阅读说明：本技术 单氯胺和过氧化物化合物的协同组合及使用其进行微生物控制的方法 (Synergistic combination of monochloramine and peroxide compounds and methods of using the same for microbial control ) 是由 J.P.布扬多 M.L.里德 B.简斯 于 2019-01-08 设计创作，主要内容包括：用于控制易遭受微生物侵害的产品、材料、或媒介物例如可发酵的或发酵用媒介物中或上微生物的生长的方法,其通过用以对于控制不想要的微生物生长而言协同杀微生物有效的组合量包括单氯胺和至少一种过氧化物化合物的水溶液处理而进行。还描述了杀微生物水溶液,其以对于控制至少一种微生物的生长而言协同杀微生物有效的组合量含有单氯胺和至少一种过氧化物。(A method for controlling the growth of microorganisms in or on a product, material, or vehicle susceptible to attack by microorganisms, such as a fermentable or fermenting vehicle, by treatment with an aqueous solution comprising monochloramine and at least one peroxide compound in a combined amount synergistically microbiocidally effective for controlling the growth of undesirable microorganisms. Also described is an aqueous microbiocidal solution comprising monochloramine and at least one peroxide in a synergistically microbiocidally effective combined amount for controlling the growth of at least one microorganism.)

1. A method of controlling the growth of at least one microorganism in or on a product, material, or vehicle susceptible to attack by a microorganism, the method comprising treating the product, material, or vehicle with an aqueous solution comprising (a) monochloramine and (b) at least one peroxide compound, wherein components (a) and (b) are present in a synergistically microbiocidally effective combined amount to control the growth of the at least one microorganism.

2. The method of claim 1, wherein the material or vehicle is a fermentable mash or solution, wood pulp or paper, wood chips, lumber, paints, leather, adhesives, coatings, animal skins, tanning liquors, paper mill liquors, fiberglass, dairy processing, poultry processing, meat packaging facilities, meat processing, metalworking fluids, petrochemicals, pharmaceutical formulations, cooling water, recreational water, dyes, clays, mineral slurries, cationic surfactants, formulations with cationic surfactants, influent water, digester effluent, pasteurizer, cosmetic formulations, rinse formulations, fabric, geological, drilling lubricants, or agrochemical composition for crop or seed protection.

3. The method of claim 1, wherein the microorganism is a bacterium, a fungus, an algae, or a combination thereof.

4. The method of claim 1, wherein the material or vehicle is in the form of a solid, dispersion, emulsion, mash, slurry, or solution.

5. A method of controlling the growth of at least one contaminant microorganism in a fermentable carbohydrate-containing feedstock comprising contacting the fermentable carbohydrate-containing feedstock with (a) monochloramine and (b) at least one peroxide compound, wherein components (a) and (b) are present in a synergistically microbiocidally effective combined amount for controlling the growth of at least one contaminant microorganism in the fermentable carbohydrate-containing feedstock.

6. The method of claim 5 wherein said monochloramine is present in said fermentable carbohydrate-containing feedstock at a concentration of from 0.1ppm to 750ppm and said at least one peroxide compound is present in said fermentable carbohydrate-containing feedstock at a concentration of from 0.1ppm to 750 ppm.

7. The method of claim 5 wherein said monochloramine is present in said fermentable carbohydrate-containing feedstock at a concentration of from 1ppm to 450ppm and said at least one peroxide compound is present in said fermentable carbohydrate-containing feedstock at a concentration of from 5ppm to 450 ppm.

8. The method of claim 5 wherein the monochloramine and the at least one peroxide compound are added to the fermentable carbohydrate-containing feedstock in a weight ratio of from 0.001:1 to 1: 0.001.

9. The method of claim 5, wherein the peroxide compound is a hydroperoxide, an organic peroxide, an inorganic peroxide, a peroxy-releasing compound, or any combination thereof.

10. The method of claim 5, wherein the microorganism is a bacterium.

11. The method of claim 5, wherein the fermentable carbohydrate-containing feedstock comprises fermentable carbohydrates derived from grains, cellulose, fruits, non-grain vegetables, or any combination thereof.

12. A process for producing ethanol by fermentation under controlled growth of contaminating microorganisms comprising:

a) adding (a) monochloramine and (b) at least one peroxide compound to a fermentable carbohydrate-containing feedstock to provide a treated feedstock, wherein components (a) and (b) are present in a synergistically microbiocidally effective combined amount for controlling the growth of at least one contaminating microorganism in the treated feedstock;

b) fermenting the treated feedstock in a vessel in the presence of yeast to produce a fermented mash comprising ethanol and solid content; and

c) distilling the fermented mash to separate at least a portion of the ethanol from stillage including the solids content.

13. The method of claim 12 wherein monochloramine and the at least one peroxide compound are added to the feedstock containing fermentable carbohydrates before, after, or both before and after the feedstock is introduced into a fermentor vessel and yeast is present.

14. The method of claim 13 wherein monochloramine and the at least one peroxide compound are added to the fermentable carbohydrate-containing feedstock prior to introducing the treated feedstock into a fermentor vessel and combining with yeast.

15. The method of claim 14 wherein at least a portion of the at least one peroxide compound is added to the fermentable carbohydrate-containing feedstock prior to adding the monochloramine to the fermentable carbohydrate-containing feedstock.

16. The method of claim 14 further comprising providing a holding vessel upstream of a fermenter vessel in which the fermentable carbohydrate-containing feedstock is temporarily held prior to being conducted to the fermenter vessel through a conduit, wherein the monochloramine and the at least one peroxide compound are added to the fermentable carbohydrate-containing feedstock in the holding vessel and in the conduit prior to being introduced into the fermenter vessel.

17. A method according to claim 12 wherein the addition of (a) monochloramine and (b) at least one peroxide compound to the fermentable carbohydrate-containing feedstock is provided without reducing the yeast population of yeast present in the vessel for fermentation.

18. The method of claim 12 wherein the addition of (a) monochloramine and (b) at least one peroxide compound to the fermentable carbohydrate-containing feedstock reduces the total lactic acid and acetic acid produced in the fermentation compared to fermentation in the absence of the addition of compounds (a) and (b) to the fermentable carbohydrate-containing feedstock.

19. The method of claim 12, wherein the fermentation is conducted in the absence of added antibiotics.

20. The method of claim 12, wherein the fermentable carbohydrate-containing feedstock comprises a carbohydrate-containing flowable feedstock derived from corn in an aqueous vehicle.

21. The method of claim 12, wherein the microorganism is a bacterium.

22. The method of claim 12 wherein the monochloramine is added to the fermentable carbohydrate-containing feedstock at a concentration of 0.1ppm to 750ppm and the at least one peroxide compound is added to the fermentable carbohydrate-containing feedstock at a concentration of 0.1ppm to 750 ppm.

23. The method of claim 12 wherein said monochloramine is present in said fermentable carbohydrate-containing feedstock at a concentration of from 1ppm to 450ppm and said at least one peroxide compound is present in said fermentable carbohydrate-containing feedstock at a concentration of from 5ppm to 450 ppm.

24. The method of claim 12 wherein the monochloramine and the at least one peroxide compound are added to the fermentable carbohydrate-containing feedstock in a ratio of from 0.001:1 to 1: 0.001.

25. The method of claim 12, wherein the peroxide compound is a hydroperoxide, an organic peroxide, an inorganic peroxide, a peroxy-releasing compound, or any combination thereof.

26. The process of claim 12, wherein the peroxide compound is a hydroperoxide having the structure R-O-H, wherein R is hydrogen or a linear, branched, and/or cyclic alkyl group having 1 to 20 carbon atoms and may optionally be interrupted by one or more oxygen and/or carbonyl groups.

27. The process of claim 12, wherein the peroxide compound is an organic peroxide having the structure R '-O-R ", wherein R' and R" are independently linear, branched, and/or cyclic alkyl groups having 1-20 carbon atoms and may optionally be interrupted by one or more oxygen and/or carbonyl groups.

28. The method of claim 12, wherein the peroxide compound is an inorganic peroxide selected from the group consisting of: alkali metal peroxide, alkaline earth metal peroxide, transition metal peroxide, or any combination thereof.

29. The method of claim 12, wherein the peroxide compound is a peroxy-releasing compound selected from the group consisting of: alkali metal percarbonate, alkaline earth metal percarbonate, transition metal percarbonate, alkali metal perborate, alkaline earth metal perborate, transition metal perborate, or any combination thereof.

30. The method of claim 12, wherein the pH of the fermentable carbohydrate-containing feedstock is from about 4 to about 7.

31. The method of claim 12, further comprising the steps of:

d) separating the stillage into a liquid-containing fraction and a solids-containing fraction;

e) optionally recycling at least a portion of the liquid-containing fraction of d) to the fermenter vessel;

f) recovering the solids-containing fraction of d) and drying at least a portion of the solids-containing fraction to produce an evaporated vapor and an antibiotic-free distillers dried grain product.

32. An aqueous solution comprising (a) monochloramine and (b) at least one peroxide compound, wherein components (a) and (b) are present in a synergistically microbicidally effective combined amount for controlling the growth of at least one microorganism.

33. The aqueous solution of claim 32, wherein said monochloramine is present in said aqueous solution at a concentration of 0.1ppm to 750ppm and said at least one peroxide compound is present in said aqueous solution at a concentration of 0.1ppm to 750 ppm.

34. The aqueous solution of claim 32, comprising said monochloramine present in said aqueous solution at a concentration of 1ppm to 450ppm, and said at least one peroxide compound present in said aqueous solution at a concentration of 5ppm to 450 ppm.

35. The aqueous solution of claim 32, wherein the monochloramine and the at least one peroxide compound are added to the aqueous solution in a ratio of 0.001:1 to 1: 0.001.

36. The aqueous solution of claim 32, wherein the peroxide compound is a hydroperoxide, an organic peroxide, an inorganic peroxide, a peroxy-releasing compound, or any combination thereof.

Technical Field

The present invention relates to synergistic combinations of antimicrobial agents in aqueous solutions or formulations and methods for their use in controlling microbial growth in a wide variety of media, substrates and in liquid systems such as ethanol fermentation systems. More particularly, the present invention relates to the use of monochloramine and peroxide compounds such as hydrogen peroxide in aqueous treatment solutions and/or for the treatment of aqueous systems.

Background

Many industrial materials and vehicles are susceptible to bacterial, fungal, and/or algal degradation or degradation when wet or subjected to treatment in water. Many types of commercial, industrial, agricultural, and wood materials or products are subject to microbial infestation or degradation that reduces or destroys their economic value. Such industrial materials and vehicles include, but are not limited to, for example, wood pulp, wood chips, lumber, adhesives, coatings, animal skins, paper mill fluids, pharmaceutical formulations, cosmetic formulations, toiletry formulations, geological drilling lubricants, petrochemicals, agrochemical compositions, paints, leather, plastics, seeds, plants, wood, metalworking fluids, cooling water, recreational water, mill feed water, wastewater, pasteurizers, digesters, tanning fluids or solutions, starches, proteinaceous materials, acrylic latex paint emulsions, and fabrics. The various temperatures at which such materials or products are manufactured, stored, or used, as well as their inherent characteristics, make them susceptible to growth, infestation, and degradation by common microorganisms such as algae, fungi, yeasts, and bacteria. These microorganisms can be introduced during manufacturing or other industrial processes by exposure to air, tanks, pipes, equipment, and humans. They may also be introduced when the material or product is used, for example by multiple opening and reclosing of the package, or as a result of stirring or removal of the material with a contaminated body.

To control degradation or degradation caused by microorganisms, a variety of industrial microbiocides are used. Workers in the industry are constantly seeking improved biocides as follows: which has low toxicity, is cost effective, and/or is also capable of exhibiting a long lasting biocidal effect against a wide variety of microorganisms under routine use.

Aqueous systems are also highly susceptible to microbial growth, attack, and degradation. These aqueous systems may be fresh water, brackish water or salt water systems. Exemplary aqueous systems include, but are not limited to, latexes, surfactants, dispersants, stabilizers, thickeners, adhesives, starches, waxes, proteins, emulsifiers, cellulosic products, metalworking fluids, cooling water, wastewater, aqueous emulsions, aqueous cleaners, coating compositions, paint compositions, and resins formulated as aqueous solutions, emulsions, or suspensions. These systems often contain relatively large amounts of water and organic materials, making them very suitable environments for microbial growth and hence attack and degradation.

Microbial degradation of aqueous systems can be manifested by a variety of problems, such as loss of viscosity, gas formation, unpleasant odor, reduced pH, demulsification, color change, and/or gelation. In addition, microbial degradation of aqueous systems can lead to fouling of associated water treatment systems (systems), which can include cooling towers, pumps, heat exchangers, pipelines, heating systems, washing systems, and other similar systems.

Another undesirable phenomenon that occurs in aqueous systems, particularly in aqueous industrial process fluids, is slime formation. Mucus formation can occur in fresh water, brackish water or salt water systems. Mucus consists of a deposit of tangled (matted) microorganisms, fibers and debris. It may be viscous (stringy), pasty, rubbery, tapioca-like, or hard, and may have a characteristic undesirable odor that is different from the aqueous system in which it is formed. The microorganisms involved in their formation are mainly spore-forming and non-spore-forming bacteria of different species, in particular in the form of envelopes secreting a gel-like substance encapsulating or enveloping the cells. Slime organisms also include filamentous bacteria, mold-type filamentous fungi, yeast, and/or yeast-like organisms. Slime reduces yields in production and causes clogging, swelling, and other problems in industrial water systems.

Some industrial processes involving fermentation, such as ethanol production processes, require microbial growth control. In these process environments, it is desirable to control unwanted microorganisms that can contaminate these processes without harming the beneficial microorganisms present or used in the system.

In ethanol production, ethanol can be produced by fermentation using a wide variety of starch-containing raw materials. Starch-based ethanol production typically involves: preparing a mass of starchy material containing or degradable into fermentable sugars, adding water to make a mash, enzymatically liquefying/saccharifying carbohydrates into fermentable sugars, and adding yeast that ferments the sugars into ethanol and carbon dioxide. Recovering ethanol by distilling the fermented mash. The distillation by-products in ethanol production are non-starchy solids containing protein, fiber, and oil, which can be processed to produce "distillers dried grains with solubles" or "DDGS". DDGS is rich in nutrients and is commercially sold as animal feed, feed additives, or plant fertilizers.

A problem in the ethanol production industry is that the ethanol fermentation system can become contaminated with bacteria, which reduces production yields. This contamination can occur in one or more vessels used in storage (holding), cultivation (fermentation) and fermentation (including pre-fermentation holding tanks, cultivation tanks, fermentation tanks, and piping and process equipment between these units). "lactic acid bacteria" are a group of bacteria that have problems in this regard. Lactic acid bacteria include, for example, species of Lactobacillus (Lactobacillus), Pediococcus (Pediococcus), Leuconostoc (Leuconostoc), and Weissella (Weissella). Acetic acid bacteria such as Acetobacter sp may also cause problems by producing acetic acid, lactic acid, or other organic acids that foul the process and reduce ethanol yield. Yeast converts sugars to ethanol, but bacteria also convert those same sugars to make lactic acid or acetic acid instead of ethanol, resulting in a reduction in ethanol production yield. To control the outbreak of such bacteria, antibiotics such as virginiamycin, penicillin, erythromycin, and tylosin have been used in ethanol fermentation processes. The risk of bacteria developing resistance to antibiotics due to their use or overuse is a concern. In addition, the problem of non-specificity of antibiotics to target bacteria and fermentation products has arisen. Attention has also been paid to the presence of antibiotic residues in DDGS intended for animal feed. For ethanol fermentation processes, alternatives to antibiotics are needed.

Oxidation-based chemistry proposed for fermentation systems based on the use of a single type of biocide does not significantly reduce and/or control bacterial growth, or may require significantly high concentrations of biocide to control bacterial growth, or is non-selective in terms of antimicrobial action. For example, chlorine dioxide (i.e., ClO) has been proposed₂) As an oxidizing biocide. However, chlorine dioxide is a strong oxidant with non-selective antimicrobial action. Chlorine dioxide attacks both unwanted bacteria and yeasts that are critical to the fermentation process. Loss of yeast translates into loss of ethanol yield and/or "lag" fermentation. Chlorine dioxide also produces chloride ions that can corrode equipment and cause iron deposits or rust spots in process equipment, as well as release iron and chromium into the process system, which can require expensive remediation.

Despite the presence of microbicides, the industry is continually seeking more cost effective techniques that provide equal or better protection at lower cost and/or at lower concentrations. The concentration of conventional microbiocides used for such applications and the corresponding cost of disposal can be relatively high. Important factors in the search for cost-effective microbiocides include the duration of the microbiocidal effect, ease of use, efficacy of the microbiocide per unit weight, and the ability to replace antibiotics for bacterial control with minimal adverse systemic or environmental impact on its own.

Disclosure of Invention

It is a feature of the present invention to provide a combination of microbicides in aqueous solution capable of synergistically controlling the growth of at least one microorganism (e.g., fungi, bacteria, algae, or mixtures thereof), for example, over a short period of time or over a long period of time. Methods of controlling the growth of at least one microorganism in or on a product, material, or vehicle with or in an aqueous solution containing a combination of said microbicides are also a feature of the present invention.

Methods and aqueous solutions are described for preventing damage during storage or yield loss in industrial processes caused by undesirable microorganisms, such as undesirable bacteria, fungi, algae, or mixtures thereof.

The present invention relates, in part, to methods of controlling the growth of at least one microorganism in or on a product, material, or vehicle susceptible to attack by the microorganism. The method comprises the following steps: treating the product, material or vehicle with an aqueous solution comprising (a) monochloramine and (b) at least one peroxide compound, wherein components (a) and (b) are present in a synergistically microbicidally effective combined amount for controlling the growth of at least one microorganism.

The present invention further provides a method for controlling the growth of at least one contaminant microorganism in a fermentable carbohydrate-containing feedstock. The method comprises the following steps: contacting the fermentable carbohydrate-containing feedstock with (a) monochloramine and (b) at least one peroxide compound, wherein components (a) and (b) are present in a synergistically microbicidally effective combined amount for controlling the growth of at least one contaminant microorganism in the fermentable carbohydrate-containing feedstock. Furthermore, the present invention provides a process for the production of ethanol by fermentation under controlled growth of contaminating microorganisms. The method comprises the following steps: a) adding (a) monochloramine and (b) at least one peroxide compound to a fermentable carbohydrate-containing feedstock to provide a treated feedstock, wherein components (a) and (b) are present in a synergistically microbiocidally effective combined amount for controlling the growth of at least one contaminating microorganism in the treated feedstock; b) fermenting the treated feedstock in the presence of yeast in a vessel to produce a fermented mash comprising ethanol and solid content, and c) distilling the fermented mash to separate at least a portion of the ethanol from a stillage comprising the solid content.

The present invention also provides an aqueous solution or formulation comprising a) monochloramine and b) at least one peroxide, wherein components a) and b) are present in a combined amount that is synergistically effective to control the growth of at least one microorganism.

Additional features and advantages of various embodiments will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of various embodiments. The objectives and other advantages of the various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description and appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate some features of the invention and together with the description, serve to explain the principles of the invention.

Drawings

FIG. 1 illustrates a process flow diagram of a method of treating an ethanol fermentation system with a combination of monochloramine and peroxide compounds to provide synergistic microbicidal control according to an embodiment of the present invention.

Fig. 2 is a bar graph of bacterial growth control in corn slurry solutions (35 wt%) treated with hydrogen peroxide (100ppm) and monochloramine added at different concentrations (25ppm or 50ppm) at different times according to an embodiment of the present invention, where the time between peroxide and monochloramine addition is 0, 10, 40 and 60 minutes, or using sequential monochloramine additions at both 0 and 40 minutes, and including untreated "blank" samples for comparison.

Fig. 3 is a bar graph depicting the effect of hydrogen peroxide concentrations (100ppm and 200ppm) on bacterial growth control in corn slurry solutions (35 wt%) treated with hydrogen peroxide and varying concentrations (25ppm or 50ppm) of monochloramine ("oxazamine") according to embodiments of the present invention, and samples treated with oxazamine alone (100ppm and 200ppm) for comparison.

Fig. 4 is a bar graph depicting the effect of hydrogen peroxide concentrations (100ppm, 200ppm, and 1000ppm) on bacterial growth control in corn slurry solutions (35 wt%) treated with hydrogen peroxide and varying concentrations (100ppm or 200ppm) of monochloramine ("oxazimine") according to embodiments of the present invention, and samples treated with oxazimine alone (100ppm and 200ppm) were used for comparison.

Fig. 5 is a bar graph depicting the effect of hydrogen peroxide concentrations (100ppm and 200ppm) on bacterial growth control (as bacteria reduction in log) in corn slurry solutions (35 wt%) treated with hydrogen peroxide and varying concentrations (25ppm, 50ppm, 75ppm, and 100ppm) of monochloramine ("oxaramine") according to embodiments of the present invention, and samples treated with either hydrogen peroxide alone (100ppm or 200ppm) or oxaramine alone (25ppm, 50ppm, 75ppm, or 100ppm) were used for comparison.

Detailed Description

The present invention provides methods of controlling the growth of one or more microorganisms in or on a product, material, or vehicle susceptible to attack or contamination by microorganisms by treating with an aqueous solution (or formulation) comprising a combination or mixture of a) monochloramine and b) at least one peroxide compound, such as hydrogen peroxide or other peroxides. The monochloramine and the peroxide compound may preferably be present in a combined amount that is synergistically effective to control the growth of at least one microorganism. Synergistic combinations of these microbiocides used in the methods and formulations of the present invention can provide greater antimicrobial effect than the sum of the individual microbiocides and, thus, can provide improved performance over combinations that are only additive in terms of antimicrobial efficiency. The microbiocidally or synergistically effective amounts can vary depending on the material or vehicle to be treated and can be determined routinely by those skilled in the art in view of this disclosure for a particular application. a) The combined use of monochloramine and b) at least one peroxide compound provides superior microbicidal activity over a wide range of microorganisms at low or other concentrations. The term "microbicide" or "biocide" as used herein may refer to a chemical substance capable of controlling bacteria in a selective manner.

The present invention can be used to provide growth control of at least one contaminating microorganism in any environment in which monochloramine is used. The present invention can be used to control microbial growth in higher organic load environments, such as in industrial ethanol fermentation processes, pharmaceutical processes, or other processes involving fermentation where a fermentable carbohydrate-containing feedstock is present. These methods may include the steps of: contacting a fermentable carbohydrate-containing feedstock with (a) monochloramine and (b) at least one peroxide compound in a combined amount that is synergistically microbiocidally effective for controlling the growth of at least one contaminant microorganism in the fermentable carbohydrate-containing feedstock. While not wishing to be bound by any theory, the peroxide compound may act as a scavenger to allow monochloramine to have a greater effect per unit time without adversely affecting yeast health in the fermentation process. As other advantages, the combined use of monochloramine and peroxide compounds in an ethanol fermentation process may provide elimination or reduction of antibiotics in the fermentation, reduction of lactic acid and acetic acid production in the fermentation, increased yeast cell growth, survival, budding and viability in the fermentation, increased ethanol production in corn ethanol production, improved plant runnability, reduced production costs, increased value of dried distillers grains for animal feed in corn ethanol production, and/or other improvements, or any combination of these improvements.

The present invention provides an aqueous solution or formulation as follows: which can be used in the method of the present invention, has a) monochloramine and b) at least one peroxide present in a combined amount that is synergistically effective to control the growth of at least one microorganism. The term "aqueous solution" as used herein may, as an example, refer to a solution that is predominantly water (e.g., more than 50% water by volume, such as more than 75%, more than 95%, or more than 99% water by volume) and that retains the solution properties of water. When the aqueous solution contains a solvent other than water, water is typically the predominant solvent.

The pH of the aqueous solution may be from about 4 to about 12, for example from about 4 to about 11, or from about 4 to about 10, or from about 4 to about 9, or from about 4 to about 8, or from about 4 to about 7, or from about 4 to about 6, or from about 5to about 11, or from about 7 to about 10, or from 7.1 to 12, or from 7.5 to 10, or from 8 to 10. The aqueous solution may further comprise at least one pH control agent, such as at least one acid or at least one base, or the aqueous solution may not comprise a pH control agent. If a pH control agent is included, the aqueous solution may include at least one acid, such as sulfuric acid and/or other acids, or at least one base, such as sodium hydroxide and/or other bases. The addition or presence of at least one base in addition to the monochloramine and peroxide compounds in the aqueous solution may provide optimal control of pathogenic bacteria. Some industrial processes involve lower pH conditions in aqueous systems during at least a portion of the process, such as an ethanol fermentation process, which may be fermented at a lower pH (e.g., about 4 to about 5.5). The fermentable carbohydrate-containing feedstock useful for ethanol fermentation may have a pH of from about 4 to about 12, or from about 4 to about 7. Prior to reaching the fermentation vessel, the fermentable carbohydrate-containing feedstock may be treated with an aqueous solution combining a synergistically effective combined amount of monochloramine and peroxide compounds (and optionally at least one base or pH control agent) to control the growth of at least one undesirable microorganism in the feedstock. This pre-fermentation treatment may be carried out with or without pH adjustment of the fermentable carbohydrate-containing feedstock in a pipeline upstream of (before) the vessel(s) in which the fermentation is carried out (e.g., before the location where the fermenting yeast and nutrients are introduced and combined with the fermentable carbohydrate-containing feedstock), in a process unit or apparatus, or a combination of these.

Instead of adding the aqueous solution of the present invention to the material or vehicle to be treated, the monochloramine and peroxide compound (e.g., hydrogen peroxide), and if used, at least one base, may be independently added to the product, material, or vehicle to be treated, such as shown for the ethanol fermentation process. If added separately, these components are added separately so that the final amount of the mixture of monochloramine and peroxide compound at the time of use may preferably be an amount that is synergistically effective to control the growth of at least one microorganism in the treated product, material, or vehicle. In an ethanol fermentation process, the peroxide compound and monochloramine may be added to a feedstock containing fermentable carbohydrates or other process fluids independently in a holding vessel located prior to the fermentation vessel, or independently in a line located prior to the fermentation vessel, or independently in both of these process equipment or other process units or equipment located prior to the fermentation vessel. Alternatively or additionally, the peroxide compound and monochloramine may be added directly to the fermentation vessel, or after the fermentation vessel, or any combination of these different points of introduction.

The combined use of a) monochloramine and b) at least one peroxide compound in an aqueous solution is useful in preserving various types of products, vehicles, or materials susceptible to attack by at least one microorganism. In the present invention, an aqueous solution comprising a) monochloramine and b) at least one peroxide compound (and optionally at least one base or pH control agent) is useful in the preservation of or control of at least one microorganism in various types of industrial and/or food products, vehicles, or materials susceptible to attack by microorganisms. The material or vehicle may be in the form of a solid, dispersion, emulsion, mash, slurry, or solution. Such vehicles or materials include, but are not limited to, for example, fermentation vehicles (media)/materials (as shown), dyes, pastes, wood, leather, fabrics, pulp, wood chips, tanning liquor, paper mill liquor, fiberglass, dairy processing, poultry processing, meat processing (e.g., beef, pork, lamb, or chicken), meat packaging equipment, animal slaughterhouses, polymer emulsions, paints, paper and other coatings and sizing agents, metalworking fluids, geological drilling lubricants, petrochemicals, cooling water systems, recreational water, mill influent, wastewater, pasteurizers, digesters, pharmaceutical formulations, cosmetic formulations, and rinse formulations.

The combined use of a) monochloramine and b) at least one peroxide compound (and optionally at least one base or pH control agent) in aqueous solution can be used to treat or preserve the following materials and vehicles: including, but not limited to, for example, mash or solution containing fermentable carbohydrates (as shown), wood pulp, wood chips, lumber, adhesives, coatings, animal hides, paper mill liquors, pharmaceutical formulations, cosmetic formulations, toiletry formulations, geological drilling lubricants, petrochemicals, agrochemical compositions, paints, leather, plastics, seeds, vegetation, wood, metalworking fluids, cooling water, recreational water, mill feed water, waste water, pasteurizers, cookers, tanning liquors or solutions, starches, proteinaceous materials, acrylic latex paint emulsions, and fabrics.

The combined use of a) monochloramine and b) at least one peroxide compound (and optionally at least one base or pH control agent) in aqueous solution can be used to treat or preserve aqueous systems, such as aqueous systems that are susceptible to microbial growth, attack, and degradation. These aqueous systems may be or include, but are not limited to, fresh water, brackish water, or brine systems. Exemplary aqueous systems include, but are not limited to, latexes, surfactants, dispersants, stabilizers, thickeners, adhesives, starches, waxes, proteins, emulsifiers, cellulosic products, metalworking fluids, cooling water, wastewater, aqueous emulsions, aqueous cleaners, coating compositions, paint compositions, and resins formulated as aqueous solutions, emulsions, or suspensions. Additionally, microbial degradation of aqueous systems can be prevented or controlled using the present invention, including, but not limited to, associated water treatment systems (which can include cooling towers, pumps, heat exchangers, and pipelines, heating systems, washing systems, and other similar systems, etc.).

The combined use of a) monochloramine and b) at least one peroxide compound (and optionally at least one base or pH controlling agent) in aqueous solution can also be used to protect or treat or preserve food, such as fresh (fresh) food (e.g., vegetables and fruits) or meat, or dairy products or processes, and/or surfaces (countertops) in contact with food, for example to extend shelf life. The present invention can be used to protect or treat facilities that process food (meat, fruits, vegetables), including but not limited to surfaces (countertops) and machinery and equipment (appliances) that come into contact with food or animals.

The combined use of a) monochloramine and b) at least one peroxide compound (and optionally at least one alkali or pH control agent) in aqueous solution may also be useful in agrochemical formulations for protecting seeds or crops from microbial spoilage.

According to the methods of the present invention, controlling or inhibiting the growth of at least one microorganism comprises reducing and/or preventing such growth.

It is further understood that by "controlling" (i.e., preventing) the growth of at least one of the microorganisms, the growth of the microorganism is inhibited. In other words, the microorganism does not grow or does not substantially grow. "controlling" the growth of at least one microorganism maintains the population of microorganisms at a desired level, reduces the population to a desired level (even to an undetectable limit, e.g., a zero population), and/or inhibits the growth of the microorganism. Thus, in the present invention, a product, material, or vehicle susceptible to attack by at least one microorganism can be preserved from such attack and the resulting spoiling and other deleterious effects caused by the microorganism. Further, it is also to be understood that "controlling" the growth of at least one microorganism also comprises biometrically reducing and/or maintaining a low level of at least one microorganism such that the infestation caused by said microorganism and any resulting spoiling or other detrimental effects are reduced, i.e. the microorganism growth rate or the microorganism infestation rate is slowed down and/or eliminated.

When two chemical microbiocides are mixed and added to the product, or added independently, three results are possible:

1) the chemicals in the product produce an additive (neutral) effect.

2) The chemical in the product has an antagonistic effect, or

3) The chemicals in the product produce a synergistic effect.

The additive effect has no economic advantage over the individual components. Antagonistic effects can have negative effects. Only synergistic effects with a lower probability than additive or antagonistic effects will produce positive effects and therefore have an economic advantage.

It is known in the microbiocidal literature that there is no theoretical way to predict additive, antagonistic, or synergistic effects when two biocides are mixed to produce a new formulation. There is also no way to predict the relative proportions of the different biocides needed to produce one of the three effects described above.

Thus, the combination of a) monochloramine and b) at least one peroxide compound (and optionally at least one base or pH control agent) in aqueous solution preferably achieves superior (i.e. greater than additive) microbicidal activity even at low concentrations for a wide variety of microorganisms. Examples of such microorganisms include fungi, bacteria, algae, and mixtures thereof, such as, but not limited to, for example, Lactobacillus (Lactobacillus), Pediococcus (Pediococcus), Leuconostoc (Leuconostoc) and Weissella (Weissella), Acetobacter sp, Trichoderma viride (Trichoderma viride), Aspergillus niger (Aspergillus niger), Pseudomonas aeruginosa (Pseudomonas aeruginosa), Enterobacter aerogenes (Enterobacter aeogenenes), Klebsiella pneumoniae (Klebsiella pneumoniae), and Chlorella sp. The microorganism may be an unwanted bacterium or bacteria. The unwanted bacteria may be unwanted bacteria in ethanol fermentation, such as lactobacillus, pediococcus, leuconostoc and weissel species, acetobacter, or others. The combination of a) monochloramine and b) at least one peroxide compound of the present invention may have low toxicity.

Monochloramine (NH)₂Cl) (also referred to herein as MCA) may be obtained or made in situ. In dilute aqueous solutions, chloramine is produced by the reaction of ammonia with sodium hypochlorite:

NH₃+OCl^-→NH₂Cl+HO^-。

this is also the first step in the synthesis of Raschig (Raschig) hydrazine. The reaction is carried out in a slightly basic vehicle (pH8.5 to 11). The chlorinating agent that plays a role in this reaction is hypochlorous acid (HOCl), which must be generated by protonation of hypochlorite and then reacted with nucleophilic substitution of hydroxyl (hydroxy) groups for amino groups. The reaction occurs most rapidly at about pH8. At higher pH values, the concentration of hypochlorous acid is lower, at lower pH values ammonia is protonated to form ammonium ions NH₄ ⁺It does not react further. The chloramine solution can be concentrated by vacuum distillation and by passing the vapor through potassium carbonate, which absorbs water. Chloramines can be extracted with ether. Gaseous chloramines can be obtained from the reaction of gaseous ammonia with chlorine (diluted with nitrogen):

pure chloramine can be prepared by passing fluoroamine through calcium chloride:

2 NH₂F+CaCl₂→2 NH₂Cl+CaF₂。

methods for in situ chloramine generation are known and can be modified for use in the methods of the invention. For example, rather than adding pure chloramine to the product, material, or system, a sodium hypochlorite solution or chlorine gas can be added with ammonia or an ammonium salt to generate chloramine in situ prior to or while combining with the peroxide compound. A single type of chloramine or a combination of different chloramines may be used.

"peroxide compound" refers to the following compounds: it may be a hydroperoxide, organic peroxide, inorganic peroxide, peroxy-releasing compound, or any combination thereof. The hydroperoxide can have the structure R-O-H, wherein R is hydrogen or a linear, branched and/or cyclic alkyl group (radical) having 1 to 20 carbon atoms and can optionally be interrupted by one or more oxygen and/or carbonyl groups. The organic peroxide may have the structure R '-O-O-R ", wherein R' and R" are independently linear, branched, and/or cyclic alkyl groups (radicals) having 1-20 carbon atoms and may optionally be interrupted by one or more oxygen and/or carbonyl groups. The inorganic peroxide may be selected from alkali metal peroxides, alkaline earth metal peroxides, transition metal peroxides, or any combination thereof. The peroxy group releasing compound may be selected from alkali metal percarbonates, alkaline earth metal percarbonates, transition metal percarbonates, alkali metal perborates, alkaline earth metal perborates, transition metal perborates, or any combination thereof. The peroxide compound may be or include hydrogen peroxide (H)₂O₂). Mixtures of peroxide compounds may be used, for example, hydrogen peroxide and different peroxide compounds.

Peroxide compounds may be more stable or may function better in acidic environments, while MCA may function better in alkaline environments. As indicated, since some industrial processes, such as the ethanol fermentation step, are typically carried out under acidic pH conditions, any adjusted aqueous solution pH as part of the treatment of the vehicle is 7 or higher, if performed as an option, preferably at least partially or completely prior to the fermentation step. The fermenting yeast cannot tolerate a pH well below pH 3-4 or above 8-8.2 without adversely affecting the fermentation process. The ethanol fermentation process may be treated with an aqueous solution of the present invention that combines a peroxide compound and monochloramine and optionally adds a pH control agent that seeks to reduce or avoid adverse effects on the yeast or other components of the fermentation process.

As an option, at least one base may be present or included in the aqueous solution to adjust, for example, the pH to fine tune for optimal effect from a biocidal efficiency point of view, or cost point of view, or both, or a synergistic effect between the peroxide compound and MCA. Any base may be used herein as a pH adjusting adjuvant for adjusting pH (e.g., raising pH). The base may be an alkali metal hydroxide, an alkaline earth metal hydroxide, or any combination thereof. The base may be sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, sodium carbonate, or any combination thereof. Preferred bases for pH adjustment may include water soluble bases such as sodium hydroxide, potassium hydroxide, or mixtures thereof. The base may be used as an aqueous solution. The base may be added to the aqueous solution prior to treatment of the product, material or vehicle, and/or may be added to the product, material or vehicle, or both, prior to or after treatment with the aqueous solution. As indicated, the base may be used as a pH control agent. If it is desired to lower the pH, such as, for example, to provide or maintain a pH of no greater than 12 or other pH values having a pH range of about 4 to about 12 (e.g., about 4-11, or 4-10, or 4-9, or 4-8, or 4-7, or 4-6, or other values), a pH control agent that is at least one acid may be used. If used, the at least one acid may be acetic acid, citric acid, hydrochloric acid, sulfuric acid, or other acids, or alum, or any combination thereof.

The amount of base, if added, may be an amount that adjusts the aqueous solution to a desired pH or range. The concentration of the base can be any commercially available concentration (e.g., 0.1N or 0.01N, or concentrated base) and/or can be diluted to any desired or suitable concentration. The base may be present in the following concentrations: such that the aqueous solution has a pH of from about 4 to about 12, alternatively from about 5to about 12, alternatively from about 6 to about 11, alternatively from about 7 to about 10, alternatively from about 7.1 to about 9.9, alternatively from about 7.5 to about 9.5, alternatively from about 8 to about 9, or other values.

The aqueous solution to which the at least one base may be added may be a stock or flow stream of an aqueous fluid that already contains monochloramine, but that is not yet containing peroxide compounds. For example, after the at least one base is added to the aqueous fluid comprising monochloramine, the resulting base-treated aqueous fluid may be further modified by the addition of the peroxide compound, before the aqueous fluid comprising all three components is introduced into the aqueous system (or product, material, or vehicle) to be treated. As another option, an aqueous fluid comprising monochloramine and the at least one base may be added to the aqueous system (or product, material, or vehicle) to be treated, and the peroxide compound may be added separately to the aqueous system upstream or downstream thereof. As another option, the at least one base, monochloramine, and peroxide compound may be added independently to the aqueous system (or product, material, or vehicle) to be treated, wherein the aqueous solution is prepared substantially simultaneously with treatment therewith. The aqueous system or vehicle that can be treated with the aqueous solution in any of these ways can be an aqueous fluid (e.g., water alone, or a predominantly water solution, or other water-based solution) stored in a pool, container, or a flowing aqueous fluid or open flowing stream in a conduit, or other aqueous system. The liquid system or vehicle may be an animal sink or raceway through which potable water flows or stops. As stated, the present invention also contemplates the independent addition of the monochloramine and at least one peroxide compound, e.g., peroxide compound and, if used, the at least one base or pH control agent, to a product, material, or vehicle. According to this option, each component is added separately to the product, material, or vehicle such that the final amount of each component present at the time of use may preferably be an amount that is synergistically effective to control the growth of at least one microorganism.

The monochloramine and at least one peroxide compound, and if used, the at least one base or pH control agent, may be added independently to the product, material, or vehicle, or to a system or environment containing the product, material, or vehicle. When added independently, the monochloramine and the peroxide compound, and if used, the at least one base or pH control agent, can each be added simultaneously, nearly simultaneously (within 0.1 seconds to 5 minutes of each other, e.g., within 5 seconds of each other, within 10 seconds of each other, within 30 seconds of each other, within 1 minute of each other, within 2 minutes of each other, within 5 minutes of each other, or within 10 minutes of each other), sequentially, and in any order (e.g., either the peroxide compound first or the monochloramine first). Further, in this option or in any embodiment of the invention, the monochloramine may be formed in situ in the presence of the product, material, or vehicle to be treated or protected (or just prior to the MCA contacting the product, material, or vehicle to be treated or protected). The formation of monochloramine in situ may be carried out before or after the presence of the peroxide compound. After the addition (or formation) of the monochloramine and peroxide compound, and if used, each of the at least one base or pH control agent, in a liquid solution, vehicle or environment, mixing or agitation can optionally be used to mix the two (or three) components together for any amount of time (e.g., 1 second to 10 minutes or more). The components may be applied by: spraying, atomizing, coating, dipping, or any other technique/application that allows the product, material, vehicle, or system to be contacted with each of a) monochloramine and b) at least one peroxide compound.

The microbiocides in the aqueous solutions of the present invention may be used "as is" or may be formulated first with a solvent or solid carrier. Suitable solvents include, for example, water; glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; a glycol ether; alcohols such as methanol, ethanol, propanol, phenethyl alcohol and phenoxypropanol; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate, butyl acetate, triacetyl citrate, and triacetin; carbonates such as propylene carbonate and dimethyl carbonate; and mixtures thereof. The solvent may be selected from the group consisting of water, glycols, glycol ethers, esters, and mixtures thereof. The hydrogen peroxide can be used in commercially available or synthetic forms as a solution in water (e.g., at a concentration of from about 3 wt.% to about 98 wt.%, or from about 10 wt.% to about 75 wt.%, or from about 20 wt.% to about 60 wt.%, or from about 30 wt.% to about 50 wt.%, or from about 35 wt.% to about 45 wt.%, or about 40 wt.%, or other concentrations). Suitable solid carriers include, for example, cyclodextrins, silica, diatomaceous earth, waxes, cellulosic materials, alkali and alkaline earth (e.g., sodium, magnesium, potassium) metal salts (e.g., chlorides, nitrates, bromides, sulfates), and charcoal.

The components (a) Monochloramine (MCA) and (b) at least one peroxide compound (and optionally at least one base or pH control agent) may also be formulated in the form of a dispersion. The solvent component of the dispersion may be an organic solvent or water. Such dispersions may contain adjuvants such as, for example, cosolvents, thickeners, antifreeze agents, dispersants, fillers, pigments, surfactants, biodispersants, sulfosuccinates, terpenes, furanones, polycations, stabilizers, scale inhibitors and/or anti-corrosion additives.

When components (a) Monochloramine (MCA) and (b) at least one peroxide compound (and optionally at least one base or pH control agent) are formulated in a solvent, the formulation may optionally contain a surfactant. When such formulations contain surfactants, they are typically in the form of emulsion-type concentrates, emulsions, microemulsion-type concentrates, or microemulsions. Emulsion-type concentrates form emulsions upon addition of a sufficient amount of water. Microemulsion-type concentrates form microemulsions upon addition of sufficient amounts of water. Such emulsion-type and microemulsion-type concentrates are generally well known in the art; preferably, such formulations are surfactant free. For further general and specific details regarding the preparation of various microemulsions and microemulsion-type concentrates, U.S. patent No.5,444,078 may be consulted.

For the purposes of the present invention, the formulations of the present invention may be free of other microbicides, and/or free of metal-containing compounds, and/or free of organic acids, and/or free of antibiotics, and/or free of surfactants, and/or free of any active other than monochloramine and peroxide compounds.

As mentioned above, the components (a) Monochloramine (MCA) and (b) at least one peroxide compound (and optionally at least one base or pH controlling agent) are preferably used in a synergistically effective amount in aqueous solution. (a) The weight ratio of (a) to (b) varies depending on the type of microorganism and the product, material, or vehicle to which the aqueous solution is applied. In view of the present disclosure, one skilled in the art can readily determine an appropriate weight ratio for a particular application without undue experimentation. The weight ratio (weight: weight) of component (a) to component (b) used in the aqueous solution or formulation ranges from 1:1000 to 1000:1(0.001:1 to 1:0.001), or from 1:99 to 99:1, or from 1:50 to 50:1, or from 1:40 to 40:1, or from 1:30 to 30:1, or from 1:20 to 20:1, or from 1:10 to 10:1, or from 1: 5to 5:1, or from 1:4 to 4:1, or from 1:3 to 3:1, or from 1:2.5 to 2.5:1, or from 1:2 to 2:1, or from about 1:1.5 to 1.5:1, or from about 1:1.25 to 1.25:1, or from about 1:1.1 to 1.1:1, or from about 1:10 to 1:1, or from 1: 5to 1:1, or from 1:1 to 1.5:1, or from 1:1, or from 1:1, Or from about 1:4 to 1:2, or from about 1: 5to 1: 3. These weight ratios may be for the aqueous solution to be treated and/or may be the weight ratios of the aqueous solutions prepared and used to treat the aqueous solution.

For example, in an aqueous solution or formulation, MCA may be present at the following concentrations: from 0.1ppm to 50,000ppm, or from 0.1ppm to 10,000ppm, or from 0.1ppm to 5,000ppm, or from 0.1ppm to 1,000ppm, or from 0.1ppm to 750ppm, or from 0.1ppm to 500ppm, or from 0.1ppm to 250ppm, or from 0.1ppm to 100ppm, or from 0.1ppm to 75ppm, or from 0.1ppm to 50ppm, or from 1ppm to 5,000ppm, or from 1ppm to 1,000ppm, or from 1ppm to 750ppm, or from 1ppm to 450ppm, or from 1ppm to 250ppm, or from 5ppm to 250ppm, or from 10ppm to 250ppm, or from 15ppm to 250ppm, or from 20ppm to 250ppm, or from 25ppm to 250ppm, or from 1ppm to 225ppm, or from 1ppm to 200ppm, or from 1 to 175ppm, or from 1 to 150ppm, or from 1ppm to 100ppm, or from 1ppm to 250ppm, or from 1ppm to 250, Or from 15ppm to 150ppm, or from 20ppm to 150ppm, or from 25ppm to 150ppm, or from 50ppm to 150ppm, or from 5ppm to 125ppm, or from 5ppm to 100ppm, or from 5ppm to 75ppm, or from 5ppm to 50ppm, or from 10ppm to 100ppm, or from 15ppm to 100ppm, or from 20ppm to 100ppm, or from 25ppm to 100ppm, or from 50ppm to 100ppm, or from 10ppm to 90ppm, or from 10ppm to 75ppm, or from 10ppm to 50ppm, or from 10ppm to 25ppm, or from 15ppm to 80ppm, or from 25ppm to 80ppm, or from 15ppm to 75ppm, or from 15ppm to 60ppm, or from 15ppm to 50ppm, or from 20ppm to 60ppm, or from 25ppm to 50ppm, and the peroxide compound may be present at a concentration of: 0.1ppm to 50,000ppm, 0.1ppm to 10,000ppm, or from 0.1ppm to 5,000ppm, or from 0.1ppm to 1,000ppm, or from 0.1ppm to 750ppm, or from 0.1ppm to 500ppm, or from 0.1ppm to 250ppm, or from 0.1ppm to 100ppm, or from 0.1ppm to 75ppm, or from 0.1ppm to 50ppm, or from 1ppm to 5,000ppm, or from 1ppm to 1,000ppm, or from 1ppm to 750ppm, or from 1ppm to 450ppm, or from 5ppm to 450ppm, or from 1ppm to 350ppm, or from 5ppm to 350ppm, or from 1ppm to 250ppm, or from 5ppm to 250ppm, or from 10ppm to 250ppm, or from 15ppm to 250ppm, or from 20ppm to 250ppm, or from 25ppm to 250ppm, or from 1ppm to 225ppm, or from 1ppm to 200ppm, or from 1ppm to 1ppm, or from 1ppm to 250ppm, or from 1ppm to 1ppm, or from 1ppm to 250ppm, or from 1ppm, or from 25ppm to 250ppm, or from 1ppm to 250ppm, or, Or from 5ppm to 150ppm, or from 10ppm to 150ppm, or from 15ppm to 150ppm, or from 20ppm to 150ppm, or from 25ppm to 150ppm, or from 50ppm to 150ppm, or from 5ppm to 125ppm, or from 5ppm to 100ppm, or from 5ppm to 75ppm, or from 5ppm to 50ppm, or from 10ppm to 125ppm, or from 15ppm to 125ppm, or from 20ppm to 125ppm, or from 25ppm to 125ppm, or from 50ppm to 125ppm, or from 10ppm to 100ppm, or from 10ppm to 75ppm, or from 10ppm to 50ppm, or from 15ppm to 90ppm, or from 20ppm to 90ppm, or from 25ppm to 70ppm, or from 25ppm to 60ppm, or from 25ppm to 90ppm, or from 25ppm to 75ppm, or from 25ppm to 50 ppm. These ppm concentrations may be for the aqueous solution to be treated and/or may be ppm concentrations of the aqueous solution prepared and used to treat the aqueous solution. These dosages, and others described herein, may be calculated or measured or may be considered residual ppm amounts present in the aqueous solution being treated.

As a precise option in the present invention, MCA may be present in an aqueous solution or formulation in a concentration of from 30ppm to 100ppm or from 50ppm to 100ppm, and the peroxide compound may be present in a concentration of from 75ppm to 125ppm or below 200 ppm. These amounts allow, inter alia, to increase the bacterial count control in a way that would not be possible if MCA or peroxide were used alone at the same concentration.

Typically, for aqueous solutions having a pH of from about 4 to about 12 and, if used, a base or pH control agent, a synergistically effective response (e.g., a fungicidal, bactericidal, or algicidal response) can be obtained when the combination of component (a) and component (b) is used at concentrations ranging from: about 0.1 to 5% (i.e., 50,000ppm) MCA, preferably from 0.1 to 750ppm, more preferably from 1 to 450ppm, even more preferably from 1 to 250ppm, and most preferably from 1 to 100 ppm; and from 0.1ppm to 50,000ppm of the oxide compound (e.g., peroxide compound), preferably from 0.1ppm to 750ppm, more preferably 1ppm to 450ppm, even more preferably 1ppm to 250ppm, and most preferably 5ppm to 100 ppm. In general, an effective fungicidal, bactericidal, or algicidal response can be obtained when the synergistic combination is used at concentrations ranging from: about 0.1ppm to 1% (i.e., 10,000ppm) MCA, preferably 0.1ppm to 750ppm, more preferably 1ppm to 450ppm, and most preferably from 1ppm to 100 ppm; and from about 0.1ppm to 5,000ppm of the peroxide compound (e.g., hydrogen peroxide), preferably 0.1ppm to 750ppm, more preferably 5to 450ppm, and most preferably 5ppm to 150 ppm. These ppm concentrations may be for the aqueous solution to be treated and/or may be ppm concentrations of the aqueous solution prepared and used to treat the aqueous solution.

Depending on the particular application, the aqueous solution may be prepared in liquid form by dissolving, dispersing, or forming in situ in water or other aqueous fluid, monochloramine and at least one peroxide compound and, if used, at least one base or pH control agent. The preservative comprising the aqueous solution of the present invention can be prepared in the form of an emulsion by emulsifying it in water, or emulsifying it by adding a surfactant if necessary. Additional chemicals such as pesticides may be added to the aforementioned formulations and aqueous solutions depending on the intended use of the formulation.

The mode of application as well as the rate of application of the aqueous solution of the present invention may vary depending on the intended use. The aqueous solution may be applied to the material or product by spraying or brushing. The material or product in question can also be treated by immersion in a suitable formulation of the aqueous solution. In a liquid or liquid-like vehicle, the aqueous solution may be added by pouring, or by metering with a suitable device, so that a dispersion or solution of the aqueous solution may be produced.

Fermentation systems that can be treated with the synergistic microbicidal combination of the present invention include systems for the production of ethanol fermentation systems and pharmaceutical fermentation systems, or other fermentation systems. The ethanol fermentation system may include those for corn ethanol, sugarcane-to-ethanol, dry-milled ethanol, wet-grain (grain) ethanol, wheat-to-ethanol, barley-to-ethanol, oat-to-ethanol, rye-p-ethanol, sorghum-to-ethanol, cellulose-to-ethanol, beet-to-ethanol, rice-to-ethanol, or other ethanol fermentation systems.

The process according to the invention can be practiced in conventional ethanol production plants with modifications that can be readily made in view of the present invention. Referring to fig. 1, a process for treating an ethanol fermentation system with the synergistic microbicidal combination of the present invention is shown generally as involving the introduction of a combination of hydrogen peroxide or other peroxide compound and Monochloramine (MCA) in combination or providing a combination thereof in a system via one or more of introduction locations (42), (43), (44), (46), (47), (49), wherein other exemplary features of the system include, as an option, (1) coarse grinding (10) to produce ground corn (15), and that the ground corn (15) can be mixed in a pre-liquefaction step in a mixing tank (20) with an alpha-amylase or other liquefying enzyme and water (21) to form a pre-liquefied corn mash (25). Pre-liquefied corn (25) may be fed to a jet heater (30) for heating liquefaction to produce a heated liquefied corn mash (35), and the heated liquefied corn mash (35) may be combined in a digestion step in a storage vessel (40) with alpha-amylase (and/or other liquefying enzymes) and water (41) to produce a liquefied corn mash (45). A portion of the liquefied corn mash (45) may be combined with glucoamylase and/or other saccharifying enzymes, nutrient sources, yeast, and water (51) in an incubation tank (50) to produce inoculating yeast (55), which may be fed to a fermentor vessel (60). The remainder of the liquefied corn mash (45) may be fed to the fermentor vessel (60) via line (48). The portion of liquefied corn (45) fed via line (48) may be combined with seeding yeast (55) and glucoamylase, a nitrogen-containing nutrient source, and water (61) in a fermentor vessel (60) to produce a fermentation composition (65). The fermentation composition may be sent to a fermentation tank (70) and then to a reboiler (80) for recovering crude ethanol (95) from the overhead stream (85) in a condenser (90). The crude ethanol (95) may be sent to a molecular sieve unit (100) for separation of ethanol (105) from by-products (106). Stillage or reboiler bottoms (87) can be sent to centrifuge (110) where wet distillers solids ("DGS") (115) and centrate (117) (liquid-containing fractions) are separated in centrifuge (110). All or a portion of the centrate (117) may optionally be recycled as a reflux to the mixing tank (20), the incubation tank (50), and/or the fermentor (60). The centrate (117) that is not recycled may be fed to the evaporator (130), where it may be concentrated to produce a syrup (135), and the syrup (135) may be combined with wet DGS (115) and sent to the dryer (120), where the DDGS (125) may be prepared. Alternatively, the wet DGS (115) may be dried in the absence of syrup (135) to produce distillers dried grains ("DDG") (not shown). To simplify the illustration in fig. 1, additional pumps, heat exchangers, and other conventional equipment that may be used in the process are not shown.

As shown in fig. 1, as an option, the peroxide compound and monochloramine may be added in synergistically effective combined amounts at one or more locations (44), (42), (43), (47) before the fermentation vessel (60), at location (46) in the fermentation vessel (60), at one or more locations (49) after the fermentation vessel (60), or any combination thereof. As a preferred option, the peroxide compound and monochloramine are added in a synergistically effective combined amount, at least at one or more locations (e.g. at least at one or more of locations (44), (42), (43), (47)) before the fermentation vessel (60). The treatment may be performed with or without pH adjustment of the fermentable carbohydrate-containing feedstock prior to introduction into the fermentation vessel (60) in a holding vessel (40), piping (48), an incubator (50) (not shown) or other process unit/equipment (e.g., pump), or in any combination of these options. The peroxide compound and monochloramine may be added from the same aqueous solution to a holding vessel (40), a line (48) (e.g., using 42 and alternate line 43 shown in phantom), or a return line (47), or any combination of these or other process equipment located prior to the fermentation vessel (60). The peroxide compound and monochloramine may be added separately to the fermentable carbohydrate-containing feedstock in a holding vessel (40), or separately to line (48) as shown by (42) and (43) in figure 1, or separately to the return line (47), or any combination of these or other process equipment located prior to the fermentation vessel (60). The peroxide compound and monochloramine may be added to the reservoir (40) from the same aqueous solution or separately (44), and then additional monochloramine (43) may be added in line (48) to the mash discharged from the reservoir (40). The mixing of the separately introduced peroxide compound and monochloramine into the feedstock or other process fluid upstream of the fermentation vessel may be provided by the presence of a vortex in the process unit as follows: a stirrer in the process unit; or an in-line static mixer in a pipeline, or a pump; or the peroxide compound and monochloramine are introduced before the bend or bends in the piping which encounter a vortex in the fluid passing through the piping; or other device arrangements or combinations of these. The combined peroxide compound and monochloramine can survive in the treated process system in the presence of an organic load (e.g., a feedstock containing fermentable carbohydrates) for about 5to about 10 minutes, or other time period. By adding the peroxide and monochloramine components to the process fluid at a location or locations sufficiently close in time to the fermentation vessel prior to introduction to the fermentation vessel, control of lactic acid, acetic acid, or both, in the fermentation vessel during fermentation can be provided, even if the peroxide compound and monochloramine are not added directly to the fermentation vessel, which is another option of the invention. The peroxide compound and monochloramine may be introduced into the fermentation vessel (60) from a single aqueous solution or separately as shown by (46). The peroxide compound and monochloramine may be introduced into the fermented composition (65) after discharge from the fermentation vessel (60) from a single aqueous solution as shown by (49) (e.g., at a fermentation tank or other post-fermentation process unit/equipment or piping as shown) or separately.

Other aspects, equipment, and details of ethanol fermentation chemistry, processes, and systems may be based on those used in ethanol production facilities, such as those described in U.S. patent No.8,951,960 and U.S. patent application publication No.2017/0107543, which are incorporated herein by reference in their entirety.

The microbicidal and synergistic activity of the above combinations has been confirmed using standard laboratory techniques as described below. The following examples are intended to illustrate, but not limit, the present invention.