Selective ring opening of decalin for LCO upgrading: a complex reaction system from a single model-molecule

National @ ECI2D+LDF:NCY:LPI:DLA:CGEInternational audienceLight Cycle Oil (LCO) from Fluid Catalytic Cracking (FCC) is becoming an important source for gas oil production, although deep hydrotreatment steps are needed to face its poor ignition properties. While hydrogenation of poly-aromatics is insufficient to significantly increase the cetane number of the LCO mixture, the conversion of these hydrocarbons into linear alkanes (2-ROPs) and alkyl-cycloalkanes/alkyl-benzenes (1-ROPs) through selective ring opening (SRO) is highly desirable, leading also to an improvement of the fuel cold-flow properties and a decrease of soot formation. SRO consists in reducing the number of rings while retaining the carbon number of the starting molecules. Besides SRO, competing parallel and consecutive reactions such as hydrogenation/dehydrogenation, cracking, and skeletal isomerization (Sk-Iso) affect the final fuel composition and quality. This complex reaction network makes difficult the complexity of the analytical investigation of the process, even when model molecules (such as decalin or tetralin) are involved. As an example, more than 350 C10 molecules were detected by conventional gas chromatography (GC) downstream a decalin hydroconversion test, with very short retention time differences between GC peaks [1]. The present study investigates the separation and identification of the products in such complex reaction mixtures by means of several GC techniques, including two-dimensional GC-MS (Figure 1). While these analytical aspects are often neglected in the literature [2], this work points out the added value of accurate chemical compound identification, as a crucial step to gain insight into the reaction mechanism. In turn, this provides important information on the nature of the relevant catalytic functions in bifunctional systems. In the present case study of SRO on conventional transition metal sulfides (NiW supported on amorphous silica-alumina), the acidic or hydrogenolytic nature of the process (i.e., involving acidic or metallic catalytic sites) is investigated by evaluating the nature of ring opening products.1] S. Rabl, , PhD thesis, University of Stuttgart, 2011[2] L. Piccolo, S. Nassreddine, G. Toussaint, C. Geantet, J. Chromatogr. A 1217 (2010) 5872

decalin ring-opening over niws/sio2-al2o3 catalysts in the presence of h2s

SSCI-VIDE+ECI2D+NCY:LPI:DLA:CGEInternational audienceSelective ring opening (SRO) is an attractive route for promoting cetane index of LCO feeds in order to get high quality diesel fuel. High performing noble metal based catalysts have been proposed for this purpose; however, considering the possibility of performing SRO in the hydrotreating units, thio-resistant catalysts for SRO would be more adapted. In the present study, we investigated the performance in decalin conversion of bifunctional NiW sulfide catalysts deposited on silica alumina. Impact of acidity by modulating Si/Al content or promoting by P or F was studied, as well as the improvement of the hydrogenation/hydrogenolysis function by the use of chelating agents (citric acid). The analytical investigation performed in this work relied on comprehensive two-dimensional GC-MS. A 3D view of a typical GCxGC chromatogram obtained from the analysis of liquid samples collected is shown in Figure 1. A careful separation of obtained product families disclosed important information on hydrogenolysis or hydrogenation characters of catalytic sites in the complex reaction network involved

Selective ring opening of decalin for LCO upgrading: a complex reaction system from a single model-molecule

National @ ECI2D+LDF:NCY:LPI:DLA:CGEInternational audienceLight Cycle Oil (LCO) from Fluid Catalytic Cracking (FCC) is becoming an important source for gas oil production, although deep hydrotreatment steps are needed to face its poor ignition properties. While hydrogenation of poly-aromatics is insufficient to significantly increase the cetane number of the LCO mixture, the conversion of these hydrocarbons into linear alkanes (2-ROPs) and alkyl-cycloalkanes/alkyl-benzenes (1-ROPs) through selective ring opening (SRO) is highly desirable, leading also to an improvement of the fuel cold-flow properties and a decrease of soot formation. SRO consists in reducing the number of rings while retaining the carbon number of the starting molecules. Besides SRO, competing parallel and consecutive reactions such as hydrogenation/dehydrogenation, cracking, and skeletal isomerization (Sk-Iso) affect the final fuel composition and quality. This complex reaction network makes difficult the complexity of the analytical investigation of the process, even when model molecules (such as decalin or tetralin) are involved. As an example, more than 350 C10 molecules were detected by conventional gas chromatography (GC) downstream a decalin hydroconversion test, with very short retention time differences between GC peaks [1]. The present study investigates the separation and identification of the products in such complex reaction mixtures by means of several GC techniques, including two-dimensional GC-MS (Figure 1). While these analytical aspects are often neglected in the literature [2], this work points out the added value of accurate chemical compound identification, as a crucial step to gain insight into the reaction mechanism. In turn, this provides important information on the nature of the relevant catalytic functions in bifunctional systems. In the present case study of SRO on conventional transition metal sulfides (NiW supported on amorphous silica-alumina), the acidic or hydrogenolytic nature of the process (i.e., involving acidic or metallic catalytic sites) is investigated by evaluating the nature of ring opening products.1] S. Rabl, , PhD thesis, University of Stuttgart, 2011[2] L. Piccolo, S. Nassreddine, G. Toussaint, C. Geantet, J. Chromatogr. A 1217 (2010) 5872

Selective ring opening of decalin over bifunctional MxSy/zeolite catalysts

RMN+ECI2D+CGE:DLA:LPI:CLOInternational audienceSulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we performed the screening of MxSy supported on HY zeolite in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8% H2S concentration. Catalytic bifunctionality was investigated by changing the nature of the Transition Metal Sulfide ( TMS = Re, Ru, Rh, Ir, Cr, V and Ni sulfides were investigated). The addition of platinum group sulfides ( Re, Rh, Ir) and RuS2 improve 10 times the catalytic activity of HY zeolite alone, decreased coke deposition and dehydrogenation and increased selectivity towards RO products. For non platinum metals Cr, and V sulfides were less active but Ni sulfide present interesting properties. The reactions lead to several products families, the dominant ones being skeletal-isomerization products (SkIPs) and ring-opening products (ROPs- 1 or 2 rings opening) with a small contribution of 2ROPs. GCGC technique can unambiguously discriminate between all these C10 SkIPs and ROP products [ ]. Whatever the TMS used, the mechanism mainly proceeds from skeletal isomerization induced by the acidity of the zeolite but the hydrogen activation properties of platinum based metal sulfides are beneficial to the activity and stability of the catalyst

Selective ring opening of decalin over bifunctional MxSy/zeolite catalysts

RMN+ECI2D+CGE:DLA:LPI:CLOInternational audienceSulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we performed the screening of MxSy supported on HY zeolite in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8% H2S concentration. Catalytic bifunctionality was investigated by changing the nature of the Transition Metal Sulfide ( TMS = Re, Ru, Rh, Ir, Cr, V and Ni sulfides were investigated). The addition of platinum group sulfides ( Re, Rh, Ir) and RuS2 improve 10 times the catalytic activity of HY zeolite alone, decreased coke deposition and dehydrogenation and increased selectivity towards RO products. For non platinum metals Cr, and V sulfides were less active but Ni sulfide present interesting properties. The reactions lead to several products families, the dominant ones being skeletal-isomerization products (SkIPs) and ring-opening products (ROPs- 1 or 2 rings opening) with a small contribution of 2ROPs. GCGC technique can unambiguously discriminate between all these C10 SkIPs and ROP products [ ]. Whatever the TMS used, the mechanism mainly proceeds from skeletal isomerization induced by the acidity of the zeolite but the hydrogen activation properties of platinum based metal sulfides are beneficial to the activity and stability of the catalyst

Transition metal sulfides on zeolite catalysts for selective ring opening

International audienceBifunctional catalysis combining acidic catalysts and sulfide active phases is usually related to hydrocracking catalysts which balances the hydrogenation function of a NiMo (NiW) alumina supported sulfide catalysts and the acidic function of a zeolite. The discovery of sulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we studied the properties of various transition metal sulfides (TMS) supported on Y zeolite in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8% H2S concentration. This screening shows high activities for noble metal based sulfides with a mechanism which proceeds by skeletal isomerization induced by the zeolite. Catalytic activity was improved by the use of ternary sulfides such as Ni1-xRuxS2 or NiRh2S4 on Y zeolites. High decalin conversion levels can be reached below 250°C with more of 20% of ring opening products and thanks to the use of comprehensive GC, a detailed mechanism of the SRO of decalin is given

Selective ring opening of decalin over bifunctional MSx/zeolite catalysts

MICROSCOPIE:RMN+ECI2D+DLA:LPI:FSI:CLO:CGEInternational audienceNon

Selective ring opening of decalin over bifunctional MSx/zeolite catalysts

MICROSCOPIE:RMN+ECI2D+DLA:LPI:FSI:CLO:CGEInternational audienceNon

Selective ring opening of decalin over bifunctional RuS2/zeolite catalysts

RMN+ECI2D+LPI:DLA:CLO:CGEInternational audienceThe discovery of sulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we studied the properties of RuS2 supported on several zeolites in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8% H2S concentration. Catalytic bifunctionality was investigated by changing the Ru loading or support acidity. The addition of RuS2 strongly improved catalytic activity of an HY zeolite, decreased coke deposition and dehydrogenation and increased selectivity towards RO products. The mechanism mainly proceeds from skeletal isomerization induced by the acidity of the zeolite but the hydrogen activation properties of RuS2 are beneficial to the activity and stability of the catalyst