CLEANING IN THE SUGAR INDUSTRY

[0001] The present invention relates to the field of sugar industries, especially the cleaning of facilities, including reactors, evaporators, containers, valves, pipes and other ducts used in the manufacture of sugar from natural plant materials such as for example sugar cane or sugar beet.

[0002] In the preparation of sugar from plants, the sugar industry uses evaporators to concentrate the juice. During these concentrations deposits appear over time. The accumulation of these deposits can cause disturbances in heat exchange or even prevent some heat exchange, which can lead to very significant economic consequences.

[0003] It is therefore necessary to clean such deposits, when they become too large and eventually hinder manufacturing yields. These cleaning stages impose production stops, and must therefore for the shortest possible, while of course being the most effective.

[0004] Today, the cleaning of these deposits occurs most often chemically with chelating agents such as sodium salt of EDTA, eg as described in the application WO2003 / 106735, or in the middle acid, for example using hydrochloric acid, but also sulfuric or sulfamic acid as described for instance in "Chemical cleaning of sugar mill evaporators" WOS Doherty, Proc. Aust. Soc. Sugar Cane Technol., (2000), 22, 341 -346.

[0005] These deposits encountered in the sugar industry typically consist of a type of scale formed on factors such salts, such as calcium carbonate, calcium oxalate, iron oxides, calcium phosphate, hydroxyapatite and aconitate, mostly calcium and / or magnesium, as described in "Development of descriptor tools for the characterization of Australian sugar mill scale evaporator" Rackemann DW et al., Proc. Int. Soc. Sugar Cane Technol., (2010), 27, 1-12.

[0006] The problem encountered in cleaning this type of pie is the great difficulty of solubilizing aconitates, or aconitic acid salts. The aconitic acid is equivalent to the citric acid dried and was principally present in trans form in the sugar cane and beets. aconitic acid is found mainly in the form of tri-calcium salts and mixed salts of di-calcium and magnesium, not commercially available.

[0007] However, even today, the literature describes only little problem with the difficulty of solubilizing aconitates, an example being the removal of the salts by washing with chelating agent solution as EDTA salts as previously reported (see WO2003 / 106735 or "descriptor Development of tools for the characterization of Australian sugar mill scale evaporator" Rackemann DW et al., ibid., so that the skilled person today knows that effectiveness of EDTA salts for the removal of deposits in the sugar industry.

[0008] EDTA is however now considered may present vis-à-vis environmental risks, including the aquatic environment, when used as a raw material for detergents. In addition, the biodegradability of EDTA is less than 10% (see "European Union Risk Assessment Report, Edetic acid (EDTA), PL-1, 49 (2004)).

[0009] In the work reported in "Chemical cleaning of sugar mill evaporators" WOS Doherty, Proc. Aust. Soc. Sugar Cane Technol., (2000), 22, 341 -346, however, we learned that dilute acids, such as sulfamic acid, hydrochloric acid and sulfuric acid, allow a slow attack aconitic acid salts.

[0010] Although effective, hydrochloric acid (HCl), however, has many disadvantages, among which include the release of toxic fumes, noxious, irritating, tear, and the problems of effluent because of the large amounts of chlorides discharged into the environment.

[0011] Furthermore, due to its chemical nature, the HCl concentration is limited to about 37%, while it might be interesting, if not desirable to have concentrations much higher acids to eliminate such total deposits which accumulates in the preparation of sugar.

[0012] Sulfuric acid is only little used on an industrial scale, particularly because of its corrosive nature. Similarly, sulfamic acid, whose releases are considered harmful to the environment, especially to aquatic organisms, is not an acid that can be widely used industrially.

[0013] Other acids also may be used, such as phosphoric acid phosphates which releases however represent a big problem for the environment. Indeed, the use of phosphoric acid is now more than challenged, due to phosphate discharges it generates.

[0014] It has also been proposed to use organic acids, such as, for example, acetic, citric, oxalic, glycolic, lactic, formic, etc.

However their acidity is lower than the above mineral acids, their effectiveness is less and requires the use of larger quantities of products.

[0015] In addition, some of the abovementioned acids are in solid form, which leads to difficulties in handling and formulation (powdery powders), and therefore are not preferred acids for use in the present invention . Moreover some of these organic acids are considered harmful. This is the case of oxalic and glycolic acid.

[0016] The work of DW Rackemann et al. ( "Enhanced performance of caustic soda used for the removal of scale in sugar mill evaporators" International Sugar Journal, (2008), 110, 344-349) teach that sodium hydroxide is ineffective to dissolve calcium salts whose calcium aconitate. Further washing with sodium hydroxide must be followed by an acid wash (phosphoric acid, formic acid, sulfamic acid, sulfuric acid, hydrochloric acid). However, this method is not very effective because the sodium hydroxide residues neutralize the acid and it is advisable to replace the acid by EDTA.

[0017] Thus, a suitable formulation appears to be a formulation containing 13% sodium hydroxide, 10% EDTA and 2% sodium gluconate. EDTA is however not a product that we can continue to use, particularly for the reasons mentioned above.

[0018] There remains a need for products, formulations and methods to overcome the drawbacks listed above, especially a need for acid to effectively remove deposits observed in the facilities used for the manufacture of sugar, in particular from raw materials of plant origin and most preferably from sugar cane and sugar beet, and more generally in systems used for processes involving at least one step of evaporation of water from a mixture comprising at least one acid salt aconitic likely to drop.

[0019] There remains a particular need for special products, formulations and methods to dissolve quickly and effectively aconitic acid salts, especially salts of magnesium and / or calcium aconitic acid while preserving the environment, that is to say of products, formulations and processes that comply with environmental and labor standards in force, and does not have the drawbacks associated in particular with irritating gaseous emissions associated with the use of hydrochloric acid, or linked to the corrosive effects, in particular sulfuric acid.

[0020] Thus, a first object of the present invention to provide products and effective formulations for dissolving the acid salts of aconitic in particular and more generally of deposit cleaning processes encountered in manufacturing facilities sugar, especially in sugar industries.

[0021] Another object of the present invention to provide an effective alternative to acid commonly used in this application while avoiding waste and harmful waste to the environment, as well as toxic and malodorous gaseous emissions.

[0022] Other objects and advantages will appear from the description of the present invention which follows, an invention which achieves the above objects in whole or at least in part. Indeed, the Applicant has now discovered that it is possible to clean effectively the solid deposits comprising at least one salt of aconitic, and without having to use EDTA, salts EDTA or strong organic acids known in the prior art.

[0023] In the description of the invention that follows is meant by the term "cleaning" means the removal and / or dissolution of deposits comprising at least one salt of aconitic acid, preferably a calcium salt and / or magnesium, such removal may be partial or complete, preferably complete, without having the aforementioned disadvantages, especially disadvantages on the environment, the drawbacks associated with gas and other clearances as will be described now.

[0024] It has been discovered that it is possible to effectively clean solid deposits comprising at least one salt of aconitic and usually encountered in industries employing at least one step of evaporation of water from a mixture comprising at least one acid salt aconitic likely to deposit, using a formulation based on at least one alkane sulfonic acid.

[0025] The formulations based on at least one alkane sulfonic acid in particular exhibit a performance at least equal or even improved compared to the hydrochloric acid which is the acid usually used in this field, or compared with salts ethylenediaminetetraacetic acid (EDTA).

[0026] The alkane sulfonic acids have the advantage on the one hand to be less corrosive than hydrochloric acid, does not generate chlorides, be biodegradable and does not release toxic or odorous products, that of being less polluting than phosphoric acid, due to the phosphate released into the environment. Furthermore alkanesulfonic acids can be used as more than that concentrated hydrochloric acid.

[0027] As already indicated, the use of the present invention can be applied quite interesting in industries employing at least one step of evaporation of water from a mixture comprising at least one acid salt aconitic likely to drop, especially in the manufacture of sugar from natural plant materials, such as eg sugar cane or sugar beet.

[0028] In effect, the acid-based formulations (s) alkane-sulfonic acid (s) have in particular a greater ease of use and handling compared to products and formulations typically used for cleaning solid deposits comprising aconitic acid salts. Indeed, the use of acid-based formulations (s) alkanesulfonic (s) does not occur or little toxic gassing, irritating or tear.

[0029] Thus, according to a first aspect, the present invention relates to the use of at least one alkanesulfonic acid of formula R-SO3H, wherein R represents a saturated hydrocarbon chain, linear or branched, having from 1 to 4 carbon atoms, for cleaning of solid deposits comprising at least one aconitic acid salt. [0030] As indicated above, this type of solid deposit is usually encountered in industries employing at least one step of evaporating water from a mixture comprising at least one acid salt aconitic likely to deposit, and in particular during the manufacture of sugar from natural plant materials, such as eg sugar cane or sugar beet.

[0031] Thus, the invention relates to the use of at least one alkanesulfonic acid as an active compound for the cleaning of solid deposits comprising at least one acid salt aconitic, said solid deposits is usually found in industries involving employing at least a step of evaporating water from a mixture comprising at least one acid salt aconitic likely to drop, especially in the manufacture of sugar from natural plant materials, such as e.g. sugar cane or sugar beet.

[0032] More particularly the invention relates to the use of at least one alkanesulfonic acid for cleaning surfaces contaminated with solid deposits comprising at least one acid salt aconitic, on all types of surfaces.

[0033] Even more specifically, the present invention provides a formulation, adapted in particular to replace the use of hydrochloric acid to deposit the cleaning comprising at least one salt aconitic acid, or more simply "aconitates" in remainder of this description, said formulation comprising at least one alkanesulfonic acid which is a biodegradable acid, low toxicity, release no or little irritating or tear gas, do not generate harmful effluents to the environment and can be used a more concentrated form as hydrochloric acid.

[0034] The aconitates, and in particular the aconitates encountered in the sugar industry are well known in the art and result, especially after many cycles of evaporation of aqueous solutions of sugar, in solid deposits, more or less compact. The aconitates encountered are predominantly calcium aconitates and / or magnesium, and may be present in the solid deposits in combinations with other salts. Illustrative non-limiting examples of other salts that may be present in solid deposits include carbonates, such as calcium carbonate, phosphates, such as tricalcium phosphate,

hydroxyapatite, oxalates, such as calcium oxalate, sulfates, such as calcium sulfate, iron oxides, and others.

[0035] The use of the present invention allows the cleaning of aconitates, more generally deposits comprising at least one aconitate, and which may be present on all types of surfaces, especially hard surfaces, in particular metal (iron, aluminum, steels, etc.), wood, polymers (plastics, paints, lacquers, varnishes), glass, stone, ceramic, porcelain, earthenware and others.

[0036] For the purposes of the present invention, the term "cleaning", cleaning, stripping, of all types of surfaces, as indicated previously, soiled, coated, covered, in whole or in part by the residues, scales, deposits, dried or still wet, generated during the preparation of products obtained from plants, particularly from sugar cane or sugar beet, by removal, dissolution, said residues, scales and deposits in general .

[0037] As indicated above, the term "cleaning" also refers to partial or complete removal of solid deposits comprising at least one aconitate, and which may have made mass of unplanned manner, undesirable or unwanted, in installations comprising reactors, evaporators, containers, valves, hoses, pipes and others, used during the manufacture of sugar from natural plant materials, such as eg sugar cane or sugar beet, which are usually removed / eliminated by other chemical and / or mechanical, such as brushes, trowels, shovels, picks, hammers, jackhammers, and others.

[0038] In the present invention, the term preferably alkanesulfonic acid the alkane-sulphonic acids of formula R-SO3H, wherein R represents a saturated hydrocarbon chain, linear or branched, having from 1 to 4 carbon atoms.

[0039] The alkane sulfonic acid used in the context of the present invention are preferably chosen from methanesulfonic acid, ethanesulfonic acid, n-propane-sulfonic acid, / ' so- propane-sulfonic acid, n-butane-sulfonic acid, / ' n-butane-sulfonic acid, sec-butane-sulphonic acid, tert-butane-sulphonic acid, and mixtures of two or more of them in all proportions.

[0040] According to a preferred embodiment, the alkane sulfonic acid used in the context of the present invention is methanesulfonic acid or ethanesulfonic acid, so Most preferably the acid used is methanesulfonic acid.

[0041] Thus, the use according to the present invention uses at least one alkane sulfonic acid selected from alkane sulfonic acids straight or branched chain having 1 to 4 carbon atoms, and preferably at least of methane-sulphonic acid (AMS).

[0042] Said at least one alkanesulfonic acid used in the context of the present invention can be used as such, or in combination with one or more other components, that is to say in formulation. Any type of formulation comprising at least one alkanesulfonic acid is suitable. Generally, the formulation comprises 0.01% to 100% by weight of alkanesulfonic acid, more typically 0.05% to 90% by weight, in particular from 0.5% to 75% by weight, inclusive, acid (s) alkanesulfonic (s), relative to the total weight of said formulation.

[0043] The formulation is an aqueous formulation for example, organic or aqueous-organic. The formulation may be prepared as a concentrated mixture, said concentrated mixture can be diluted by the end user. Alternatively, the formulation can also be a ready-to-use formulation, that is to say, it does not need to be diluted. Finally, within the meaning of the present invention, the formulation may be a pure alkanesulfonic acid, or a mixture of pure alkanesulfonic acids, that is to say, the formulation may contain only one or more acids -sulfoniques without further formulation of additive or other solvent or diluent.

[0044] The acid concentration (s) alkanesulfonic (s) in the formulation depends on many factors, among which there may be mentioned the quantity of deposits to be cleaned, the nature and form of the surface being cleaned, the temperature which is applied the formulation, and others. The skilled person will adapt without overexertion, the appropriate concentration of acid in the formulation.

[0045] Thus preferred concentrated solutions, for example from 60% to 100%, preferably about 70% to 100% by weight of acid (s) alkanesulfonic (s), relative to the total weight of said formulation when one wishes to remove large amounts of deposits, or the surface insensitive to acids materials. Preferred are less concentrated solutions of 0.01% to 60%, preferably 0.05%

50% for the lower amounts of deposits to be removed, or for cleaning still wet deposition, and / or on surfaces sensitive to acid attack.

[0046] One can for example use of methanesulfonic acid in aqueous solution sold by Arkema under the name Scaleva ® , or under the name Lutropur ® marketed by BASF, ready for use or diluted water in the proportions indicated above.

[0047] In addition to the one or more alkane sulfonic acids, the formulation used in the present invention may optionally comprise one or more additives well known to those skilled in the art, such as those selected from:

• solvents, hydrotropic agents or solubilizers (e.g. alcohols, esters, ketones, amides, and others),

• biocides, disinfectants (bromoacetic acid, peracetic acid, hydrogen peroxide, and others),

• rheological agents or texture or thickening or gelling agents (sugars, polysaccharides, alginates, silica, amorphous silica, gums and others)

• organic or inorganic acids (e.g. sulfuric, phosphoric, nitric, sulfamic, acetic, citric, formic, lactic, glycolic, oxalic, etc.),

• alkali metal salts, alkaline earth metal, particularly fluorides, chlorides, iodides, bromides of alkaline and / or alkaline earth metals, preferably chlorides and fluorides, preferably fluorides yet including sodium fluoride or calcium

• flame retardants,

• preservatives,

• anionic, cationic, nonionic or amphoteric (such as alcohols and / or ethoxylated amines, alkyl and / or aryl sulfonates) emulsifiers, detergents, soaps, and the like;

• foaming agents, defoamers,

• anti-gels (e.g. ethylene glycol, propylene glycol, and others);

• colorants,

• corrosion inhibitors,

• parfums, agents odorants,

and other additives known to the skilled person.

[0048] The formulation in aqueous form is particularly advantageous in processes called "cleaning in place" (or "cleaning in place" or "CIP" in English).

[0049] In addition, the use of acid (s) alkane (s), in particular of methanesulfonic acid, to control the acid content, in order to be able to better adjust the acidity of the cleaning solution for optimum cleaning of the reactors, pipes, evaporators .... This control of acid content can be achieved by any method known per se, for example by conductivity.

[0050] Alternatively, the formulation is a formulation in gel form. It has indeed been observed that the formulations in the form of acid gel (s) alkane-sulfonic acid (s) are very effective for removing deposits comprising aconitates, as described above, not only due to frost him -even allowing a longer action of the acid active ingredient (the gel "adheres" longer on the surfaces, with respect to an aqueous formulation), but also has an improved cleaning power as compared to other formulations gels.

[0051] Thus, in another aspect, the present invention relates to the use of a formulation in gel form comprising:

• 0.01% to 97% by weight, preferably from 0.05% to 75% by weight and more particularly from 0.5% to 70% by weight of at least one alkanesulfonic acid, preferably methanesulfonic acid;

• 0.1% to 30% by weight, preferably from 0.5% to 15% by weight and more particularly from 1% to 10% by weight of at least one gelling agent;

• 0.1% to 30% by weight, preferably from 0.5% to 15% by weight of at least one additive selected from those mentioned above; and

• the remainder to 100% water and / or organic solvent,

for the cleaning of solid deposits comprising at least one aconitic acid salt.

[0052] The gelling agents and surfactants used in the formulations in gel form can be of any type. The skilled person will, without any particular difficulty and drawing on examples below, choose and adapt the nature of gelling agents and suitable surfactants.

[0053] According to another aspect, the present invention relates to the use of a formulation in the form of foaming gel. The foaming gels are indeed all

particularly interesting due to the fact that they produce a sticky foam, ie an adherent foam to the soiled surfaces while generally requiring less consumption of cleaning acid active material, and have the advantage of being rinsed so quite effective, that is to say, they can be removed in a simpler and more efficient, while requiring less quantity of water.

[0054] Thus, the present invention also relates to the use of a formulation in the form of foaming gel comprising:

• 0.01% to 97% by weight, preferably from 0.05% to 75% by weight and more particularly from 0.5% to 70% by weight of at least one alkanesulfonic acid, preferably methanesulfonic acid;

• 0.1% to 30% by weight, preferably from 0.5% to 15% by weight and more particularly from 1% to 10% by weight of at least one foaming agent;

• from 0 to 30% by weight, preferably from 0.5% to 15% by weight and more particularly from 1% to 10% by weight of at least one gelling agent;

• from 0 to 30% by weight, preferably from 0.5% to 15% by weight of at least one additive selected from those mentioned above, which preferably 0 to 10% by weight, preferably 0.1 to 5% by weight of a solubiliser or hydrotrope, and from 0 to 20% by weight, preferably from 0.5% to 10% by weight of at least one surfactant; and

• the remainder to 100% water and / or organic solvent,

for the cleaning of solid deposits comprising at least one aconitic acid salt.

[0055] Depending on the field and mode of application, the formulation may be prepared as a concentrate and diluted before use to obtain the expected effectiveness as to the viscosity and foaming power.

[0056] In the formulation of foaming gel above, the foaming agent may be selected from foaming agents commonly used by those skilled in the art, and preferably from amine oxides, such as:

• dimethylalkylamine oxides, the alkyl chain is a "fatty" chain, for example containing 10 to 30 carbon atoms, preferably 12 to 22 carbon atoms;

• oxides ethoxylated amines; and

• mixtures of two or more of them.

[0057] The use of at least one ethoxylated amine oxide, such as, not limited to the Cecajel ® OX100 from CECA, or Aromox ® T12 from Akzo alone or combination with at least one dimethylalkylamine oxide allows to bring stability to the foaming gel.

[0058] The foaming agents, and in particular those described above, generally form gels when mixed with water, that is to say they increase the viscosity of the formulation, without that it being necessary to add a gelling agent. However the addition of such a gelling agent is not excluded from the present invention.

[0059] Among the solubilizing agents or hydrotropes useful in the formulations according to the invention, mention may be made, by way of example and not limited to the sodium xylene or cumene sulphonates. Such agents are however not essential in acid formulations according to the invention.

[0060] An aqueous formulation, organic or aqueous-organic, in the form of solution, gel or as a foaming gel, particularly preferred is a formulation comprising from 0.01% to 95%, preferably 0.05% to 75%, more preferably from 0.5% to 50% by weight of methanesulfonic acid.

[0061] The formulations used according to the present invention, whether in liquid form, gels or foaming gels, concentrated or diluted, can be applied by any method known to those skilled in the art, and in particular under pressure, or using a spray gun.

[0062] The acid concentration (s) alkanesulfonic (s) can vary within very large proportions, depending on the nature and amount of residue to be removed, but also according to the nature of the surfaces to be cleaned.

[0063] The invention also relates to a solid deposit cleaning process comprising at least one salt of the acid aconitic, wherein aconitate deposition can be found in all types of industries employing at least one evaporation step water from a mixture comprising at least one acid salt aconitic likely to drop, especially in the sugar manufacturing industry from natural plant materials, such as eg sugar cane or beet sugar.

[0064] The present invention relates to a cleaning process (ie solubilization and / or disposal), at least partially, and preferably completely, of a solid deposit

comprising at least one acid salt aconitic, whether in wet or dried form, for example, taken in mass, and present on all types of surfaces, especially hard surfaces, in particular metal (iron, aluminum, steel and other ), wood, polymers (plastics, paints, lacquers, varnishes), glass, stone, ceramic, porcelain, earthenware and others.

[0065] Thus, the present invention relates to a deposit removing method comprising at least one salt aconitic acid, as defined above, present, for example on all surfaces, as indicated previously, soiled, coated, covered in whole or in part by residues, scales, deposits, dried or still wet, generated during the preparation of products obtained from plants, particularly from sugar cane or sugar beet.

[0066] More particularly, the method of the present invention comprises at least one contacting step an effective amount of at least one alkane sulfonic acid, as defined above, preferably methanesulfonic acid, in an aqueous formulation, organic or aqueous-organic, in the form of solution, gel or foaming gel, as just described, with a solid deposit comprising at least aconitic acid to be removed, by contact, immersion, sprinkling, spraying, application of a more or less thick layer, optionally using appropriate tools known to those skilled in the art (brushes, brushes, spatulas, and others), said contacting step being optionally followed by one or more stages of rinsing and / or drying.

[0067] The temperature at which the method is performed, and particularly the contacting step may vary within wide limits and is generally between -20 ° C and + 150 ° C, preferably between 0 ° C and 80 ° C, more preferably between 10 ° C and 80 ° C. According to a preferred embodiment, the temperature is room temperature or a temperature between room temperature and about 80 ° C.

[0068] It may thus be envisaged to temperature the alkanesulfonic acid and the surface to be treated, this temperature may be the same or different, or to set temperature is the alkanesulfonic acid, or the surface to be treat.

[0069] It is thus treat Outdoors, surfaces contaminated by solid deposits at ambient temperature (e.g. 10 ° C) using an acid formulation (s)

alkane-sulfonic acid (s) heated to 70 ° C, or treating surfaces contaminated by solid deposits at an elevated temperature (e.g. about 100 ° C) using an acid formulation (s) alkane- sulfonic acid (s) at ambient temperature (e.g. 20 ° C). It can also be envisaged to immerse the surface to be treated in an acid formulation (s) alkanesulfonic (s) carried for example at a temperature of about 60 ° C, for instance to remove solid deposits in valves, pipes, and others.

[0070] In the method of the invention, it should be understood that it is possible to use at least one alkanesulfonic acid or formulation comprising at least one alkane sulfonic acid, as described above.

[0071] Finally, after the processing step (s), by contacting and rinsing (s), if any (s), the cleaned surface may be, where appropriate and if necessary dried by any method known those skilled in the art, for example air, under a stream of more or less hot air oven, by heating (electric, heat lamps), wiping (absorbent papers or textiles), and others.

[0072] As indicated above, the alkanesulfonic acid is advantageously implemented in the form of a formulation, such as an aqueous formulation, organic or aqueous-organic liquid, gel or foaming gel, as defined above .

[0073] In the method of the invention as just described, the term effective amount for an amount of cleaning residues, scale, and in general solid deposits comprising at least one acid salt aconitic .

[0074] This amount can vary within wide limits, depending on the surfaces to be treated and the amount of solid deposits, temperature and pressure of the formulation used, the desired duration of the cleaning process, and others.

[0075] Thus, the amount of acid will advantageously be established to allow a thorough cleaning, or as complete as possible, of solid deposits of aconitates, while using a minimum amount of acid (s), essentially for economic reasons .

[0076] This solid deposits aconitates cleaning operation can be repeated one or more times depending on the amount and nature of solid deposits, and their degree of encrustation on treated surfaces.

[0077] The contacting of an effective amount of at least one alkanesulfonic acid is followed by a reaction time required for dissolution of the solid deposits that are to be eliminated, this reaction time can vary from several seconds to several hours or even days, depending on the temperature at which is performed the cleaning, the application pressure of the acid (s) alkanesulfonic (s), the nature of the formulation comprising said at least one acid alkane-sulfonic acid, the amount of deposits to be removed, their degrees of incrustation, and the nature of the surfaces to be treated.

[0078] The treatment with at least one alkanesulfonic acid as just defined may optionally be accompanied and / or preceded and / or followed by one or more washings, preferably preceded by one or prewashes several, if necessary, using a base formulation comprising at least one inorganic or organic base, preferably an inorganic base, e.g. an alkali metal hydroxide or alkaline earth metal, for example sodium hydroxide in all concentrations. These basic washes are so entirely preferably carried out before, or after, or before and after, but preferably not simultaneously with the cleaning with said at least one alkane sulfonic acid, in order to

[0079] The treatment with at least one alkanesulfonic acid as just defined may optionally be accompanied and / or followed by one or several mechanical operations (agitation, scraping, brushing, and others), in order to improve the acid chemical action, if necessary.

[0080] As indicated above, treatment can be followed by one or more rinsing operations, for example with water, solvent (s) or mixture (s) water / solvent (s).

[0081] In the method of the invention as just described, the term "effective amount" an amount to the dissolution and removal of all or part of the dirt residues, flakes, dried or not , of solid deposits comprising at least one aconitic acid salt.

[0082] This amount can vary within wide limits, depending on the surfaces to be treated and the amount of solid deposits, temperature, pressure of the

formulation used, the nature of the formulation used, the desired duration of the phase and other method.

[0083] Thus, the amount of acid will advantageously be adjusted to allow a total elimination or at least partially, preferably completely, residues, scales, dried or not, said solid deposits of aconitates, while observing a minimum amount of acid (s), essentially for economic reasons.

[0084] The alkane-sulfonic acids, including methane-sulfonic acid, have proved effective for the cleaning of solid deposits of aconitates, especially solid deposits found in the sugar processing industry, particularly from sugar cane or sugar beet, without generating irritating and tear gassing.

[0085] Moreover, the use of at least one alkanesulfonic acid of the present invention has the advantage of not generating little or no corrosion, especially when cleaning metal surfaces (especially in many sugar industries), corrosion that is often observed on said metal surfaces during the use of more or less concentrated acid solutions.

[0086] The alkane sulfonic acids may also be used at high concentrations, in order to increase their efficiency, concentrations which can be 50%, 70% or even 100% by weight, while the maximum concentration of hydrochloric acid not can be up to 37%, because of the intrinsic chemical nature of this acid.

[0087] In addition, alkane sulfonic acids used in the present invention, compared with arylsulphonic acids, the advantage of generating a lower chemical oxygen demand (COD) at the stations of treatment of effluents, and therefore enable a higher concentration of organic waste in said stations.

[0088] The formulations used in the context of the present invention may contain phosphorus compounds, such as for example phosphates, for example from phosphoric acid, but in small amounts, for example less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, based on the total weight of the formulation, still in order to minimize as possible the harmful emissions to the environment. [0089] In addition, the formulations used in the context of the present invention can contain sulfur compounds, such as for example sulfates, for example, from sulfuric acid, but in small amounts, for example less than 10% by weight, preferably less than 5% by weight,

[0090] The formulations used in the context of the present invention may contain chlorinated compounds, such as for example chlorides, for example, from hydrochloric acid, but in small amounts, for example less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, based on the total weight of the formulation.

[0091] The formulations used in the context of the present invention can contain nitrogen compounds such as for example nitrates, for example from nitric acid, but in small amounts, for example less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, based on the total weight of the formulation.

[0092] The present invention described above shows that it is possible to remove solid deposits aconitates on all types of surfaces, such as, and not limited to the metal surfaces (iron, steel, copper, alloys , and others), concrete, cement, tiles, porcelain, wood, paper, paperboard, textiles, polymers (plastics, varnishes, paints, lacquers), glasses, and others.

[0093] The present invention also shows that it is possible to clean said residue surfaces, dried or not undesirable, but also to remove solid deposits which may have caked in various containers, evaporators, conduits, valves, and others, and which are usually eliminated by little environmentally acids and / or which are corrosive vis-à-vis the surfaces to be treated.

[0094] Thus, the alkane sulfonic acids can advantageously be used to replace commonly known acids and used by the art for the removal of solid deposits of aconitates in many application areas, including which include, but not limited to, sugar industries.

[0095] It is understood that the use of the present invention allows not only the cleaning of solid deposits of aconitates, but more so

concomitant cleaning of other type (s) (s) stain (s) may be present (s) on the surfaces to be treated, due to the acidic nature of the alkanesulfonic acid used.

[0096] For example, alkane sulfonic acids used in the context of the present invention can be effective for cleaning any kind of dirt such as rust, scale, but also all types of organic stains including inherent in the manufacture of sugar from plants as described above.

[0097] The present invention is now illustrated by the following examples, without presenting any limiting character and can not therefore be understood as capable of restricting the scope of the invention as claimed.

[0098] To assess the effectiveness of alkanesulfonic acids in cleaning deposits comprising aconitic acid salts, first preparing an acid calcium salt aconitic then performs dissolution tests.

example 1

Preparation of tricalcium aconitate trihydrate: Ca 3 (C 6 H 3 06) 2 - 3H 2 0

[0099] The preparation is described in the thesis of Niconor Niconey Reece

University of Louisiana; December 2003, "Optimizing aconitate removal During clarification".

[0100] In a 500 mL four-necked equipped with a magnetic stirrer, a water condenser, a temperature probe and a pH probe, were introduced 8 g of trans-aconitic acid (0.0457 mol, molecular weight = 174). then made up to 133 g with ultra pure water. The solution is then neutralized with potassium hydroxide (NaOH) to pH 0.2 M 1 1, 3, then the pH is adjusted to a value of 6 with hydrochloric acid solution (HCI) 1 N.

[0101] The solution is then heated to 85 ° C and then are added 228.5 ml of a calcium chloride 0.3M solution whose pH has been previously adjusted to 6 with 1N HCl

[0102] The reaction medium is heated for 3 hours at 85 ° C and a precipitate appears, the medium is then filtered hot. 10.6 g is recovered of a solid which is washed 3 times with 30 mL of hot water.

[0103] After drying in an oven under vacuum of 50 mbar for 48 hours at room temperature, 7.4 g of a white solid which was characterized by analysis of its carbon content, hydrogen and calcium, and are in accordance with the formula CasiCeHsOe ^ - 3 (H 2 O).

Measurement of the solubility of tricalcium aconitate trihydrate

[0104] To a 50 mL three-necked flask equipped with a magnetic stirrer, a condenser and a temperature probe, are introduced 30 g of aqueous solution of 1 M. The salt prepared as described above ( tricalcium aconitate trihydrate) was then added in portions of about 0.1 g, until the appearance of undissolved crystals (saturation of the medium).

[0105] The percentage of dissolved salt is calculated using the following formula:

% Salt dissolved = m / (M + m)

where M represents the mass of acid solution, and m is the mass of salt introduced.

[0106] Table 1 below summarizes the results of dissolution of tricalcium aconitate trihydrate at 20 ° C.

- Table 1 -

[0107] Sulfuric acid is very effective vis-à-vis the solubility of aconitic acid salts. The methanesulfonic acid has surprisingly comparable efficacy to that of hydrochloric acid slightly greater than that of sulfamic acid. The methanesulfonic acid is much less corrosive than hydrochloric acid, the evolved vapors are irritating and toxic to the user. More methanesulfonic acid is biodegradable.

[0108] Finally, sulfamic acid whose releases are also considered harmful to the environment, particularly to aquatic organisms, is not an acid that can be widely used industrially.

claims

1. Use of at least one alkanesulfonic acid of formula R-SO3H, wherein R represents a saturated hydrocarbon chain, linear or branched, having from 1 to 4 carbon atoms, for cleaning of solid deposits comprising at least one salt aconitic acid.

2. Use according to claim 1, wherein the alkanesulfonic acid is selected from methanesulfonic acid, ethanesulfonic acid, n-propane-sulfonic acid, / ' so-propane sulfonic acid, n-butane-sulfonic acid, iso-butane-sulfonic acid, sec-butane-sulphonic acid, tert-butane-sulphonic acid, and mixtures of two or more thereof in all proportions.

3. Use according to claim 1 or claim 2 wherein the alkanesulfonic acid is methanesulfonic acid or ethanesulfonic acid, preferably methanesulfonic acid.

4. Use according to any preceding claim, wherein said at least one alkanesulfonic acid is used in the form of formulation, the amount of acid (s) alkanesulfonic (s) ranging from 0.01% to 100%, more typically from 0.05% to 90%, in particular from 0.5% to 75% by weight, inclusive, based on the total weight of said formulation.

5. Use according to any preceding claim, wherein said at least one alkane sulfonic acid is present in an aqueous formulation, organic or hydro-organic, concentrated, ready to use or to be diluted before use.

6. Use according to any preceding claim, wherein at least one alkanesulfonic acid is used in combination with one or more additives selected from:

• solvents, hydrotropic agents or solubilizers or gelling agents (e.g. alcohols, esters, ketones, amides, and others),

• biocides, disinfectants (bromoacetic acid, peracetic acid, hydrogen peroxide, and others),

• rheological agents or thickeners or texture (sugars, polysaccharides, alginates, silica, amorphous silica, gums and others)

• organic or inorganic acids (e.g. sulfuric, phosphoric, nitric, sulfamic, acetic, citric, formic, lactic, glycolic, oxalic, etc.),

• flame retardants,

• preservatives,

• anionic, cationic, nonionic or amphoteric (such as alcohols and / or ethoxylated amines, alkyl- and / or arylsulphonates), emulsifiers, detergents, soaps, and the like;

• foaming agents, defoamers,

• anti-gels (e.g. ethylene glycol, propylene glycol, and others);

• corrosion inhibitors,

• colorants,

• parfums, agents odorants,

and other additives known to the skilled person.

7. Use according to any preceding claim, wherein at least one alkanesulfonic acid is used in liquid formulation, gel or gel-foaming.

8. solid deposits cleaning method comprising at least one salt of the acid aconitic, comprising at least one contacting step an effective amount of at least one alkanesulfonic acid, preferably methanesulfonic acid sulfonic acid, with said solid deposits to be removed, by contact, immersion, sprinkling, spraying, application of a more or less thick layer, optionally using appropriate tools known to those skilled in the art (brushes, brushes, spatulas , and others), said contacting step being optionally followed by one or more stages of rinsing and / or drying.

9. A method according to claim 8, characterized in that it is performed at a temperature between -20 ° C and + 150 ° C, preferably between 0 ° C and 80 ° C, more preferably between 10 ° C and 80 ° C, preferably at room temperature or at a temperature between room temperature and about 80 ° C.

10. Use according to any one of claims 1 to 7, for the cleaning of solid deposits comprising at least one salt of aconitic acid, on all types of surfaces, especially metal surfaces, concrete, cement, tiles, tile , stone, porcelain, wood, paper, paperboard, textiles, polymers (plastics, varnishes, paints, lacquers), glasses, and others.