Maraisa Gonçalves

APROVEITAMENTO DE RESÍDUO DE BIODIESEL PARA PREPARAÇÃO DE CARVÕES ÁCIDOS COM ELEVADA ATIVIDADE CATALÍTICA NA REAÇÃO DE ETERIFICAÇÃO DO GLICEROL

UTILIZATION OF BIODIESEL WASTE FOR ACID CARBON PREPARATION WITH HIGH CATALYST ACTIVITY IN THE GLYCEROL ETHERIFICATION REACTION. Environmentally friendly acid carbon (CG) catalysts, containing a high amount of sulfonated and oxygenated groups, were prepared from glycerin, a biodiesel waste. CGs were produced by glycerin carbonization in the presence of H2SO4 at 1:3 m:m ratio in a closed autoclave at 180°C for different times: 0.25; 1; 3 and 6 hours (CG-0.25h; CG-1h; CG-3h and CG-6h, respectively). The catalyst properties for all carbons were evaluated in the glycerol etherification reaction with tert-butyl alcohol (TBA). The yield for mono-tert-butyl glycerol (MTBG), di-tert-butyl glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG) was high and very similar for all CGs, of about 43% and 20% for the MTBG and DTBG + TTBG, respectively. Furthermore, the activity of these catalysts were close to those obtained using a commercial resin, Amberlyst-15, of about 50% and 27% for MTBG and DTBG + TTBG, respectively.Environmentally friendly acid carbon (CG) catalysts, containing a high amount of sulfonated and oxygenated groups, were prepared from glycerin, a biodiesel waste. CGs were produced by glycerin carbonization in the presence of H2SO4 at 1:3 m:m ratio in a closed autoclave at 180oC for different times: 0.25; 1; 3 and 6 hours (CG-0.25h; CG-1h; CG-3h and CG-6h, respectively). The catalyst properties for all carbons were evaluated in the glycerol etherification reaction with tert-butyl alcohol (TBA). The yield for mono-tert-butyl glycerol (MTBG), di-tert-butyl glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG) was high and very similar for all CGs, of about 43% and 20% for the MTBG and DTBG + TTBG, respectively. Furthermore, the activity of these catalysts were close to those obtained using a commercial resin, Amberlyst-15, of about 50% and 27% for MTBG and DTBG + TTBG, respectively.

UTILIZATION OF BIODIESEL WASTE FOR ACID CARBON PREPARATION WITH HIGH CATALYST ACTIVITY IN THE GLYCEROL ETHERIFICATION REACTION

UTILIZATION OF BIODIESEL WASTE FOR ACID CARBON PREPARATION WITH HIGH CATALYST ACTIVITY IN THE GLYCEROL ETHERIFICATION REACTION. Environmentally friendly acid carbon (CG) catalysts, containing a high amount of sulfonated and oxygenated groups, were prepared from glycerin, a biodiesel waste. CGs were produced by glycerin carbonization in the presence of H2SO4 at 1:3 m:m ratio in a closed autoclave at 180°C for different times: 0.25; 1; 3 and 6 hours (CG-0.25h; CG-1h; CG-3h and CG-6h, respectively). The catalyst properties for all carbons were evaluated in the glycerol etherification reaction with tert-butyl alcohol (TBA). The yield for mono-tert-butyl glycerol (MTBG), di-tert-butyl glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG) was high and very similar for all CGs, of about 43% and 20% for the MTBG and DTBG + TTBG, respectively. Furthermore, the activity of these catalysts were close to those obtained using a commercial resin, Amberlyst-15, of about 50% and 27% for MTBG and DTBG + TTBG, respectively.Environmentally friendly acid carbon (CG) catalysts, containing a high amount of sulfonated and oxygenated groups, were prepared from glycerin, a biodiesel waste. CGs were produced by glycerin carbonization in the presence of H2SO4 at 1:3 m:m ratio in a closed autoclave at 180oC for different times: 0.25; 1; 3 and 6 hours (CG-0.25h; CG-1h; CG-3h and CG-6h, respectively). The catalyst properties for all carbons were evaluated in the glycerol etherification reaction with tert-butyl alcohol (TBA). The yield for mono-tert-butyl glycerol (MTBG), di-tert-butyl glycerol (DTBG) and tri-tert-butyl-glycerol (TTBG) was high and very similar for all CGs, of about 43% and 20% for the MTBG and DTBG + TTBG, respectively. Furthermore, the activity of these catalysts were close to those obtained using a commercial resin, Amberlyst-15, of about 50% and 27% for MTBG and DTBG + TTBG, respectively.

A Parametrization Approach for 3D Modeling of an Innovative Abduction Brace for Treatment of Developmental Hip Dysplasia

Developmental hip dysplasia (DHD) is frequently encountered in the pediatric orthopedic practice. DHD is characterized by dislocation of the femoral head in the acetabulum. In Brazil are diagnosed three times more cases than the world average (5–8 cases for 1,000 births). The lack of treatment leads to long-term morbidity, abnormal gait, chronic pain and arthritis. Early detection and treatment with a Pavlik harness results in improved outcomes. After 6 months of age, closed or open reduction with spica casting is required for 4 months to treat a persistent hip dislocation. Plaster is used for orthopedic immobilization due the low cost, moldability and good mechanical resistance. However, there are several risks and complications due to the use of spica cast in DHD treatment: Skin problems due to lack of adequate hygiene (itching, ulceration, dermatitis and infection), formation of pressure areas, plaster fracture (11% of cases) and fever. Digitization techniques have been explored for production of customized hip abduction brace by additive manufacturing. However, it is not possible to keep a child standing still to perform 3D scanning of the hip and legs region. The goal of this research was to develop an alternative approach for acquisition of the external geometry of the infant to create 3D model of an abduction brace. The parameterization technique created includes: The creation of a virtual 3D model of a child’s body using the MakeHuman software; Articulation of the hip region of the model to the position required in the treatment of DHD with the Blender software; Definition of the parameters required for the modeling of a hip abduction brace. A DHD pediatric orthopaedist approved the methodology created. Innovations in the area of assitive technology can bring many benefits to the user in the process of rehabilitation.

Mesoporous activated carbon from polyethyleneterephthalate (PET) waste: pollutant adsorption in aqueous solution

Mesoporous activated carbons (ACs) of high surface area were prepared from low cost and highly available powdered PET waste (generated during PET bottle recycling). Different chemical activating agents were employed. ZnCl2 produced an AC of 700 m2 g−1, containing mainly small mesopores (≈2 nm), whereas activation with K2CO3 produced carbons with larger mesopores (≈4 nm) and high BET surface area (up to ≈1400 m2 g−1). The investigation of the weight impregnation ratio of K2CO3/PET waste (1/1, 0.5/1 and 0.25/1) revealed that 1/1 generates the largest amount of mesopores (83%) besides high BET surface area (1210 m2 g−1). These ACs were used as adsorbents for the methylene blue (MB) and victoria blue B (VB) dyes in order to evaluate the potential adsorption of organic contaminants of different molecular sizes from water. The MB adsorption was mainly dependent on the ACs’ surface area, regardless of their pore size. The ACK 0.5/1 presented the highest MB adsorption capacity (625 mg g−1), considerably higher than that of a commercial AC (303 mg g−1). On the other hand, the highest adsorption amount of the bulky pollutant VB was obtained for the ACK 1/1 (323 mg g−1), possibly due to its higher mesoporosity and the presence of large mesopores of ≈4 nm size. These findings demonstrate the potential application of PET waste to produce value added products, such as activated carbons, for adsorption of organic contaminants from water, including relatively large pollutants.

SELECTIVE HYDROGENOLYSIS OF GLYCEROL TO PROPYLENE GLYCOL IN A CONTINUOUS FLOW TRICKLE BED REACTOR USING COPPER CHROMITE AND Cu/Al2O3 CATALYSTS

Fil: Sepulveda, Jorge. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Investigaciones en Catalisis y Petroquimica ; Argentina