NMR and FTIR characterization of petroleum residues: structural parameters and correlations

Abstract

Resíduos pesados de petróleo podem ser usados como matéria-prima na produção de diversos materiais de carbono, como piches, isotrópicos e anisotrópicos, e diferentes tipos de coque. A caracterização química destes resíduos, e de materiais de carbono em geral, é um desafio que deve ser abordado para que se possa otimizar adequadamente estes processos de produção. Neste trabalho, resíduos de petróleo de diferentes refinarias foram analisados por RMN, FTIR e análise elementar. Parâmetros de análise foram otimizados para a técnica de RMN e espectroscopia no infravermelho por refletância difusa, uma técnica geralmente aplicada a materiais sólidos, mas que gerou espectros de boa qualidade para estas amostras. Correlações foram encontradas entre os índices de aromaticidade por RMN e FTIR, um parâmetro largamente usado no estudo da formação da mesofase, bem como entre a razão C/H e o índice de aromaticidade. Outros parâmetros estruturais de interesse também foram determinados.Heavy petroleum residues can be used as raw materials in the production of various carbon products, notably isotropic and anisotropic pitches and different types of coke. The chemical characterization of these residues, and carbon materials in general, is a challenge that has to be addressed in order to allow the adequate optimization of production processes. In this study, petroleum residues of different refineries were studied by NMR, FTIR and elemental analysis. Optimum parameters were determined for NMR analysis and diffuse reflectance spectroscopy (DRIFTS), a technique that is usually applied to solid materials but was shown to yield good quality spectra for these samples. Correlations were found between NMR and FTIR results for the aromaticity index, a structural parameter widely used in the study of mesophase formation in pitches, as well as between C/H ratios and the aromaticity index. Other structural parameters of interest were also obtained.

Characterization of Hydrotreated Decant Oils. Effect of Different Severities of Hydrotreating on Decant Oil Chemical Composition

“…One work combined nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and elemental analysis results to determine structural parameters of a decant oil sample. 6 Linear correlations between the aromatic indexes obtained from NMR and FTIR as well as between this parameter with the C/H ratios obtained from elemental analysis were found. 6 In this study, an untreated decant oil and six hydrotreated samples were characterized by elemental analysis, 1 H and 13 C NMR, asphaltene content, average boiling point, API gravity, gas chromatography/mass spectrometry (GC/MS), and viscosity.…”

Emprego de subprodutos da produção de piches de petróleo na síntese de nanoesferas de carbono

“…representar a faixa de propriedades tipicamente encontradas para este material, sendo caracterizadas por picnometria, espectroscopia de infravermelho e ressonância magnética nuclear [8] , extrografia [9] e análise elementar. Os condensados foram vaporizados e alimentados em um forno tubular vertical mantido a 1200 °C, a uma taxa de 15 mL/h.…”

Karakteristik Beberapa Jenis Antibiotik Berdasarkan Pola Difraksi Sinar-X (XRD) Dan Spektrum FTIR

“…Teknik spektrometri infrared digunakan untuk penentuan struktur senyawa-senyawa organik. Teknik ini biasanya digabung dengan teknik Nuclear Magnetic resonance (NMR), Spektrometer massa, bahkan digabung dengan XRD (11).…”

“…Perkembangan teknik sampling pada spektroskopi infrared saat ini dan dilengkapinya FTIR dengan Attenuated Total Reflectance (ATR) maka pengukuran spektrum infrared dari berbagai sampel dapat dilakukan secara lebih mudah.Teknik FTIR sudah berhasil digunakan untuk menentukan residu petrolium (11), spesifikasi karbon organik di dalam tanah (12), komposisi keju (13), struktur protein (14), dan identifikasi bakteri (15). Berbagai studi telah menunjukkan bahwa spektroskopi FTIR dapat memberikan informasi karakteristik struktural suatu senyawa organik makromolekul.…”