Comparativo das propriedades do carvão ativado oriundo da semente de uva e carvão ativado produzido a partir do bagaço na clarificação de vinho

Abstract

In Brazil, the Serra Gaúcha region is known for its great wine production. According to 2018 records from the Brazilian Wine Institute, 663.2 million kilograms of grapes were harvested in Brazil, in which the state of Rio Grande do Sul responsible for 90% of this harvest. From the grape destined for the manufacture of juices and wines, about 20% of the biomass made up of seeds, peels, and stalks are not incorporated in the final product. Consequently, a large amount of solid agro-industrial waste is generated. An alternative for the use of this residue, especially seeds and bagasse, which are materials rich in carbon, is the production of activated carbon, in addition to reducing the amount of waste to be treated and adequately packaged. Activated carbon can be reinserted on the production line or destined for other purposes. Activated coals are porous materials with a high surface area, which makes them excellent adsorbents, which have numerous applications ranging from common air filters to the removal of pollutants present in industrial effluents, and with a rapidly expanding market. Activated coals are often used as color and macroparticles removal agents. Thus, this work proposes a study for the production of activated carbon obtained from grape seeds or grape bagasse from the wine industry. Therefore, they can be used as clarifying/bleaching agents in wines. In this work, activated charcoals were prepared from grape seeds, and activated charcoals from bagasse, which comprises the husks and seeds. The effect of acidic chemical activation and basic chemical activation of precursor materials on the morphological characteristics of active carbons were evaluated. For this, a solution of H3PO4 7.7 mol L-1 was used as an acidic medium, in a 1:1 ratio. A KOH solution, in a 1:1 ratio (w/w) was used as a basic medium. The carbonization processes were carried out at a heating rate of 5 ºC / min from room temperature until the final temperature 500 ºC for 1 h, totaling 2.6 h of process, a total yield of 42% was obtained in the process pyrolysis. Some studies were analyzed in order to determine the properties of activated carbon, using the nitrogen adsorption and desorption methods, Scanning electron microscopy, and Infrared spectroscopy. Afterward, a comparison was made between studies using activated carbon for wine clarification, and to remove some toxins present in the bulk of the wine, keeping in mind that clarification can?t change the original properties, like flavor and odors, of the wine, and the activated carbon, should be able to endure multiple uses. [resumo fornecido pelo autor]