Fertiliser containing spent grains and / or coffee grounds

Abstract

One aspect of the invention relates to a fertiliser which comprises zeolite and a by-product formed by organic matter, the organic by-product consisting of spent grains and / or coffee grounds. The fertiliser satisfies the inequation in formula (l), where m(Z) denotes the mass of the zeolite (in the dry state) in a sample of the fertiliser, m(SPOs) denotes the mass of the dry residue of the organic by-product in the sample and m(eau) denotes the mass of the water contained in the sample. Preferably, the zeolite and the organic by-product together contribute to at least 80 wt.%, preferably at least 90 wt.%, of the dry residue of the fertiliser. Another aspect of the invention relates to a method for using the fertiliser in agriculture.

Description

DP. PNSA.0003 / PC 1 FERTILIZER CONTAINING COFFEE GROUNDS AND / OR COFFEE GROUNDS Technical Field

[0001] In general, the invention relates to a fertilizer containing brewers' grains and / or coffee grounds for use in agriculture, including viticulture, arboriculture, market gardening, horticulture, and forestry. The fertilizer may be in solid form, as a powder, grains, or granules, or as a seed coating. Technological background

[0002] In the field of fertilizers (in English: “fertilizing products”), we can observe a growing effort of innovation, linked to the constant environmental and societal pressure that farmers are under regarding the use of synthetic products, but also to the growing awareness of the essential role of the relationships between soil microorganisms and plants: this is what is characterized as sustainable agriculture.

[0003] In the context of this document, the term "fertilizer" is used to refer to a substance or mixture of substances applied or intended to be applied to plants, their rhizosphere, or the soil, for the purpose of providing plants with nutrients, improving their nutritional efficiency, or improving the soil. There are several categories of fertilizers, including fertilizers, soil amendments (such as organic or inorganic soil amendments), and combination fertilizers.

[0004] The use of synthetic mineral fertilizers leads, over several years, to a depletion of soil organic matter.

[0005] Despite the fact that the soil contains only a small percentage by mass of organic matter, generally between 1 and 10% by mass, this is very important for the functioning of the soil and the entire ecosystem.

[0006] Indeed, organic matter plays multiple roles in ecological processes: it constitutes a reservoir of nutrients which, through mineralization, are made available for absorption by plants. Organic matter has a high cation exchange capacity (CEC) which reinforces that of clay, with which it forms the "clay-humus complex." This complex is DP. PNSA.0003 / PC 2 nutrient cation binder (e.g., Ca 2+ , Mg 2+ K + , N / A +etc.) and thus forms a reservoir of nutrients. Organic matter contributes to soil structure, promotes aeration by flocculating clays, and therefore reduces the soil's vulnerability to crusting. Thanks to their water retention capacity, organic matter increases the soil's available water reserves.

[0007] Fertile soil requires a regular replenishment of its biodegradable organic matter to ensure nutrient circulation and maintain sufficient microbial biodiversity. Therefore, a regular and substantial supply of labile organic matter is necessary.

[0008] Fertile soil needs readily biodegradable organic matter to maintain microbial biodiversity. This fresh, energy- and carbon-rich organic matter is called labile organic matter. Sustainable soil management practices emphasize the stabilization of added organic matter. Stable organic matter acts as a durable (slowly degradable) substrate within the soil.

[0009] The C / N ratio (the mass ratio between carbon and nitrogen) is an indicator that allows us to judge the degree of evolution of organic matter, that is to say its ability to decompose more or less rapidly in the soil.

[0010] The humification of organic matter depends on its carbon and nitrogen content. The decomposition and mineralization of organic matter require carbon as an energy source and nitrogen for the synthesis of proteins necessary for microorganisms.

[0011] The C / N ratio of the biomass constituted by soil microorganisms is approximately 8. The nutritional balance of microorganisms is at a C / N ratio of 24.

[0012] We are therefore seeking a technical solution for adding organic matter to soils that is compatible with microbial life and soil function. General description of the invention

[0013] A first aspect of the invention relates to a fertilizer, comprising zeolite and a by-product formed from organic matter ("organic by-product"), DP. PNSA.0003 / PC 3 The organic by-product consists of spent grain and / or coffee grounds. The fertilizer satisfies the inequality m(z)xioo > 8 + ln f m eau ' m(J> PO s )+m water)+m Z) \.m SPO s (1) where m(Z) denotes the mass of the zeolite (dry) in a sample of the fertilizer, m(SPOs) the mass of the dry residue of the organic by-product in the sample, and m(water) the mass of the water contained in the sample. The function In denotes the natural logarithm. The mass of water corresponds to the difference between the mass of the fertilizer sample and the mass of the dry residue of the sample. Note that if, with the exception of the organic by-product, all the ingredients of the fertilizer are dry, the sum m(SPO s ) + m(ea ) in the denominator of the ratio on the left side corresponds to the mass of the organic by-product in the wet state.

[0014] Preferably, we also have: znnm(Z)xl00. - / z^\ max (ymin ; 0.8 X y opt ) _m(SPOs)+m(water)+m(z) x Yopt, (2) O Ù Ymin = 8 +ln Yopt = +GsPO^ X Ymin 'and the max function( X lJ X 2) identifies the maximum value among its arguments and x2. It has been empirically determined that y opt represents the optimal ratio between the mass of zeolite m(Z) and m(SP0s) + m water) + m(Z). In an even more preferred way, we have max (v min ; 0.9 X y opt ) < — - - - — - — - — — < 1.2 X y 0Dt (3)

[0015] According to some embodiments of the invention, the mass ratio of zeolite to organic by-product in the dry residue of the fertilizer (i.e. the mass ratio of dry zeolite residue to dry organic by-product residue) can be between 0.10 and 5, preferably between 0.25 and 4, and more preferably between 0.33 and 3.

[0016] Zeolites are minerals composed of a microporous alum inosilicate skeleton, the internal voids of which are filled with cations and water molecules. Zeolites have the general empirical formula: M x / n[(AlO2)x(SiO2)y].wH2O where M represents a cation of the alkali and alkaline earth metal groups (groups 1 and 2 in the modern numbering system according to DP. PNSA.0003 / PC 4 (IUPAC, formerly IA and HA) with valence n, w is the number of water molecules, the y / x ratio represents the molar ratio between Si and Al and is greater than or equal to 1, and the part in brackets indicates the composition of the microporous skeleton. The presence of Al 3+ in the microporous skeleton (on sites that would otherwise be occupied by Si 4+ ) results in a negative charge which is compensated by the M cations in the interstices of the skeleton.

[0017] Brewers' grains are insoluble residues from cereal brewing. They are by-products of breweries and distilleries producing alcoholic beverages or biofuels (biofuel, bioethanol) and are primarily used in animal feed. Brewers' grains have seen a significant increase in availability due to the growth in global biofuel production. The moisture content (i.e., the ratio of the mass of water in a sample to the total mass of the sample) of fresh brewers' grains can reach 70 to 80% by mass. Dehydrated brewers' grains can have a dry matter content of approximately 90%. The fertilizer according to the first aspect of the invention may comprise fresh, ensiled (fermented), or dehydrated (partially or completely) brewers' grains.

[0018] Coffee grounds are the residue from coffee percolation. In their raw state, the moisture content of this "waste" is over 70% by mass.

[0019] This fertilizer is suitable for adding organic matter to soils. Organic matter originates from human activity, where it is considered a by-product (or even waste), or a co-product if it undergoes full economic valorization. Coffee grounds and spent grains are valuable, labile organic materials rich in carbon, but they need to be prepared before use as soil amendments to make them compatible with microbial life and soil function, and to enhance their capacity. Combining coffee grounds and / or spent grains with zeolite helps stabilize the organic matter, absorb excess moisture (if the spent grains and / or coffee grounds are applied wet), aerate the mixture, and reduce clumping. Furthermore, zeolite increases the soil's cation exchange capacity.Once applied, the zeolite will neither be destroyed nor leached and will retain its absorption, desorption, and cation exchange properties. The zeolite is present in the fertilizer. DP. PNSA.0003 / PC 5 as an active ingredient, actively contributing to the fertilizer's effectiveness, and therefore cannot be considered a mere excipient. Zeolite is capable of adsorbing cations (e.g., NH4+). + ) products produced during the mineralization of organic matter and delay their release into the soil. The fertilizer according to the invention thus allows for slower and more sustained nitrification and, consequently, better assimilation by plants.

[0020] Preferably, the organic by-product and the zeolite together contribute at least 80% by mass, and preferably at least 90% by mass, of the dry residue of the fertilizer. The remainder may include a fertilizer, a binder (for the manufacture of granules), additives, fillers (inert), etc. The term "fertilizer" in the context of this document refers to a substance or mixture of substances intended to provide plants with nutrients in order to improve their growth and increase the yield and / or quality of a crop. We distinguish different categories of nutrients, including macro-elements (or macronutrients), which are nitrogen (N), phosphorus (P) and potassium (K), secondary elements such as calcium (Ca), sulfur (S) and magnesium (Mg), as well as trace elements, which include iron (Fe), manganese (Mn), molybdenum (Mo), copper (Cu), boron (B), zinc (Zn) and others.Fertilizers are also divided into different categories. Simple fertilizers are those that supply only one of the three macro-elements (N, P, or K). Compound fertilizers contain several nutrients, including at least one macro-element. Binary fertilizers combine two macro-elements (NP, NK, or PK fertilizers), while ternary fertilizers combine all three macro-elements (NPK fertilizers). The various fertilizers can be part of the fertilizer according to the invention within the limits indicated above. Examples of binders include bentonite, cellulosic derivatives such as carboxymethyl cellulose (CMC), methylcellulose, ethylcellulose, etc. Examples of fillers include chalk, dolomite, etc.

[0021] Brewers' grains and / or coffee grounds can be incorporated into the fertilizer in their raw, i.e., moist state, in the mixture with the zeolite. Zeolite has a high water retention rate (>40% by mass, >50% by mass, or >60% by mass, depending on the type of zeolite). Empirically, it has been found that adding a quantity of zeolite to a given amount of fresh brewers' grains and / or moist coffee grounds (e.g., moisture content >70% by mass) satisfies inequality (1). DP. PNSA.0003 / PC 6 This allows for an aerated product that keeps well. As a general rule, the quantity of zeolite can be reduced (within the limits stated above) if the spent grain and / or coffee grounds are drier, i.e., if the spent grain and / or coffee grounds have undergone a preliminary drying step before being mixed with the zeolite.

[0022] Given that the water content of the fertilizer may vary due to the condition of the ingredients and / or possible subsequent drying steps, in this disclosure, the mass ratios between the different ingredients of the fertilizer are preferably stated in relation to dry matter (dry residue).

[0023] According to preferred embodiments of the invention, the fertilizer has a moisture content of 10% (mass) or more, preferably 20% (mass) or more.

[0024] The dry residue of a sample is obtained by drying the sample in an oven at a temperature of 105°C until the mass remains constant. The dry matter content is determined as the ratio between the mass of the dry residue and the initial mass of the sample. The dry residue and the dry matter content are preferably determined according to CEN / TS 17773 (2022), which provides further details on the procedures to be followed. The mass of water contained in the sample is calculated from the difference in mass between the sample in its initial state (more or less wet) and its dry residue. The mass of any other volatile components up to the temperature of 105°C is then included in the mass of the water, in accordance with standard practice.

[0025] Preferably, the fertilizer zeolite has a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 based on the Fraunhofer diffraction model, less than or equal to 5 mm, or less than or equal to 3 mm, preferably less than or equal to 1 mm, more preferably less than or equal to 500 pm, even more preferably less than or equal to 200 pm.

[0026] In one embodiment, the organic by-product consists of spent grain. Alternatively, the organic by-product may consist of coffee grounds. However, it is also possible for the organic by-product to consist of both spent grain and coffee grounds. In this case, the mass ratio of spent grain to coffee grounds is preferably between 0.05 and 20, more preferably between 0.1 and 10, and even more preferably between 0.33 and 3. DP. PNSA.0003 / PC 7

[0027] Numerous zeolites are classified into several families. Clinoptilolite (a lamellar-monoclinic zeolite) and chabazite (a hexagonal-cubic zeolite) are considered particularly effective in this context due to their content of exchangeable cations (Ca, K, and Na) and their cation exchange capacities. Synthetic zeolites also exist that can be used within the framework of the present invention, but in this context, natural zeolites are preferred, especially those from deposits selected for their purity. Preferably, the term "zeolite" in this context refers to a natural zeolite chosen from the analcime family, such as analcime, pollucite, wairakite, bellbergite, bikitaite, boggsite, and brewsterite.the chabazite family such as chabazite, willhendersonite, cowlesite, dachiardite, redingtonite, epistilbite, erionite, faujasite, ferrienite and herschelite; the gismondite family such as amicite, garronite, gismondite, gobbinsite, gmelinite, gonnardite and goosecreekite; the harmotome family such as harmotome, phillipsite and wellsite; the heulandite family such as clinoptilolite, heulandite, laumonite, levyne, mazzite, merlinoite, montesommaite, mordenite and maricopaite; the natrolite family such as mesolite, natrolite, scolecite, offretite, paranatrolite, paulingite and perlialite; the stilbite family such as barrerite, stilbite, stellerite, thomsonite, tschernichite and yugawaralite; sodium dachiardite;and tetranatrolite. Preferably, the fertilizer zeolite comprises chabazite, clinoptilolite, erionite, mordenite, or phillipsite. Most preferably, the zeolite comprises or consists of clinoptilolite and / or chabazite. Preferably, the zeolite comprises at least 50% by mass, preferably at least 75% by mass, of chabazite and / or clinoptilolite. It should be noted that natural zeolite may contain impurities, e.g., levels of feldspar, illite, or quartz. Natural zeolite comprises, preferably, at least 40% (by mass), and more preferably at least 60% (by mass), and even more preferably at least 80% (by mass) of pure zeolite.

[0028] According to a preferred embodiment, the zeolite comprises or consists of zeolite doped with sodium, calcium, or potassium (hereinafter: "modified zeolite"), as described in document WO 2024 / 194414 A1. The modified zeolite may be produced by impregnation with zeolite (natural or synthetic). DP. PNSA.0003 / PC 8 with a solution containing sodium, calcium, or potassium ions, e.g., a solution of sodium nitrate (NaNO₃), sodium hydroxide (NaOH), and / or sodium chloride (NaCl), calcium nitrate (Ca(NO₃)₂), or potassium nitrate (KNO₃). Modifying the zeolite by impregnation with a sodium, calcium, or potassium-based solution improves the adsorption capacities and adsorption rates of NH₄⁺ ions. + Modifying the zeolite by impregnating it with a sodium-based solution (preferably a sodium nitrate solution) improves its NH4 ion adsorption capacity.+ at high temperature. Impregnation of the zeolite increases the cation exchange capacity and can also increase the volume ratio of the zeolite mesopores, promoting the adsorption of ammonium ions NH4 + and improving its heat resistance.

[0029] Because zeolite is formed from a microporous aluminosilicate skeleton, the valence electrons of the oxygen atoms are not balanced within the tetrahedron, resulting in a negative charge. Positively charged cations tend to be captured. These cations are weakly bound to the aluminosilicate and are therefore relatively easily exchanged. This cation exchange mechanism in zeolite plays an important role in ammonium adsorption, as the cations released by the zeolite are replaced by NH4 ions. + .

[0030] Different zeolites can have different selectivities for different cations. The selectivity of a zeolite for a cation M can be denoted a(M). Most natural zeolites have a(NH4)₄ + ) > a(K + ) > a(Sr + ) > a(Na + ) > a(Ca 2+ The modification of the zeolite (preferably initially a natural zeolite) involves doping with sodium, calcium, or potassium ions, so that these are subsequently exchanged for the ammonium ion NH4 + for which the zeolite has a higher affinity compared to the ion with which it has been doped. The doping cation is preferably selected based on the zeolite such that the selectivity of the zeolite for the ammonium ion NH4 +is greater than the selectivity for the doping cation. Depending on the type of zeolite chosen, the preference of the chosen cation for doping may vary between Na + , That 2+ , or K + .

[0031] Like Na ions + are normally the weakest bound to zeolite compared to K + , Mg 2+ , That 2+ and Cu 2+ Sodium doping is currently considered the most preferred. During the modification of the zeolite (during doping), cations naturally present in the interstices of the skeleton are altered. DP. PNSA.0003 / PC 9 microporous vesicles of the zeolite are replaced by doping ions, e.g., Na+ ions + These can then be exchanged with ammonium ions NH4 + We can observe that the Na ions + , That 2+ and K +give the modified zeolite a higher ion exchange capacity and thus improve the adsorption of the ammonium ion.

[0032] The production of modified zeolite (preferably sodium-doped zeolite) may involve drying and / or calcining the zeolite after impregnation. Calcination can be carried out at temperatures ranging from 300°C to 800°C. It should be noted that calcining unmodified (undoped) zeolite significantly reduces its ammonium ion adsorption capacity. In contrast, modified zeolite, preferably zeolite modified by impregnation with a nitrate-based solution, e.g., sodium nitrate, calcium nitrate, or potassium nitrate, exhibits improved capacity when subjected to heat treatment, particularly calcination. Modified zeolite displays good heat resistance in both calcination processes and the production of synthetic fertilizers.

[0033] The mesoporous volume and specific surface area of ​​the zeolite are factors that can affect its ammonium adsorption capacity. Nitrate salts (e.g., sodium nitrate, calcium nitrate, or potassium nitrate) are known to decompose and release oxygen gas at elevated temperatures. This gas release can destroy some of the zeolite's micropores, creating larger pores. Therefore, the zeolite's pore structure can be modified to enhance its NH4 ion adsorption capacity. +Specifically, this is achieved by impregnation with NaNO₃, followed by a calcination step. For this reason, a sodium nitrate solution is the preferred choice for sodium doping of zeolite, as heat treatments and / or high-temperature reactions will decompose the sodium nitrate, releasing oxygen and destroying some of the zeolite's micropores, creating larger pores. In particular, heat treatment of sodium nitrate-doped zeolite further increases its NH₄⁺ ion adsorption capacity and rate. + of zeolite if we compare it to those of doped zeolite but without heat treatment.

[0034] When applied to the soil, the zeolite in the fertilizer improves the mineralization of organic matter, and it will gradually capture and distribute NH4 ions. + resulting from the mineralization of organic matter, thus allowing regular nitrification DP. PNSA.0003 / PC 10 by reversible retention of NH4 + This fertilizer limits nitrous oxide and nitrogen oxide emissions, as well as losses through leaching and volatilization. It helps retain nutrients, particularly nitrogen, near the roots by enhancing the cation exchange capacity (CEC) induced by the zeolite's high CEC. Consequently, the fertilizer also reduces nitrous oxide (N₂O) emissions. The use of modified zeolite, especially sodium-doped zeolite, further improves the reduction of these emissions and increases the reversible retention capacity of nutrient cations.

[0035] According to one embodiment, the invention therefore combines zeolite modified by doping with sodium, calcium or potassium and spent grain and / or coffee grounds in a fertilizer.

[0036] Preferably, the fertilizer has a carbon-to-nitrogen mass ratio (C / N ratio) greater than 8, e.g., between 10 and 15.

[0037] The fertilizer can be packaged in the form of granules or pellets.

[0038] The fertilizer can also be formulated as a seed coating. One aspect of the invention may therefore relate to a seed coated with the fertilizer.

[0039] According to a particularly preferred embodiment of the fertilizer, the fertilizer satisfies the system of inequalities (2), the zeolite and the organic by-product together contribute at least 80% by mass, preferably at least 90% by mass, of the dry residue of the fertilizer, the organic by-product consisting of a mixture of brewers' grains and coffee grounds, the mass ratio of brewers' grains to coffee grounds being between 0.05 and 20, preferably between 0.1 and 10, the zeolite has a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 based on the Fraunhofer diffraction pattern, less than or equal to 3 mm, preferably less than or equal to 1 mm, more preferably less than or equal to 500 µm, even more preferably less than or equal to 200 µm, the water content by weight of the fertilizer is 10% or more, preferably 20% or more, and the mass carbon to nitrogen ratio (C / N ratio) of the fertilizer is greater than 8.Preferably, the zeolite and the organic by-product together contribute at least 90% by mass of the dry residue of the fertilizer, the mass ratio between the spent grain and the coffee grounds being between 0.1 and 10, the zeolite has a diameter D90, measured by laser granulometry in agreement. DP. PNSA.0003 / PC 11 with ISO 13320:2020 based on the Fraunhofer diffraction model, less than or equal to 500 pm, more preferably less than or equal to 200 pm, the water content by weight of the fertilizer is 10% or more, preferably 20% or more, and the mass carbon to nitrogen ratio (C / N ratio) of the fertilizer is greater than 8. Preferably, the zeolite comprises at least 75% by mass of chabazite and / or clinoptilolite doped with sodium, calcium or potassium.

[0040] Another aspect of the invention relates to a method of using the fertilizer, in which the fertilizer dosage is such that it provides, per hectare and per application, the equivalent of 200 to 2000 kg, preferably 300 to 1000 kg, and more preferably 400 to 600 kg, of dry matter. Therefore, if the fertilizer has a moisture content of TE % (by mass), the values ​​indicated in dry matter equivalents are to be multiplied by 100 / (100-TE) to obtain the mass of fertilizer per hectare and per application. Detailed description of preferred embodiments.

[0041] Brewers' grains and coffee grounds are by-products of the food industry that could be used as fertilizer ingredients. However, neither can be used in its raw state, mainly due to its perishability (tendency to mold and be contaminated by mycotoxins).

[0042] Cereal grains are cereal residues (e.g., barley, wheat, etc.) obtained during the brewing or distillation process. The quantity of spent grains produced in Europe alone amounts to nearly 3.5 million tons per year. They represent approximately 85% of brewery waste.

[0043] The pH of distillers' grains is typically between 4 and 5, which is too acidic for spreading in their raw state. Distillers' grains have a nitrogen content of approximately 30% and a C / N ratio of around 15. In addition to phosphorus, distillers' grains contain mineral salts that are sources of elements such as magnesium (Mg), potassium (K), iron, etc., and many amino acids. Distillers' grains are a valuable source of nitrogen and can be transformed into nutritious and structural humus.

[0044] The main disadvantage of brewery spent grains is their excessively low pH and their perishability.

[0045] Global coffee grounds production amounts to nearly 7 million tons per year. Coffee grounds are the residue from coffee percolation. In their raw state, this DP. PNSA.0003 / PC 12 Coffee grounds have a moisture content of over 70% (by mass). They typically contain 3% (by mass) nitrogen, with a carbon-to-nitrogen ratio (C / N) of approximately 24:1. This high C / N ratio promotes the growth of microorganisms at the expense of plants (nitrogen starvation). The pH of coffee grounds is 6.5, and they contain elements such as magnesium, potassium, copper, and phosphorus. Therefore, coffee grounds can serve as a carbon source and can be transformed into humus, which is both nutritious and improves soil structure. The main drawbacks of coffee grounds are their high C / N ratio and their perishability.

[0046] Adding zeolite to spent grains and / or coffee grounds helps to reduce moisture and aerate the mixture, which can then be used directly in fields or crops.

[0047] Zeolite can capture ammoniacal nitrogen from the mineralization of organic matter because it has a high affinity for the NH4 ion. + The fertilizer according to the invention thus allows for slower and more sustained nitrification and, consequently, better assimilation by plants.

[0048] Zeolite also allows for better mineralization of the organic matter supplied by coffee grounds and / or spent grains through better soil aeration, better clay flocculation, a lower degree of humidity, and better development of microorganisms.

[0049] Zeolite also improves the cation exchange capacity of soils, the CEC, and, in particular, it improves the exchange of NH4 cations + derived from the mineralization of spent grain and / or coffee grounds. Example 1

[0050] According to a preferred embodiment of the fertilizer, fresh brewer's grains with a moisture content between 70% (mass) and 80% (mass) and (dry) zeolite with a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 based on the Fraunhofer diffraction model, less than or equal to 500 pm, e.g., 200 pm, are used.

[0051] Fresh distillers' grains have a shelf life of 2 to 5 days. For every 100 parts (by mass) of fresh distillers' grains (containing, given the moisture content indicated above, between 70 and 80 parts (by mass) of water), add between 20 and 40 parts (by mass), preferably between 20 and 30 parts (by mass), of zeolite, mixing in a blender (e.g., a DP. PNSA.0003 / PC 13 The mixture is blended using a ribbon, a mixer, or a granulator (e.g., a rotary drum or disc granulator) until a homogeneous mixture is obtained. The zeolite absorbs some of the water from the spent grains, resulting in a fertilizer in the form of an aerated product with a longer shelf life. The lower the moisture content, the longer the shelf life. Tests with 25 parts (by mass) of zeolite added to 100 parts (by mass) of fresh spent grains (high moisture content, but not precisely measured) showed that the product could be stored for more than a month.

[0052] If no additional ingredients are added to the mixture, the zeolite and distillers' grains together contribute 100% by mass of the fertilizer's dry residue. However, it is possible to add one or more other ingredients, e.g., an N, P, K, NP, NK, PK, or NPK fertilizer; a complex fertilizer containing one or more secondary or micronutrients; a binder, e.g., bentonite, methylcellulose, ethylcellulose, etc.; or a filler, e.g., micronized chalk or dolomite. The addition of such ingredients is subject to the condition that the zeolite and distillers' grains together contribute at least 80% by mass of the fertilizer's dry residue. The maximum permissible mass of the dry residue from the additional ingredients therefore depends on the moisture content of the distillers' grains and the zeolite, and on the mass ratio of distillers' grains to zeolite.

[0053] In this example, the zeolite / spent grains mass ratio in the dry residue of the fertilizer is between 0.67 and 2.

[0054] If the distillers' grains available for mixing with zeolite are partially dried, the zeolite input can be reduced so that the zeolite / distillers' grains mass ratio in the dry residue of the fertilizer remains within the range of 0.67 to 2. Example 2

[0055] According to another preferred embodiment of the fertilizer, coffee grounds and (dry) zeolite with a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 based on the Fraunhofer diffraction model, are used, less than or equal to 500 pm, e.g., 200 pm.

[0056] The moisture content of coffee grounds can reach 80% (by mass). The moisture content of (partially) dried coffee grounds will be lower. Assuming the coffee grounds have a moisture content of 80% (by mass), we add, per 100 parts (by mass) DP. PNSA.0003 / PC 14 Coffee grounds (containing, given the moisture content indicated above, 80 parts (by mass) of water) and between 20 and 30 parts (by mass) of zeolite are mixed in a mixer (e.g., ribbon mixer), blender, or granulator (e.g., drum or rotary disc) until a homogeneous mixture is obtained. The zeolite absorbs some of the water contained in the coffee grounds. Tests with 25 parts (by mass) of zeolite added to 100 parts (by mass) of coffee grounds (high moisture content, but not precisely measured) showed that the product could be stored for more than a month.

[0057] If no additional ingredients are added to the mixture, the zeolite and coffee grounds together contribute 100% by mass of the fertilizer's dry residue. However, it is possible to add one or more other ingredients, e.g., an N, P, K, NP, NK, PK, or NPK fertilizer; a complex fertilizer containing one or more secondary or trace elements; a binder, e.g., bentonite, methylcellulose, ethylcellulose, etc.; or a filler, e.g., micronized chalk or dolomite. The addition of such ingredients is subject to the condition that the zeolite and coffee grounds together contribute at least 80% by mass of the fertilizer's dry residue. The maximum permissible mass of dry residue of additional ingredients therefore depends on the water content of the coffee grounds and zeolite, and the mass ratio between the coffee grounds and the zeolite.

[0058] If the moisture content of the coffee grounds is 80% (by mass), the zeolite / coffee grounds mass ratio in the dry residue of the fertilizer is between 1 and 1.5. If the coffee grounds have been (partially) dried before mixing with the zeolite, the zeolite application can be reduced so that the zeolite / dried grains mass ratio in the dry residue of the fertilizer remains within the range of 1 to 1.5. Example 3

[0059] According to another preferred embodiment of the fertilizer, fresh brewer's grains and coffee grounds are used as organic matter. The organic matter is mixed with zeolite having a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 based on the Fraunhofer diffraction model, less than or equal to 500 pm, e.g., 200 pm.

[0060] For organic matter, the mass ratio between the dry residue of the spent grains and the dry residue of the coffee grounds is chosen preferably between 0.05 and 20, and preferably between 0.1 and 10. Per 100 parts (mass) of wet organic matter DP. PNSA.0003 / PC 15 (moisture content: 80%, therefore containing 80 parts (by mass) of water), add between 20 and 40 parts (by mass), preferably between 20 and 30 parts (by mass), of zeolite, mixing in a mixer, blender, or granulator (e.g., drum or rotary disc) until a homogeneous mixture is obtained. The zeolite absorbs some of the water contained in the spent grains and coffee grounds, resulting in a fertilizer in the form of an aerated product with a longer shelf life.

[0061] If no additional ingredients are added to the mixture, the zeolite and organic matter together contribute 100% by mass of the fertilizer's dry residue. However, it is possible to add one or more other ingredients, e.g., an N, P, K, NP, NK, PK, or NPK fertilizer; a complex fertilizer containing one or more secondary or micronutrients; a binder, e.g., bentonite, methylcellulose, ethylcellulose, etc.; or a filler, e.g., micronized chalk or dolomite. The addition of such ingredients is subject to the condition that the zeolite and organic matter together contribute at least 80% by mass of the fertilizer's dry residue. The maximum permissible mass of dry residue from the additional ingredients therefore depends on the moisture content of the organic matter and the zeolite, and on the mass ratio of organic matter to zeolite.

[0062] In this example, the zeolite / organic matter mass ratio in the dry residue of the fertilizer is between 0.67 and 2.

[0063] If the organic matter available for mixing with zeolite is partially dried, the zeolite input can be reduced so that the zeolite / organic matter mass ratio in the dry residue of the fertilizer remains in the range between 0.67 and 2.

[0064] In Examples 1 to 3, the zeolite preferably comprises at least 75% by mass of chabazite and / or clinoptilolite. The zeolite may be modified zeolite, doped with sodium, calcium, or potassium. A zeolite modified by sodium ion doping exhibits a higher and faster ammonium ion adsorption capacity than the zeolite (typically a natural zeolite) used as the raw material. Modifying the zeolite by doping with sodium ions improves ammonium adsorption capacity at high temperatures. Doping the zeolite also increases its cation exchange capacity, promoting NH4 adsorption. + . DP. PNSA.0003 / PC 16

[0065] It is noted that for organic matter (spent grains and / or coffee grounds) containing 80% (mass) water in its wet state, the ratio y min corresponds to 9.39 (if all other fertilizer ingredients are dry) and the ratio y optcorresponds to 22.66. Therefore, at least 10.36 kg of zeolite should be used per 100 kg of wet organic matter. Preferably, systems of inequalities (2) or (3) are used to determine the preferred quantities of zeolite. According to (2), between 22.14 kg and 51.5 kg of zeolite per 100 kg of wet organic matter is preferably used, the optimal mass of zeolite per 100 kg of wet organic matter (corresponding to the ratio y) opt ) being 29.3 kg. According to (3), between 25.6 kg and 37.3 kg of zeolite is preferably used per 100 kg of 80% (mass) moist organic matter.

[0066] While specific embodiments have just been described in detail, those skilled in the art will appreciate that various modifications and alternatives to these can be developed in light of the overall lesson provided by this disclosure of the invention. Therefore, the specific arrangements and / or methods described herein are intended to be given solely by way of illustration, without any intention of limiting the scope of the invention, which is determined by the extent of the related claims.

Claims

DP. PNSA.0003 / PC 17 Demands 1. Fertilizer, comprising: o an organic by-product, the organic by-product consisting of spent grains and / or coffee grounds; o of zeolite; m(Z)xlOO In 7 m(water) \ the fertilizer being characterized in that m(J> PO s}+m(water)+m(Z) 8 + \m(SPO s )J' where m(Z) denotes the mass of zeolite in a sample of fertilizer, m(SPOs) the mass of dry residue of organic by-product in the sample and m(water) the mass of water contained in the sample.

2. The fertilizer according to claim 1, in which znnxm(Z)xlOO. - max (y min ; 0.8 X y opt ) _m(SPOs)+m(water)+m(z) x Yopt, where Ymin = 8 + Yopt = (1 + x Ymin and the max(-;-) function identifies the maximum value among its arguments.

3. The fertilizer according to claim 1 or 2, in which max, z, z,. m(Z)xlOO, z. (v min ; 0.9 X y 0Dt ) < — - - - — - — - — — < 1.2 X y 0Dt ,r min> i optj m SPO s )+m water)+m Z) ' op ' 4. The fertilizer according to any one of claims 1 to 3, wherein the zeolite and the organic by-product together contribute at least 80% by mass, preferably at least 90% by mass, of the dry residue of the fertilizer.

5. The fertilizer according to any one of claims 1 to 3, wherein the zeolite has a diameter D90, measured by laser granulometry in accordance with ISO 13320:2020 on the basis of the Fraunhofer diffraction pattern, less than or equal to 5 mm, preferably less than or equal to 3 mm, preferably less than or equal to 1 mm, more preferably less than or equal to 500 pm, still more preferably less than or equal to 200 pm.

6. The fertilizer according to any one of claims 1 to 5, having a moisture content of 10% (mass) or more, preferably 20% (mass) or more.

7. The fertilizer according to any one of claims 1 to 6, wherein the organic by-product consists of distillers' grains. DP. PNSA.0003 / PC 18 8. The fertilizer according to any one of claims 1 to 6, wherein the organic by-product consists of coffee grounds.

9. The fertilizer according to any one of claims 1 to 6, wherein the organic by-product consists of a mixture of spent grain and coffee grounds, the mass ratio of spent grain to coffee grounds being between 0.05 and 20, preferably between 0.1 and 10, more preferably between 0.33 and 3.

10. The fertilizer according to any one of claims 1 to 9, wherein the zeolite comprises chabazite, clinoptilolite, erionite, mordenite, phillipsite or synthetic zeolite.

11. The fertilizer according to claim 10, wherein the zeolite comprises at least 50% by mass, preferably at least 75% by mass, of chabazite and / or clinoptilolite.

12. The fertilizer according to any one of claims 1 to 11, wherein the zeolite comprises or consists of zeolite doped with sodium, calcium or potassium.

13. The fertilizer according to any one of claims 1 to 11, wherein the zeolite comprises or consists of sodium-doped zeolite.

14. The fertilizer according to any one of claims 1 to 11, zeolite comprises or consists of calcium-doped zeolite.

15. The fertilizer according to any one of claims 1 to 11, wherein the zeolite comprises or consists of potassium-doped zeolite.

16. The fertilizer according to any one of claims 1 to 15, the fertilizer having a carbon-to-nitrogen mass ratio (C / N ratio) greater than 8, preferably between 10 and 15.

17. The fertilizer according to any one of claims 1 to 16, in the form of granules or pellets.

18. The fertilizer according to any one of claims 1 to 16, in the form of a seed coating.

19. The fertilizer according to claims 2, 4, 5, 6, 9, and 16, in combination with any one of claims 17 and 18. DP. PNSA.0003 / PC 19 20. The fertilizer according to claims 2, 4, 5, 6, 9, 11, 12 and 16, in combination with one of claims 17 and 18.

21. Method of using the fertilizer according to any one of claims 1 to 20 in agriculture, wherein the dosage of the fertilizer is such that it provides, per hectare and per application, between 200 and 2000 kg, preferably between 300 and 1000 kg, more preferably 400 to 600 kg, of dry matter.

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