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

Abstract

Different severities of hydrotreatment were performed on a raw decant oil and one of its subsequent hydrotreated decant oils. Six hydrotreated decant oils with different chemical composition were obtained during this process. The products obtained from the raw decant oil showed difficulty in sulfur removal. Higher desulfurization was obtained after repassing the first drum of product (EI-132) at a reduced feed rate (LHSV 0.5h −1 ), higher temperature (734°F and 750°F), and higher reactor pressure (8.3 MPa). Several analyses were performed to characterize the decant oils: elemental analysis, 1 H and 13 C NMR, asphaltene content, average boiling point, API gravity, GC/MS, and viscosity. Two structural parameters derived from the 1 H NMR spectra and elemental analyses were calculated: aromaticity (fa) and the fraction of aromatic edge carbons carrying substituents (σ). All the information gathered from the different techniques was helpful to understand the chemical transformations taking place during hydrotreatment of decant oils. It was observed that hydrogenation of aromatic rings and hydrodealkylation were the dominant reactions in the severely hydrotreated decant oils (EI-137 and EI-138) while the formation of alkyl side chains was observed in the low and intermediate hydrotreated decant oils, (EI-133 and EI-134) and (EI-135 and EI-136), respectively.

Separation of Toluene-Insoluble Solids in the Slurry Oil from a Residual Fluidized Catalytic Cracking Unit: Determination of the Solid Content and Sequential Selective Separation of Solid Components

“…The solid content in SLO evaluated in the form of sediment content by ASTM D4870 is greater than the content of toluene insolubles by ∼50%; sediment is found to be composed of toluene insolubles and heavy asphaltenes. However, heavy asphaltenes are probably soluble in SLO, which is usually highly aromatic with a limited content of saturates (Table ), although asphaltenes may be precipitated by adding or mixing with an aliphatic stream or molecular saturation of aromatics via hydroprocessing. − Terminologies, such as “soft coke” or sludge, are usually used for the sediment with a large portion of asphaltenes. Thus, ASTM D4870 can be used to estimate the existent and potential sludge formation of heavy oils .…”

Reactivity of sulfur compounds in FCC decant oils for hydrodesulfurization over CoMoS2/Al2O3 catalysts

“…FCC-DO is a highly aromatic product composed 70-90% of aromatics that also contains 0.5-3.5% sulfur, 0.1-0.3% nitrogen, and 1-3% asphaltenes [1][2][3]. Since FCC-DO has a moderate molecular size and high aromaticity, it is considered as a raw material for producing needle cokes [4][5][6][7]. Also, FCC-DO is used as a feedstock for mesophase pitch to produce a carbon fiber [8,9] and raw material for carbon black [10].…”

“…The S compounds in FCC-DO are critical factors in quality control as they can cause puffing in the thermal processes for the production of carbon materials [11,12]. The S compounds in FCC-DO are thus required to be removed to obtain premium carbon materials [6,13].…”

Molybdenum Carbide and Sulfide Nanoparticles as Selective Hydrotreating Catalysts for FCC Slurry Oil to Remove Olefins and Sulfur

“…The hydrotreating of various straight-run or cracking distillates (i.e., gasoline, diesel, and vacuum gas oil) and residues is extensively achieved using the transition metal sulfides supported on porous materials as catalysts [11][12][13][14][15]. Despite the pioneering research of SLO hydrotreating over alumina-supported Co-Mo or Ni-Mo catalysts that has been reported, their main concern was to remove the sulfur in SLO and thus control the sulfur levels in needle coke [16][17][18][19]. In contrast, detailed information on olefins removal of SLO through selective hydrotreating is extremely limited.…”