Characterization of the functional chemical structure of sulphur in polyaromatic compounds from heavy petroleum fractions

PETR 34

Roberto Rodrigues Coelho, coelho@cetem.gov.br1, Ian Hovell, hovell@cetem.gov.br1, Andre Lopes de Souza2, and Krishnaswamy Rajagopal, raja@eq.ufrj.br3. (1) Centro de Tecnologia Mineral – CETEM, Avenida Ipê, Nº 900, Cidade Universitária, CEP 21941-590 Rio de Janeiro, Brazil, (2) LATCA -Laboratório de Termodinâmica e Cinética Aplicada - Escola de Química, Universidade Federal do Rio de Janeiro, C.P. 68452, DEQ/EQ/UFRJ, Cidade Universitária, CEP 21949 900. Rio de Janeiro, Brazil, (3) LATCA - Laboratório de Termodinâmica e Cinética Aplicada - Escola de Química, Universidade Federal do Rio de Janeiro, C.P. 68452, DEQ/EQ/UFRJ, Cidade Universitária, CEP 21949 900. Rio de Janeiro, Brazil
The study of sulphur and its functionality in polyaromatic heteroatoms from heavy crude oil and petroleum fractions with emphasis on the structure of the average molecule is relevant because of its economical and environmental impact. A methodology is proposed for the characterization of: thiophene, benzothiophene, dibenzothiophene, thioetheres and cyclic sulphides, which are most resistant to hydrotreatment and desulphurisation processes. Theoretical IR spectra of organic sulphur compounds were obtained by quantum mechanical ab-initio Hartree-Fock calculations, identifying the frequencies corresponding to the vibrational transition of the C-S bond. The relationship between deconvoluted experimental and theoretical IR spectra was obtained. Using theoretical IR and experimental DRIFTS spectra of asphaltenes from a Brazilian vacuum residue, the organic sulphide component of an average molecule was studied. The functionality of sulphur in this polyaromatic compound was identified as being of a tetrahydro thioxanthene type. The support from CNPq , CNPq/CTPETRO and CENPES/PETROBRAS is acknowledged.
 

2nd International Symposium on Hydrotreating/Hydrocracking Technologies
8:30 AM-11:50 AM, Monday, 11 September 2006 Palace -- Presidio Room, Oral

Division of Petroleum Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006