LCO Upgrading via Distillation and Hydroprocessing Technology

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LCO upgrading via distillation & hydroprocessing technology Vasiliki Dagoniku, Stella Bezergianni, and Dimitrios Karonis Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.8b04024 • Publication Date (Web): 10 Jan 2019 Downloaded from http://pubs.acs.org on January 13, 2019

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LCO upgrading via distillation & hydroprocessing technology Vasiliki Dagonikou a, b, Stella Bezergianni a*, Dimitrios Karonis b a Chemical Process and Energy Resources Institute – CPERI, Centre for Research and Technology Hellas – CERTH, 6th km Harilaou-Thermis GR-57001, Thermi, Thessaloniki, Greece b National Technical University of Athens, Zografou Campus, 9, Iroon Polytechniou str, 15780 Zografou, Athens, Greece KEYWORDS Light Cycle Oil, distillation, light cut, hydroprocessing

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ABSTRACT

Light cycle oil (LCO) has been proven by previous studies that is almost impossible to attain automotive diesel fuel specifications by hydroprocessing. In this study, in order to overcome the inhibitory properties of LCO such as high refractory sulfur species content and high aromatic content, a distillation of LCO up to 350 °C was realized with the objective of isolating the heavy sulfur species and polyaromatic compounds which are difficult to be removed via hydroprocessing. Considering the boiling point of refractory heavy sulfur species, it is expected that these sulfur species which are difficult to be hydrodesulfurized, will be isolated within the heavy LCO fraction (350+). Moreover, it is expected that some additional properties like density, aromatic content and cetane number will be improved after distillation. The light cut (350-), LCO_cut, improved in content of inhibitory compounds, was used as feed in a hydroprocessing unit in order to get a final product that could approach diesel quality. The results show that hydrotreatment of LCO_cut leads to further enhanced liquid products in comparison with the corresponding liquid product of pure LCO hydroprocessing. Especially, in high temperature (380 °C) the sulfur content, the poly-aromatic content and the density of the final product reaches 21 mg/kg, 3% and 0.8900 g/ml respectively, while all the other properties are under the limits as regards the automotive diesel fuel specifications.


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INTRODUCTION The increasing demand of diesel fuel instigates the scientific community to investigate innovative methods and new feedstocks in order to cover the current diesel demand. The light cycle oil (LCO), the main by-product of the FCC units, could be a potential diesel substitute as its boiling range is between 180-360 °C (diesel range)(1). However, its high sulfur and aromatics content, its high density and low cetane number inhibit the direct usage of LCO as a diesel fuel(1). So far, due its low quality and value, LCO is used as low-grade fuel additive or is blended to heating oils and residual fuel oil as viscosity cutter(2), (3), (4). Until now, several researchers have made efforts to improve LCO quality and meet the current stringent diesel fuel specifications via hydroprocessing, a widespread technology applied in refineries for upgrading fossil fuels ranging from light petroleum naphtha to vacuum gas oils and residue(5), (6). Although hydroprocessing is an effective technology for middle petroleum fractions upgrading, in the case of LCO this technology is not adequate to lead to a useful product(7). Despite the fact that the total sulfur content of LCO is lower than the sulfur content of conventional straight run gasoil (SRGO), deep hydrodesulfurization (HDS) of LCO cannot be achieved yet. The main reason for this is that sulfur compounds in LCO are present in the alkyl derivatives of dibenzothiophene, especially dimethyldibenzothiophene (C2-DBT). These compounds are poor in HDS reactivity and are classified as the most refractory compounds in conventional HDS process as they cause steric hindrance(2), (8), (9). Reactivity of the alkyldibenzothiophenes decreases in the presence of inhibitors like polyaromatics and nitrogen compounds, normally found in the LCO feed(9). Respectively, the presence of high aromatic content adversely affects the HDS of refractory sulfur species contained in LCO(7), because the aromatic species as well as refractory sulfur species compete for the hydrogenation active sites


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on the catalyst. Since aromatic species are present in significantly larger quantities, they overwhelm the sulfur species at the hydrogenation sites(7). Moreover, during the hydrogenation of LCO a large amount of heat is generated due to the very exothermic aromatic saturation reactions and a large amount of hydrogen is consumed, thus the stand alone implementation of this process is not in practice(10). For all the aforementioned reasons, the co-hydroprocessing of LCO with petroleum fractions improves LCO quality but is not an efficient and adequate technology to produce a product which meets diesel specifications. In this study in order to overcome these inhibitory properties, a distillation of LCO was conducted up to 350 °C with the intention of hydrotreating only the light LCO fraction which is rich in mid-distillate molecules. The light cut of LCO (350-), LCO_cut, free from refractory sulfur species and high poly-aromatic content and with improved density, is expected to further attain diesel specifications via hydroprocesing. EXPERIMENTAL SECTION Methodology As mentioned above the main target of this study is to upgrade LCO quality combining distillation and hydroprossesing technologies. The LCO used in this study is provided by a Greek refinery and was produced from a FCC unit using as feedstock VGO which has already been hydrotreated in a mild hydrocracker. The fact that the heavy sulfur compounds remained in LCO, constitutes possibly the most refractory factor of LCO upgrading via hydro processing. In order to characterize the type of sulfur compounds, the determination of sulfur compounds analysis was performed in the Centre for Research and Technology Hellas (CERTH). According to the identification results of sulfur compounds (Table 1), the highest sulfur percentage corresponds to


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LCO cut (350+) reaching almost 50% of the total sulfur content of LCO. This is expected as it is known that the heaviest sulfur compounds, which are present in LCO, lie in heavy fractions due to their high molecular weight. Moreover, the boiling point of heavy sulfur compounds such as dibenzothiophenes (DiBzTh) with substituents and tribenzothiophenes (TriBzTh) with substituents is up to 350 °C according to Table 1. It is worth also noting that the content of substituted DiBzTh, the removal of which is a particularly difficult process, reaches 35% of the total sulfur content in LCO(9), (11), (12). Table 1. Sulfur species distribution in LCO Based on the above findings, the 350°C cut-point of LCO was selected as a threshold, separating the light LCO cut (350-) for further catalytic hydrotreatment. Considering Table 1, it is estimated that the light LCO cut (350-) will be free from most of the heavy sulfur species, which though are difficult to remove solely via a hydrotreatment process. These refractory sulfur species remain in the heavier fraction/residue (350+) after distillation. Apart from heavy sulfur species removal, it is expected that other properties like density and aromatic content will also be separated from the light LCO cut (350-) after distillation. For all the aforementioned reasons, the temperature of 350 °C for LCO fractionation was chosen. LCO Distillation The LCO distillation up to 350 °C took place in a batch distillation unit of the Chemical Process & Energy Resources Institute (CPERI) of the Centre for Research and Technology Hellas (CERTH). This batch distillation unit operates under vacuum at 10 mbar pressure and has a capacity of 40 l, while it is fully automated. The diagram of the distillation unit is shown in Scheme 1. The distillation yield corresponds to about 80% of light LCO cut and 20% of heavy


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LCO cut. In particular, in this study the distillation of 22 l LCO yielded 18 l of light fraction (350-) and 4 l of heavy residue (350+). Scheme 1. Flow diagram of CPERI/CERTH vacuum distillation unit Hydroprocessing of light LCO_cut Following the distillation of LCO, the light LCO cut was led to a hydroprocessing unit in order that the quality of the final liquids products of light LCO_cut is evaluated and compared with the corresponding ones of final liquids products of total LCO, produced in previous studies. The hydroprocessing experiments took place in the small-scale hydroprocessing pilot plant VB01 of CPERI/CERTH. VB01 consists of a feed system, a reactor system, and a product separator system, as is schematically depicted in Scheme 2. The feed system includes a heated liquid-feed tank and gas-feed section, through which the high-pressure hydrogen is introduced at the required flow-rates. The reactor system consists of a single fixed-bed reactor with six independent heating zones and six thermocouples spread evenly along the reactor length, sustaining the desired temperature profile within the reactor. The reactor product passes through the product separation system, where it is first cooled via a cooling zone and then flashed via a high-pressure low temperature separator (HPLT). Scheme 2. Simplified schematic diagram of CPERI/CERTH hydroprocessing plant In total, three experiments of distilled LCO hydroprocessing were conducted under three different temperatures (340 °C, 360 °C and 380 °C) keeping the other operating parameters constant: P= 1200psig, LHSV= 1hr-1, H2/oil= 500nl/l (P, LHSV, H2 /oil) were kept constant, while a commercial NiMo/γ-Al3O2 catalyst was used, as it is proven that NiMo-type catalysts


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have higher activity in HDS of LCO than CoMo(13). The reason that these operating conditions have been chosen is that they are in the range of typical operating conditions of HDT diesel and are according to previous studies that LCO hydrotreating was tested(3) (5) (7). The quality of the final liquid products was compared with the corresponding ones produced from pure LCO hydroprocessing. In order to evaluate the quality of the final liquid products, all necessary analyses were performed in the Laboratory of Fuels Technology and Lubricants of the School of Chemical Engineering of the National Technical University of Athens. More specifically, the density of the total liquid product was measured via an Anton-Paar density/ concentration meter DMA 4500 according to EN ISO 12185. The sulfur content of the feed and liquid products was determined with the EN ISO 20846 while the derived cetane number (DCN) was measured by EN 16144 test method. Also, the distillation curve was determined according to the EN ISO 3405 method and the aromatics content was measured by the liquid chromatography method based on EN 12916. Finally, hydrogen was measured by the Oxford Instruments NMR MQA 7020 method and the gas product quality was analyzed via the UOP 539 method. RESULTS AND DISCUSSION In order to examine the effect of LCO distillation in the quality of the final liquid product of hydroprocessing, the comparison between the hydroprocessing of whole LCO with the hydroprocessing of light LCO cut is realized. The main properties of LCO feed and of hydroprocessed LCO products of the three temperatures were examined in previous study. Table 2 depicts the comparison between the main properties of the two feeds (whole LCO and light


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LCO cut). The properties from the hydroprocessing of the LCO and the LCO_cut at the three temperatures are given in Table 3 and Table 4 respectively. Table 2. Properties of LCO and light LCO_cut feeds Table 3. Properties of LCO products Table 4. Properties of light LCO_cut products Sulfur Content As it was expected the distillation fraction of LCO up to 350 °C reduced the total sulfur content of LCO feed about 38% as the sulfur content was reduced from 4900 mg/kg to 3031 mg/kg. It is worth mentioning that there is a divergence between the theoretical estimate of sulfur content and the actual one. Especially, according to the theoretical estimate the expected sulfur content would be 1680mg/kg and the real sulfur content is 3031 mg/kg. This can be attributed to the error method of sulfur species identification and to the fact that the separation via distillation is never perfect. Considering the hydrodesulfurized products, the distillation of LCO feed led to an extra reduction of about 20-37% at the sulfur content of final liquid products in comparison to the corresponding ones of the whole LCO in all the temperatures tested. The most intense improvement in HDS was observed at the high temperature of 380 °C where the sulfur content of the final liquid product decreased at 21 mg/kg, an encouraging value which almost reaches the automotive diesel fuel specification (10 mg/kg). Respectively, the sulfur content of the final liquid product of the whole LCO hydroprocessing was 110 mg/kg at the high temperature. All these results constitute the proof of the primary estimation that the refractory heavy sulfur species were removed via distillation and so the HDS efficiency is much higher.


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Figure 1. Comparison of HDS of LCO with HDS of LCO_cut In order to evaluate the effect of feedstock properties on the HDS effectiveness, a kinetic analysis of the HDS reactions takes place. In general, kinetic studies can be approached in two ways: intrinsically or apparently.(14) In this initial approach, kinetic parameters that are determined are apparent rate constant and reaction order using the models of previous studies. As it is known, according to Arrhenius law, the reaction order is the tool for activation energy estimation by plotting the inverse of absolute temperature against the logarithm of apparent kinetic constant (1/T vs ln kap). The most interesting of this analysis is that the two parameters (reaction order and the activation energy) are calculated using experimental data(14), (15) (16).As the two feedstock types used (LCO and LCO_cut) in this study have different sulfur content; 4900 mg/kg and 3031 mg/kg respectively, this kinetic approach is attractive. For estimation reaction order and apparent kinetic constant, the following equation is used;

 1  n)kap   Sp    S 1f n   LHSV 

1/1 n

Equation 1

where Sp and Sf are the total concentrations of sulfur in product and feed, respectively, kap and n are the apparent rate constant and reaction order, respectively, and LHSV is the liquid hourly space-velocity(15). Based on some assumptions according to previous studies and on data depicted in Table 3 and Table 4, the reaction order is calculated for the intermediate temperature (360 °C) and an indicative value of a rate constant is considered. Similarly, if we consider a constant reaction


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order value for the two feedstocks, for instance 1.65 as many researchers do, we can evaluate the apparent kinetic constants and by extension the activation energy(15). In Table 5, the reaction order and the activation energy of HDS reactions are depicted and its values are in the agreement of those reported in the literature(14) (15)(16). In the case of LCO_cut feedstock, reaction order is lower (1.6) than the corresponding one of LCO feedstock (1.9). This tendency is confirmed by literature data and is attributed to the fact that the LCO feedstock has high sulfur content and high content of sulfur refractory compounds. So, in general the increase in reaction order depends on the origin of feedstock. On the contrary, this trend is not observed at activation energy so it is concluded that there is no a linear relationship between sulfur content in the feed and activation energy. The activation energy of LCO_cut is higher than the corresponding one of LCO. This phenomenon can be attributed to changes in the (assumed) reaction mechanism or interference of physical phenomenon such as diffusion(17). Table 5. Reaction order and activation energy of HDS at 360 °C of LCO and LCO_cut feedstocks Density Concerning the density value, the distillation of LCO feed improved about 1.3% the density value of LCO_cut feedstock. An improved value of products is also observed in the case of Light LCO_cut as feedstock. The most intense improvement is observed at the high temperature where the density value was reduced about 7.5% in comparison with the density value of the LCO feedstock. Although a certain density decrease observed in all products of LCO_cut, none of the density values of products reached the diesel specification (0.820-0.845 g/ml)(18).


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Figure 2. Comparison of density of LCO HDS products with LCO_cut HDS products Aromatic Content Firstly, it is worth noting that the polyaromatic content of LCO_cut feed is about 4% reduced in comparison with the corresponding one of LCO feed. Concerning the comparison between liquid products, an intense reduction of the polyaromatic compounds content is noticed in LCO_cut products. Especially, at the intermediate (360 °C) and the high temperature (380 °C), all the liquid LCO_cut products meet diesel specification, while at the low temperature (340 °C) the polyaromatic content of the LCO_cut product approaches almost the upper limit of 8% m/m(19). Generally, it is known that the hydrodearomatization reaction is favored at high temperatures(20). Finally, it is shown that distilled products present a lower aromatic content. This can be attributed to the fact that the heavy sulfur compounds existed in LCO feed limited the effectiveness of hydrodearomatization reactions(21). Figure 3. Comparison of aromatic content of LCO HDS products with LCO_cut HDS products Cetane Number As it is known the cetane number relies on aromatic content and its values are inversely proportional(22), (23). In view of this, it is expected that as the aromatic content of distillated feed and products decreased (Figure 3), the cetane number of the corresponding ones will increase. This is confirmed by Figure 4, where the derived cetane number of LCO_cut products increased up to 4 units in comparison to the LCO products. The trend between the two properties (aromatic content and cetane number) is the same while increasing the temperature (Figure 3 and Figure 4). At high temperature, the distillation of LCO feed led to liquid product with derived cetane


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number value of 30.5, so an increase of 10 % is observed in comparison with the corresponding liquid product of pure LCO hydroprocessing. Nevertheless, considering that the minimum cetane number requirement in Europe is 51, none of the products meet this specification(18). Figure 4. Comparison of cetane number of LCO HDS products with LCO_cut HDS products Distillation According to the diesel specification for distillation range, the boiling point of 95% of the final liquid product has to be up to 360 °C. The yield of all the liquid products was estimated as the percentage (vol.%) that has the above boiling point. According to Figure 5, the yield of all the final liquid products reaches 100%. So, it is concluded that the distillation of LCO feed not only improves the main properties of liquid products but it also doesn’t influence the distillation yield of LCO and LCO_cut products. Figure 5. Comparison of distillation curve of LCO HDS products with LCO_cut HDS products Mixing ratio of liquid products with diesel After gathering and evaluating all the above results, it is worth estimating the percentage of liquid product which could be added to diesel pool aiming the sulfur diesel fuel specification (10%) to be satisfied. This approach aims to prove that although a part of LCO remains unused after the distillation (≈20%), the final exploitation portion of LCO is higher. In order to calculate the mixing ratio, five types of diesel were indicatively considered: ‘Diesel 1’ with 2 mg/kg S, ‘Diesel 2’ with 3 mg/kg S, ‘Diesel 3’ with 4 mg/kg S, ‘Diesel 4’ with 5 mg/kg S, and ‘Diesel 5’ with 6 mg/kg S. Moreover, the mixing ratios were calculated only for the products of high temperatures as the most encouraging results of sulfur content occurred. It is evident in Figure 6


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that the distillation of LCO feed increases significantly the potential mixing ratios of final liquid products at a percentage which varies between 22-32 % for all the types of diesel. So the quantity of LCO which is removed as the heavy distillation residue, is replaced by a product with improved properties which approach diesel specifications. Finally, it is worth noting that the lower sulfur content diesel is used, the higher mixing ratio occurred. Figure 6. Mixing ratios of products in diesel pool with 10 mg/kg S Similarly with above approach, the corresponding mixing ratios of products in diesel pool were calculated regarding the density diesel fuel specification. All the calculations are based in the assumption that the density of the final diesel is 0.845g/ml. Especially, the density value of all the five indicative types of diesel were considered: ‘Diesel 1’ with 0.82 g/ml, ‘Diesel 2’ with 0.825 g/ml, ‘Diesel 3’ with 0.83 g/ml, ‘Diesel 4’ with 0.835 g/ml, and ‘Diesel 5’ with 0.82 g/ml. Moreover, the products used for calculations, occurred by high temperature experiments as its present the most efficient results. As it is depicted in Figure 7, the distillation of LCO feed leads to an increase between 2% and 5% of the liquid product which can be potentially mixed in diesel pool. Combining the above results, the density is characterized as the suspending property in comparison with the sulfur because the percentage of the permitted mixing ratio is reduced significantly. Figure 7. Mixing ratios of products in diesel pool with 0.845 g/ml density CONCLUSION In this study, the distillation and the hydroprocessing technology were combined in order to achieve a more efficient method for the upgrade of LCO to be achieved. The findings of this


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study validate that the distillation of LCO, exploiting only the light cut (cut point temperature 350 °C), led to products with improved properties after hydroprocessing at all the three temperatures that were tested (340 °C, 360 °C, and 380 °C). In particular, the most intense improvement was observed at the high temperature. Sulfur content and density of LCO_cut product were improved by 30% and 7.5% respectively in comparison with the corresponding liquid product of pure LCO hydroprocessing at the high temperature (380 °C). Regarding the polyaromatic content, all the liquid distilled products reached the diesel specification, while its cetane number increased markedly. Also, it is worth noting that the distillation yield of all the final distillated products achieve 100%. Finally, the fraction of the hydroprocessed distilled products which can be added to diesel pool, increased significantly in the case of LCO_cut products. AUTHOR INFORMATION Corresponding Author *E mail: [email protected] *Fax:+30-2310-498-380 ACKNOWLEDGMENTS The authors wish to express their appreciation at Aspropyrgos Refinery of Hellenic Petroleum (HELPE) for the LCO and catalyst supply.


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REFERENCES (1) Nylen U.; Sassu L.; Melis S.; Järås S.; Boutonnet M. Catalytic ring opening of naphthenic structures Part I. From laboratory catalyst screening via pilot unit testing to industrial application for upgrading LCO into a high-quality diesel-blending component. Applied Catalysis A. 2006, 299, 1-13. (2) Liu Zh.; Zheng Y.; Wang W.; Zhang Q.; Jia L. Simulation of hydrotreating of light cycle oil with a system dynamics model. Applied Catalysis A: General. 2008, 339, 209–220. (3) Peng Ch.; Fang X.; Zeng R.; Guo R.; Hao W. Commercial analysis of catalytic hydroprocessing technologies in producing diesel and gasoline by light cycle oil. Catalysis Today. 2016, 276, 11-18. (4) Sharafutdinov I.; D. Stratiev D.; Shishkova I.; Dinkov R.; Petkov P. Industrial investigation on feasibility to raise near zero sulfur diesel production by increasing fluid catalytic cracking light cycle oil production. Fuel Processing Technology. 2012, 104, 211–218. (5) Diez F.; Gates B.C. Deactivation of a Ni-Mo/y-A1203 Catalyst: Influence of Coke on the Hydroprocessing Activity. Ind. Eng. Chem. Res. 1990, 29, 1999-2004. (6) Bezergianni S.; Dagonikou V. Effect of CO2 on Catalytic Hydrotreatment of Gas-Oil, The Canadian journal of Chemical Engineering, 2015, 9999, 1-7.


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(7) Azizi N.; Ali S.A.; Alhooshani K.; Kim T.; Lee Y.; Park J.; Miyawaki J.; Yoon S.; Mochida I. Hydrotreating of light cycle oil over NiMo and CoMo catalysts with different supports. Fuel Processing Technology. 2013, 109, 172–178. (8) Yang H.; Chen J.; Fairbridge C.; Briker Y.; Inhibition of nitrogen compounds on the hydrodesulfurization of substituted dibenzothiophenes in light cycle oil. Fuel Processing Technology. 2004, 85, 1415– 1429. (9)

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(10) Tailleur R.G. Low-emission diesel production by upgrading LCO plus SR diesel fractions. Catalysis Today. 2008, 130, 492–500. (11) Tóth C.; Sági D.; Hancsók J. Diesel Fuel Production by Catalytic Hydrogenation of Light Cycle Oil and Waste Cooking Oil Containing Gas Oil. Top Catal. 2015, 58, 948–960. (12) Betancourt P.; Marrero S.; Pinto-Castilla S.; V-Ni-Mo sulfide supported on Al2O3: Preparation, characterization and LCO hydrotreating. Fuel Processing Technology. 2013, 114, 21–25. (13) Choi K.-H.; Sano Y.; Korai Y.; Mochida I. An approach to the deep hydrodesulfurization of light cycle oil. Applied Catalysis B: Environmental. 2004, 53, 275–283. (14) Mapiour M., Kinetics and Effects of H2 Partial Pressure on Hydrotreating of Heavy Gas Oil, University of Saskatchewan, October 2009.


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(15) Ancheyta J.; Angeles M.J.; Macias M.J.; Marroquin G.; Morales R. Changes in Apparent Reaction Order and Activation Energy in the Hydrodesulfurization of Real Feedstocks. Energy Fuels. 2002, 16(1), 189-193. (16) Reséndiz E.; Ancheyta J.; Rosales-Quintero A.; Marroquin G. Estimation of activation energies during hydrodesulfurization of middle distillates. Fuel. 2007, 86, 1247–1253. (17) Ferdous D.; Dalai A.K.; Adjaye J. Hydrodenitrogenation and Hydrodesulfurization of Heavy Gas Oil Using NiMo/Al2O3 Catalyst Containing Boron: Experimental and Kinetic Studies. J. Ind. Eng. Chem. Res., 2006, 45(2), 544-552. (18) Automotive fuels - Diesel - Requirements and test methods. EN 590, September 2013, Brussels (19) EN 12916 - Petroleum products — Determination of aromatic hydrocarbon types in middle distillates — High performance liquid chromatography method with refractive index detection; 2006. (20) Palos R.; Gutiérrez Al.; Arandes J.M.; Bilbao J. Catalyst used in fluid catalytic cracking (FCC) unit as a support of NiMoP catalyst for light cycle oil hydroprocessing. Fuel. 2018, 216, 142–152. (21) Varga Z.; Hancsók J.; Nagy G.; Kalló D. Hydrotreating of gasoils on bimetallic catalysts effect of the composition of the feeds. Studies in Surface Science and Catalysis. 2005, 158 (B), 1891-1898.


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(22) Gutiérrez Al.; Arandes J.M.; Castaño P.; Olazar M.; Javier Bilbao J. Preliminary studies on fuel production through LCO hydrocracking on noble-metal supported catalysts. Fuel. 2012, 94, 504-515. (23) Karonis D.; Nikoloudakis Ch. Upgrade of light cycle oil by solvent extraction in multiple stages, Preprints Division of Energy and Fuels. 2012, 57(2), 1007-1010.


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Table 1. Sulfur species distribution in LCO Sulfur Species

Boiling Point (°C)

Sulfur Species Distribution (%)

Sulfur Species Distribution (mg/kg)

AlkylTh

84

0.06

2.9

BzTh Substituted BTh DiBzTh Substituted DiBzTh Substituted TriBzTh Heavy Others Total

221 243

0.15

7.4 626.7

332.5 364.9

12.79 3.75 34.96

>365 >365 -

183.8 1713.0 916.3

18.7 24.36 5.23 100

1193.6 256.3 4900.0


19

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 32

Table 2. Properties of LCO and light LCO_cut feeds Feed Type S (mg/kg) Density (g/ml) Mono-Aromatic Content (%) Poly-Aromatic Content (% m/m) Total-Aromatic Content (%m/m) Derived Cetane Number

LCO 4900

Light LCO_cut Test Method 3031 EN ISO 20846

0.9612

0.9493

EN ISO 12185

17.0

16.2

EN 12916

57.3

53.5

EN 12916

74.3

69.7

EN 12916

14.6

18.4

EN 16144

Distillation

EN ISO 3405

IBP

193.2

158.5

10

243.9

239.5

30

274.3

265.3

50

294.9

279.8

70

322.2

297.2

90

358.0

322.8

FBP

383.0

341.4


20

Page 21 of 32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 3. Properties of LCO products

S (mg/kg)

LCO (340°C) 420

LCO (360°C) 220

LCO (380°C) 110

Density (g/ml)

0.9068

0.9029

0.9039

57.4

51.1

48.4

9.5

10.4

13.4

66.9

61.5

61.8

26.5

27.5

27.3

IBP

143.6

146.0

146.2

10

252.4

249.8

250.5

30

271.1

268.4

270.0

50

295.6

292.8

296.6

70

336.6

336.6

343.3

90

362.5

376.7

379.3

FBP

229.2

223.6

223.9

Feed Type

Mono-Aromatic Content (%) Poly-Aromatic Content (% m/m) Total-Aromatic Content (%m/m) Derived Cetane Number Distillation


21

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 32

Table 4. Properties of light LCO_cut products Light

Light

Light

LCO_cut

LCO_cut

LCO_cut

(340°C)

(360°C)

(380°C)

S (mg/kg)

117

59

21

Density (g/ml)

0.9040

0.8947

0.8900

53.2

51.3

48.1

8.7

6.0

5.6

61.9

57.3

53.7

27.4

29.2

30.2

IBP

186.2

182.4

162.8

10

227.4

224.7

218.7

30

248.9

246.1

242.2

50

262.7

259.2

256.6

70

280.0

277.2

276.1

90

308.1

307.0

306.7

FBP

330.4

333.0

334.5

Feed Type

Mono-Aromatic Content (%) Poly-Aromatic Content (% m/m) Total-Aromatic Content (%m/m) Derived Cetane Number Distillation


22

Page 23 of 32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 5. Reaction order and activation energy of HDS at 360 °C of LCO and LCO_cut feedstocks

Reaction order, n

Activation Energy, Ea (kcal/mol)

LCO

1.9

20.0

LCO_cut

1.6

23.9


23

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 32

Scheme 1. Flow diagram of CPERI/CERTH vacuum distillation unit


24

Page 25 of 32 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Scheme 2. Simplified schematic diagram of CPERI/CERTH hydroprocessing plant


25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

HDS (%)

Energy & Fuels

100 99 98 97 96 95 94 93 92 91 90 89

Page 26 of 32

LCO LCO_Cut

340

360 Temperature (°C)

380

Figure 1. Comparison of HDS of LCO with HDS of LCO_cut


26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Density (gr/ml)

Page 27 of 32

0.908 0.906 0.904 0.902 0.9 0.898 0.896 0.894 0.892 0.89 0.888 0.886 0.884

LCO LCO_Cut 340

360 Temperature (oC)

380

Figure 2. Comparison of density of LCO HDS products with LCO_cut HDS products


27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Aromatic Content (%)

Energy & Fuels

100 90 80 70 60 50 40 30 20 10 0

Page 28 of 32

Mono Poly 9.5

57.

LCO (340)

8.7

10.4

6.0

13.4

53.2

51.1

51.3

48.4

LCO_Cut (340)

LCO (360)

LCO_Cut (360) LCO Fraction

LCO (380)

5.6

48.1

LCO_Cut (380)

Figure 3. Comparison of aromatic content of LCO HDS products with LCO_cut HDS products


28

Page 29 of 32

40 Derived Cetane Number

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

35 30 25 20

LCO LCO_Cut

15 10 330

340

350

360 370 Temperature (°C)

380

390

Figure 4. Comparison of cetane number of LCO HDS products with LCO_cut HDS products


29

Energy & Fuels

400 350 Temperature (oC)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 30 of 32

300 Diesel Range

250

LCO Feed LCO_Cut Feed LCO 340

200

LCO 360 LCO 380 LCO_Cut 340

150

LCO_Cut 360 LCO_Cut 380

100 0

20

40 60 Recovery (%)

80

100

Figure 5. Comparison of distillation curve of LCO HDS products with LCO_cut HDS products


30

Page 31 of 32

50 Sulfur of Final Diesel: 10mg/kg

45 Mixing Ratio in Diesel (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

40

LCO LCO_cut

35 30 25 20 15 10 5 0 Diesel 1

Diesel 2

Diesel 3 Diesel Type

Diesel 4

Diesel 5

Figure 6. Mixing ratios of products in diesel pool with 10 mg/kg S


31

Energy & Fuels

50 Density of Final Diesel: 0.845 g/ml

45 Mixing Ratio in Diesel (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 32 of 32

40

LCO LCO_cut

35 30 25 20 15 10 5 0 Diesel 1

Diesel 2

Diesel 3 Diesel Type

Diesel 4

Diesel 5

Figure 7. Mixing ratios of products in diesel pool with 0.845 g/ml density


32

LCO Upgrading via Distillation and Hydroprocessing Technology

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