BR-102024018082-A2 - Catalysts based on clay minerals modified with niobium oxide and/or copper oxide, their production process and use for optimized degradation of vegetable oils.

BR102024018082A2BR 102024018082 A2BR102024018082 A2BR 102024018082A2BR-102024018082-A2

Abstract

This invention describes an innovative composition, production methodology, and applications of a material based on mineral clay modified with niobium oxide and/or copper oxide. Using vermiculite as a support, the process involves the impregnation of these oxides, taking advantage of the layered structure of vermiculite which offers advantages such as the presence of exchangeable cations and expansion capacity, allowing promising modifications to develop new materials with the addition of various chemical species. In this context, niobium oxide and copper oxide were impregnated to create a material with structural characteristics and acidic properties suitable for degrading vegetable oils, generating a product rich in oleic acid (47%) and palmitic acid (20%). These acids are of great interest in various industries, such as food, cosmetics, and chemicals, playing an essential role due to their beneficial properties and wide applications. It is used in the production of edible oils, margarines, bakery products, cosmetics, and also has applications in the manufacture of detergents, lubricants, fungal inhibitors, biofuels, and various chemical products.

Inventors

MARCIO RODRIGO OLIVEIRA DE SOUZA
ANA PAULA DE MELO ALVES GUEDES
AMANDA DUARTE GONDIN
ARUZZA MABEL DE MORAIS ARAÚJO
TATIANA RITA DE LIMA NASCIMENTO

Assignees

UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE
UNIVERSIDADE FEDERAL DA PARAÍBA

Dates

Publication Date: 20260317
Application Date: 20240902

Claims (8)

1. “Process for producing catalysts based on clay minerals modified with Niobium Oxide” characterized by containing the following steps: 1st step - acid treatment of natural vermiculite (V0), where the clay mineral is activated by mineral acids (0.01 g to 0.2 g of clay per mL of acid at concentrations of 1 mol.L-1 to 2.5 mol.L-1) under heating from 70 °C to 90 °C, with constant stirring for 2 to 4 hours; 2nd step - 2 g to 3 g of acidic vermiculite are impregnated with niobic acid using its precursor salt NH^NbO^O^^O^^O at a concentration of 0.01 mol.L-1 to 0.005 mol.L-1 in 100 mL; Step 3 - NaOH is slowly added at a rate of 0.5 mol.L-1 to 1 mol.L-1 until the solution reaches pH 7.0; Step 4 - The material is then placed in an oven at a temperature of 65 °C to 70 °C for 72 hours and then dried at a temperature of 65 °C to 70 °C for another 24 hours; Step 5 - The solid is washed and dried in an oven at a temperature of 45 °C to 50 °C for 24 hours; Step 6 - Calcination of the solid obtained in the previous step at a temperature of 300 °C to 650 °C.
2. “Process for producing catalysts based on clay minerals modified with Niobium Oxide and Copper Oxide” characterized by containing the following steps: 1st step - acid treatment of natural vermiculite (V0), where the clay mineral is activated by mineral acids (0.01 g to 0.2 g of clay per mL of acid at concentrations of 1 mol.L-1 to 2.5 mol.L-1) under heating from 70 °C to 90 °C, with constant stirring for 2 to 4 hours; 2nd step - 2 g to 3 g of acidic vermiculite are impregnated with niobic acid using its precursor salt NH4NbO(C2θ4)2(H2θ)?3H2θ at a concentration of 0.01 mol.L-1 to 0.005 mol.L-1 in 100 mL to 150 mL; Step 3 - 0.5 mol.L-1 to 1 mol.L-1 NaOH is slowly added until the solution reaches pH 7.0; Step 4 - The material is then placed in an oven at a temperature of 65 °C to 70 °C for 72 hours and then dried at a temperature of 65 °C to 70 °C for another 24 hours; Step 5 - 1 g to 2 g of the material resulting from the previous step is mixed with 100 mL to 150 mL of 0.01 to 0.005 mol.L-1 copper nitrate trihydrate and stirred at 150 rpm for 24 hours at room temperature; Step 6 - The solid is washed and dried in an oven at a temperature of 45 °C to 50 °C for 24 hours; Step 7 - Calcination of the solid obtained in the previous step at a temperature of 300 °C to 650 °C.
3. “Process”, according to claims 1 and 2, characterized by the fact that the catalysts are produced with low-cost (vermiculite) and highly abundant (niobium) materials, exhibiting a yield of 75% and a cost of R$ 3 to R$ 5 for the production of 1 g.
4. “Use of catalysts based on clay minerals modified with Niobium Oxide obtained according to the process described in claim 1” characterized by favoring processes in which the optimized degradation of vegetable oils is observed, due to the fact that the composites obtained confer thermal stability to the fatty acids.
5. “Use of catalysts based on clay minerals modified with Niobium Oxide and Copper Oxide obtained according to the process described in claim 2” characterized by favoring processes in which the optimized degradation of vegetable oils is observed, due to the fact that the composites obtained confer thermal stability to the fatty acids.
6. "Use of catalysts", according to claims 1 to 5, characterized by the fact that they act with the action of efficient catalytic compounds, providing the formation of selected acidic compounds from the oleic and palmitic acid families.
7. “Clay mineral-based catalysts modified with niobium oxide for optimized degradation processes of vegetable oils obtained according to the process described in claim 1” characterized by the fact that niobium acquires a stable structure with oxygen, thus increasing its catalytic activity.
8. “Clay mineral-based catalysts modified with niobium oxide and copper oxide for optimized degradation processes of vegetable oils obtained according to the process described in claim 2”, characterized by the fact that copper acquires redox properties and provides active sites, thus increasing the catalytic activity in the degradation of vegetable oils.

Description

Field of invention [001] The present invention consists of a new catalytic material, its production process and its use for the degradation of vegetable oils. The degradation of oil by pyrolysis using these catalysts produces oleic acid and palmitic acid as the main byproducts, which are quite important for the chemical, petrochemical, cosmetic and food industries. [002] The new catalytic material presented in this invention has a capacity for degrading vegetable oils comparable to synthetic materials, with the advantage of being derived from an abundant source in Brazilian territory. The process for obtaining this catalytic material requires a short preparation time and low cost, and it can be used or produced for catalytic applications where the objective is to obtain materials with high thermal stability. Fundamentals of the invention [003] Brazil has the world's largest reserves of vermiculite, whose natural form is widely used in various applications. These include: raw materials for ceramics, the manufacture of explosives, the production of plastics, highly plastic paints, the creation of semi-precious stones, and the manufacture of fireproof pipes. [004] Vermiculite is a clay mineral with hydrated lamellar structures, composed of varying amounts of magnesium, aluminum, and iron. Its hardness can range from 2.1 to 2.8 on the Mohs scale and it has a specific gravity of 2.5 g/cm3. The name "vermiculite" is related to its unique characteristic of expanding when heated to high temperatures, where its particles move in a worm-like manner due to the evaporation of water vapor present in the interlayer spaces. [005] The chemical structural formula of vermiculite, known in the literature, can be represented as X4(Y2-3)Ow(OH^M.nH2O. In this formula, M represents exchangeable cations (Mg2+, Ca2+, Ba2+, Na+, K+) located in the interlayer space, which compensate for the negative charge of the layer. Y refers to octahedral cations such as Mg2+, Fe2+, Fe3+, Al3+, while X corresponds to tetrahedral cations such as Si or Al. Therefore, the value of X can vary from 0 to 5 depending on the origin of the mineral. The lamellar crystal structure is formed by the unit cell of the 2:1 group clay minerals, composed of an octahedral sheet MgO2(OH)4 symmetrically coupled between two tetrahedral silicon sheets. [006] Vermiculite clay stands out for its versatility and abundance in the country. Brazil holds 14% of the world's reserves, concentrated mainly in five states. [007] In the context of national production, niobium oxide was chosen to modify vermiculite due to the rich availability of this element in Brazilian territory. Brazil is the world's largest producer of niobium, holding more than 90% of the known reserves of this element on the planet. [008] Niobium oxide is widely used in various scientific and technological applications due to its properties, such as high thermal stability, acidity, and selectivity. [009] Niobium oxides and their compounds are widely used in catalysis, performing functions as promoters, supports, redox materials and acid catalysts. Materials containing niobium have demonstrated effectiveness as catalysts in various processes, including alcohol dehydration, hydrolysis, oxidation, esterification, photocatalysis, among others. [0010] Niobium oxide can act as a catalyst in oxidation and degradation reactions of complex molecules present in vegetable oils, promoting the breaking of ester bonds and other components and facilitating their transformation into simpler products. Niobium acquires a stable structure when combined with oxygen, which increases its catalytic activity. Furthermore, due to its high thermal stability, niobium oxide is advantageous in processes involving high temperatures, such as the degradation of vegetable oils. According to the literature, niobium oxide can also offer selectivity in certain reactions, contributing to directing the desired end products of vegetable oil degradation, such as fatty acids and other useful compounds. [0011] Modification with copper oxide occurs due to its catalytic and redox properties. As an active phase in catalysts, copper oxide provides active sites that favor oxidation processes, which can promote the breakdown of complex molecules into smaller components, such as fatty acids and other simple compounds, in vegetable oils. In addition, copper oxide can facilitate esterification and transesterification reactions, which are fundamental in the transformation of vegetable oils into biofuels and byproducts useful for the chemical industry. [0012] Therefore, the use of copper oxide not only accelerates the degradation of vegetable oils, but also increases the efficiency and selectivity of the catalytic processes involved, making it a viable choice in applications related to sustainability and biofuel production. [0013] In view of the foregoing, the catalyst of this invention represents a promising approach to solving the challenges of instability in