Documento


ESTUDO TEÓRICO DE ESTRUTURA, PROPRIEDADES E REATIVIDADE DE TRIGLICERÍDEOS E ÉSTERES DE ÁCIDOS GRAXOS ENVOLVIDOS NA PRODUÇÃO E COMPOSIÇÃO DO BIODIESEL

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The present work aims the study of structural and thermodynamic properties for process involving triglycerides (TG), fatty acid esters (EAG) and biodiesel through theoretical and chemometrical methodologies. The study of the transesterification reaction of triglycerides (TG) using cyclodextrin (CD) as a potential catalyst were also carried out. Initially, through a Box-Behnken 34 factorial design, the effects of the variables involved in molecular dynamics simulation (MD) of inclusion compounds formed between trilaurylglyceride (TLG 12:0) and α-CD were evaluated. The results lead to an appropriated MD heating protocol for the treatment of TG@n.CD systems with specific values for the variables involved in the process: time of heating (W), equilibrium time (E), time step of the dynamics (S) and dielectric constant of the medium (C). Starting from the best protocol, MD studies were developed contemplating inclusion complexes formed between TG models used the biodiesel synthesis trilaurylglyceride (TLG 12:0), tripentadecanoylglyceride (TPDG 15:0), trihexadecanoylglyceride (THDG 16:0), triestearylglyceride (TESG 18:0), trioleylglyceride (TOG 18:1), trilinoleylglyceride (TLLG 18:2) e trilinolenylgliceride TLNG 18:3) and native α-CD and modified cyclodextrin (α-CD-NH2). The results pointed out a correlation between the stability of the TG@1.α-CD inclusion compounds and size and saturation degree of the triglyceridic included chain. The catalytic potential of CD the transesterification reaction of TG was also investigated through geometry optimization and vibrational harmonic frequencies calculations via DFT. The results show thermodynamic evidences for such proposal using α-CD as catalyst. Besides, theoretical infrared and Raman spectra were determined for some TG and EAG species, looking for the elucidation of possible methods capable to contribute for the experimental analysis of biodiesel. Some interesting fingerprints were noticed in the spectrum of saturated and unsaturated species, allowing the characterization of complex mixtures obtained in the biodiesel production

ASSUNTO(S)

quimica triglicerídeos biodiesel ciclodextrina triglycerides biodiesel cyclodextrin




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