GB2141419A - Fertilizer composition from vinasse - Google Patents

Abstract

Solid composition of complex organo-mineral fertilizer, comprising: a) the solid product from the desalting by means of sulphuric acid and in the presence of an organic solvent, of an effluent from the industrial processes of fermentation of the sugars (vinasse); b) at least one organic or inorganic compound, bearer of phosphorous and/or nitrogen. o

Description

SPECIFICATION Fertilizer composition The present invention relates to a solid composition of complex organo-mineral, water-soluble fertilizer. The invention relates also to a process for preparing such composition of fertilizer.

The UK Patent No 2030127 granted on March 30, 1983, describes and claims a process for desalting the effluents from the industrial fermentation processes of the sugars, by means of the treatment of such effluents with either a mineral or an organic acid, in the presence of a relatively volatile solvent.

This process is mainly used for selectively precipitating the potassium salts from the beet molasses vinasses, which, after having been deprived of the most of their potassium content, form a valuable componentforfodders, which are mainly intended for polygastric cattle, as it is described in the UK Patent Application Nr. 8203063 filed on February 3,1982.

The present invention is essentially based on the observation that the products from the desalting by means of sulphuric acid, in the presence of an organic solvent, of the effluent streams from the fermentation process of the sugars, in addition to containing large concentrations of potassium, are free from phytotoxic substances and moreover contain relatively large quantities of other mineral elements, as well as of useful organic products, which pass, unchanged or practically unchanged, through the fermentation and desalting processes. Therefore, according to the present invention, the said solid products from the desalting stage are used, after a suitable preliminary integration, as components for compositions of fertilizers.

Accordingly, the present invention relates to a solid composition of complex organo-mineral fertilizer, comprising: a) the solid product from the desalting by means of sulphuric acid and in the presence of an organic solvent, of an effluent stream from the industrial fermentation processes of the sugars (vinasse); b) at least one either organic or inorganic compound bearer of phosphorous and/or nitrogen.

The composition of fertilizer according to the present invention suitably contains total nitrogen in a quantity of not less than 3% of its weight (with at least the 1.5% by weight in the form of organic nitrogen), not less than 4% by weight of phosphorous (as expressed as P2O5), not less than 5% by weight of potassium (as expressed as K20), and not less than 8% by weight of organic carbon.

The suitable raw material for preparing the above shown a) component of the fertilizer composition according to the present invention, are the effluents from the industrial fermentation processes of the sugars, as for instance the effluents from the industrial fermentation of molasses, or more generally of sugar containing solutions which are obtained by extraction from plants such as the sugar beet, the sugar cane and the sugar sorghum. Such effluents are generally named as "vinasses". As raw materials, still other effluents from the industrial fermentation processes of the sugars can be used, such as e.g. the residues from the production of citric acid, glycerine, glutamic acid, lactic acid, butyl alcohol and acetone, and of the antibiotic substances.These all previously described possibilities are based on the observation that the fermentation processes, which are carried out on sugar containing extracts from plants, are active on the carbohydrates contained in the raw material, at the same time leaving the minerals and the proteins initially contained in the material under fermentation, practically unchanged. Hereunder, all these raw materials shall be generally indicated as "vinasse".

According to the process within the purpose of this invention, a vinasse containing from 35% to 65% by weight, and preferably from 50% to 60% by weight of dissolved solids, is placed in contact with sulphuric acid. To this purpose, concentrated sulphuric acid is preferably used, e.g. sulphuric acid with a specific gravity of about 1.84 kg/l. It is however possible to use aqueous diluted sulphuric acid, even if it is not generally profitable to use sulphuric acid with a specific gravity lower than 1.69 kg/l. The quantity of sulphuric acid to be added to the vinasse is a function of the potassium titre of the vinasse itself. A quantity of sulphuric acid is generally used, within the range from 1.3 to 1.8 kg/kg of potassium in the vinasse. The contact between the vinasse and the sulphuric acid is suitably carried out in a closed reaction vessel, having stirring means.

One fundamental feature of the process according to the present invention, is that the desalting reaction of the vinasse is carried out in the presence of an organic solvent, which is soluble in the reaction medium, and is inert towards the other components of the reaction mixture.

Organic solvents which are suitable to this purpose, are the lower aliphatic alcohols (such as methanol and ethanol) and the ketones (such as acetone and methylethyl-ketone).

The most preferred solvent among these is the ethanol, in view of its low toxicity, large availability at iow cost, and as this solvent causes the said precipitate to be obtained with such physical characteristics, as to make the subsequent treatments of separation, drying and blending easy. It is not necessary that the organic solvent used be anhydrous, and moreover the used quantity of such solvent is not critical, although it can be advisably used in the ratio in the range from 10 to 25 parts by volume, per 100 volumes of the vinasse.

In the practical embodiment of the process according to the present invention, the suphuric acid is added to the vinasse, which is being stirred in a closed reaction vessel. A few minutes lates (e.g. after 3 minutes), the organic solvent is added to the charge under stirring. After a further time of from 20 to 60 minutes has elapsed, the stirring is discontinued, the precipitated solid is then separated, such as by centrifuging. All the previously described operations are carried out at room temperature (20 - 25 C), or at temperatures close to the room temperature.

The precipitated and separated solid matter is then submitted to a drying stage, which is suitably effected at temperatures lower than 130"C, and possibly under a lower than atmospheric pressure.

The component a) of the fertilizer composition according to the present invention is thus obtained. Such a) component contains primary chemical elements of the fertilizer power and more particularly, potassium and nitrogen, secondary elements such as calcium, magnesium, and sulphur, and trace elements, such as manganese, zinc, copper, boron and iron. The said a) component contains also.organic products, which cause the said a) component to contain a high percentage of organic carbon from biological origin, and aminoacids too are present, which are bearers of organic nitrogen.

More particularly, when raw materials are used, which consist of vinasse effluents from the distillation processes of the beet molasses, or of the sugar cane molasses, or vinasse effluents from the production of citric acid from the beet molasses, it is possible to obtain the a) component of the fertilizer composition with a potassium titre generally higher than 10% and tipically of 15% by weight, with an organic carbon content higher than 10% and tipically comprised within the range from 15% to 25% by weight, and with a content of non ammoniac nitrogen of the order from 0,5% to 5% by weight.

The solid composition of fertilizer according to the present invention is prepared by mixing the above described a) component with a b) component comprising at least one organic and/or inorganic compound, bearer of phosphorous and/or nitrogen. As the b) component, any organic or inorganic fertilizer actually known in the art can be used, such as for instance urea, nitrates and ammonium sals as bearers of nitrogen; blood meal and concentrated vinasses from beet molasses as bearers of nitrogen and organic carbon; superphosphates, such as for instance supertriple, phosphoric acid or its salts, as bearers of phosphorous.

Obviously, if desirable, also a potassium bearing salt can be added to the composition, such as potassium chloride and potassium sulphate.

The ratio of the quantities of the a) and of the b) components of the composition is adjusted as a function of the nature of these components, as well as of the wished titres of nitrogen, phosphorous and potassium in the composition itself.

An advantage of the present invention is indeed that it is possible to obtain a solid composition of complex organo-mineral fertilizer with a desired and constant titre of nitrogen, phosphorous and potassium, even when using, as the raw material, the effluents from the industrial fermentation processes of the sugars, whose characteristics are variable.

In any cases, the solid composition of complex organo-mineral fertilizer according to the present invention is soluble in water and has the characteristics of a good fertilizer not only from the chemical view-point, but also in that it is derived from a solely vegetable raw material, which has been preliminarly submitted to processes of fundamentally biological character, and is therefore completely free of phytotoxic substances.

An advantage resulting from the use of fertilizer composition according to the present invention, is that a part of the fertilizing elements which have been withdrawn from the soil during the vegetative cycle of the sugar plants, can be recovered and used as fertilizer again; and in addition to this, at the same time eliminating the pollution problems arising from the effluents of the industrial fermentation processes.

The following experimental Examples are illustrative only, and in no way they are to be considered as limitative of the invention.

Example 1 In a closed reaction vessel equipped with stirring means, containing 250 kg of vinasses from the distillation of concentrated beet molasses, containing 52% by weight of dissolved solid matter, kg of concentrated sulphuric acid (specific gravity 1.84 kg/l) are added, and, after a few minutes under stirring, 33 kg of aqueous ethanol (specific gravity 0.82 kg/l) are added.

After about one hour of slow stirring, the resulting precipitate is separated by centrifuging, by means of a decanter centrifuge, sent to a drying oven operating at 80"C, in the vacuum, and weighed. 41 kg of a product are thus obtained, which will be referred to hereunder as "potassic saline", which is submitted to chemical analysis. The results of the analysis are shown in the Tables 1 and 2.

More particularly, the main chemical characteristics of the potassic saline are shown in Table 1, as expressed as % by weight on a dry matter basis, and in Table 2 the aminoacids are shown, which are contained in the potassic saline, the concentrations being always expressed as % of the weight of the dried product.

TABLE 1 Ashes 58.22 Organic matter 41.78 Total nitrogen 2.84 Ammoniac nitrogen 0.16 Organic carbon 17.50 Hydrogen -2.45 Potassium 14.99 Sodium 4.80 Calcium 2.03 Magnesium 1.20 Manganese 0.23 Iron 0.091 Boron 0.0070 Copper 0.0023 Zinc 0.0095 Sulphates 23.08 Phosphates 0.25 Chlorides 1.85 TABLE 2 Lysine 0.05 Histidine 0.03 Arginine 0.03 Aspartic acid 0.36 Threonine 0.17 Serine 0.16 Glutamic acid 3.95 Phenylalanine 0.06 Glycine 0.21 Alanine 0.45 Proline 0.17 Methionine 0.03 Isoieucine 0.18 Leucine 0.15 Tyrosine 0.16 Betaine 4.12 The potassic saline has therefore a title N: P2O5: K2O: MgO respectively of 3:0:18:2.

The potassic saline which has been prepared as previously shown, is used as a component in the formulation of organo-mineral fertilizers, with differenttitres of N, P205 and K2O.

More particularly, in a mixer-granulation mill, urea, (NH4)2HPO4 and/or supertriple are added to the potassic saline, in the quantities shown in Table 3. The so obtained mixtures, homogenized and granulated, are examples offertilizer compositions according to the present invention.

TABLE 3 a) Organo-mineral fertilizer for base manuring 4-12-12 N P205 K2O (N:P2O5:K2O) (%) (%) (%) (%) Potassicsaline 67.8 1.9 0.1 12.2 (2.82:0.18:18) Supertriple 27.7 - 12.2 (0:44:0) Urea 4.5 2.1 - (46:0:0) 100.0 4.0 12.3 12.2 b) Organo-mineral fertilizer for base manuring 7-13-13 Components N P205 K2O (N:P2O5:K2O) ( (%) (%) (0/a) Potassicsaline 72.2 2.0 0.1 13.0 (2.82:0.18:18) (NH4)2HPO4 27.8 5.0 12.8 (18:46:0) 100 7.0 12.9 13.0 c) Organo-mineral fertilizer for indoor maize manuring 17-8-10 Components N P205 K2O (N:P205:K2O) (%) (%) (%) (%) Potassicsaline 55.6 1.6 0.1 10.0 (2.82:0.18:18) (NH4)2HPO4 17.4 3.1 8.0 (18:46::0) Urea 27.0 12.4 - (46:0:0) 100.0 17.1 8.1 10.0 In the compositions a), b) and c) previously described, the quantity of organic carbon resulted to be 11,8; 12.6; and 9.7 respectively.

Example 2 In a closed reaction vessel equipped with stirring means, containing 250 kg of vinasse from the distillation of beet molasses, concentrated to a content of 59% of dissolved solid matter, 15 kg of concentrated sulphuric acid (specific gravity 1.84 kg/l) are added, and, after a few minutes of stirring, 33 kg of aqueous ethanol (specific gravity 0.82 kg/l) are added.

After about one hour of slow stirring, the precipitate thus obtained is separated by centrifuging by means of a decanter centrifuge. The moist product (65.2 kg at 65% of dry matter) is introduced in a second reaction vessel and mixed with 32 kg of aqueous ethanol (specific gravity 0.82 kg/l1).

After some minutes of rapid stirring, the precipitate is separated by centrifuging, and sent to a drier-granulating mill, operating under atmospheric pressure and equipped with a condensate recovery device.

32.6 kg of a granular product are thus obtained, whose chemical composition is shown in Table 4, where the concentration values are expressed as % on the weight of dry matter.

TABLE 4 Ashes 74.5 Organic matter 25.5 Total nitrogen 2.0 Ammoniac nitrogen traces Organic carbon 12.0 Hydrogen 2.1 Potassium 19.3 Magnesium 1.1 Phosphates 0.38 The so obtained potassic saline has therefore a titre N:P2O5:K2O:MgO of 2:0:23:1.

Such potassic saline is integrated with synthetic products, and in addition to these, with nitrogen and organic carbon bearer products, more particularly concentrated vinasses from beet molasses and blood meal, in the quantities shown in Table 5. The homogenized and granulated or pelletized mixtures are examples of fertilizer compositions according to the present invention.

TABLE 5 a) Organo-mineral fertilizer for base manuring 4-12-14 Components N P205 K20 (N:P205:K20) (%) ( (%) (%) Potassicsaline 62.5 1.25 - 14.50 (2.0:0:23.2) Supertriple 27.5 - 12.10 (0:44:0) Blood flour 5.0 0.50 0.04 0.03 (10.0:0.9:0.6) Urea 5.0 2.30 - (46.0:0:0) 100.0 4.05 12.14 14.53 b) Organo- mineral fertilizer for fodder field manuring 7-10-16 Components N P205 K2O (N:P2O5:K2O) (%) (%) (%) (%) Potassicsaline 72.0 1.44 - 16.70 (2.0:0:23.2) (NH4)2HPO4 21.8 3.92 10.03 (18.0:46.0:0) Conc. vinasses 3.5 0.16 - 0.06 (4.67:0:1.75) Urea 3.7 1.70 - (46.0:0::0) 100 7.22 10.03 16.76 c) Organo-mineral fertilizer for market garden man;uring 5-9-18 Components N P205 K2O (N:P205:K2O) ( (%) (%) (%) Potassicsaline 79.0 1.58 - 18.30 (2.0:0:23.2) (NH4)2PO4 19.5 3.51 8.97 (18.0:46.0:0) Conc. vinasses 1.5 0.07 - 0.03 (4.67:0:1.75) 100 5.16 8.97 18.33 'Example 3 In a closed reaction vessel equipped with stirring means, containing 247 kg of vinasses from the distillation of sugar cane molasses, concentrated to the 38% of dissolved solid matter, 13.5 kg of concentrated sulphuric acid (specific gravity 1.84 kg/l) are added and, after some minutes of stirring, 34 kg of aqueous ethanol (specific gravity 0.82 kg/l) are added.After about one hour of slow stirring, the thus obtained precipitate is separated by centrifuging by means of a decanter centrifuge, sent to a drying oven operated at 800C under vacuum, and weighed.

33.2 kg of product are so obtained, which is submitted to the chemical analysis, whose results are shown in Table 6, where the concentration values are expressed as % on the weight of the dry product TABLE 6 Ashes 61.40 Organic matter 38.60 Total nitrogen 0.52 Ammoniac nitrogen traces Organic carbon 13.14 Hydrogen 1.78 Potassium 15.47 Magnesium 0.70 Phosphates 0.63 The titre of the so obtained potassic saline is therefore: N:P2O5:K2O:MgO = 0.5:0.5:18.5:1.

By integrating this potassic saline, formulations of organo-mineral fertilizers are obtained, which are similar two those shown in the preceeding Examples 1 and 2.

Example 4 In a closed reaction vessel equipped with stirring means, containing 253 kg of vinasse effluents from the production of citric acid from beet molasses, such vinasse having been concentrated at a content of 57% of dissolved solids, 14.5 kg of concentrated sulphuric acid (specific gravity 1.84 kg/l) are added and, after some minutes of stirring, 34 kg of aqueous ethanol (specific gravity 0.82 kg/l) are added. After about one hour of stirring, the thus obtained precipitate is separated by centrifuging, by means of a basket centrifuge, sent to a drying oven operated at 80"C under vaccum, and weighed. 69.6 kg of product are thus obtained, which is submitted to chemical analysis, whose results are shown as % on the weight of the dry product, in Table 7.

TABLE 7 Ashes 39.20 Organic matter 61.80 Total nitrogen 4.55 Ammoniac nitrogen 0.31 Organic carbon 24.90 Hydrogen 3.36 Potassium 11.79 Magnesium 0.43 Phosphates 0.46 The potassic saline thus obtained has therefore a titre N: P2O5: K2O: MgO of 4.5:0.3:14:1.

By integrating such potassic saline, formulations are obtained of organo-mineral fertilizers similar to those shown in the preceeding Examples 1 and 2.

Attention is drawn to the application filed by us on the same day as the present application.

Claims (8)

1. A fertilizer composition comprising (a) the product from the desalting, by means of sulphuric acid and in the presence of an organic solvent, of an effluent from an industrial fermentation of sugar, and (b) at least one organic or inorganic material containing phosphorus and/or nitrogen; the composition having a total nitrogen content of not less than 3% by weight, an organic nitrogen content of at least 1.5% by weight, a phosphorus content (expressed as P205) of not less than 4% by weight, a potassium content (expressed as K2O) of not less than 5% by weight, and an organic carbon content of not less than 8% by weight.

2. A composition as claimed in claim 1, component (a) thereof having been obtained by bringing the effluent into contact with sulphuric acid, adding an organic solvent to the resulting mixture, and separating and drying the resulting precipitate.

3. A composition as claimed in claim 1 or 2, wherein the effluent has a solid content of from 35 to 65% by weight, wherein the sulphuric acid has a specific gravity of from 1.69 to 1.84 kg/litre, and wherein the sulphuric acid is used in an amount of from 1.3 to 1.8 parts by weight per part by weight of potassium in the effluent.

4. A composition as claimed in any of claims 1 to 3, wherein the organic solvent is used in an amount of from 10 to 25 parts by volume per 100 parts by volume of the effluent.

5. A composition as claimed in any of claims 1 to 4, wherein the organic solvent is a lower alcohol or a lower ketone (wherein "lower" denotes the presence of a group or groups containing 1 to 6, preferably 1 to 4, carbon atoms).

6. A composition as claimed in claim 5, wherein the organic solvent is ethanol.

7. A composition as claimed in any of claims 1 to 6, wherein component (b) is urea, a nitrate, an ammonium salt, a superphosphate, phosphoric acid, a salt of phosphoric acid, blood meal, or concentrated vinasse.

8. A composition as claimed in claim 1, substantially as described in any of the foregoing Examples.