Poli (líquidos iônicos) celulósicos aplicados como catalisadores heterogêneos para transformação química do CO2 em carbonatos cíclicos

• Autor(a) principal: Rodrigues, Daniela Maffi
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/8367
• topic: Utilização de CO2; Poli(líquidos Iônicos); Celulose; Carbonatos Cíclicos; Carbon Capture and Utilisation(CCU); Poly(Ionic Liquid)s; Cellulose; Cyclic Carbonates; ENGENHARIAS

Carbon capture and storage (CCS) and carbon capture and utilisation(CCU) technologies has been pointed out as possibilities to mitigate the effects caused by the massiverelease of CO2 into the atmosphere. The use of CO2 in cycloaddition reactions toepoxides obtaining cyclic carbonates is an interesting possibility to reduce CO2emission. Cyclic carbonates are products of great applicability as solvents in the chemical industry and are used as raw material for a wide range of products. Meanwhile, the use of CO2 for a cycloaddition reaction requires a large amount of energy being necessary the use of catalysts in order to optimize such reactions. Poly (ionic liquids) (PIL) are alternative catalysts due its selective, recyclability and conversion. In this work, cellulosic poly(ionic liquids) (CPIL) obtained from rice husk were testedas heterogeneous catalyst. Cellulose extraction was carried out by chemical method. A chemical modification of the cellulose fibers was carried out by the treatment with citric acid and functionalization with 3 mmol of the ionic liquids BMIM Cl, TBAB, TBPB and BMPYRR to form CPIL-BMIM, CPIL-TBA, CPIL-TBP and CPIL-BMPYRR), without addition of solvents. Cyclo addition reactions were carried out with propylene and styrene oxides with different CO2 pressures(25, 30 and 40 bar) and temperatures (90, 110 and 120 °C) for 6 h. The obtained product was characterized by gas chromatography (GC), Fourier Transform Infrared Spectroscopy(FTIR)and Nuclear Magnetic Resonance (1H NMR). The results showed better yields for CPIL-TBP and CPIL-TBA, whose values were 53.2% and 39% respectively for propylene carbonate and 67.3% for styrene carbonate using CPIL-TBP. When the ZnBr2 cocatalyst was used, there was an increase in the catalytic activity of these catalysts. For CPIL-TBP the yields were 71.4% for propylene carbonate and 78.7% for styrene carbonate. For CPIL-TBA the increase in propylene carbonate yield was 67.7%.