UPF: SYNTHESIS OF A PLANT OIL CLARIFYING SORBENT BASED ON LOCAL RAW MATERIALS

ABSTRACT

This article highlights that the demand for environmentally friendly food products is significantly increasing due to population growth. As a solution, the synthesis of highly effective sorbents for the production of ecologically clean vegetable oils based on local raw materials was studied.

One of the urgent tasks of chemistry and ecology is to develop a technology for obtaining sorbents with high sorption properties based on local raw materials for the production of high-quality cotton and sunflower oils. This technology aims to apply the obtained sorbents in bleaching, purification, and clarification processes, as well as to reduce the consumption of reagents that have a negative impact on the environment.

This article emphasizes that the demand for environmentally friendly food products is significantly increasing due to population growth. As a solution, the synthesis of highly effective sorbents for the production of ecologically clean vegetable oils based on local raw materials was studied. The objects of the research were urea, orthophosphoric acid, formalin, and Khovdak bentonite.

АННОТАЦИЯ

В этой статье подчеркивается, что спрос на экологически чистые продукты питания значительно возрастает из-за роста населения. В качестве решения был изучен синтез высокоэффективных сорбентов для производства экологически чистых растительных масел на основе местного сырья.

Разработка технологии получения сорбентов с высокими сорбционными свойствами на основе местного сырья для производства высококачественных хлопковых и подсолнечных масел и использование полученных сорбентов в процессах отбеливания, очистки, отстаивания, а также снижение расхода реагентов, оказывающих негативное воздействие на окружающую среду, является одной из актуальных задач химии и экологии.

В этой статье подчеркивается, что спрос на экологически чистые продукты питания значительно возрастает из-за роста населения. В качестве решения был изучен синтез высокоэффективных сорбентов для производства экологически чистых растительных масел на основе местного сырья. Объектами исследования являются карбамид, ортофосфорная кислота, формалин и Xовдакский бентонит.

Keywords: sorption, local raw materials, urea, orthophosphoric acid, formalin, UPF-1 (urea, phosphoric acid, formalin), Khovdak bentonite.

Ключевые слова: сорбция, местное сырье, мочевина, ортофосфорная кислота, формалин, MФФ-1 (мочевина, фосфорная кислота, формалин), ховдакский бентонит.

Introduction

As a result of global population growth, the demand for environmentally friendly food products is significantly increasing. The development of technology for obtaining sorbents with high sorption properties based on local raw materials to produce high-quality vegetable oils, the use of these sorbents in bleaching, purification, and clarification processes, as well as reducing the consumption of reagents that negatively impact the environment, is of crucial importance as one of the urgent tasks in chemistry and ecology.

Currently, worldwide research is being conducted on the development of technologies for obtaining purifiers with sorption properties and sorbents with a weakly acidic medium, suitable for improving the quality of vegetable oils, and the scientific basis for their application [2, pp. 27-30] [3, pp. 10-13] [4, p. 225]. In this regard, special attention is being paid to obtaining sorbents with stable sorption properties by activating specially composed clay powders with an acid solution, their application in the purification of vegetable oils, as well as enhancing the desorption properties of the bleaching agents used.

Several scientists have studied how composite materials prevent the leaching of mineral substances from agricultural soils and create favorable conditions for plant nutrition [5, pp. 75-78] [6, p. 314]. Additionally, research was conducted on testing synthesized polymer compositions for stabilizing mobile saline sands during the stabilization of shifting sands of the Aral Sea [7, p. 112]. The results of studying new complexes of calcium and magnesium salts and urea adduct in the soil were examined and analyzed.

Materials and methods

2.1. Reaction of urea with orthophosphoric acid and formalin

For the synthesis, 0.3 moles of urea were measured using analytical scales and melted in a fume hood using a heating furnace with a magnetic stirrer. 15.6 ml of orthophosphoric acid was added to the melted liquid urea and stirred intensively until foam formed. After complete foam formation, it was removed from the furnace and stirred continuously until cooled. Once cooled, this foam was poured onto paper and dried. After drying, 25.2 ml of formalin and urea adduct were placed into a beaker and melted using a magnetic heater. After the entire mass dissolved, a clear, viscous, thick solution formed. Without stopping the stirring, it was cooled and poured onto paper, then dried in a drying oven for 2 hours. The dried mixture was then ground in a porcelain mortar.

In the synthesis of an ion-treated composite material based on UPF-1 and Khovdak bentonite, a white mixture obtained from adduct urea and formalin was dried in a drying oven at a temperature of 110°C for 6 hours without forming a membrane. The resulting solid was ground in a porcelain mortar. Raw bentonite from a special quarry was ground to a uniform size in a porcelain mortar, both powdered substances were soaked in distilled water and mixed in a 2:1 ratio. Mixing was carried out manually in a porcelain mortar with a pestle for 30-40 minutes. The resulting mixture was dried under ultraviolet radiation at a temperature of 80°C for 3-6 hours.

The composite material, synthesized based on the reaction of urea with orthophosphoric acid and formalin, contains electron-donating atoms - oxygen, nitrogen, and phosphorus - capable of forming intramolecular compounds with calcium

(II). The synthesized polymers are granular, sparingly soluble in solvents, but soluble in certain amounts of water and ethanol. The obtained product underwent heat treatment. The thermal stability of the product was determined using differential thermal analysis.

To study the physicochemical, physical-mechanical, and sorption properties of the synthesized product, they were converted into the active OH+ form. It was found that the high-molecular-weight products of the urea adduct, synthesized with orthophosphoric acid, exhibit high-volume exchange and complex formation properties when converted to the OH+ form in an aqueous solution of sodium hydroxide.

2.2. Study of the structure and properties of the obtained product complexes

Complex compounds form more rapidly in a methyl alcohol medium compared to other solvents (ethanol, water). The obtained product complexes possess sufficient thermal stability.

IR spectroscopy was used to obtain information about the structure and properties of the obtained product complexes. The bond strength between the metal and various ligands was studied. In the IR spectrum of the urea adduct and ammonium phosphate polymer, absorption lines of C-H bonds were observed in the 1600 cm-1 region. In the complex compound of the urea adduct with ammonium phosphate and calcium (II) salt, the line at 1600 cm-1 shifts to the higher frequency region by 20-40 cm-1. The frequency of C=O valence vibrations increases due to the formation of the C=O → Me²⁺ bond.

Hence, it can be concluded that the complexing ability of the metal ion is determined by the magnitude of the shift in the characteristic absorption line of the

polymer ligand. The change in the vibration frequency of the C-H group indicates the formation of an H → Me bond, which involves p- and d-electron orbitals.

The exchangeability of the composite material and its exchange rate depend on the nature of all active groups identified in the polymer.

If, during an experiment or production process, exchange occurs only in the counterion part, then we are talking about the working capacity of the membrane. This value depends on the pH of the solution and the filtration rate through the polymer layer, the size of the polymer particles, ion-exchange columns, the concentration and temperature of the electrolyte, ion exchange, and the nature of the solvent.

2.3. Efficiency of composite material

When studying the effectiveness of the composite material in vegetative vessels, it was found that due to an increase in the concentration of washed salts, the electrical conductivity of water absorption increased by 4.18 g/l, and the dry residue (amount of washed salts) increased by 17.67 g/l (Figure 1). 1). 2).

Figure 1. Effect of the composite material on the degree of vegetable oil clarification

Figure 2. Effect of the composite material on the amount of vegetable oil clarification

The results are based on the arithmetic mean (n=3-4)

Figure 3. Effect of the composite material on the amount of chloride ions in vegetable oil clarification

Figure 4. Effect of the composite material on the composition of vegetable oil and the amount of sulfate ions

The results are based on the arithmetic mean (n=3-4).

The selective transfer of Cl- ions into the solution was 28.4% compared to the control and had a lesser effect compared to sulfate ions (Fig. 2, 3, 4).

Results and discussion

To obtain information about the structure and properties of the obtained product complexes, IR spectroscopy was used. The bond strength between the metal and various ligands was studied. In the IR spectra of the urea adduct and formalin polymer, absorption bands of C=O and C-H bonds were observed in the regions of 1600 cm−1 and 1400 cm−1, respectively. Figure 2.

Figure 5. IR spectrum of a membrane based on urea adduct and formalin

Figure 6. IR spectrum of the complex compound of a membrane based on urea adduct and formalin with a mercury (II) ion

From this, it follows that the complexing ability of the metal ion is determined by the magnitude of the shift in the characteristic absorption line of the polymer ligand. The change in the vibration frequency of the C-H group indicates the formation of an O → Me bond involving p- and d-electron orbitals.

The exchange capacity of the membrane and its exchange volume depend on the nature of all active groups identified in the membrane. If exchange occurs only in the counteragent during the experimental or production process, then we are referring to the working volume of the membrane. This value depends on the pH of the solution and the filtration rate through the membrane layer, the size of the membrane particles, ion exchange columns, the concentration and temperature of the electrolyte, ion exchange, and the nature of the solvent.

During the studies, when determining the static exchange volume (SEV), an aliquot of the filtrate was prepared after establishing equilibrium by adding an OH- form membrane to the neutral salt solution. The total exchange capacity can only be determined under static conditions. When a reagent solution is used in exchange, the counter-ions bound to the given membrane form a poorly dissociated compound, and this reaction proceeds to completion. Strong alkalis are used as reagents.

During the sorption process, the membranes were immersed in a 0.1 N NaOH solution for 2 days and converted to OH-form. After this, the membranes were cut into sections with a diameter of 10 mm and a length of 25 cm, and a 0.1 N solution of CuCl₂, HgSO₄, and PbSO₄ salts was passed through the membrane surface at a rate of 2 ml/min. As a result of the examination, it was established that the membrane was saturated with ions within 2 hours. For this, the following formula was used:

Here, CE is the amount of metal ion absorbed by a specific membrane, mmol/g;

C₀ and C_p are the concentrations of the metal ion solution before and after sorption, respectively, measured in mmol/dm³.

V is the volume of solution, ml; g is the membrane weight, grams.

As can be seen from the following table, the membranes have good exchange capacity. This sparks interest in studying the kinetic properties of these membranes. The sorption of 0.1 normal solutions of copper, mercury, and lead onto the membranes

was studied. The synthesized membranes effectively sorb transition metal ions. Based on the degree of sorption on the membrane, the studied ions can be arranged in the following order:

Cu²⁺> Hg²⁺>Pb²⁺

To determine the application areas of the synthesized membranes, the sorption properties of these polymers were studied in detail and compared with numerous ionomers.

The kinetics of copper ion sorption on the synthesized membrane was studied in its 0.1 N sulfate solution. For this, the change in copper sorption over time was determined. It was established that the membrane obtained from the urea- orthophosphoric acid adduct has a high sorption capacity for copper ions (Fig. 5).

Furthermore, the resulting membrane has the property of effectively sorbing many other metal ions. It also exhibits a selective effect on heavy organic compounds and some precious metals.

A new ion-carrying membrane was synthesized based on the adduct of urea- orthophosphoric acid. During the sorption process, the membranes were immersed in a 0.1 N NaOH solution for 2 days and converted to OH- form.

Figure 7. Dynamic exchange volume of Cu²⁺ ions per unit time

IR spectra of the ion-carrying membrane based on urea and formalin adduct were recorded in the range from 3502 cm-1 to 610 cm-1. Vibrations from 610 cm-1 to 720 cm-1 correspond to the C-O bond. From 720 cm-1 to 760 cm-1, (CH2) x group vibrations are recorded. The vibrations recorded at 1010-1065 cm-1 indicate that CH2 groups can form a cycle on the membrane. CH2 groups were detected in the range of 1410-1480 cm 1. Observation of the deformation plane vibration characteristic of secondary amines in the range of 1580-1640 cm-1 indicates the presence of the -NH- group. Valence vibrations at 3450-3600 cm-1 are also characteristic of primary amines, which also indicate the presence of an NH group in the membrane.

Table 1.

IR spectra of the UPF-1 membrane and the complexes formed by its sorption

In the synthesized complex compounds, the Cu-H bond was observed at 322 cm-1, the Cr-H bond at 422 cm-1, the Zn-H bond at 418 cm-1, the Ni-H bond at 408 cm-1, and the Co-H bond at 422 cm-1. This can also be observed in the decrease of the absorption band of the valence vibrations of the secondary amino group, appearing in the region of 3350 cm 1. It was noted that the absorption band of the amino group decreased to 3330 cm-1, chromium to 3261 cm-1, zinc complex to 3357 cm-1, nickel complex to 3346 cm-1, and cobalt to 3340 cm-1. In complexes with metal sulfate

sorption, absorption bands characteristic of the Me-O bond  was observed in the range of 457-482 cm-1 (Table 1, Fig. 6).

Analysis of the IR spectrum of the UPF-1 ion exchanger modified with Khovdak bentonite showed that new absorption spectra appear at 1298 cm-1 (R=O bond) and 2120 cm-1 (-OH bond R- (OH)). After coordination, it was observed that the absorption frequency of the R=O bond decreased by 8-26 cm-1, while the valence vibrations of -OH and secondary amino groups increased by 7-42 cm-1 and 23-115 cm-1, respectively. From this, it can be concluded that coordination occurs through the oxygen atom of the R=O bond (Table 2, Fig. 7).

Table 2.

IR spectra of UPF-1-B ionite and its complexes formed because of sorption

Figure 8. IR spectrum of Cu (II) ion absorbed by the ion exchanger

Figure 9. IR spectrum of Co (II) ion absorbed by the ion exchanger

As a result of the research, the yield and water consumption of the polymer- polymer complex and non-polymer complex mines were compared. The results are presented in the table below.

Conclusion

In conclusion, the clarification and purification of vegetable oils is one of the most crucial processes in the industrial production of this product. More specifically, this process is called adsorption purification. Its main purpose is to remove not only coloring agents, but also proteins and mucilaginous substances in the oil, as well as residues from alkaline refining. The term ‘adsorption processing of oils’ indicates that this process is carried out using sorbents. Sorbents are substances capable of absorbing impurities present during the preparation of oil for full consumption. After treatment with adsorbents, the oil appears brighter and under certain conditions can become almost colorless.

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