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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item The Physical and Chemical Properties of Activated Nanocarbon produced from Robusta (Coffea Canephora) Coffee Pulp under slow pyrolysis method(Universidade Federal de Lavras, 2023-01-09) Nurmalita, Nurmalita; Raihan, Raudhatul; Jalil, Zulkarnain; Nur, Syahrun; Setiawan, AdiThis study examines the physical and chemical properties of nano-activated carbon obtained from Robusta coffee pulp. It also examines the potential use of Robusta coffee pulp biomass as a raw material for hydrogen storage. In this investigation, the dried coffee pulp samples were carbonized using the slow pyrolysis method at temperatures of 400°C and 500°C. A biochar product was obtained and activated using NaOH and ZnCl2 solutions. The analysis results Fourier Transform Infra-Red (FTIR) suggested that both carbonization and activation processes with NaOH or ZnCl2 solutions were unable to removed the caffeine content in coffee pulp. The Differential Calorimetric Analysis/Thermogravimetric Analysis (DSC/TGA) indicated that coffee pulp carbonization reached optimality within the temperature range of 400 to 500°C. Furthermore, the Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS) and N2-adsorption isothermal analysis showed that the surface pores of activated carbon had a honeycomb-like structure with a size greater than 0.7 nm which is applicable for hydrogen storage material.Item Improvement of soluble coffee aroma using an integrated process of supercritical CO2 extraction with selective removal of the pungent volatiles by adsorption on activates carbon(Brazilian Society of Chemical Engineering, 2006-01-18) Lucas, S.; Cocero, M. J.In this paper a two-step integrated process consisting of CO2 supercritical extraction of volatile coffee compounds (the most valuable) from roasted and milled coffee, and a subsequent step of selective removal of pungent volatiles by adsorption on activated carbon is presented. Some experiments were carried out with key compounds from roasted coffee aroma in order to study the adsorption step: ethyl acetate as a desirable compound and furfural as a pungent component. Operational parameters such as adsorption pressure and temperature and CO2 flowrate were optimized. Experiments were conducted at adsorption pressures of 12-17 MPa, adsorption temperatures of 35-50ºC and a solvent flow rate of 3-5 kg/h. In all cases, the solute concentration and the activated particle size were kept constant. Results show that low pressures (12 MPa), low temperatures (35ºC) and low CO2 flowrates (3 kg/h) are suitable for removing the undesirable pungent and smell components (e.g. furfural) and retaining the desirable aroma compounds (e.g. ethyl acetate). The later operation with real roasted coffee has corroborated the previous results obtained with the key compounds.Item Produção e caracterização de carvão ativado produzido a partir do defeito preto, verde, ardido (PVA) do café(Sociedade Brasileira de Química, 2009) Ramos, Paulize H.; Guerreiro, Mário C.; Resende, Eliane C. de; Gonçalves, MaraísaThe black, green and sour coffee defect (PVA) contributes with 20% of the total coffee production. It should be separate from the normal coffee grains in order to improve the final quality of the beverage. In this way, the present work has the objective to use the PVA reject for the production of activated carbon. The activated carbon (CA) was prepared from PVA defect using zinc chloride as activating agent. The prepared material (CA PVA) was characterized and the adsorption tests were carried out using as organic models methylene blue (AM) and reactive red (VR). The CA PVA revealed to be more efficient in the removal of the organic contaminants compared to a commercial activated carbon.Item Preparação de carvão ativado em baixas temperaturas de carbonização a partir de rejeitos de café: utilização de FeCl3 como agente ativante(Sociedade Brasileira de Química, 2008) Pereira, Elaine; Oliveira, Luiz C. A.; Vallone, Andréa; Sapag, Karim; Pereira, MárcioFerric chloride as a new activating agent was used to obtain activated carbons from agroindustrial waste. This material was prepared at three temperatures of pyrolysis, 200, 280 and 400 ºC. The carbonaceous materials obtained after the activation processes showed high specific surface areas (BET), with values higher than 900 m² g-1. The materials showed different behaviors in the adsorption of methylene blue dye and reactive red textile dye in water solutions. An important fact in the use of FeCl3 as an activating agent is that the activation temperature is at 280 ºC, well below of those commonly employed in chemical or physical activations described in the literature.Item Preparação e caracterização de carvão ativado produzido a partir de resíduos do beneficiamento do café(Sociedade Brasileira de Química, 2008) Brum, Sarah Silva; Bianchi, Maria Lucia; Silva, Vanésia Liane da; Gonçalves, Maraísa; Guerreiro, Mário César; Oliveira, Luiz Carlos Alves deCoffee fruit processing is one of the most polluting activities in agriculture due to the large amount of waste generated in the process. In this work, coffee parchment was employed as precursor for the production of carbons activated with ZnCl2 (CAP). The material was characterized using N2 adsorption/desorption at 77 K, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The material showed a surface area of 521.6 m²g-1 and microporous structure. CAP was applied as adsorbent for the removal of methylene blue dye in aqueous medium. The adsorption capacity was found to be about 188.7 mg g-1.