OA21728A - Fertilizer based on oil mill and oil palm residues and its manufacturing process. - Google Patents

Abstract

The invention relates to a fertilizer or fortifier, granulated or not, for plants, obtained by composting a mixture of at least two components of the oil palm and residues from the oil palm mill: liquid effluents, settling sludge, stalks, palm leaves, oil palm ferns, fibers of spent pulp of palm seed, thin inflorescences of oil palm. The invention also relates to the method for obtaining the fertilizer which comprises the following steps: harvesting and drying of the raw materials, grinding, formulation, fermentation, maturation and granulation. <img file="OA21728A_A0001.tif"/> Single Plate – Fig. 1

Description

DESCRIPTION OF THE INVENTION

Fertilizer based on oil mill residues and oil palm and its manufacturing process

The invention relates to the field of agriculture and specifically concerns a granulated or non-granulated organic fertilizer, obtained by composting various compounds essentially comprising oil palm waste, as well as residues from oil palm oil mills.

The invention also relates to the process for obtaining the fertilizer or organic fertilizer.

Fertilizers are organic or mineral substances, often used in mixtures, and intended to provide plants with additional nutrients, in order to improve their growth, and to increase the yield and quality of crops. The action of providing fertilizer is called fertilization. Fertilizers are part, with amendments, of fertilizing products, and more generally are part of consumable agricultural supplies. Fertilization is practiced in agriculture, horticulture, forestry and during gardening activities. Fertilizers have been used since Antiquity, where phosphates from bones, calcined or not, nitrogen from animal and human manure, potassium from ashes were added to the soil empirically. In fact, to carry out the process of their vegetative life, plants need water, nearly twenty nutrients that they find in mineral form in the soil, carbon dioxide (CO2) brought by the air, and solar energy necessary for chlorophyll synthesis.

There are three main types of fertilizers: organic fertilizers, mineral or chemical fertilizers, and organo-mineral fertilizers.

Organic fertilizers are generally of animal or plant origin, they come from living matter, but they can also be synthesized, such as urea. These are fertilizers derived from animal matter: animal and human excrement, industrial waste such as slaughterhouse waste (dried blood, roasted horn), fish waste, water treatment sludge and plant matter: green waste, composted or not, plants grown specifically as green fertilizer, or prepared for this purpose, such as nettle manure, or algae.

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Mineral fertilizers are fertilizers of mineral origin. They provide plants with essential nutrients in a directly assimilated form. Their use compensates for the loss of nutrients exported from farms in the organic matter of harvested products. They are substances of mineral origin, produced by the chemical industry, or by the exploitation of natural deposits of phosphate and potash. They can be simple, i.e. containing only one nutrient (nitrogen, phosphate or potassium), or compound, i.e. containing two or three nutrient elements.

As for organo-mineral fertilizers, they result from the mixture of mineral fertilizers and organic fertilizers. Nitrogenous organic materials generally represent 25 to 50% of the finished products. The other constituents of the fertilizer, simple and mineral salts, providing nitrogen, potassium and phosphorus in appropriate forms, are diluted in the organic materials.

Composting is a biological process of converting organic matter into a product similar to soil, rich in humic and mineral compounds called compost. It is an aerobic reaction. For example, it allows the recovery of livestock by-products, biomass or organic waste of household and/or industrial origin into a natural, stabilized and hygienic product. Composting is an operation during which organic waste is degraded under controlled conditions, in the presence of atmospheric oxygen and humidity (water), by the combined action of bacteria, fungi, microorganisms and macroorganisms. The product is transformed into nutrient-rich humus, which can be incorporated into the soil in order to enrich it.

The composting process consists of a series of several operations implemented following physicochemical parameters that last over time. The different stages implemented are:

- the mixture of the different constituents of the compost;

- the degradation phase also called fermentation, during which the mixture is aerated. This aeration can be done by turning the pile, or by means of static devices, for example aeration rails under the compost through which air is blown into

[3] mixing. This phase can last from 3 to 12 weeks, and sees the temperature of the pile increase rapidly then decrease gradually;

- the maturation phase, during which the compost is stored in piles, with little or no aeration;

- a screening stage: possibly located between fermentation and maturation, allows a fine fraction, the compost, to be separated from a coarse fraction called screening rejects, reintegrated at the start of composting.

The sources of organic components used for the preparation of organic fertilizers by composting are numerous and very varied. The oil palm sector involves processing plants that produce crude oil for consumption, as well as numerous solid and liquid discharges. This highly developed sector in Côte d'Ivoire generates each year approximately 500,000 tons of oils and a minimum of two million cubic meters of effluents, discharged into natural environments. This waste with a negative environmental footprint, not complying with discharge standards, gives rise to complaints from local populations due to the unsanitary conditions of natural waterways. Indeed, Côte d'Ivoire produces each year nearly 1.8 million tons of palm seed. This production makes it the second largest African producer of palm oil behind Nigeria, which produces nearly 2 million tons per year. The palm sector, which is crucial for the Ivorian economy, and in particular for its rural areas, is developing a value chain which provides a living, directly and indirectly, for some two million people.

On analysis, discharges from oil palm mills are both sources of organic matter and very significant economic losses. These discharges drain monthly nearly 655 tons of suspended solids (SS), consisting of minerals and fatty acids, a loss of oils and fats of 8.81 tons, or 2,642,100 FCFA of financial losses each month, for a price of 300,000 FCFA per ton of HPV, and 574 tons of organic matter. In short, the results indicate that the effluents in their current state do not comply with spreading standards, and therefore cannot be systematically used on the agronomic level. A formulation should be carried out

[4]

In order to make oil palm mill waste profitable, application PCT/CN2010/074157 entitled "Process for preparing organic fertilizer from empty palm oil fruit clusters", describes a process for preparing organic fertilizer from empty palm oil fruit clusters and liquid waste, comprising the following steps: shredding the empty fruit cluster into strips; sequentially adding additional substances: first mud or grass carbon soil, and then cellulose and urea fermentation bacteria, and spraying with water; composting the substances at a high temperature for fermentation; forming the substances into at least one of organic fertilizers, organic/inorganic compound fertilizers and bio-organic fertilizers. However, this process, which uses only two types of palm waste, has the disadvantage of incorporating some chemicals.

The aim of the present invention is to propose a type of organic fertilizer composed entirely of residues and waste from the oil palm industry.

In order to achieve the intended objective, the present invention is a fertilizer obtained by composting a mixture of at least two components of the oil palm and residues from the oil palm mill. The invention therefore consists of liquid effluents, settling sludge, stalks, palm leaves, oil palm ferns, spent palm seed pulp fibers and oil palm male inflorescences.

The invention is a solid product, granulated or not, intended to be used for the fertilization of cereal crops, fruits and citrus fruits, market garden products and agroforestry plants, in nurseries, as well as in the growth phase. Its use improves the structure of soils, increases the water and nutrient retention capacity in the soil, stimulates microbial activity and increases yield.

In one embodiment, the method of manufacturing the fertilizer according to the invention comprises the following unit operations:

- Step 1: harvesting and transporting plant raw materials: this step consists of harvesting the stalks, palm leaves, oil palm ferns, male inflorescences

[SJ of oil palm and collect the fibers of exhausted pulps of seed. All these components are then transported to the production area;

- Step 2: drying of the plant raw materials: all the leaves are dried to reach a humidity level of between 20 and 25%, suitable for the requirements of the grinder;

- Step 3: grinding of the plant raw materials: all the cut leaves are suitably ground separately to give powders with a particle size less than or equal to 2 mm in diameter in order to facilitate their homogeneity and their biochemical degradation;

- Step 4: formulation of the fertilizer: the different powders of plant raw materials are mixed with the oil palm effluents according to the following preferred proportions: 25 to 50% of palm plant powder; 50 to 75% of oil palm effluents, the mixture is then homogenized to give a raw fertilizer.

- Step 5: fermentation: the raw fertilizer, under agitation, is constantly soaked in effluent leaving the oil mill for at least five days. During this operation, the raw fertilizer powder is both moistened and enriched with other minerals and organic substances, while all the microflora and macroflora contained in the effluent decompose the organic substances it contains, to give a moist powder;

Step 6: Fertilizer maturation: This operation lasts on average 10 days. The previously obtained wet powder is stored to allow additional time for the microflora and macroflora it contains to continue to gently decompose its organic components and refine them to produce a less wet powder used as fertilizer;

- Step 7: Granulation: this step is optional and aims to transform the powdered fertilizer into granules in order to improve its conservation and use;

The fertilizer in accordance with the invention is used by spreading at rates which can vary from 7 to 40 t/ha depending on the type of crops grown.

Analyses of basic nutrients show that the fertilizer according to the invention complies with standard NFU 44-051 which sets limit contents for trace metal elements.

[6] (ETM), in organic trace compounds (OTC), in microorganisms and inert elements and impurities of organic fertilizers.

The fertilizer according to the invention has many advantages: it allows the recovery of all the by-products and waste from the oil palm, as well as most of the residues or cakes from the industrial processing of palm and palm kernel seeds. It also provides significant additional gains to operators of palm groves and oil palm mills.

The other characteristics and advantages of the invention will appear much more clearly on reading the detailed description which presents a non-limiting exemplary embodiment based on figure 1.

The non-limiting example of the fertilizer according to the invention is a semi-industrialized process which makes it possible to produce appreciable quantities of fertilizer. This process involves three components of the oil palm and extends over seven steps described as follows:

- Step 1: harvesting and transporting palm leaves and stalks: this operation consists of harvesting the stalks and palm leaves. In a preferred embodiment, the cutting of the palms is carried out in the plantations during pruning and fruit bunch harvesting activities. The products are then transported to the composting plant where they will be dried or not before being crushed.

In a preferred embodiment, the leaves are cut using scissors or poles and arranged in windrows. The collection and transfer of the leaves is done by harvesting equipment such as tricycles, then conveyed by trailers;

- Step 2: drying of the plant raw materials: the palm leaves and stalks are dried to reach a humidity level of between 20 and 25% suitable for the requirements of the crusher. In a preferred embodiment, the drying is carried out using a solar dryer in the form of a tray and with a sliding closure. The humidity level of the leaves is constantly monitored by taking samples;

- Step 3: grinding of the plant raw materials: the leaves and the cut stalks are suitably ground separately to give powders with a particle size of less than 2 mm in diameter. In one embodiment, this operation is carried out using an electric grinder type: 6J-180, with a production capacity of 100 kg/h;

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- Step 4: formulation of the fertilizer: the palm leaf and stalk powders previously obtained are put together, in a particular method, in equal parts, then homogenized to give a mixture of flours which constitutes the raw fertilizer;

- Step 5: fermentation: the raw fertilizer under agitation is constantly soaked in effluent leaving the oil mill for at least five days. During this operation, all the microflora and macroflora contained in these waters decompose the organic matter of the powder. During this time, the paste obtained is enriched with other minerals and organic substances contained in the water. In a preferred embodiment, the fermentation takes place in a cylinder-shaped reactor equipped with an agitator. The reactor is constantly supplied with raw fertilizer by a screw pump and with effluents by a vertical pump. The effluent flow rate is controlled by a system that incorporates a storage chamber where the effluents arrive from the oil mill via a swing gate and a non-return valve. The configuration of this system is such that the flow rate of the mixer exceeds the hourly discharge flow rate of the effluents. Thus, the flow rates of conveying the raw materials to the mixer are controlled in order to comply with the formulations. And the fertilizer being prepared is constantly discharged after its stay towards the maturation tank;

- Step 6: Fertilizer maturation: the raw fermented fertilizer is transported and stored in the maturation tank where it can stay for an average of 10 days. The microflora and macroflora already present continue to gently and deeply decompose the organic components. It is during this operation that biological activity is intense in order to obtain a compost of nutritional and mechanical quality that complies with the standard for amendments and supports;

- Step 7: Granulation: the fertilizer obtained is stored in bulk or granulated using a granulator. Granulating the fertilizer improves its conservation and use.

Claims (9)

1- Fertilizer or fortifier for plants, characterized in that said fortifier is a solid product, granulated or not, obtained by composting a mixture of powders of at least two components of the oil palm such as stalks, palm leaves, oil palm ferns, spent seed pulp fibers, male inflorescences, as well as oil mill residues including liquid effluents, settling sludge, and in that said fertilizer is intended to be used for fertilizing cereal crops, fruits and citrus fruits, market garden products as well as agroforestry plants, by improving soil structure, increasing the water and nutrient retention capacity in the soil, and stimulating microbial activity. 2- Fertilizer or plant fortifier according to claim 1, characterized in that the manufacturing process comprises: harvesting and transport, drying, grinding, formulation, fermentation, maturation and granulation. 3- Fertilizer or plant fortifier according to claim 2, characterized in that the harvest and transport consists of collecting and selecting the components such as the stalks, leaves, ferns, male inflorescences, fibers of exhausted pulp of oil palm seeds, and transporting them to the composting plant. 4- Fertilizer or plant fortifier according to claim 2, characterized in that the grinding consists of transforming, after drying, the different components into powders by reducing their size to a particle size less than or equal to 2 mm in order to facilitate their homogeneity and biochemical degradation. 5- Fertilizer or plant fortifier according to claim 2, characterized in that the formulation consists of mixing the powders and/or pastes obtained after grinding in preferential proportions containing: 25 to 50% of palm plant powder; 50 to 75% of palm effluents, and homogenizing the mixture to give a raw fertilizer. I [9] 6- Fertilizer or plant fortifier according to claim 2, characterized in that the fermentation consists of mixing, with stirring, the raw fertilizer with oil mill effluents for at least five days so that all the microflora and macroflora contained in these waters decompose the organic matter of the mixture of powders and enrich it with other minerals and organic substances contained in the water, to give a wet fertilizer. 7- Fertilizer or plant fortifier according to claim 2, characterized in that the maturation consists of storing the moist fertilizer for at least ten days in order to allow the microflora and macroflora which it already contains to refine the decomposition of the organic components. io 8- Fertilizer or plant fortifier, according to claim 2, characterized in that the granulation consists of transforming the fertilizer powder into grain to improve its conservation and use. 9- Fertilizer or plant fortifier, according to all the preceding claims, characterized in that the use of said fertilizer is done by spreading at rates which can vary from 15.7 to 40 t/ha depending on the type of crops grown.