly five times as energy
efficient and much more waste water efficient than the
competing technology of reverse osmosis. Unlike the other
competing technology, Ion Exchange, it does not require salts or
acids to recycle, so does not generate secondary waste. Any of
the above is a sufficient selling point alone. The market is
limitless, and would include salt-less water softeners, anything
that goes into a can, such as the beverage industry, cleaning up
lakes, municipal water supplies, aquaculture, agriculture,
pharmaceuticals, semiconductors, electroplating,etc..
The existing industry is very boiler plate, and has fifty to one
hundred year old products.
If this needs name brand credibility,
Lawrence Livermore National Labs is also working on this, and
was on CNN and in the 11/28/95 Wall Street Journal..
Unfortunately for them, they did not cite my prior art patents,
five issued, one allowed, and more pending.
Interested parties should get in touch with Marc Andelman at
drgonfly@biosource.ultranet.com, or call 508 853 8803, or
FAX 508 853 8772,
snail mail
Marc Andelman
Biosource Inc.
1 Parkton ave, Worcester, MA 01605
Licences are available for many different markets worldwide. A
small part of this is licenced in Japan already, to a Japanese
chemical company.
A product could be immediately developed with off the shelf
products.
Overview of Flow Through Capacitor (FTC)
versus other common technologies
technology
Reverse Osmosis or RO
Description
pushes the feed solution through a membrane at high
pressure.
Drawbacks
Not dead ended Ion exchange is a waste water
technology ; that is, it wastes water. Many more gallons of feed
solution are wasted out the other end than are purified.
Fragility The RO membranes compact over a few years
life span at most, and can often be completely destroyed by
many common feed species, such as Chlorine and Calcium. This
fragility also makes them difficult to sterilize. Fouling of
membranes is a serious problem for RO
expensive - apparatus are relatively large, taking up
lots of floor space
technology
electrodialysis
description uses an electric field to push ions through
alternating membranes of different fixed charge, causing
concentration of ionic species that one desires to separate.
drawbacks
as with RO , also not dead ended,
Fragility - same sorts of problems as with RO membranes
fouling of membranes
expensive
technology
flocculation
advantages
flocculants are very cheap
drawbacks
creates a sludge, often considered hazardous waste under
RCRA, which is very expensive to get rid of. Hazardous waste
generators have to put their name on their barrels of waste, and
are liable in perpetuity. This makes technologies(i.e. flow
through capacitors) which lend themselves to closed cycle, in
house recycling , and closed loop waste schemes attractive
technology
ion exchange
drawbacks
Ion exchange, such as a water softening resin, require chemicals
such as salts, acids, or bases to regenerate and recycle the resin.
This generates secondary waste, as well as consume expensive
and difficult to handle chemicals. The secondary waste makes
ion exchange a cat in the hat solution.
flow through capacitor
disadvantages
generally limited to ionic species, same as electrodialysis, and
ion exchange, but not RO.
advantages
Extreme low energy cost, typically less than 3KW hours per
thousand gallons ( and less, with energy recover ). A comparable
RO application would be around 15KW hours/thousand gallons,
using up tens of thousands of dollars of electricity per year in a
large installation
Very low wastewater- The FTC can release the absorbed ions as
a highly concentrated waste, and can even purify a solid
product. Reverse Osmosis (RO) on the other hand, is difficult
to engineer for less than 50% wastewater. Wastewater down the
drain is another enormous cost saving. Either this or the
electricity saving alone could not only pay for the Flow Through
Capacitor, but could easily justify a retrofit.
Unlike Ion exchange, the FTC can remove all ions at once.
Unlike Ion exchange, does not require use of regenerant
chemicals.
rectification This device can actually chromatographically
resolve different ionic species, unlike any of the other above
techniques except ion exchange chromatography. However,
unlike ion exchange, salt form of ions does not have to be
changed ( but can be if desired). Moreover, the surface charge of
the absorbent is now a completely controllable parameter,
unlike ion exchange where the solid phase charge is fixed.
There is therefore enormous potential for this process not only
for purification of inorganic ions , but also for biologic ions
such as proteins, DNA, whole cells, etc.
inexpensive and potentially durable - These devices have been
made out of cheap and inert materials such as activated carbon
and graphite, available for 57 cents a pound. Cost figures from
small prototypes are less than five cents per gallon per day
capacity. This can lead to a ridiculously low capital cost, and
further optimization is possible.
Fast and Small- On a volume basis, flow through capacitors are
nearly as fast as ion exchange, which is pretty fast and makes an
apparatus perhaps an order of magnitude smaller than RO.
Rough calculations based on the small capacitor indicate
roughly somewhere above 2000 G.P.D. or so per cubic foot of
capacitor bed, for a 90% purification. Much greater
purifications are easily possible, at a slower flow rate.
Easy to operate- Does not require complex regeneration
schemes , therefore potentially a lot easier to operate and design
into a system.
Potential applications
Package plants for apartment complexes, cities, towns.
Purification of water for boiler feed, pharmaceutical industry
water, semiconductor manufacture, beverages, canned food,
washing the cans, creation of gigantic systems to purify outlets
from sewerage plants, or even whole rivers, systems to" mine"
polluted water to recover the valuable phosphates, nitrates.
Recovery and recycling of plating wastes. For residential use,
this would make possible a salt-less water softener. There has
been talk in the US congress about outlawing the use of water
softeners due to the pollution they cause, but this has been
quashed due to the lack of available technology. Anyone with a
home water softener is probably drinking more than the
recommended amount of sodium. Also Point Of Use
applications such as under the sink or counter top filters, water
vending machines, office coolers, filters built into coffee and tea
machines, refrigerator ice makers, etc.. Medical applications
would include an extremely rapid method to replace dialysis.
US patent summary
PATN Patent Bibliographic Information
WKU Patent Number: 05415768
TTL Title of Invention: Flow-through
capacitor
ISD Issue Date: 19950516
NCL Number of Claims: 36
ECL Exemplary Claim Number: 1
EXP Primary Examiner: Therkorn; Ernest
G.
NDR Number of Drawings Sheets: 7
NFG Number of Figures: 16
ABST Abstract
A flow-through capacitor and a controlled charge
chromatography column system using the capacitor for the
purification of a fluid-containing material, which column
comprises an inlet for a fluid to be purified and
an outlet for the discharge of the purified fluid, and a
flow-through capacitor disposed within the column. The
flow-through capacitor comprises a plurality of spirally-wound,
stacked washer or rods to include a first electrically conductive
backing layer, such as of graphite, and a first high surface area
conductive layer secured to one side of the backing
layer, such as carbon fibers, and a second high surface area
conductive layer secured to the opposite side of the backing
layer, the high surface area material layers arranged to face each
other and separated by a nonconductive, ion-permeable spacer
layer to insulate electrically the backing and conductive layer.
The system includes a DC power source to charge the respective
conductive layers with different polarities whereby
a fluid-containing material passing through the column is
purified by the electrically conductive, high surface area
stationary phase and the retention thereof onto the high surface
area layer and permitting, for example, the purification of
aqueous solutions of liquids, such as salt, and providing for the
recovery of a purified liquid.
SUMMARY OF THE INVENTION
The present invention relates to a flow-through capacitor and
method of manufacture and operation and a chromatographic
system and method employing the flow-through capacitor for
the purification of fluids.
The invention concerns a flow-through capacitor for use in
the electrical separation of a fluid, such as for example, but not
limited to, a liquid containing one or more ionic components
therein to be separated or concentrated, and which flow-through
capacitor comprises a porous, first high surface area, electrically
conductive material to act as an anode and a porous, second
high surface area, electrically conductive material to
act as a cathode. The capacitor also includes an ionically
conductive or permeable, electrically insulating spacer material
between the first and second high surface area materials to
isolate electrically the first and second, high surface area
materials. The first and second high surface area materials are
configured in the flow-through capacitor to face
directly each other with only the spacer material intervening.
The flow-through capacitor also includes electrical leads
adapted to connect the anode and cathode of the respective high
surface area materials to a source of electrical power, and
typically includes a housing to contain the flow-through
capacitor with an inlet to direct a fluid to be separated into the
flow-through capacitor and into the space between the first and
second high surface area materials of the capacitor, and an
outlet to recover the separated, purified fluid stream and a
concentrated fluid stream.
It has been discovered that a significant and surprising
improvement in the efficiency of the electrical separation or
purification of a fluid is accomplished when the geometry of the
flow-through capacitor is designed such that the first and
second high surface area layers directly face each
other across only an insulating spacer layer without the
employment of a conductive backing layer interposed
therebetween. Optionally, where a conductive backing layer is
employed, the flow-through capacitor includes
electrically conductive backing material layers having opposite
sides and with the first and second electrically conductive high
surface area materials disposed respectively and secured to the
opposite sides of a pair of the conductive backing material to
produce a flow-through capacitor which includes adjacent
layers, either in spiral, stacked, rod or robe form or in other
geometry form, comprising a first high surface area material and
electrically conductive backing material and a second
high surface area material and an electrically nonconductive
spacer material adjacent either side of the first high surface area
material and the second high surface area material to form an
anode-cathode unit of the flow-through capacitor.
A wide variety of different geometries may be employed in
the flow-through capacitor consistent with having the high
surface area material representing the anode and cathode pairs
of each anode-cathode unit facing each other as alternating
anode-cathode pairs to enhance the quality and efficiency of the
electrical fluid separation. The anode and cathode units
may be partially or completely enclosed employing electrically
conductive backing layers with the high surface area material
generally in layer form facing each other or by omitting the
electrically conductive backing layer material entirely and using
the first and second high surface area material, an
anode-cathode of enhanced or intrinsically greater electrical
conductivity. Since the proportion of the high surface area
material or layer is increased in the present geometry relative to
the optional use of electrically conductive backing layers and
insulating spacer materials and layers, the amount of either
required is also reduced, which permits a more compact
geometry and allows the anode and cathode layers to be closer
to each other; therefore, diminishing harmful, internal resistance
of the flow-through capacitor. It has been discovered that a
flow-through capacitor of this type of geometry provides for
increased speed of purification of the fluids therethrough and
with an increase in the efficiency of the fluid purification.
The invention also includes a method for the purification of a
fluid containing one or more ionic components therein by
electrical separation and which method comprises introducing a
fluid, particularly a liquid having one or more ionic components
therein to be removed or reduced in concentration, into the inlet
of a housing which contains a flow-through capacitor as
described, with the anode and cathode of each anode-cathode
unit in the flow-through capacitor electrically connected to a
DC power supply to provide a controlled charge on the
anode-cathode layers in the flow-through capacitor. The method
includes passing the liquid to be purified between the direct
facing anode-cathode layers and within the
spacer material, while the anode and cathode have different
charges to permit controlled charge absorption of one or more of
the ionic materials in the fluid to be purified onto the one or
both high surface area materials; and discharging the purified
fluid from the outlet of the housing and removing periodically a
concentrated liquid containing the absorbed ionic materials. The
method is particularly adapted to the employment of an aqueous
solution containing one or more ionic salts to provide a purified
aqueous solution with removal or reduction or
separation of one or more of the ionic salts in the solution.
The high surface area conductive material employed in the
flow-through capacitor may be employed in various forms, but
usually is employed in layer-type form. The high surface area
material useful in the practice of the invention may comprise a
wide variety of electrically conductive materials, alone or in
combination, such as, but not limited to: activated
carbon in particle, fiber, or mixtures thereof; activated carbon
particles bonded or retained together with a binder material to
form a continuous high surface area material; woven or
non-woven activated carbon fibrous sheets or cloth; compressed,
activated carbon particles or fibers; or metal, electrically
conductive particles. The high surface area material
may include one or more electrical conductivity enhancing
additives or treatments, such as the use of activated carbon
fibers or particles coated or plated with a conductive material of
metal like palladium or platinum series black. For example, one
high surface area material comprises compressed, activated
carbon particles or fibers or mixtures with homogeneous mixed
conductivity enhancers, such as graphite, acetylene
black, noble metals or noble metal plated materials, fullerenes,
or conductive ceramics or conductive polymers. In another
example, the high surface area material may comprise a woven
carbon fiber cloth with activated carbon strands interwoven or
admixed with strands of a material of enhanced electrical
conductivity, including graphite fibers, noble metals and
conductive polymers. The high surface area material may
include conductive ceramics, conductive polymers, fullerene
material, azite and other conductive material. The electrical
conductivity of the high surface area material may be enhanced
by employing an electrically conductive backing material as a
backing layer, or by adding electrical conductivity
enhancers, such as powdered graphite and acetylene black
homogeneously mixed therewith, or by using a high surface area
material which itself is intrinsically, highly electrically
conductive without any backing layer or enhancer. The high
surface area material may also be activated carbon
treated with a chemical, like alkali, such as potassium
hydroxide, or a halogen, like fluorine, to increase the surface
area and conductivity. Activated carbon material of greater than
about 1000 square meters per gram surface area are preferred.
In one embodiment, the high surface area comprises an
activated carbon fiber woven layer which provides for electrical
conductivity and high porosity, although any other material
which is highly electrically conductive and which has
micropores can be employed for the high surface active area.
Optionally but desiredly, where the separation of certain
fluids are involved, such as with biological fluids, proteins and
organic molecules, the high surface area material may be
processed or treated to reduce the adhesion or absorption of
such molecules to the high surface materials. Typical treatments
would include the use of fluorocarbons, silicones, and
other surfactant-type materials on the high surface area
materials.
The insulating spacer material, usually in layer form, is
placed between the high surface area material to provide
electrical insulation of the anode-cathode pair and is fluid
porous and nonconductive to the flow of electrons, but which is
ionically permeable or conductive to allow the passage
therethrough of ions or ionic carriers. The insulating material
may comprise a porous woven or non-woven fibrous material
composed for example of polymeric or natural fibers or mixtures
thereof, such as olefinic fibers, like polypropylene; polyamide
fibers, like nylon; fiberglass; polyester fibers and fluorocarbon
fibers. The insulating material may also comprise microporous,
polymeric membrane materials of ionically conductive materials,
such as fluorocarbon, polyamide membranes, like Nafion.RTM.
material (a trademark of E. I. Du Pont de Nemours & Co.).
The insulating material may also comprise nonconductive
particles, such as ceramic, silica, polymeric or other
non-insulating material particles, alone or in a mixture formed
in a bed on sheet material. The insulating spacer material
generally has a thickness of less than about 10 mils and a
porosity or molecular cut off of less than about 30 microns, e.g.
10 microns or less, and requires a cut-off of less than the
molecular cut-off of the conductive high surface area material.
The flow-through capacitor is composed of at least one and
typically a plurality of the alternating anode-cathode units, or, if
desired, may be prepared and formed in various geometric forms
and may include a spiral-wound, washer or disk stacked or flat
sheet comprising one layer of a high surface area material, each
with or without an electrically conductive backing layer and
omitting the second insulating layer. The anode-cathode pairs
may also comprise rod or tube-like geometries. The
composite tubes or rods may be any geometrical shape,
including polygons, like hexagons, square, rectangles, triangles
or be circular or elliptical. Moreover, each single high surface
area layer may have one or multiple conductive solid rods or
tubes running inside or through the material to
provide greater conductivity.
Electrical leads are connected to each of the alternate
anode-cathode pairs of electrodes, either connected directly to
the high surface area material where no conductive backing
layer is used or to the electrically conductive backing material.
In one preferred embodiment, the electrical leads are integrally
formed and extend from the high surface area material
or the conductive backing material, which integrally formed
leads reduce electrical resistivity. The electrical leads connect
the series of separate anode-cathode units and are connected to
a DC power supply.
The conductive backing material, such as in layer or other
form, where employed, can be composed of any electrically
conductive material, such as a metal film, for example, of
aluminum, or more particularly, of an electrically conductive
carbon, particularly graphite, in thin foil form.
Where used, the high surface area electrically conductive
material is secured or placed adjacent and on both sides of the
electrically conductive backing material. Generally, the
conductive backing material comprises a graphite foil or a
conductive metal like silver or titanium or other metal or alloys,
on which palladium or platinum black is electrodeposited to
enhance the conductivity, and also selected for their
corrosion-resistant properties. Optionally and preferably, the
conductive backing material may be porous and, for example,
have a plurality of holes to permit liquid flow therethrough.
The thickness of the high surface area material and the
spacer material and the conductive backing material, where
employed, may vary as desired, and generally may range, for
example, from about 1.0 to 10 mils for the conductive backing
material, where employed, and from about 25 to 300 mils
for the high surface area material and about 10 to 100 mils for
the spacer material.
The flow-through capacitor may comprise a spirally-wound
flow-through capacitor which comprises a plurality of spaced
apart layers of the selected material with the high surface area
material layers facing each other and separated by the insulating
spacer material and optionally on either side of a conductive
backing layer, the spacer material defining a flow channel to
permit the flow of the fluid therethrough and the layers
spirally-wound about a hollow central core, the central core
acting as the inlet or outlet of the flow-through capacitor and
typically being porous or having a plurality of holes throughout
its length so as to permit the fluid to be separated or purified
into the porous spacer layer. The flow path of the fluid may be
down through the central core from the outside of
the flow-through capacitor. Generally, the flow-through
capacitor may be sealed at each end and has anode and cathode
leads typically which are integral with the high surface area
material layer or with the conductive backing layer where
employed, which leads are adapted to be connected
through insulation in the housing to a DC control power supply
and control system.
In another embodiment, the flow-through capacitor may
comprise a plurality of stacked washers or disks secured about a
central, nonconductive porous tube or support means with the
washer ends sealed. The central tube may be porous or have
holes punched therein or may be a rod having a plurality of
longitudinal grooves therein for the passage of fluid. The
washers or disks may comprise in series a first high surface area
layer separated by an insulating layer and facing a second high
surface area layer or where, optionally, a conductive backing is
employed, high surface area layers are secured on the opposite
sides of the backing, and thus comprise a sequence
of each anode-cathode unit of an electrically conductive backing
layer, a high surface area layer on one side of the backing layer
and an insulating spacer material layer, and on the opposite side
of the backing layer, a second high surface area layer and an
insulating layer. Generally, the washers are arranged in
sequence as described and stacked about the
central tube and secured together in a compressed, contacting
arrangement for the pressure of threaded end caps or threaded
rods on each side or other means within a housing. The number
of stacked washers may vary asdesired. Th
Technical Details
Message-ID:
<4bif34$ofs@caesar.ultra.net>Path:
arc1-ca.pugleaf.net!unknown!not-for-mailShow Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 10df74,c4d692d458933c2d,start X-Google-Attributes: gid10df74,public From: Marc Andelman <drgonfly@biosource.ultranet.com> Subject: Water, the next oil industry Date: 1995/12/24 Message-ID: <4bif34$ofs@caesar.ultra.net> X-Deja-AN: 122732008 organization: UltraNet Communications, Inc. newsgroups: ca.environment