CA3179616A1 - High alkaline high foam cleaner for maritime applications - Google Patents

Abstract

An aqueous caustic composition for cleaning a cargo hold on a ship, said composition comprising: - a caustic component; - water; - a polyacrylate polymer surfactant; and - a microemulsion comprising: o a nonionic alkyl polyglucoside surfactant; o water; o an alkanolamine; o DDBSA; o a hydrophobic component; and - optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.

Description

HIGH ALKALINE HIGH FOAM CLEANER FOR MARITIME APPLICATIONS
FIELD OF THE INVENTION
The present invention is directed to novel composition for use in the cleaning of pipes, equipment, and open vessels used in transport of bulk materials, such as grain, coal and the like.
BACKGROUND OF THE INVENTION
Several materials typically carried in the cargo hold of ships require water to wash the cargo hold after unloading, these include: ammonium nitrate; ammonium sulfate; potash;
salt; urea; and soda ash.
However, other materials carried in the cargo hold of ships will require more than a simple water wash, these include but are not necessarily limited to: coke; coal; pig iron;
aluminum dross; pyrite; lead; copper;
iron ore; clay; dolomite; anthracite; bauxite; magnetite; talc; petcoke;
wheat; peat moss; and fly ash.
It then becomes very important for transporters to be able to clean the cargo hold of their ships prior to loading a different material thereinto.
When cleaning cargo holds at or in close proximity of a port, transporters must be careful to follow local applicable regulations with respect to the disposal of hold washings. In some cases, it may prove necessary to retain washing onboard or dispose ashore using road tankers or approved facilities. In many cases, only approved companies can carry out the disposal of hold washings, and regulations require paper work and even receipts to prove that protocols were followed when washing the cargo holds of ships.
After removal of the bulk materials from the cargo holds, it is desirable to sweep remaining material starting the washing of the cargo hold. Removal of the solid leftover material prior to washing will avoid unwanted build-up of residue in hold bilges and will as a consequence, avoid any potential difficulties during the pumping of washing water.
A cleaning of cargo hold is understood to mean a thorough cleaning and drying of any trace of previous cargo in frames, beams, girders, and other structure. It is also important to, at the same time as the cleaning is being carried out, inspect the surfaces to remove and indications of any loose rust and or paint scale anywhere in the cargo hold, bulkheads, upper and lower hopper spaces, underneath of hatch covers and tank top.

Date Regue/Date Received 2022-10-21 There are several reasons why it is important to clean a cargo hold before a subsequent shipment is undertaken. A first one and perhaps the most important one is to avoid cargo contamination which can lead to cargo damage and subsequent claims or legal action. In many cases, improper cleaning can lead to authorities preventing a ship from leaving port until issues related to cleaning are resolved. Time wasted in port translates to a loss of revenue for a ship operator. Remaining residues of a previous shipment may not only damage the next load, but can also damage the surfaces by damaging the paint finish and cause corrosion inside the cargo hold which is highly undesirable.
After discharging Coal or pet coke, which leave staining, it is often necessary to use heavy-duty alkaline detergents, which are applied as an emulsion, need time to take effect and are rinsed away with seawater.
Commercially available cargo hold cleaners which are formulated to create a high foam contain, in one instance, fatty alcohol ethoxylates; potassium hydroxide; disodium metasilicate; disodium cocoamphodiacetate; and 2-(2-butoxyethoxy)ethanol.
Sodium (or disodium) metasilicate is soluble in water and can be used as an emulsifying agent or a suspension agent when formulated to make soaps or detergents. It does carry a number of hazard statements due to its nature, some of these statements include 'harmful if swallowed', 'causes severe skin burns and eye damage', 'causes skin irritation', 'causes serious eye irritation', and 'may cause respiratory irritation'.
While a valuable additive to foaming compositions, especially for the cleaning of ship cargo holds, it is desirable to develop formulations which are as effective if not moreso, but safer for the operators and users of such foaming cargo hold cleaning compositions. Hence, the removal of sodium metasilicate from compositions would necessarily yield a safer product for users.
Generally, the quality of a cleaner is associated with its ability to produce a lot of foam. However, for industrial cleaning purposes, long-life foams (a foam which takes a long period of time to subside) can be undesirable as the foam would stay for long time which lengthens the duration of the cleaning process and reduce hours of production. Hence, formulations that have high foamability but also controlled foam life are necessary. For open vessel cleaning formulations having shorter foam life are more desirable.
Formulations with high reduction of contact angles and controlled foam life were developed for hard surface cleaning.

2 Date Regue/Date Received 2022-10-21 Hard surface cleaning compositions are well known and are deployed in a variety of applications, and are utilized for cleaning and disinfecting processing, packaging, manufacturing and transfer equipment in a variety of industrial processing plants. Conventionally, alkaline cleaners, acidic cleaners, bactericides, etc. have been utilized for cleaning-in-place (CIP cleaning) applications for long time.
It has also become important for cleaning solutions to be formulated in such a way as to have less impact on the environment (to be "green") and provide increased safety for transportation, storage and the personnel handling them. One way in which this is encouraged is through a program of the United States Environmental Protection Agency, known as the Design for the Environment Program ("DfE"). DfE
certifies "green" cleaning products through the Safer Product Labeling Program.
US patent application number 2008/0119382A1 discloses a foamable composition comprising: a) at least one anionic surfactant chosen from a salt of an alkyl sulfate and a salt of an alkyl ether sulfate in an amount of about 0.01 to about 1% by weight of the composition; b) at least one glycol ether in an amount of about 0.1 to about 1.5% by weight of the composition; c) at least one alcohol in an amount of about 2 to about 6% by weight of the composition; and d) water. Also disclosed is a foamable composition comprising: a) at least one anionic surfactant chosen from a salt of an alkyl sulfate and a salt of an alkyl ether sulfate; b) at least one glycol ether; c) at least one alcohol; and d) water, wherein the composition has a run-down time of greater than about 15 seconds on a vertical glass surface across a distance of 10 cm.
In light of the state of the art, there still exists a need for high pH
compositions to clean the cargo holds of ships, which can be used at a lower temperature while still remaining effective. Moreover, a high pH composition that can clean both the organic soils and inorganic scales simultaneously would reduce the time of cleaning, thus reducing the cost of cleaning as well as the environmental impact of doing so.
Preferably, it is also desirable to seek out compositions that accomplish the cleaning as efficiently (or even more so) than currently used compositions but which offer a better HSE profile for people using such compositions.
In light of the prior art, while there are many available types of cleaning compositions, there is still a need for caustic composition which can provide effective cleaning of vessels from both the organic soils and inorganic scales simultaneously, said composition would preferably provide a high foaming effect but with a controlled duration so as to not be damaging to the steel to which they are exposed and would, in most preferable cases, provide an increased level of HSE for workers handling the compositions.

3 Date Regue/Date Received 2022-10-21 SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a caustic composition for use in washing the cargo holds of ships. Preferably, the present invention relates to a microemulsion-containing caustic composition for use in cleaning a ship's cargo hold. Preferably, the microemulsion-containing caustic composition can dissolve and/or remove organic soils, inorganic scales or other contaminants simultaneously.
According to a first aspect of the present invention, there is provided a caustic composition for use in cleaning various equipment, containers, vessels and the like.
According to another aspect of the present invention, there is provided an aqueous caustic composition for cleaning a cargo hold on a ship, said composition comprising:
- a caustic component; and - a microemulsion comprising:
o water;
o a nonionic alkyl polyglucoside surfactant;
o a polyacrylate polymer surfactant;
o a hydrophobic component; and o optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.
According to another aspect of the present invention, there is provided an aqueous caustic composition for cleaning a cargo hold on a ship, said composition comprising:
- a caustic component;
- water;
- a polyacrylate polymer surfactant; and - a microemulsion comprising:
o a nonionic alkyl polyglucoside surfactant;
o water;
o an alkanolamine;
o DDBSA;
o a hydrophobic component; and - optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.

4 Date Regue/Date Received 2022-10-21 Preferably, the nonionic alkyl polyglucoside surfactant is present in a concentration ranging from 1 to 20 wt % of the total weight of the microemulsion. More preferably, the nonionic alkyl polyglucoside surfactant is present in a concentration ranging from 1 to 6 wt % of the total weight of the microemulsion.
Preferably, the polyacrylate polymer is present in an amount of up to 2 wt. %
of the total weight of the composition. More preferably, the polyacrylate polymer is present in an amount of up to 1 wt. % of the total weight of the composition.
Preferably, the anionic surfactant is present in a concentration of up to 5 wt % of the total weight of the composition. More preferably, the anionic surfactant is present in a concentration of up to 2 wt % of the total weight of the composition.
Preferably, the hydrophobic component is a hydro-treated heavy naphthenic petroleum distillate.
More preferably, the hydro-treated heavy naphthenic petroleum distillate is pale oil.
Preferably, caustic component is present in an amount ranging from 20 to 60 wt% of the total weight of the composition. More preferably, said caustic component comprises:
25% NaOH, 4% Lysine and 71 % water. Preferably, said caustic component is present in an amount ranging from 25 to 45 wt% of the total weight of the composition.
According to a preferred embodiment of the present invention, said foam lasts for a duration of time ranging between 10 and 60 minutes.
Preferably, said anionic surfactant is selected from the group consisting of:
DDBSA and Plurafac CS-10.
Preferably, said polyacrylate polymer surfactant is Sokalan PA 20 CL.
Preferably, said nonionic alkyl polyglucoside surfactant is Triton BG-10.
According to a preferred embodiment of the present invention, said polycarboxylate low-foaming anionic surfactant has an impact on one or more of the following: foam height;
foam duration; and combinations thereof.
Date Regue/Date Received 2022-10-21 According to a preferred embodiment of the present invention,said composition has an advancing contact angle (OA) of less than 80 degrees and a receding contact angle (OR) of less than 30 degrees. More preferably, said composition has an advancing contact angle (OA) of less than 70 degrees and a receding contact angle (OR) of less than 25 degrees.
More preferably, said composition has an advancing contact angle (OA) of less than 60 degrees and a receding contact angle (OR) of less than 20 degrees. Even more preferably, said composition has an advancing contact angle (OA) of less than 50 degrees and a receding contact angle (OR) of less than 10 degrees.
According to a preferred embodiment of the present invention, said composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer of less than 45 mN/m. Preferably, said composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer ranging between 25 and 35 mN/m.
According to a preferred embodiment of the present invention, said caustic component is present in an amount ranging from 20 to 60 wt% of the total weight of the composition.
Preferably, said caustic component is present in an amount ranging from 20 to 45 wt% of the total weight of the composition.
According to a preferred embodiment of the present invention, the foam controlling agent has an impact on one or more of the following: foam height; foam duration; and combinations thereof.
According to an aspect of the present invention, there is provided a method for cleaning a cargo ship hold while controlling the foam life in a foaming composition useful therefor, said method comprising the following:
- providing a cargo hold on a ship;
- providing said foaming composition comprising:
- a caustic component;
- water;
- a polyacrylate polymer surfactant; and - a microemulsion comprising:
= a nonionic alkyl polyglucoside surfactant;
= water;
= an alkanolamine;
= DDBSA;

Date Regue/Date Received 2022-10-21 = a hydrophobic component; and = a polycarboxylate low-foaming anionic surfactant as a foam controlling agent;
- exposing a surface of the cargo hold vessel to the foaming composition for a period of time sufficient for the foaming composition exposed to said surface to remove any contaminants present thereon; and - optionally, rinsing said surface.
Preferably, the foam lasts for a duration of time ranging from more than 5 minutes to less than 30 minutes.
According to a first aspect of the present invention, the first anionic surfactant comprises polycarboxylate.
According to a first aspect of the present invention, the second nonionic surfactant comprises an alkyl polyglucoside.
Preferably, the composition has an advancing contact angle (OA) of less than 80 degrees and a receding contact angle (OR) of less than 30 degrees. Even more preferably, the composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer of less than 40 mN/m. Even more preferably, the composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer ranging between 25 and 35 mN/m.
Preferably, the caustic component is present in an amount ranging from 20 to 60 wt% of the total weight of the composition. More preferably, the caustic component is present in an amount ranging from 25 to 45 wt% of the total weight of the composition.
According to a preferred embodiment of the present invention, the foam controlling agent has an impact on one or more of the following: foam height; foam duration; and combinations thereof.
BRIEF DESCRIPTION OF THE FIGURES
The invention may be more completely understood in consideration of the following description of various embodiments of the invention in connection with the accompanying figure, in which:

Date Regue/Date Received 2022-10-21 Figure 1 is a graphical representation of the foam height over time for a number of compositions according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to a preferred embodiment of the present invention, there is provided a caustic foaming composition for cleaning a cargo hold on a ship, said composition comprising:
- a caustic component;
- water;
- a polyacrylate polymer surfactant; and - a microemulsion comprising:
o a nonionic alkyl polyglucoside surfactant;
o water;
o an alkanolamine;
o DDB SA;
o a hydrophobic component; and optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.
Triton BG-10 is a nonionic surfactant intended for use in metal cleaners, paint strippers, and highly alkaline detergents. Its manufacturer (DOW) states that it provides good detergency and wetting properties, and is capable of producing a moderate to highly stable foam. It is made of alkyl polyglucosides and is stated to be a readily biodegradable material.
According to another preferred embodiment of the present invention, the anionic surfactant is Plurafac CS-10. Plurafac CS-100 is known as a low foaming anionic surfactant with high-temperature stability and great caustic solubility (up to 35% NaOH and 50% KOH solution).
It is recommended for use in bleach-free alkaline CIP cleaners or any low foaming formulation. Plurafac CS-10 can sequester calcium and magnesium ions which is the functionality of the chelating agents, which makes compositions containing such suitable for use with hard water. It can also emulsify oil, and tolerate silicates and phosphates. It is soluble in highly caustic solutions (35% NaOH). However, like most anionic surfactants, it is not soluble in highly acidic solutions (14.1 % HC1).
According to an aspect of the present invention, there is provided a composition to be used to clean cargo holds on ships contaminated with one or more of the following: coal;
green delayed petcoke; calcined petcoke; and sulfur.

Date Regue/Date Received 2022-10-21 According to a preferred embodiment of the present invention, the composition is adapted to remove heavy-duty hydrocarbon. Preferably, the composition can be diluted to suit other cleaning requirements.
According to a preferred embodiment of the present invention, the composition is considered non-harmful to the environment. The various requirements across the globe with respect to water safety and discharge into open seas are met with the preferred composition according to the present invention.
According to a preferred embodiment of the present invention, the composition is easy to use and safe for operators to employ even in closed-off areas or areas where other operators are present.
According to a preferred embodiment of the present invention, the surfactant is a multifunctional polycarboxylate anionic surfactant. More preferably, the surfactant is Plurafac CS-10.
According to another preferred embodiment of the present invention, the surfactant is a polycarboxylated anionic surfactant. One example of this type of surfactant is anionic Plurafac CS-10.
Plurafac CS-100 is known as a low foaming anionic surfactant with high-temperature stability and great caustic solubility (up to 35% NaOH and 50% KOH solution). Highly recommended for bleach-free alkaline CIP cleaners or any low foaming formulation. Plurafac CS-10 can sequester calcium and magnesium ions which is the functionality of the chelating agents. This ability to chelate makes the formulation suitable for use with hard water.
According to a preferred embodiment of the present invention, the first surfactant component is a nonionic alkyl polyglucoside surfactant (such as Triton BG-10) and is present in a concentration ranging from 1 to 10 wt % of the total weight of the composition. More preferably, the nonionic alkyl polyglucoside surfactant is present in a concentration ranging from 1 to 6 wt % of the total weight of the composition.
The polycarboxylated anionic surfactant. surfactant can sequester calcium and magnesium ions eliminating the need for chelating agents and also can dissolve calcium and magnesium scales and other scales.
According to a preferred embodiment of the present invention, the second surfactant component is a multifunctional polycarboxylate low-foaming anionic surfactant (such as Plurafac CS-10 ) and is present in a concentration of up to 5 wt % of the total weight of the composition.
More preferably, the Date Regue/Date Received 2022-10-21 polycarboxylate low-foaming anionic surfactant is present up to 2 wt % of the total weight of the composition. Even more preferably, the polycarboxylate low-foaming anionic surfactant is present up to 1 wt % of the total weight of the composition According to a preferred embodiment of the present invention, a third surfactant is present.
Preferably, the third surfactant is a polyacrylate polymer (such as Sokalan PA 20 CL) which is present in an amount of up to 2 wt. % of the total weight of the composition. Preferably, the polyacrylate polymer is present in an amount of up to 1 wt. % of the total weight of the composition.
According to a preferred embodiment of the present invention, the caustic component is present in a concentration ranging from 30-60 wt % of the total weight of the composition when the caustic component is 50% NaOH, for example. This leads to final caustic concentrations ranging from 15 to 30 wt %. More preferably, the caustic component makes up 60 wt % of the total weight of the composition. Preferably, a solution of 50% sodium hydroxide will make up 60 wt% of the total alkaline cleaning composition.
The rest of the composition is made up with water. Examples of water which is used in the manufacturing of the caustic cleaning composition according to the present invention include pure water, ion exchange water, soft water, distilled water, and tap water. These may be used alone or in combination of two or more. Of these, tap water and ion-exchanged water are preferably used from the viewpoints of economy and storage stability. "Water" is the sum of water contained in the form of crystal water or aqueous solution derived from each component constituting the cleaning composition of the present invention and water added from the outside, and the entire composition when water is added is 100%.
According to a preferred embodiment of the present invention, the caustic component is selected from the group consisting of: potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and combinations thereof; and a modified caustic composition comprises one of the above mentioned caustic component (potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide) in combination with a causticity modifying additive, wherein said causticity modifying additive can provide an extended (more methodical and linear) buffering effect to the caustic composition as well as greatly lowering the freezing point and providing an increased level of dermal protection. Examples of such modified caustic composition can be found in Canadian patent applications CA 3,023,705; CA 3,023,613; CA 3,023,610; and CA 3,023,604.
Preferably, the caustic component is selected from the group consisting of: sodium hydroxide;
potassium hydroxide; sodium metasilicate; and combinations thereof. More preferably, the caustic component is sodium hydroxide.
Date Regue/Date Received 2022-10-21 According to a preferred embodiment of the present invention, the modified caustic composition comprises:
- a caustic component selected from the group consisting of: potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and combinations thereof;
and - a causticity modifying additive selected from the group consisting of:
taurine; gamma-aminobutyric acid; aminovaleric acid; aminocaproic acid; aminocapric acid;
sulfopyruvic acid;
sulfobutanoic acid; sulfopentanoic acid; sulfohexanoic acid; phosphonium zwitterions with either a sulfonic acid or carboxylic acid group selected from the group consisting of: 2-hydroxyethyl triphenylphosphonium sulfate zwitterion; (Z- hydroxyethyptrimethylphosphonium sulfate zwitterion (M.W. of 200.2); (3- hydroxy-n- propyl)triphenylphosphonium sulfate zwitterion (M.W.
of 400.4); (2-hydroxy-1- methyl-n- propyl) trimethylphosphonium sulfate zwitterion (M.W. of 228.3); (3-hydroxy-n- propyptri-n- butylphosphonium sulfate zwitterion (M.W.
of 340.5); (Z -hydroxy-1,2- diphenylethyl)- triethylphosphonium sulfate zwitterion (M.W. of 394.5); (3-hydroxy-n- propyl)dimethylphenylphosphonium sulfate zwitterion (M.W. of 276.3); (Z-hydroxy-n-butyl)triisopropylphosphonium sulfate zwitterion (M.W. of 312.4); (3 -hydroxy -1- methyl- n-buty1)-n-butyl-di-n-propylphosphonium sulfate zwitterion (M.W. of 340.5); and (3-hydroxy- 2-ethyl- 4 methyl-n-penty1)-n-butyldiphenylphosphonium sulfate zwitterion (M.W.
of 450.6); -phophoric acid ester group with an amine group; and phosphonic and phosphinic acids and their esters with an amine group.
According to a preferred embodiment of the present invention, the caustic component is selected from the group consisting of: potassium hydroxide; sodium hydroxide; and combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic component is present in a concentration of up to 40 wt % of the modified caustic composition. Also preferably, the caustic component is present in a concentration ranging from 5 to 40 wt % of the modified caustic composition. More preferably, the caustic component is present in a concentration ranging from 10 to 30 wt % of the modified caustic composition. Most preferably, the caustic component is present in a concentration ranging from 15 to 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the caustic component is present in a concentration of 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the causticity modifying additive is present in a concentration ranging from 4 wt% to 25 wt % of the composition. Preferably, the causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the Date Regue/Date Received 2022-10-21 composition. More preferably, the causticity modifying additive is present in a concentration ranging from wt% to 10 wt % of the composition.
According to another preferred embodiment of the present invention, the modified caustic composition comprises:
- a caustic component selected from the group consisting of: potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and combinations thereof;
and - a causticity modifying additive selected from the group consisting of:
monoethanolamine;
diethanolamine; triethanolamine; aminomethyl propanol; propanolamine;
dimethylethanolamine;
and N- methylethanolamine. Preferably, the additive is monoethanolamine.
According to a preferred embodiment of the present invention, the caustic component is selected from the group consisting of: potassium hydroxide; sodium hydroxide; and combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic component is present in a concentration of up to 40 wt % of the modified caustic composition. Also preferably, the caustic component is present in a concentration ranging from 5 to 40 wt % of the modified caustic composition. More preferably, the caustic component is present in a concentration ranging from 10 to 30 wt % of the modified caustic composition. Most preferably, the caustic component is present in a concentration ranging from 15 to 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the caustic component is present in a concentration of 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the causticity modifying additive is present in a concentration ranging from 4 wt% to 25 wt % of the composition. Preferably, the causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the composition. More preferably, the causticity modifying additive is present in a concentration ranging from

5 wt% to 10 wt % of the composition.
According to yet another preferred embodiment of the present invention, the modified caustic composition comprises:
- a caustic component selected from the group consisting of: potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and combinations thereof;
and - a causticity modifying additive which is glycine.

Date Regue/Date Received 2022-10-21 According to a preferred embodiment of the present invention, the caustic component is selected from the group consisting of: potassium hydroxide; sodium hydroxide; and combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic component is present in a concentration of up to 40 wt % of the modified caustic composition. Also preferably, the caustic component is present in a concentration ranging from 5 to 40 wt % of the modified caustic composition. More preferably, the caustic component is present in a concentration ranging from 10 to 30 wt % of the modified caustic composition. Most preferably, the caustic component is present in a concentration ranging from 15 to 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the caustic component is present in a concentration of 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the causticity modifying additive is present in a concentration ranging from 4 wt% to 25 wt % of the composition. Preferably, the causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the composition. More preferably, the causticity modifying additive is present in a concentration ranging from wt% to 10 wt % of the composition.
According to yet another preferred embodiment of the present invention, the modified caustic composition comprises:
- a caustic component selected from the group consisting of: potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and combinations thereof;
and - a causticity modifying additive selected from the group consisting of:
lysine monohydrochloride;
threonine; methionine; glutamic acid; and taurine. Preferably, the causticity modifying additive is lysine monohydrochloride or taurine. More preferably, the causticity modifying additive is lysine monohydrochloride.
According to a preferred embodiment of the present invention, the caustic component is selected from the group consisting of: potassium hydroxide; sodium hydroxide; and combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic component is present in a concentration of up to 40 wt % of the modified caustic composition. Also preferably, the caustic component is present in a concentration ranging from 5 to 40 wt % of the modified caustic composition. More preferably, the caustic component is present in a concentration ranging from 10 to 30 wt % of the modified caustic composition. Most preferably, the caustic component is present in a concentration ranging from 15 to 25 wt % of the modified caustic composition. According to a preferred embodiment of the present invention, the caustic component is present in a concentration of 25 wt % of the modified caustic Date Regue/Date Received 2022-10-21 composition. According to a preferred embodiment of the present invention, the causticity modifying additive is present in a concentration ranging from 4 wt% to 25 wt % of the composition. Preferably, the causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the composition. More preferably, the causticity modifying additive is present in a concentration ranging from wt% to 10 wt % of the composition.
According to another aspect of the present invention, there is provided a microemulsion composition for use as a cleaner in the treatment of cargo holds. Preferably, the microemulsion composition are developed to be soluble in highly caustic solutions. A composition according to a preferred embodiment of the present invention, was dissolved in a modified caustic comprising sodium hydroxide and lysine (molar ratio of 29:1) both in the presence and in the absence of Sokalan PA
20 CL. The resulting microemulsion (whose composition is listed in Table 2) is soluble and resulted in clear amber solution.
Thermal stability testing showed that this composition is stable at 45 C.
Triton BG-10 is a nonionic alkyl polyglucoside surfactant intended for use in metal cleaners, paint strippers, and highly alkaline detergents. Its manufacturer (DOW) states that it provides good detergency and wetting properties, and is capable of producing a moderate to highly stable foam. It is made of alkyl polyglucosides and is stated to be a readily biodegradable material.
Sokalan PA 20 CL is a polyacrylate polymer that is highly dispersible and is highly effective in suspending particulates and helps to prevent re-deposition of suspended soils back onto surfaces. Sokalan PA 20 can be more specifically described as an acrylic acid homopolymer.
Sokalan PA 20 is an effective dispersing agent for organic and inorganic solids. It can be used as a slurry viscosity reducer; a dispersing agent, an anti-redeposition agent for particulate soils; and as a scale inhibitor.
According to another aspect of the present invention, there is provided a microemulsion containing caustic composition for use as a cleaner for maritime uses.
Example 1 A preferred emulsion was prepared prior to incorporating into the composition used as a cargo hull cleaner. Table 1 (below) describes the components and quantities used to prepare a microemulsion for incorporation into a caustic composition according to a preferred embodiment of the present invention.

Date Regue/Date Received 2022-10-21 Table 1: Composition and stability of a microemulsion prepared according to a preferred embodiment of the present invention Ingredient microemulsion (wt%) DI Water 78.5 MEA 0.5 Triton BG-10 15 Pale Oil 40 1 Total 100 Observations Ambient temperature Clear amber solution Dodecylbenzene Sulfonic Acid (DDBSA) is a thick, light yellow to brown liquid that is soluble in water. As an extremely versatile cleaning agent, DDBSA is commonly used to make detergents and other cleansing products such as shampoos and hair conditioners. It can be corrosive to metals and human tissue.
Monoethanolamine (or ethanolamine, hereinafter MEA is a colorless, viscous liquid, organic chemical compound also known as Ethanolamine. Its primary use is for feedstock in the production of detergents, emulsifiers, polishes, pharmaceuticals, corrosion inhibitors, and chemical intermediates. MEA
is a viscous, hygroscopic amino alcohol with an unpleasant ammonia-like odor.
Its chemical formula is C2H7NO and its CAS # is 141-43-5. It is a component of lecithin and is widely distributed in biological tissue. It is a solid below 51 F and is used as a surfactant, fluorimetric reagent, and to remove CO2 and H2S from natural gas and other gases. MEA is produced by reacting ethylene oxide with aqueous ammonia.
Pale Oil 40 is an oily viscous liquid comprising hydro-treated heavy naphthenic petroleum distillates. Naphthenic base oils offer high solvency, low pour points, and good color characteristics, low paraffin (wax) content. In the preferred composition according to the present invention, it forms the hydrophobic part of the microemulsion.
According to a preferred embodiment of the present invention, a number of caustic formulations were developed using the microemulsion of Example 1. Table 2 (below) lists the components and quantities used to prepare a caustic composition according to a preferred embodiment of the present invention. The stability of these compositions was assessed and are also presented in the table.
Date Regue/Date Received 2022-10-21 Table 2: Composition and stability of several microemulsions prepared according to a preferred embodiment of the present invention Ingredient Example 2 Example 3 (wt%) (wt%) DI Water 3.5 2.5 Modified Caustic Soda 90 90 Microemulsion (Ex. 1) 6.5 6.5 Sokalan PA 20 CL 0 1 Observations Ambient temperature Clear amber solution Clear amber solution 45 C for 1 week Clear amber solution Clear amber solution 45 C for 2 weeks Clear amber solution Clear amber solution According to a preferred embodiment of the present invention, the modified caustic soda used in the composition comprises 25% NaOH, 4% Lysine and 71 % water.
Further compositions were prepared by compounding the composition CFP8 with varying amounts of a third surfactant, Plurafac CS-10. The compositions prepared are listed in Table 3 below. The stability of these compositions was assessed and are also presented in the table.
Table 3: Composition of various preferred embodiments of the present invention Ingredient Example 3 Example 4 Example 5 (wt%) (wt%) (wt%) CFP8 99.5 99 98 Plurafac CS-10 0.5 1 2 Observations Ambient temperature Clear amber solution Clear amber solution Clear amber solution 45 C for 1 week Clear amber solution Clear amber solution Turbid/ Separation 45 C for 2 weeks N/A N/A
Plurafac CS-10 was added to formula CFP8 at three different concentrations (0.5, 1 and 2 wt%).
The formulas were evaluated for thermal stability at 45 C and for foamability. The formulas where 0.5 and 1 wt% of Plurafac CS-10 was present were thermally stable. Plurafac CS-10 (BASF) is a multifunctional polycarboxylate low-foaming anionic surfactant that is provided as 50% aqueous solution.
It is effective in removing inorganic scales, it can sequester calcium and magnesium ions, emulsify oil, and tolerate silicates and phosphates. It is soluble in highly caustic solutions (35% NaOH). However, like most Date Regue/Date Received 2022-10-21 anionic surfactants, it is not soluble in highly acidic solutions (14.1 %
HC1). It has limited stability in high caustic solutions, especially at high temperatures.
According to another preferred embodiment of the present invention, a foam controlling agent is present in the composition. Preferably, the a foam controlling agent is an anionic surfactant such as Plurafac CS-10. Plurafac CS-10 is known as a low foaming anionic surfactant with high-temperature stability and great caustic solubility (up to 35% NaOH and 50% KOH solution).
It is recommended for use in bleach-free alkaline cleaners or any low foaming formulation. Plurafac CS-10 can sequester calcium and magnesium ions which is the functionality of the chelating agents, which makes compositions containing such suitable for use with hard water.
Interestingly, the addition of low-foaming Plurafac CS-10 decreased the Half Lifetime of foam significantly while not affecting the foamability (the amount of initial foam generated). The foamability is important for cleaning. However, controlling the duration of the foam within certain time frame is also important to ensure effective disposal of the cleaning agent once the cleaning operation is concluded. If the half-life of the foam is too long, the cleaning steps take longer than they should and consequently, it costs money to the operator. It is preferable to have optimized the foam duration to a point where it is sufficiently long to enable one to perform a cleaning operation but not too long as to add undue time to said cleaning operation.
The efficiency of cleaning can be explained using the dynamic contact angle measurements using the diluted formulas to 2% v/v and measured on parafilm using Kruss Force Tensiometer. Advancing (aCA) and Receding (rCA) Contact Angles were measured.
Table 4 shows that the cleaning formulas decreased the contact angle for parafilm from 120 (aCA) and 95 (rCA) when measured with water to 50 and 50 (aCA) and 0-9 (rCA).
The critical surface tension for wetting coal particulates is 45 mN/m below which the solution can effectively wet the coal and remove it for the surfaces. All formulas developed here have surface tension below 30 mN/m.
Formulations Dilution In order to perform the surface tension, dynamic contact angle, and foamability tests, the formulations were diluted to a concentration of 2 % v/v.

Date Regue/Date Received 2022-10-21 Surface Tension Wilhelmy Plate method was used to measure the surface tension of the diluted formulations using a Kruss 100C force tensiometer.
Dynamic Contact Angle Dynamic contact angle measurements were conducted using the Wilhelmy plate method with a Kniss 100C force tensiometer. A parafilm plate was used as a hydrophobic surface to measure the efficiency of the formulations in reducing the contact angles. The advancing and receding contact angles (OA and OR) were measured. They are indicative of how efficient the formulation can change the wettability of a hydrophobic surface to be more water-wet for easier cleaning of the surfaces. The advancing angles (OA) is always higher than the receding contact angles (OR) as the plate advances in the fluid dry. But while receding, the molecules were already oriented at the surface.
Dynamic Foam Analyzer DFA100C from Kniss was used to measure the foamability and foam stability of the different formulations made. DFA100C is equipped with 40 mm internal diameter glass column with a fit glass of 16-40 lam pore size (FL4503-G3). The column is fixed in between infrared source and receiver to automatically measure the height of the foam overtime.
50 mL of formulations was placed inside the column with a syringe to prevent any foaming during this step. Then, air is subsequently injected through the fit glass filter at rate of 0.3 mL/min for 20 seconds.
Foamability was calculated based on the maximum height during foaming. Foam stability was measured based on the foam height after 5, 15, and 20 minutes. For the best formulations, extended foam stability was conducted to measure the decay half-life time (I1/2).
Table 4 lists the results for surface tension measurements, advancing contact angle, and receding contact angle. Table 4 also contains information regarding the foam half-life (in minutes).
Table 4: Composition of various preferred embodiments of the present invention diluted to 2% v/v and their respective Advancing (aCA) and receding (rCA) contact angles and surface tension were measured SFT (mN/m) aCA ( ) rCA ( ) Foam Half Lifetime (min) CFP7 28.56 49.04 8.52 60 min CFP8 28.11 47.97 0.0 60 min CFP8-1 10 min Date Regue/Date Received 2022-10-21 CFP8-2 10 min CFP8-3 10 min In light of the results set out in Table 4, it is established that preferred embodiments of the present invention have the right characteristics (surface tension, advancing contact angle, and receding contact angle) to be effective cleaning compositions for use in contaminant removal in a ship's cargo hold.
As seen in Figure 1, CFP7 and CFP8 showed a significantly stable foam with a half-lifetime longer than 60 minutes. However, when Plurafac CS-10 was added into CFP8-1, CFP8-2, and CFP8-3, the foam lifetime decreased significantly as the concentration of Plurafac CS-10 was increased. The foam half-lifetime was about 10 minutes only. A stable foam is desirable however, with a half-life of over 60 minutes, the foam generated by CFP7 and CFP8 can hinder the cleaning process.
Conversely, each one of CFP8-1, 2, and 3 generated a good foam with a half life of less than 10 minutes which makes it very attractive for use a cargo hold cleaner. As it can be rinsed shortly after having been applied and does not unnecessarily extend the time taken to clean.
Other components may also be added to the cleaning solution of the present invention to add a variety of properties or characteristics, as desired. For instance, additives may include colorants, fragrance enhancers, anionic or nonionic surfactants, corrosion inhibitors, defoamers, pH stabilizers, stabilizing agents, or other additives that would be known by one of ordinary skill in the art with the present disclosure before them.
While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by those skilled in the relevant arts, once they have been made familiar with this disclosure that various changes in form and detail can be made without departing from the true scope of the invention in the appended claims.

Date Regue/Date Received 2022-10-21

Claims (29)

1. An aqueous caustic composition for cleaning a cargo hold on a ship, said composition comprising:
- a caustic component; and - a microemulsion comprising:
o water;
o a nonionic alkyl polyglucoside surfactant;
o a polyacrylate polymer surfactant;
o a hydrophobic component; and o optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.

2. An aqueous caustic composition for cleaning a cargo hold on a ship, said composition comprising:
- a caustic component;
- water;
- a polyacrylate polymer surfactant; and - a microemulsion comprising:
o a nonionic alkyl polyglucoside surfactant;
o water;
o an alkanolamine;
o DDBSA;
o a hydrophobic component; and - optionally, a polycarboxylate low-foaming anionic surfactant as a foam controlling agent.

3. The composition according to claim 1 or , where the nonionic alkyl polyglucoside surfactant is present in a concentration ranging from 1 to 20 wt % of the total weight of the microemulsion.

4. The composition according to any one of claims 1 to 3, where the nonionic alkyl polyglucoside surfactant is present in a concentration ranging from 1 to 6 wt % of the total weight of the microemulsion.

5. The composition according to any one of claims 1 to 4, where the polyacrylate polymer is present in an amount of up to 2 wt. % of the total weight of the composition.
Date Regue/Date Received 2022-10-21

6. The composition according to any one of claims 1 to 5, where the polyacrylate polymer is present in an amount of up to 1 wt. % of the total weight of the composition.

7. The composition according to any one of claims 1 to 6, where the anionic surfactant is present in a concentration of up to 5 wt % of the total weight of the composition.

8. The composition according to any one of claims 1 to 7, where the anionic surfactant is present in a concentration of up to 2 wt % of the total weight of the composition.

9. The composition according to any one of claims 1 to 8, where the hydrophobic component is a hydro-treated heavy naphthenic petroleum distillate.

10. The composition according to claim 9, where the hydro-treated heavy naphthenic petroleum distillate is pale oil.

11. The composition according to any one of claims 1 to 10, wherein said caustic component is present in an amount ranging from 20 to 60 wt% of the total weight of the composition.

12. The composition according to claim 11 wherein said caustic component comprises: 25% NaOH, 4% Lysine and 71 % water.

13. The composition according to any one of claims 1 to 12, wherein said caustic component is present in an amount ranging from 25 to 45 wt% of the total weight of the composition.

14. The composition according to any one of claims 1 to 13, wherein said foam lasts for a duration of time ranging between 10 and 60 minutes.

15. The composition according to any one of claims 1 to 14, wherein said anionic surfactant is selected from the group consisting of: DDBSA and Plurafac CS-10.

16. The composition according to any one of claims 1 to 15, wherein said polyacrylate polymer surfactant is Sokalan PA 20 CL.

17. The composition according to any one of claims 1 to 16, wherein said nonionic alkyl polyglucoside surfactant is Triton BG-10.

Date Regue/Date Received 2022-10-21

18. The composition according to any one of claims 1 to 17 wherein said polycarboxylate low-foaming anionic surfactant has an impact on one or more of the following: foam height;
foam duration; and combinations thereof.

19. The composition according to any one of claims 1 to 18, wherein said composition has an advancing contact angle (OA) of less than 80 degrees and a receding contact angle (OR) of less than 30 degrees.

20. The composition according to any one of claims 1 to 19, wherein said composition has an advancing contact angle (OA) of less than 70 degrees and a receding contact angle (OR) of less than 25 degrees.

21. The composition according to any one of claims 1 to 20, wherein said composition has an advancing contact angle (OA) of less than 60 degrees and a receding contact angle (OR) of less than 20 degrees.

22. The composition according to any one of claims 1 to 21, wherein said composition has an advancing contact angle (OA) of less than 50 degrees and a receding contact angle (OR) of less than 10 degrees.

23. The composition according to any one of claims 1 to 22, wherein said composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer of less than 45 mN/m.

24. The composition according to any one of claims 1 to 23, wherein said composition has a surface tension (SFT) when measured using a Wilhelmy plate with a tensiometer ranging between 25 and 35 mN/m.

25. The composition according to any one of claims 1 to 24, wherein said caustic component is present in an amount ranging from 20 to 60 wt% of the total weight of the composition.

26. The composition according to any one of claims 1 to 25, wherein said caustic component is present in an amount ranging from 20 to 45 wt% of the total weight of the composition.

27. The composition according to any one of claims 1 to 26, wherein the foam controlling agent has an impact on one or more of the following: foam height; foam duration; and combinations thereof.

28. Method for cleaning a cargo ship hold while controlling the foam life in a foaming composition useful therefor, said method comprising the following:
- providing a cargo hold on a ship;
- providing said foaming composition comprising:

Date Regue/Date Received 2022-10-21 - a caustic component;
- water;
- a polyacrylate polymer surfactant; and - a microemulsion comprising:
= a nonionic alkyl polyglucoside surfactant;
= water;
= an alkanolamine;
= DDBSA;
= a hydrophobic component; and = a polycarboxylate low-foaming anionic surfactant as a foam controlling agent;
- exposing a surface of the cargo hold vessel to the foaming composition for a period of time sufficient for the foaming composition exposed to said surface to remove any contaminants present thereon; and - optionally, rinsing said surface.

29. The method according to claim 28, wherein the foam lasts for a duration of time ranging from more than 5 minutes to less than 30 minutes.

Date Regue/Date Received 2022-10-21