Microsoft Word - inner cover.docx HUNGARIAN JOURNAL OF INDUSTRY AND CHEMISTRY VESZPRÉM Vol. 41(2) pp. 109–114 (2013) INVESTIGATIONS OF BIO-GASOIL PRODUCTION PÉTER SOLYMOSI, ! ZOLTÁN VARGA, AND JENŐ HANCSÓK MOL Department of Hydrocarbon- and Coal Processing, University of Pannonia, Egyetem u. 10., Veszprém, 8200, HUNGARY !Email: solymosip@almos.uni-pannon.hu Liquid engine fuels are the main source of power for transportation in the passenger sector. It is the projection of the European Union (EU) to reach 10% utilisation of renewable fuels by 2020. To achieve this goal the EU created the 2003/30/EC and furthermore the 2009/28/EC Directives. For example, the feedstocks of these renewable engine fuels can be non-edible oil plant hybrids, such as rapeseed oils with high euric acid content obtained from special hybrids of rape (e.g. Brassica napus) waste lards (used cooking oil and slaughterhouse lards). If the preconditions of utilisation are given with respect to the sustainability and technical compatibility of motor engines and vehicle construction, these bio components can be blended with motor fuels in large quantities. Considering the properties of currently used first generation biofuels, the maximum amount of bio-component in engine fuels is approximately 7 (v/v)% fatty acid- methylester in diesel fuels. A reliable production technology of second generation biofuels, which can be blended into diesel fuels is the heterogenic catalytic hydrogenation of triglycerides and waste lards. Furthermore, isomerisation can improve the quality of a bio-paraffin mixture. In this context, we studied the isomerisation of bio-paraffin mixtures, which were obtained from the hydrodeoxygenation of vegetable oil. The characteristics of these products were favourable, such as their cetane number being higher than 75, for example. The actual EN590:2013 standard does not limit the blending ratio of the paraffinic bio-component in diesel fuels. Consequently, these products obtained by the catalytic hydrogenation of vegetable oils can be blended into gasoil by up to 10 % or even more to meet the above EU requirements with respect to the utilisation of renewable fuels. Keywords: bio gasoil, hydrodeoxygenation, catalytic conversion, biofuels, blending diesel fuels Introduction Interest in alternative fuels is on the rise due to the unequal presence of the fossil energy carriers, the periodic rise in the price of fossil fuels, the need for decreasing dependence on crude oil, and the regulations of the European Union. They can play a significant role in achieving the EU plan to reach a 10% energy ratio of total fuel consumption using alternative fuels by 2020. Thus, the application of the biofuels can be increased to a large degree in the long- and medium-terms. For example, in some countries the domestic demand on biofuels could increase to 20% by 2030, along with the decrease in the demand for engine fuels that could be up to 70%. The world’s energy production from biomass could reach 5% by 2050 [4, 5]. Accordingly, to ensure the availability of this feedstock the production costs could decrease. To achieve these goals, the EU created several directives (1998/70/EC, 2001/77/EC, 2003/17/EC, 2003/30/EC, 2003/87/EC, 2009/28/CE, and 2009/30/CE). Natural triglycerides like vegetable oils (edible or non-edible/waste) can be feedstock for biofuels as alternative energy sources [6, 7], such as special breeding non-edible oil plants [8, 9], animal fats or waste cooking oil [10, 11]. During the conversion of natural triglyceride molecules to bio-gasoil the following reactions take place [1, 2, 3]: • full saturation of double bonds (hydrogenation), • heteroatom removal o oxygen removal " hydrodeoxygenation (HDO reaction, and reduction) " decarboxylation, " decarbonylation o removing of other heteroatoms (sulphur, nitrogen, phosphorous, and metals), • isomerisation of n-paraffins that are formed during the removal of oxygen • different side reactions o hydrocracking of the fatty acid chain of triglyceride molecules, o water-gas shift reaction o methanisation, o cyclisation, aromatisation, etc. During the HDO reduction reaction normal paraffins are formed with carbon numbers that are equal to the fatty acids in triglycerides. In the case of decarboxylation and decarbonylation reactions (HDC) normal alkanes are produced, where the carbon number is one less than that of fatty acids of the original vegetable (Fig.1). Bio-gasoil is a mixture of gasoil with the boiling range of iso- and normal-paraffins. It can be obtained by the hydrogenation of vegetable oils and natural triglycerides 110 from other sources. These constitute the second generation biofuel components of diesel engines. They have good quality characteristics, such as high cetane number, good flow properties, unlimited mixability with engine fuels, and the a production line compatible with existing refinery structures [18, 19]. The actual EN 590:2013 standard does not limit the blending ratio of second generation bio-components, while the blending of biodiesel is limited to 7 v/v%. All the above mentioned aspects of alternative fuels can rationalise the investigation of the hydrogenation of non-traditional feedstock sources. These are the vegetable oils that can be obtained from non-edible hybrid oil-plants, rapeseed oil from Brassica napus with high euric acid content to produce diesel fuel blending components with good flow properties in colder conditions (below +5 °C). The freezing point of iso-paraffins from bio-sources is lower than for equal chain length normal-paraffins (Fig.1) [12-15, 17]. Thus, products with high iso-paraffin contents have more favourable cold flow properties (CFPP) with cloud points at lower temperatures (Fig.2). The aim of our work was the production of diesel gasoil blending components via the isomerisation of paraffin mixtures obtained from the hydrodeoxygenation of rapeseed oil with high euric acid content. Experimental In this work, a diesel gasoil bio-blending component production technique was investigated that meets the requirements of the EN:590 Standard with the possibility of blending it with engine fuels in unlimited quantities. Thus, the hydrodeoxygenation of natural triglycerides and further the isomerisation of the obtained bio-paraffin mixture were investigated over the Pt-SAPO-11 catalyst [16] developed in-house. The effect of the operation parameters, such as temperature, pressure, and liquid hourly space velocity (LHSV) was studied on the yield, composition, and utilisation properties of the products. Experimental Apparatus and Product Separation The experimental tests were carried out in one of the measured sections of a high-pressure reactor system containing two tubular reactors with a isothermal catalyst volume of 100 cm3. The reactor system contained all the equipment and devices applied in the reactor system of a hydrotreating plant. The apparatus is suitable for maintaining if not succeeding the industrial precision of main process parameters. Analytical Methods The main properties of the feedstock materials and products were determined by standard methods. The hydrocarbon composition of the bio-paraffin mixture was determined by high temperature gas chromatography (Shimadzu 2010 GC [column: Phonomenex Zebron MXT]). Process Parameters The ranges of the applied process parameters in the isomerisation test on the basis of our earlier experimental results [13, 14, 17, 20-23] were as follows: temperature 300–360 °C, total pressure 20–80 bar, liquid hourly space velocity (LHSV) 1.0 h-1, and H2/feed volume ratio of 400 Nm 3 m-3. Feedstock materials The feedstock of the catalytic tests was a bio-paraffin mixture, which was obtained from the hydrodeoxygenation of rapeseed with euric acid produced in Hungary. It was properly filtered as a pre-treatment. The main properties of the feedstock material are shown in Table 1. The catalyst was Pt-SAPO-11 (0.5 % Pt), the main properties of this can be found in Table 2. Figure 1: Pathways for the removal of oxygen from vegetable oils Figure 2: The freezing point of iso-paraffins as a function of the branch position 111 Results and Analysis The first step was to produce a bio-paraffin mixture with a boiling range of gasoil from rapeseed with a high euric acid content. The properties of the bio-paraffin are summarised in Table 1. The commercially available NiMo/Al2O3 catalyst was utilised for the production of the bio-paraffin mixture. During the catalytic test the employed operation parameters were as follows: 320– 380 °C, 20–80 bar, LHSV = 1.0 h-1, and H2/CH ratio of 600 Nm3 m-3 [8]. It was found that the favourable operation parameters are 340 °C, 40 bar, LHSV=1.0 h-1, and H2/CH ratio of 600 Nm 3 m-3. The tested catalyst is suitable for the production of bio-paraffin mixtures with high yields from natural triglycerides. Due to the moderate acidity of this catalyst, the formation of iso- paraffins was lower (5 wt%, Fig.3). Accordingly, the CFPP of the products was found to be high (27 °C). The product fraction produced in this way, in practice, cannot be blended into diesel fuels in low temperate zone countries. It is necessary then for the improvement of CFPP via the catalytic isomerisation of this mixture with high normal-paraffin content [10, 11]. A large amount of bio-paraffin mixture was produced in a thousand hour, long-term catalytic test. The target fraction of the isomerisation tests was the 180–360 °C boiling range, which is the boiling range of gasoil. The yield of the target products was higher than 94 % in all operation parameter combinations (Fig.4). The lighter fraction with a boiling range of up to 180 ºC contains mainly iso-paraffins, which can be outstanding gasoline blending components due to their high octane numbers (>85). We found that by adjusting the operation parameters, such as increasing the temperature, and decreasing the LHSV, the yield of the target fraction was decreased due to the higher yield of the cracking reaction. The target fraction obtained between 70% and 80% Table 1: Selected properties of the feedstock materials Properties rapeseed oil Bio-paraffin mixture kinematic viscosity at 40 °C, mm2 s-1 46.56 3.493 density at 15 °C, g cm-3 0.9804 0.7923 cloud point, °C 16 32 cetane number 42 104 compositions, % Fatty acid Paraffin C16:0 2.3 C14- 0.2 C16:1 0.1 C14 0.1 C18:0 1.2 C15 0 C18:1 28.8 C16 2.3 C18:2 12.4 C17 29.5 C18:3 8.3 C18 28.8 C20:0 0 C19 6.1 C20:1 4.8 C20 5.6 C22:0 0.1 C21 14.8 C22:1 41.8 C22 12.5 other 0.2 C22+ 0.1 Figure 3: Hydrogenation of rapeseed oil with high euric acid content (diamond: residual triglyceride, square: iso-paraffin content, cross C21/C22 ratio) Table 2: Selected properties of the isomerisation catalyst used Properties Pt/SAPO-11 Pt content, w% 0.5 Pt dispersity, % 69 BET surface area, m2 g-1 105 average pore size, nm 0.61 micropore volume, cm3 g-1 0.06 macropore volume, cm3 g-1 0.20 total pore volume, cm3 g-1 0.26 acidity, mmol NH3 g -1 0.13 acidity (rel.), mmol NH3 m -2 cat. 0.0012 112 contained C17–C22 hydrocarbons, as well as other (C13– C16) hydrocarbons from the boiling range of gasoil. The iso-paraffin content of the target fraction increased significantly with the operating temperature (Fig.5). The increase of the iso-paraffin concentration occurred at 360 °C then at higher temperatures it started to decrease, due to the thermodynamic hindrance of the exothermic reactions, and the higher rate of cracking reactions. Up to ca. 320 °C, mainly mono-branched iso- paraffins were formed and were by in large mono-ethyl- paraffins (Fig.6). The freezing points of these products are much lower than normal-paraffins and the cetane number is high enough for a fuel additive. The greater formation of mono-methyl-paraffins over the SAPO-11 catalyst can be explained by the reduced formation of iso-paraffins due to steric hindrance. At 340 °C or higher, the formation of multi-branched isomers was significant (Fig.6). These compounds have better cold flow properties (below -20 °C), but their cetane numbers are high enough (30–45) as shown in Fig.2. The favourable operation parameters in terms of bio- gasoil yield and iso-paraffin concentration were as follows: T = 360 °C; p = 40 bar; and H2/feedstock ratio = 400 Nm3 m-3. The CFPP values of the products as a function of temperature and operation pressures are shown in Fig.7. These components have low enough CFPP values to blend into diesel gasoil in moderate amounts. On the basis of the experimental results, it was concluded that the production of bio-gasoil meets the standard’s requirements with a CFPP value of max. +5 °C and 70% iso-paraffin content (Fig.8) in the case when the raw material contains 8% C17–C22 iso- paraffins. Conclusions Based on our experimental results, it was concluded that the NiMo/Al2O3 catalyst is suitable for the long-term production of bio-paraffin mixtures from natural triglycerides via catalytic hydrodeoxygenation. Furthermore, the investigated Pt-SAPO-11 catalyst is suitable for improving the quality of a bio-paraffin mixture that was obtained from the hydrodeoxygenation of rapeseed oil with high euric acid content. During the isomerisation with optimised operation parameters, the yield of the target fraction was higher than 94%. At 340 °C or higher the iso-paraffin content is close to 70%. Consequently, the cold flow property of the cloud point is lower than +5 °C. Therefore, this approach can produce gasoil bio-blending components with good utilisation properties, such as high cetane number, and low temperature values for cold flow properties. Overall, the products described here are suitable for blending components of diesel fuels with concentrations of 10% or higher. Figure 6: The composition of the products as a function of operation parameters (pressure: 40 bar, liquid hourly space velocity: 1.0 h-1) Figure 7: CFFP of the products as a function of operation parameters (liquid hourly space velocity: 1.0 h-1, H2/feed ratio: 400 Nm3 m-3) Figure 4: The yield of the target fraction as a function of operation parameters (pressure: 40 bar, liquid hourly space velocity square: 1.0 h-1, diamond 2.0 h-1, triangle 3.0 h-1) Figure 5: The iso-paraffin concentration of the target fraction as a function of operation parameters (pressure: 40 bar, liquid hourly space velocity: square 1.0 h-1, diamond 2.0 h-1, triangle 3.0 h-1) 113 Acknowledgements We acknowledge the financial support of the Hungarian State and European Union under TÁMOP-4.2.2.A-11/1/ KONV-2012-0071 and TÁMOP-4.1.1.C-12/1/KONV- 2012-0017. REFERENCES [1] HUBER G.W., O’CONNOR P., CORMA A.: Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures, Appl. Catal. A:General, 2007, 329,120-129 [2] DA ROCHA FILHO G.N., BRODZKI D., DJEGA- MARIADASSOU G.: Formation of alkanes, alkylcycloalkanes and alkylbenzenes during the catalytic hydrocracking of vegetable oils, Fuel, 1993, 72(4), 543-549 [3] SIMACEK P., KUBICKA D., SEBOR G., POSPISIL M.: Fuel properties of hydroprocessed rapeseed oil, Fuel, 2010, 89(3), 611-615 [4] SCHOLLNBERGER W.E.: Between 2020 and 2030 to be re-joined the course for the global energy mix, Erdöl Erdgas Kohle, 2013, 129(12), 2-7 (in German) [5] Shell Deutschland Oil Gmbh: Shell study sees great potential for biofuels, Erdöl Erdgas Kohle, 2012, 128(11), 407-411 (in German) [6] KRÁR M., KOVÁCS S., KALLÓ D., HANCSÓK J: Fuel purpose hydrotreating of sunflower oil on CoMo/Al2O3 catalyst, Bioresources Technology, 2010, 101(23), 9287-9293 [7] KRÁR M., KASZA T., KOVÁCS S., KALLÓ D., HANCSÓK J.: Bio-gasoils with improved low temperature properties, Fuel Proc. Techn., 2011, 92(5), 886-892 [8] SOLYMOSI P., BALADINCZ P., HANCSÓK J.: Production of motor fuels by the hydrogenation of rapeseed oil with high euric acid content, Proc. 19th EU Biomass Conference and Exhibition, Berlin, Germany, 2011, 2077-2081 [9] SOLYMOSI P., KASZA T., HANCSÓK J.: Investigation of conventional and high oleic acid content rapeseed or sunflower oils, Hung. J. Ind. Chem., 2011, 39(1), 85-90 [10] BALADINCZ P., TÓTH CS. HANCSÓK, J.: Expanding feedstock supplies of the second generation biofuels of diesel engines, Hung. J. Ind. Chem., 2010, 38(1), 1-7 [11] SOLYMOSI P., ELLER Z., HANCSÓK J.: Motor fuel purpose hydrogenation of used cooking oils, Chem. Engng. Trans., 2013, 35(2), 1351-1356 [12] HANCSÓK J., KASZA T., KOVÁCS S., SOLYMOSI P., HOLLÓ A.: Production of bioparaffins from natural triglycerides, Chem. Engng. Trans., 2011, 25, 821- 826 [13] KASZA T., HANCSÓK J.: Isomerisation of bio- paraffins over Pt-based SAPO-11 and AlMCM-41 catalysts, Műszaki Kémiai Napok, 2011, 29, 220- 225 (in Hungarian). [14] KASZA T., HOLLÓ A., THERNESZ A., HANCSÓK J.: Production of bio-gasoil from bioparaffins over Pt/SAPO-11, Chem. Engng. Trans., 2010, 21, 1225-1230 [15] HANCSÓK J., KASZA T., KOVÁCS S., SOLYMOSI P., HOLLÓ A.: Production of bio-gasoil from bioparaffins over Pt/SAPO-11, J. Cleaner Prod., 2012, 34, 76-81 Figure 8: Cold flow properties as a function of iso-paraffin concentration (solid squares: cold filtering clugging point, hollow diamonds: cloud point) 114 [16] GERGELY J., FORSTNER J., BALAI M., SZIRMAI L., PETRO J., KOVÁCS I., RESOFSZKI G., SMID L., AUER J., BALADINCZ J., SZALMÁSNÉ PÉCSVÁRI G., TÓTH L., KUBOVICSNÉ STOTZ K., KUN J., KÁNTOR L., CZÁGLER I., LŐVEI J., TÓTH E., LEFKÁNICS GY., TÁTRAI E., PÁLNÉ BORBÉLY G., ROSENBERGNÉ MIHÁLYI M., BEYER H., HANCSÓK J.: A selective hydroisomerisation catalyst preparation and application for hydrocarbons HU 225 912, 2001 (in Hungarian) [17] KASZA T., KALLÓ D., HANCSÓK J.: Quality improvement of bio-paraffin mixtures, Fuel, 2014, 120, 1-7 [18] HANCSÓK J., KRÁR M., MAGYAR SZ., BODA L., HOLLÓ A., KALLÓ D.: Investigation of the production of high cetane number biogasoil from pre-hydrogenated vegetable oils over Pt/HZSM- 22/Al2O3, Micropor. Mesopor. Mat., 2007, 101(1- 2), 148-152 [19] SRIVASTAVA S.P., HANCSOK J.: Fuels and Fuel Additives, Wiley and Sons, Hoboken, NJ, USA, 2014, pp. 121-177 [20] KASZA T., BALADINCZ P., HANCSÓK J.: Production of bio-isoparaffins by the hydroisomerisation of bioparaffins. Hung. J. Ind. Chem., 2009, 37(2), 95–99 [21] KASZA T., HANCSÓK J.: Production of depressed freezing point bio-gasoil from slaughterhouse waste lard. Hung. J. Ind. Chem., 2010, 38(1), 41– 45. [22] KASZA T., HANCSÓK J.: Isomerisation of paraffin mixtures produced from sunflower oil. Hung. J. Ind. Chem., 2011, 39(3), 363–368 [23] KASZA T.; TÓTH CS.; HANCSÓK J.: Application of improved bio-paraffins in diesel fuels, Hung. J. Ind. Chem., 2012, 40(1), 25–31