MXPA00009971A - Improved defoamer and methods of use thereof - Google Patents

Abstract

Disclosed are methods and compositions for defoaming alcoholic fermentations. An aqueous composition of polydimethylsiloxane, an ethylene oxide/propylene oxide block copolymer and a silicone/silica blend is employed to treat the fermentation for foaming.

Description

-. - - » »- -» - IMPROVED DESPIPANT AND METHODS OF USE FIELD OF THE INVENTION The present invention relates to an improved defoaming composition based on water. The present invention, more particularly, relates to an improved water-based defoaming composition which has utility in the alcoholic fermentation of sugarcane juice and corn syrup.

BACKGROUND OF THE INVENTION Anti-foaming compositions are materials used in the prevention, separation and control of unwanted foam. The foams of unwanted fluids are formed by numerous very small bubbles of mechanical or chemical origin that are generated within the liquid and that grow and accumulate on the surface of liquid faster than they melt. There are several fields in which unwanted foams are found. Foam problems can be found in polymerization, painting processes, papermaking processes, oil well drilling and refining operations, food preparation and textile dyeing operations. Coolants, hydraulic fluids, lubricants, Aviation fuels and gas absorption systems can foam with undesirable results under operating conditions. If not properly controlled, foam can reduce equipment capacity and increase processing time and expense, and in some cases, cause other damage. Although foam can be controlled in some cases by making changes in the process itself, or by the use of mechanical defoaming equipment, chemical defoaming formulations have proven and economic effectiveness. Distilleries that use sugar cane syrups and ugo as raw materials for ethanol production face various operational problems. One of the most serious problems is the generation of foam during this fermentative process. To allow the fermentation of sucrose, it is necessary to break it down into fructose and glucose which are simpler sugars according to the reaction: C12H22O11 + H20? 2C2H5OH2 + 2 C0 + 56KCal The components of the mixture under fermentation, composed mainly of sugars, electrolytes, proteins and acids, are concentrated in the liquid-air interface, generating an elastic foam.

The gases that are produced during the fermentation process, due to their lower density with respect to the liquid phase, rise to the surface and stretch the elastic film. As this film is relatively resistant to breaking, the gases remain in the upper part of the liquid causing bubble formation (ie foam).

This formed foam must be rigorously controlled to avoid spillage in the fermentation tank, which could result in loss of the yeast or ethanol. The present inventors have discovered a water-based defoaming composition that has proven to be more effective than mineral oil-based defoamers and synthetic waxes typically used in the fermentation industry.

COMPENDIUM OF THE INVENTION The present invention provides defoaming compositions that have utility in alcoholic fermentations. The defoaming compositions are water based and comprise polydimethylsiloxane oils, ethylene oxide / propylene oxide block copolymers and a silicone / silica mixture.

DESCRIPTION OF THE RELATED TECHNIQUE The polydimethylsiloxanes have been used in media not aqueous, such as residual oil reserves and crude oils as defoamers as taught in U.S. Patent Nos. 3,700,587, and 4,082,690. Liquid organo-silicon condensation products or polymers in combination with silane have been taught in US Pat. No. 2,702,793 as defoamers in oils and antifreezes. The polyvinylalkoxysilanes and polyvinylalkyloxysilanes are designed in US Pat. No. 2,862,885 to control foam in petroleum-type oils., particularly those in the viscosity range of the lubricating oil. U.S. Patent No. 3,959,175 teaches an aqueous defoaming composition containing liquid polybutene. The defoaming composition may further comprise in part hydrophobic silica and silicone oils. U.S. Patent No. 5,288,789 teaches the use of an alkylphenol and aldehyde condensate which has been polyoxyalkylated to reduce the foam in a fermentation broth.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides the composition and methods for defoaming alcoholic fermentations, comprising a polydimethylsiloxane oil, a block copolymer of ethylene oxide / propylene oxide and a mixture silicone / silica in aqueous solution. The methods comprise adding an effective defoaming amount: e this composition to the alcoholic fermentation itself. The polydimethylsiloxane oil is preferably selected from those having an average viscosity between about 300 and about 500 cST (25 ° C) and an average molecular weight (MWpro "), between about 20,000 and about 40,000 with a preferred molecular weight of Approximately 28,000 to about 30,000.These chemicals are available under the trademarks BAYSILONE OEL M and RHODOR? YL from Bayer Corp. and Rhone Poulenc, respectively.The copolymer in ethylene oxide / oxide or propylene (EO / PO) blocks Preferably it has an average Brookfield RVT viscosity between about 100 and about 600 mPAS and an average cloud point between about 20 and 50 ° C. These compounds are commercially available from Dow Chemical under the trademark Fluent Cane. / silica is preferably composed of methylated silica and a reaction product dimethylsiloxane / silica in a weight ratio of 3.0 methyl silica for 27% dimethylsiloxane / silica reaction product and has an average Brookfield RVT viscosity between 1000 and 30,000 cps. These compounds are available commercially by Dow Corning as Dow Corning A and Dow Corning 3472, respectively. For purposes of the present invention, the silicone / silica mixture can be defined as a mixture of a siloxane compound with a silica compound. The composition can be prepared in an aqueous solution with the weight ratios of polydimethylsiloxane to the block copolymers EO / PO to hydrophilic silica ranging from about 8:10:10, preferably the weight ratio is 4: 5: 5. Additional ingredients may also be added to the aqueous composition to stabilize the composition and improve the ability of the composition to disperse over the entire surface of the foam. Examples of these chemicals include, but are not limited to, polyether modified polysiloxane, xanthan gum, ethoxylated castor oil, glycerol monostearate, alcohol, sodium carbonate and glutaraldehyde. The main requirement is that the additional ingredients do not affect the yeast damaging the fermentation process. The aqueous composition can be added to the fermentation processes by being treated by conventional means. For purposes of the present invention, the phrase "an effective defoaming amount" is defined as amount of composition of the invention that will control the already formed foam. This amount will be variable based on different parameters such as sugar juice composition, yeast activity, temperature, feeding speed of the sugar / yeast juice mixture from the fermentation tanks, etc. Preferably, this amount varies from about 0.3 to about 1.0 grams per liters of ethanol produced. For purposes of the present invention, the phrase "alcoholic fermentations" is understood to include fermentation of the juice of sugar cane and fermentation of corn syrup. To illustrate this invention more clearly, the data stated below was developed. The following examples are included as illustrations of the invention and should not be construed as limiting the scope thereof.

EXAMPLES To test the effectiveness of the composition of the invention as an antifoam, a standard foam break test was employed. The general conditions of the test are as follows: Temperature 35 ° C Total time 10 minutes Air flow 2.0 L / min Ratio sugar juice / solution 210 ml / 140 ml of yeasts Brixio of juice 19 Feeding ratio of 0.2 ml / L or 0.1 Ml / 1 of juice and yeast product An air meter was connected to a graduated glass column and the indicated flow rate was applied. A solution of yeast in water was prepared as a part of yeast by two parts of water. The pH of the resulting solution was adjusted to 2.3 with H;? Oj (50%). The juice and the aqueous solution of yeast were then mixed in a 600 mL beaker in the indicated ratio. This mixture was then heated to the defined temperature. The heated mixture was then transferred to the graduated column under the injection of air.

When the foam level reached 25 cm inside the column, the antifoam was added with the feed ratio defined by the use of a 1.0 mL plastic syringe, while the stopwatch was simultaneously switched on. The effect of the product for breaking and the foam level were then recorded during the indicated times. The results of these tests are presented in Table 1. The standard was composed of 3.0- of ethylene bis stearamide, 80.0% of mineral oil with 20- of naphthenic carbons, 15.0 to 20.0% of content of aromatic carbons and 62.0% of content of parafinic carbons; and 15.0% copolymer in block EO / PO. The rest 2.0% are chemicals to stabilize and improve the application of the product. These are the same as those listed in treatment A of the invention described below.

Components of treatment A of inventiveness - (in weight? Polydimethylsiloxane oil 500 CST 1.75 (Baysilone OEL M 500 / Rhodorsyl 47 V 12500) Polydimethylsiloxane oil 12500 CST 2.25 (Baysilone OEL M 12500 / Rhodorsyl 47 V 12500) Polydimethylsiloxane oil 30000 CST 4.00 (Baysilone OEL M 30000 / Rhodorsyl 47 V 30000) Copolymers EO / PO (Fluent Cañe 152) 5.20 Copolymers EO / PO (Fluent Cañe 120) 8.00 Silica, hydrophobic amorphous silicon dioxide 0.80 (Rhodorsyl R 972) Stabilizers / improvers of the final product Polysiloxane modified with polyether (Tegopren 5863) 1.00 Xanthan gum (polysaccharide) 0.10 Ethoxylated castor oil (40 EO) (Surfon R 400) 2.00 Glycerol monostearate 0.50 Synthetic alcohol (20C) (Alfol 20 plus) 2.00 Water Sodium Carbonate 3.01 Glutaraldehyde 0.20 Table I Foam height (cm) Standard Time Treatment A Standard Treatment A (SECONDS) (0.02% (0. 02 * (0.01 ~ (0.01 active) active) active) active * 0 25 25 25 25 24 18 23 20 15 15 18 17 10 13 15 16 9 9 10 14 9 7 10 12 9 7 10 10 9 7 10 10 40 9 7 10 9 45 9 7 10 9 50 9 7 10 9 55 9 7 10 9 60 9 7 10 9 Standard Time Treatment A Standard Treatment A (MINUTES) (0.023 (0. (0.01- (0.01- active) active) active) active) 2 12 7 12 10 3 13 8 16 11 4 14 8 17 12 5 15 9 17 12 6 15 9 18 13 8 15 10 19 14 10 15 12 19 15 15 15 14 19 17 As demonstrated in Table 1, the inventive treatment was more effective as a defoamer in a sugar fermentation than the standard product currently used in the field of fermentation. This is Truthfully tested at 0.02% and 0.01% of activities. Another test was carried out with a different inventive treatment, B, which has the following formulation: These components were mixed in a stainless steel vessel with a jacket or steam coil and agitator with a constant speed mechanism. To test the effectiveness of the inventive composition as an antifoam, a standard foam break test was employed. The conditions of the test were: 5.0 hours of total fermentation at a temperature of 35 ° C. The ratio of sugar juice / yeast solution was 36L / 24L and the brixium of the juice was 19.

The product's feed ratio was 0.02 ml / 1 of a sugar juice / yeast solution mixture.

The yeast solution was added to a 80 L graduated tank of 10 in 10 liters. Then the sugar juice was added to the fermentation tank under a feed ratio of 200 ml / minute. The initial fermentation time is recorded as the initial time. The sugar juice ratio was kept constant and the height of the sugar juice / yeast solution / foam mixture was observed.

The foam reached the 70 L mark inside the fermentation tank, 1.0 ml of an antifoam was fed with a syringe. Each time the foam reaches the 70 L level, 1.0 ml of antifoam is added until the end of the fermentation process. The standard product was synthetic wax and based on mineral oil. The results of these tests are presented in Table II.

Table II The results of these tests show that the composition of the invention was more effective than the traditional treatment in inhibiting the formation of foams in a process of alcoholic fermentation. While this invention has been described with respect to the particular embodiments thereof, it is evident that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The attached clauses and this invention should generally be considered to cover all obvious forms and modifications that are within the true spirit and scope of the present invention.

Claims (1)

1. CLAIMS A method for defoaming an alcoholic fermentation, comprising the addition to the fermentation of an effective defoaming amount, of an aqueous composition containing (A) a polydimethylsiloxane oil, (B) a block copolymer of ethylene oxide / propylene oxide and (C) a silicone / silica mixture. The method, as mentioned in claim 1, wherein the polydimethylsiloxane oil has an average viscosity of about 300 to about 500 cSt at 25 ° C. The method, as mentioned in claim 2, wherein the polydimethylsiloxane oil has an average molecular weight of from about 20,000 to about 40,000. The method, as recited in claim 1, wherein the block copolymer of ethylene oxide / propylene oxide has an average Brookfield RVT viscosity between about 100 and about 600 mPAS and an average turbidity point between about 20 and 50 ° C. The method, as recited in claim 1, wherein the silicone / silica mixture comprises a reaction product of methylated dimethylsiloxane-silica / silica. The method, as mentioned in claim 1, wherein the weight ratio of (A): (B): (C) is from about 8:10:10 to about 4: 5: 5. The method, as recited in claim 1, wherein the composition further comprises an ingredient selected from the group consisting of polyether modified polysiloxane, xanthan gum, ethoxylated castor oil, glycerol monostearate, alcohol, sodium carbonate and glutaraldehyde. . The method, as mentioned in claim 1, wherein the alcoholic fermentation has yeast. The method, as mentioned in claim 1, wherein the alcoholic fermentation is selected from the group consisting of fermentation of the juice of the sugarcane and fermentation of the corn syrup. The method, as mentioned in claim 1, wherein the composition is added to the fermentation in an amount ranging from about 0.3 to about 1.0 grams per liter of ethanol produced. A defoaming composition comprising (A) a polydimethylsiloxane oil, (B) a block copolymer of ethylene oxide / propylene oxide and (C) a silicone / silica mixture. The composition, as mentioned in the claim 11, wherein the polydimethylsiloxane oil has an average viscosity of about 300 to about 500 cSt at 25 ° C. The composition, as mentioned in the claim 12, wherein the polydimethylsiloxane oil has an average molecular weight of about 20,000 to about 40,000. The composition, as mentioned in claim 11, wherein the ethylene oxide / propylene oxide block copolymer has an average Brookfield RVT viscosity between about 100 and about 600 mPas and an average turbidity point between approximately 20 and 50 ° C. The composition, as mentioned in claim 11, wherein the silicone / silica mixture comprises a reaction product silice-dimethylsiloxane / methylated silica. The composition, as mentioned in claim 11, wherein the weight ratio of (A): (B): (C) is from about 8:10:10 to about 4: 5: 5. The composition, as recited in claim 11, wherein the composition further comprises an ingredient selected from the group consisting of polyether modified polysiloxane, xanthan gum, ethoxylated castor oil, glycerol monostearate, alcohol, sodium carbonate and glutaraldehyde. . The composition, as mentioned in claim 11, also contains yeasts. The composition, as mentioned in claim 11, also contains sugar cane juice. The composition, as mentioned in claim 11, also contains corn syrup.