Virgin Heavy Gas Oil from Oil Sands Bitumen as FCC Feed

Abstract

This study deals with a systematic investigation of the fluid catalytic cracking (FCC) performance of a bitumen-derived virgin heavy gas oil (HGO) in the presence of its counterpart from bitumen-derived synthetic crude oil (SCO). The objective is to determine the amelioration effect on yield and product slate by the addition of the premium SCO HGO. The 343–525 °C cut virgin bitumen HGO was obtained from distillation of a raw Athabasca oil sands bitumen. It was then blended with different amounts of the 343 °C+ fraction of commercial SCO. Four HGO blends were prepared containing 75, 64, 61, and 48 v% of SCO HGO. Each HGO blend, as well as 100% SCO HGO, were catalytically cracked at 500 and 520 °C using a bench-scale Advanced Cracking Evaluation (ACE) unit. The results show acceptable FCC performance of bitumen virgin HGO when an adequate amount of SCO HGO is added. However, the resulting liquid product may need some quality improvement before use. Several observations, including catalyst poisoning by feed nitrogen and the refractory nature of virgin HGO, are evident and help to explain some observed cracking phenomena.

Catalytic Cracking of Diverse Vacuum Residue Hydrocracking Gas Oils

“…Over the years, laboratory fixed-bed, fluid-bed, and circulating-riser units have been used to evaluate the effect of feedstock quality on the FCC process performance [14][15][16][17][18][19][20][21][22][23][24][25]. Different characteristics of the studied feeds, employing distinct techniques for characterization, have been correlated with crackability or extent of conversion for a given set of operating conditions.…”

Empirical Models to Characterize the Structural and Physiochemical Properties of Vacuum Gas Oils with Different Saturate Contents

“…Table S6 from Supplementary material shows a comparison between measured and predicted aromatic carbon content by the empirical correlations of Dhulesia [25] and Choudhary (COP) [21], Figure 1c, Equations ( 32) and (33). These data show that the average absolute deviation increases in the order: (Equation (32); AD = 2.1 wt.%) < (Equation (33); AD = 2.8 wt.%) < (Figure 1c; AD = 3.1 wt.%) < (COP, Equation (23); AD = 3.4 wt.%) < (Dhulesia; Equation (15); AD = 7.5 wt.%). The most accurate is the prediction of VGO C A content from the information on the hydrogen content, the molecular weight and Equation ( 32), followed by information on the density and T 50% and Equation (33).…”

“…A total of 74 vacuum gas oils characterized by HPLC-MS, NMR, SARA analysis and density, refractive index, aromatic carbon content, hydrogen content, molecular weight as reported in [2][3][4]15,[33][34][35][36][37][38][39][40] were used in this study (Table S1 from Supplementary material). The empirical models evaluated in this research are summarized below: The n-d-M method was originally developed by Van Nes and van Westen [41] and relates the structural group composition determined by the use of NMR in terms of the contents of paraffinic, naphthenic and aromatic carbon to three oil physical properties: refractive index, density and molecular weight.…”

“…The performance of these processes has been shown in many studies to strongly depend on the quality of the feedstock [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The vacuum gas oil fraction from petroleum is the typical feed for the FCC [2,3,[5][6][7][8][9][10][11][12][13][14][15][16][17] and it has been explored as a feedstock for steam cracking as well [4]. Considering that in Resources 2021, 10, 71 2 of 20 both FCC and thermal cracking the reactivity of the vacuum gas oils increases with the saturate content enhancement and aromatic carbon content reduction, the information about these vacuum gas oil characteristics is of paramount importance for optimizing their performance [17].…”

“…The yield of the least valuable product from the VGO conversion processes-the unconverted VGO (bottoms) product-is defined by the content of heavy aromatics because it is difficult to crack [7,29]. Considering that the conversion level and the yields of valuable products from the VGO conversion processes depend on the contents of the saturates, aromatic carbon and heavy aromatics we investigated the properties of 74 VGOs published in the open literature [2][3][4]15,[30][31][32][33][34][35][36][37][38][39][40]. The studied VGOs had been characterized by HPLC-MS (high-performance liquid chromatography-mass spectrometry), NMR (nuclear magnetic resonance), SARA (saturates, aromatics, resins, asphaltenes) analysis and the typical physicochemical properties like density, distillation, refractive index, etc.…”