U.S. patent application number 11/040719 was filed with the patent office on 2006-02-02 for deicing compositions and methods of use.
Invention is credited to E. G. Leist.
Application Number | 20060022171 11/040719 |
Document ID | / |
Family ID | 34192915 |
Filed Date | 2006-02-02 |
United States Patent
Application |
20060022171 |
Kind Code |
A1 |
Leist; E. G. |
February 2, 2006 |
Deicing compositions and methods of use
Abstract
The invention provides a non-corrosive deicing composition
containing a deicing component, a corrosion inhibitor and a protein
solution having a pH adjusted to between about pH 5 and about pH 7.
Optionally, the deicing composition contains a corrosion inhibitor
as well. The invention also provides a method of removing snow and
ice from a road surface by applying these deicing compositions to
the ice or snow.
Inventors: |
Leist; E. G.; (Lakewood,
CO) |
Correspondence
Address: |
Sheridan Ross PC;Suite 1200
1560 Broadway
Denver
CO
80123
US
|
Family ID: |
34192915 |
Appl. No.: |
11/040719 |
Filed: |
January 21, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10384177 |
Mar 6, 2003 |
6861009 |
|
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11040719 |
Jan 21, 2005 |
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Current U.S.
Class: |
252/387 |
Current CPC
Class: |
C09K 3/185 20130101 |
Class at
Publication: |
252/387 |
International
Class: |
C23F 11/00 20060101
C23F011/00 |
Claims
1. A corrosion inhibiting composition, comprising triethanolamine
and protein solution having a pH adjusted to between about pH 5 and
about pH 7.
2. The corrosion inhibiting composition of claim 1, wherein the
composition comprises between about 30% and about 60%
triethanolamine.
3. The corrosion inhibiting composition of claim 1, wherein the
composition comprises between about 1% and about 15% protein.
4. The corrosion inhibiting composition of claim 1, wherein the
protein solution has been at least partially digested.
5. The corrosion inhibiting composition of claim 1, wherein the
protein is derived from a source selected from the group consisting
of pork hides, pork hooves, beef hides, beef hooves, grain protein
and forage protein.
6. The corrosion inhibiting composition of claim 1, wherein the
protein solution has a pH adjusted to about pH 6.
7. The corrosion inhibiting composition of claim 1, wherein the
protein solution is prepared by mixing a solid protein material
with water and heating the mixture to a temperature of between
about 40.degree. C. and about 82.degree. C. prior to adjusting the
pH.
8. The corrosion inhibiting composition of claim 1, wherein the
protein has been digested with a proteolytic enzyme selected from
the group consisting of trypsin and chymotrypsin
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/384,177, filed Mar. 6, 2003, which is incorporated in
its entirety by this reference.
FIELD OF THE INVENTION
[0002] The invention lies in the field of deicing compositions
suitable for making surfaces free of snow and ice and to methods of
using these compositions.
BACKGROUND OF THE INVENTION
[0003] Most northern cities incur considerable yearly expense in
the removal of snow and ice from streets and other outdoor surfaces
to meet the winter time needs of business, industry, and the public
in general. Reliance on mechanical means of snow or ice removal
alone, however, is insufficient, necessitating the use of deicing
salts. Rock salt or sodium chloride is the most common chemical
used for deicing, primarily because of its low cost, ease of
transportation, and readily dispersible form.
[0004] The cost of the prior art deicing salts, including sodium
chloride, calcium chloride, magnesium chloride, or rock salt, are
deceptively low given the unassumed cost of corrosion to metal
guardrails, bridge supports, metal concrete reinforcing rods and
automobiles. As such, these chemicals ultimately cost the consuming
public far more in corrosion damage than the initial material cost
would indicate. In order to overcome these corrosive properties,
chemicals such as ammonium sulfate, ammonium nitrate, ammonium
chloride, urea, alcohols and glycols have been tested as
replacements for the corrosive salts. While these chemicals reduce
corrosion, they are more expensive, difficult to apply and carry
hidden costs in the form of environmental pollution and toxic
properties.
[0005] In searching for chemicals that can be used to melt ice and
snow without causing corrosion or pollution, the preferable
chemicals should have suitable water solubility, be inexpensive to
produce on an industrial scale and be applicable by generally known
means and equipment. For these reasons, many deicing compositions
have been proposed that contain protein from food, beverage or
agricultural waste streams. For example, deicing compositions have
been proposed that contain by-products from the production of
cheese and milks, waste concentrates from the alcohol distilling
industry, byproducts of sulfite pulp mills, solubles that settle
during the fermentation of wines, and the like. These compositions
also contain corrosive salts but the protein sources appear to
reduce the corrosive effects of the salts while maintaining the
ice- and snow-melting properties. Additionally, the protein
components reduce the need for additional corrosion inhibitors in
the deicing compositions. Unfortunately, the addition of proteins
to deicing solutions causes many problems with handling and
stability characteristics of the solutions. Typically, the protein
sources are difficult, if not impossible to get fully mixed with
the other components of the deicing compositions. Further, any
deicing composition that is made containing a protein component
often forms precipitates and/or flocculates during storage prior to
use and during use as well. If the proteins do not come completely
out of solution to form a precipitate or flocculate, they still
often form gels that cause gelling of the deicing composition and
impair the ability to evenly apply and distribute the deicing
compositions.
[0006] Thus, there exists a need for protein-containing deicing
compositions with good handling and anticorrosive properties that
maintain the ability to melt snow and ice from outdoor
surfaces.
SUMMARY OF THE INVENTION
[0007] In one embodiment, the present invention is a deicing
composition that includes, a deicing component, a corrosion
inhibitor and a protein solution having a pH adjusted to between
about pH 5 and about pH 7. The deicing component can be alkali
metals or alkaline earth metal chlorides, metal sulfates,
phosphates, nitrates, amides, alcohols, glycols, long-chain amines,
ammonium sulfate, ammonium nitrate, ammonium chloride, urea,
glycerol, potassium carbonate, potassium bicarbonate, potassium
acetate, sodium chloride, calcium chloride, magnesium chloride,
calcium formate, calcium magnesium acetate, or sodium dichromate.
The deicing component can be between about 20% and about 30% of the
deicing composition. The corrosion inhibitor can be zinc, antimony,
manganese, cadmium, nickel, cobalt, tin, aluminum, amines,
carbohydrates, gluconates, acetates or citrates and preferably is
triethanol amine. The corrosion inhibitor can be between about
0.05% and about 0.5% of the deicing composition. In an alternative
embodiment, the composition can include a complex carbohydrate
component.
[0008] The protein can be derived from a source selected from the
group consisting of pork hides, pork hooves, beef hides, beef
hooves, grain protein and forage protein. The protein can be at
least partially digested, such as by proteolytic enzymatic
digestion. The protein solution can be prepared by mixing a solid
protein material with water and heating the mixture to a
temperature of between about 40.degree. C. and about 82.degree. C.
prior to adjusting the pH. The protein solution can comprise
between about 0.001% and about 0.2% of the deicing composition.
[0009] In a specific embodiment, the present invention includes an
aqueous deicing composition comprising about 29% MgCl.sub.2, about
1% triethanol amine, and about 0.1% protein solution having a pH
adjusted to between about pH 5 and about pH 7.
[0010] In a further embodiment, the present invention includes an
aqueous corrosion inhibiting composition, comprising
triethanolamine and protein solution having a pH adjusted to
between about pH 5 and about pH 7.
[0011] In another embodiment, the present invention includes a
method of removing snow and ice from a road surface comprising
applying to the snow and ice a deicing composition, comprising a
deicing component, a corrosion inhibitor and a protein solution
having a pH adjusted to between about pH 5 and about pH 7.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The deicing compositions of the present invention comprise
deicing components, corrosion inhibitors and proteins in water in
proportions effective to melt ice and snow while minimizing or
eliminating corrosive degradation of metal surfaces that come in
contact with the compositions. The deicing compositions of the
present invention contain protein components that have been fully
or partially digested. In another aspect of the present invention,
the deicing compositions contain protein components that have been
neutralized. The proteins used in these aspects of the present
invention reduce the corrosive properties of other deicing
components and have additive effects to any corrosion inhibitors
included in the deicing compositions, in addition to improving the
handling and stability of the compositions.
[0013] Deicing components suitable for use in the present invention
include, but are not limited to, alkali metal or alkaline earth
metal chlorides, metal sulfates, phosphates, nitrates, amides,
alcohols, glycols, long-chain amines, ammonium sulfate, ammonium
nitrate, ammonium chloride, urea, glycerol, potassium carbonate,
potassium bicarbonate, potassium acetate, sodium chloride, calcium
chloride, magnesium chloride, calcium formate, calcium magnesium
acetate, and sodium dichromate. These deicing components preferably
constitute between about 20% and about 30% of the final deicing
compositions of the present invention. All composition percentages
given herein are on a weight basis. Preferably, the deicing
components constitute between about 23% and about 30% of the
deicing compositions. More preferably, magnesium chloride is used
as the deicing component in an amount sufficient to provide between
about 23% and about 30% of the final deicing compositions of the
present invention. Most preferably, magnesium chloride is used as
the deicing component in an amount sufficient to provide about 29%
of the final deicing composition.
[0014] Corrosion inhibitors suitable for use in the present
invention include, but are not limited to zinc, antimony,
manganese, cadmium, nickel, cobalt, tin, aluminum, amines (e.g.,
TEA (triethanol amine), carbohydrates, gluconates, acetates and
citrates. The amount of the corrosion inhibitor to be used in the
deicing compositions of the present invention can vary widely
depending on the strength of the corrosion inhibitor as well as
cost or handling concerns associated with the different inhibitors.
Typically, the corrosion inhibitor additive of the present
invention constitutes between about 0.01% and about 1.0%, more
preferably between about 0.05% and about 0.5%, and most preferably
between about 0.25% and about 0.5% of the deicing compositions of
the present invention.
[0015] The protein component of the present invention may be
obtained from many sources. Inexpensive sources of protein suitable
for use in deicing compositions of the present invention can be
found in waste streams or byproducts of agricultural or livestock
processes. Pork and beef hides and hooves are examples of useful
sources of inexpensive protein for use in the deicing compositions
of the present invention. Additionally, grain (e.g., corn and
wheat) and forage proteins are useful in the producing the protein
additives of the deicing components of the present invention. These
protein additives can be first processed to neutralize the pH
before partially or fully digesting them prior to combining them
with the deicing and anti-corrosion components of the present
invention. This digestion and neutralization makes the protein
component of the deicing composition easier to mix with water or
other deicing composition components. Further, this protein
processing greatly improves the handling characteristics of the
final deicing composition by reducing or eliminating physical
characteristics previously seen with deicing compositions that
included protein components. For example, the deicing compositions
of the present invention that contain a neutralized or at least
partially digested protein source are resistant to precipitation,
flocculation and gelling that often occurs in protein-containing
deicing compositions of the prior art. This results in deicing
compositions having greater stability for prolonged periods between
production and application on snow or ice-covered surfaces.
[0016] The protein component of the present invention is typically
a liquid component having protein in solution, being a stable
suspension of protein, or a combination thereof. As used herein,
the term protein solution refers to such a liquid protein
component. As used herein, reference to a stable suspension means a
suspension that maintains a uniform dispersion of the protein under
typical storage conditions for at least about a month, more
preferably three months, more preferably six months and more
preferably a year. Typically, a solid protein material is converted
by mixing it with water and heating the mixture to a temperature of
between about 40.degree. C. and about 82.degree. C. When the
protein has been converted to a liquid protein source, the protein
processing can then continue with neutralization and/or digestion
of the protein in the protein solution. The protein is neutralized
or adjusted to a pH of between about pH 5 and about pH 7.
Preferably, the pH of the protein component is stabilized at about
pH 6. As used herein, reference to adjusting and/or neutralizing
the pH refers to determining the pH of a solution and if it is not
within desired or selected limits, adjusting the pH to be within
the limits. This neutralization can be performed by any methods
commonly known in the art. For example, if the protein source is
initially too alkaline, the pH can be lowered close to the desired
pH by the addition of a weak acid. Conversely, if the protein
source is initially too acidic, a weak base can be added to adjust
the pH of the protein source to the desired pH. Protein solutions
of the present invention typically have between about 10% and about
25% protein.
[0017] The protein source can also be partially or fully digested
by the addition of one or more proteolytic enzymes. Preferably,
nonspecific proteolytic enzymes such as trypsin, chymotrypsin, or
the like are used to partially or fully digest the protein prior to
the addition of the protein source to other components of the
deicing compositions of the present invention. Preferably, the
proteolytic enzyme used for the digestion is Alcalase.RTM.
(Novozymes). The proteolytic enzyme is added to the protein source
and incubated for a time sufficient to partially or fully digest
the protein present in the protein source. The incubation is
typically conducted between about 20.degree. C. and about
60.degree. C. Preferably, the incubation is conducted at room
temperature. The incubation may continue for an indefinite period
of time as there is no need to stop the digestion reaction prior to
adding other components of the deicing compositions nor is there
any need to separate or remove the proteolytic enzymes from the
digested protein source prior to use in the deicing
compositions.
[0018] The proteolytic enzyme may also be added directly to the
deicing composition following the addition of the protein if the
deicing composition includes components in which the proteolytic
enzyme retains activity. In this way, the components of the deicing
composition are combined and mixed and the proteolytic enzyme is
added and allowed to digest the protein contained within the
composition as long as the protein remains active. However, it may
be difficult to first mix the undigested protein source with the
other deicing composition components. For this reason, the
preferred method is the partial or full proteolysis of the proteins
prior to the addition of the protein source to the deicing
composition.
[0019] Hydrolyzed proteins may also be purchased commercially for
use in the deicing compositions of the present invention although
the cost of these commercial sources makes them expensive for use
and distribution on a large scale.
[0020] The processing of the protein component can be performed in
any order although, when conducted, the neutralization processing
is preferably performed first as most proteolytic enzymes have a
higher digestive activity at the more neutral pH.
[0021] The protein component of the deicing compositions is
typically present in an amount constituting between about 0.001%
and about 0.2% of the final composition and more preferably,
between about 0.01% and about 0.15%.
[0022] Optionally, the deicing compositions of the present
invention may also include a carbohydrate component. The addition
of the carbohydrate component lowers the temperature at which the
deicing compositions of the present invention are effective in
aiding the removal of snow or ice. Thus, the addition of the
carbohydrate component is preferred in circumstances in which the
temperature of the snow or ice covered surface to which the deicing
composition is to be applied is much lower than about -1.degree. C.
or -6.degree. C. Preferably, this carbohydrate component is a
complex carbohydrate such as processed corn, sugar beets, processed
forage crops (e.g., alfalfa) or soybeans. A preferred source of the
complex carbohydrate is a carbohydrate mixture obtained from corn
by soaking whole grain corn in water, milling and processing to
remove starch, followed by heat and acid processes to convert
starches to carbohydrates.
[0023] In a preferred embodiment of the present invention, the
deicing composition contains an aqueous MgCl.sub.2 deicing
component and a corrosion inhibitor package containing TEA, protein
and water. This embodiment of the invention is preferably produced
by forming a corrosion inhibitor package containing between about
30% and about 60% by weight TEA, and between about 1% and about 15%
by weight protein, with the remainder water. A separate stock
MgCl.sub.2 solution is then formed which contains between about 20%
and about 35%, preferably between about 26% and about 30%, by
weight MgCl.sub.2 in water. The deicing composition is then formed
by mixing about 1 part of the corrosion inhibitor package with
about 99 parts of the MgCl.sub.2 stock solution.
[0024] Another preferred embodiment of the present invention is a
deicing composition containing a MgCl.sub.2 deicing component, a
carbohydrate component and a corrosion inhibitor package containing
TEA, protein and water. This deicing composition is prepared by
combining a complex carbohydrate mixture with the corrosion
inhibitor package and the MgCl.sub.2 stock solutions described
above. Preferably, the final deicing composition contains between
about 85% to about 90% of the MgCl.sub.2 stock solution, between
about 0.1% to about 2% of the corrosion inhibitor package and
between about 5% and about 15% of the complex carbohydrate
mixture.
[0025] A further aspect of the present invention provides a process
for making road surfaces free of snow and ice, in which
compositions of the present invention are applied onto the road
surfaces. The composition is preferably applied onto the road
surface from a moving vehicle in an amount of sufficient to reduce
snow and ice. The handling and application of the deicing
compositions of the present invention is greatly improved by the
neutralized and digested protein component of the deicing
compositions. This treated protein component prevents gelling and
precipitation of the deicing compositions in the distribution
machinery or on the road surfaces. The application of these deicing
components to the road surface may be repeated as often as desired.
The compositions greatly reduce the damage to metallic surfaces
resulting from corrosion that is typically seen with deicing
chemicals.
[0026] The following Examples are provided to illustrate
embodiments of the present invention and are not intended to limit
the scope of the invention.
EXAMPLES
Example 1
[0027] A deicing composition is prepared as follows. A corrosion
inhibitor component is prepared by making a between 45% and 80% by
weight TEA solution in water and mixing HydroTriticum WAA, a
protein-based product used in the personal care industry and
available from Croda Chemical, resulting in 3% to 10% by weight WAA
in the TEA solution. Add this corrosion inhibitor component to a
magnesium chloride solution at between 0.25% to 1.0% of the
finished product.
Example 2
[0028] A deicing composition is prepared as follows. A corrosion
inhibitor component is prepared by making a between 45% and 80% by
weight TEA solution in water and mixing it with a protein source of
animal byproducts such as hooves and horns. A granular form of the
byproduct is obtained, usually a gelatin form, liquefied with
water, pH adjusted and digested with enzymes. The resulting mixture
has between 3% and 10% by weight of the protein solution in the TEA
solution. Add this corrosion inhibitor component to a magnesium
chloride solution at between 0.25% to 1.0% of the finished
product.
Example 3
[0029] A deicing composition is prepared as follows. A corrosion
inhibitor component is prepared by making a between 45% and 80% by
weight TEA solution in water and mixing it with a protein source of
animal byproducts such as hides. A granular form of the byproduct
is obtained, usually a gelatin form, liquefied with water, pH
adjusted and digested with enzymes. The resulting mixture has
between 3% and 10% by weight of the protein solution in the TEA
solution. Add this corrosion inhibitor component to a magnesium
chloride solution at between 0.25% to 1.0% of the finished
product.
Example 4
[0030] A deicing composition is prepared as follows. A corrosion
inhibitor component is prepared by making a between 45% and 80% by
weight TEA solution in water and mixing it with a protein source of
a forage crop such as alfalfa. Raw, or green, alfalfa (either fresh
from field or dried) is mixed with water and processed into a mulch
that is acidified and centrifuged to extract liquid protein. The
resulting mixture has between 3% and 10% by weight of the protein
solution in the TEA solution. Add this corrosion inhibitor
component to a magnesium chloride solution at between 0.25% to 1.0%
of the finished product.
Example 5
[0031] A deicing composition is prepared as follows. A corrosion
inhibitor component is prepared by making a between 45% and 80% by
weight TEA solution in water and mixing it with a protein source of
corn or soybean. Corn or soybean protein is extracted by milling
the whole grain, removing germ (oils) and by processing extract
liquid proteins. The resulting mixture has between 3% and 10% by
weight of the protein solution in the TEA solution. Add this
corrosion inhibitor component to a magnesium chloride solution at
between 0.25% to 1.0% of the finished product. The principles,
preferred embodiments and modes of operation of the present
invention have been described in the foregoing specification. The
invention which is intended to be protected herein should not,
however, be construed as limited to the particular forms disclosed,
as these are to be regarded as illustrative rather than
restrictive. Variations and changes may be made by those skilled in
the art without departing from the spirit of the present invention.
Accordingly, the foregoing best mode of carrying out the invention
should be considered exemplary in nature and not as limiting to the
scope and spirit of the invention as set forth in the appended
claims.
* * * * *