abstract
Understanding the value of refinery by-products is crucial for assessing their potential in bitumen production. To achieve this task, the asphaltic residue, vacuum residue, and three different aromatic extracts obtained as by-products in the refining process of base oils have been characterized using various methods, including standard methods for bitumen grading (penetration, softening point, Fraass breaking point, and ageing stability), SARA analysis, proton nuclear magnetic resonance spectroscopy (1H NMR), and high-performance gel permeation chromatography (HP-GPC). Additionally, the penetration index and three significant colloidal indices based on SARA fractions have been calculated. The results show that the by-products possess distinct properties and chemical compositions. The most striking fact is that the asphaltic residue lacks saturates, while the three aromatic extracts lack asphaltenes. Due to different processing conditions, the two solvent-neutral (SN) type extracts were found to be similar, though distinct from the bright stock (BS) extract, which had a higher content of saturates and a lower content of aromatics. The comprehensive characterization of these by-products (residues and extracts) is essential for understanding their structure and planning their valorization in oil refineries, for example in the production of bitumens with specific properties. When combined with statistical and phenomenological modeling, the systematic analytical procedure presented here is useful for guiding the repurposing of oil refinery by-products.
keywords
CHEMICAL-COMPOSITION; RESIDUES; ASPHALTENES; SPECTROSCOPY; FRACTIONS; CHEMISTRY; NMR
subject category
Chemistry; Energy & Fuels; Engineering
authors
Varanda, C; Almeida, MP; Portugal, I; Ribeiro, J; Silva, CM; Silva, AMS
our authors
Projects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
This work was carried out within the framework of a number of projects: CICECO-Aveiro Institute of Materials UIDB/50011/2020 (https://doi.org/10.54499/UIDB/50011/2020), UIDP/50011/2020 (https://doi. org/10.54499/UIDP/50011/2020), and LA/P/0006/2020 (https://doi.org/10.54499/LA/P/0006/2020); LAQV- REQUIMTE UIDB/50006/2020 (https://doi.org/10.54499/UIDB/50006/2020); LEPABE UIDB/00511/2020 (https://doi.org/10.54499/UIDB/00511/2020) and UIDP/00511/2020 (https://doi.org/10.54499/UIDP/00511/2020); ALiCE LA/P/0045/2020 (https://doi.org/10.54499/LA/P/0045/2020), financed by national funds via the FCT/MCTES (PIDDAC) and by the Portuguese National NMR Network (RNRMN). M.P.A. thanks the support of "H2 2-Driven Green Agenda", no. C644923817-00000037, investment project no. 50, financed by the Recovery and Resilience Plan (PRR) and the European Union - Next Generation EU.

