INVESTIGATION OF MODERN JET FUEL PRODUCTION

Transcription

1 THESES OF PHD DISSERTATION INVESTIGATION OF MODERN JET FUEL PRODUCTION Author ZOLTÁN ELLER Chemical engineer (M. Sc.) Made in Doctoral School of Chemical Engineering and Material Science, University of Pannonia Supervisor: Dr. Jenő Hancsók Chemical engineer, Eur. Ing., DSc. Professor University of Pannonia Faculty of Engineering Institute of Chemical and Process Engineering MOL Department of Hydrocarbon and Coal Processing Veszprém 2017

2 1. INTODUCTION AND OBJECTIVES Demand for jet fuels has a significant grow in recent decades. Crude oil companies and different researchers began worldwide to investigate jet fuel production from non-crude oil and non-fossil sources. At the same time to fulfill the necessary requirements of aviation production of modern, environmental friendly jet fuel with high energy content is important with small restructuring of the existing refinery technologies because to suit to the even aggravated prescriptions. Environmental friendly jet fuels with good flaming properties are produced from low sulphur- and aromatic containing hydrocarbon mixtures in the developed countries. Reason is the requirements can be fulfilled only with these compounds. Heterogeneous catalytic hydrogenation and possible isomerization of natural and/or waste triglyceride/fatty acid containing biological based feedstocks to paraffins could be a promising main route of biojet fuels with excellent performance properties and high energy content. During the research activity the aim was to produce alternative paraffinic jet fuel blending component in one- or more step special hydrocracking what is suitable to the standards from natural and waste triglyceride containing feedstocks and from its mixtures with crude oil based kerosene fraction 1

3 2. EXPERIMENTAL To fulfil the aim different industrial heteroatom removal transition metal/support catalysts (CoMo/Al 2 O 3, NiMo/Al 2 O 3 ) were studied in sulfided and non-sulfided forms. Durign the experiments the hydrocracking and deoxygenation activities of these catalysts were studied in different forms of them as a function of the process parameters and the concentration of the technical grade coconut oil (0 %, 10 %, 30%, 50 % and 100 %) in the feedstock. The sulfidating possibilities and the maintaining of sulfide state of the catalysts were investigated. Sulfide state maintaining agents were sulfur containing feedstock with dimethyl-disulfide in one case and hydrogen sulfide containing hydrogen gas in the other case. During the experiments the effects of the different sulfidating methods to the yield and quality of the liquid products were studied, moreover application possibility of sulfidating methods in an alternative jet fuel producing crude oil refinery was important to investigate too. The performance of the catalysts were compared in the applied process parameter range based on the yield, composition and performance properties of the liquid products. In case of investigation one-step production of good cold flow property alternative jet fuel. The special hydrocracking experiment was carried out on a hydroisomerizer Ph/Hmordenite catalyst with mixture of kerosene and sunflower oil because it is a high quantity triglyceride source in our country. I studied the yield and quality properties of the forming jet fuel products especially the freezing point. The experiments were carried out on the PIGNAT twin reactor system of MOL Department of Hydrocarbon- and Coal Processing. This includes all equipments of a conventional industrial hydrotreater plant. After the gas/liquid separation of reactor outlet the dried organic liquid products was fractionated to naphtha, kerosene and gas oil by distillation. Residue was the heavier part than gas oil, it included the unconverted and partially converted triglycerides. Chromatographic methods (GC, HPLC) were equipped to determinate the quantity of the products, moreover Enger-distillation, acid number, smoke point and freezing point determinating methods to evaluate the quality and performance of products. 2

4 3. NEW SCIENTIFIC RESULTS 1. I found at the special hydrocracking with different sulfidating agents of technical grade coconut oil, yield of jet fuel was higher in case of hydrogen sulfide application (highest yield: % 360 C, 1.0 h -1 ). The reason was the dimethyl disulphide resolves to hydrogen sulfide. Dimethyl disulfide occupies the active sites of the catalyst decreasing the possibility of special hydrocracking. This is confirmed with the difference between the target product yield because it is even higher with the increasing of the liquid hourly space velocity in case of the two different sulfidating agents (target product yield was higher with % in case of H 2 S). The reason is more dimethyl disulfide must be resolved what occupy more active sites. The methane from DMDS resolving decreases the partial pressure of hydrogen what is unfavourable too. a. I found quantity of target product increased well with the even sever process parameters (decreasing of liquid hourly space velocity and increasing of temperature) oppositely to the quantity of residue. However its value decreased lower than 2 % on 380 C. The reason of this high temperature compared to other feedstocks (eg. sunflower oil, rapeseed oil) is the different fatty acid composition. Coconut oil has lower hydrocarbon chains and thus has higher oxygen (14.57%) content compared to other feedstocks (11 12%). b. Sulphur content of target products decreased more in case of H 2 S with the increasing of temperature and decreasing of liquid hourly space velocity (eg. on 340 C 1 4 mg/kg with H 2 S and 4 11 mg/kg with dimethyl disulfide). The remaining sulphur content were from the dimethyl disulphide and or H 2 S and the recombination of sulphur compound, deoxygenated intermedier products and olefinic double bond containing products (these forming compunds were thiols according to a sulphur selective detector). 2. I found hydrogen sulfide containing H 2 gas is more effective than other sulfidating agents for maintaining the sulfide state of the catalyst in conditions of jet fuel blending component production with special hydrocracking. 3

5 3. I found decarbonylation/decarboxylation reactions came to the foreground on sulfided CoMo/Al 2 O 3 with the increasing of the temperature. This is opposite to the results obtained on sulfided NiMo/Al 2 O 3. According to this target product yields were lower because the forming paraffins were shorter with one CH 2 -group. a. Target product yield was higher on sulphided NiMo/Al 2 O 3 catalyst ( %) at lower process parameters (280 C, 30 bar, 1,0 3,0 h -1 ) compared to target product yields obtained on a sulphided CoMo/Al 2 O 3 ( %). At the same time the target product yiled was higher on CoMo/Al 2 O 3 catalyst ( % while on sulphided NiMo/Al 2 O 3 changed between %) on 340 C and above. This is the consequence of the ratio of HDO reactions in these conditions. The reason is the higher activity of sulphided NiMo/Al 2 O 3 catalyst. b. I found the inhibition effect of triglycerides to the desulfurization reactions but it is much lower in absolute value compared to the aromatic saturation. Sulphur content of products increased with the increasing of triglyceride content of feedstock (10 50 %) in C range (10 70 mg/kg) compared to products from pure kerosene hydrogenation (5 7 mg/kg). This effect can be decreased with the decreasing of liquid hourly space velocity or the increasing the hydrogen pressure. But these solutions are uneconomic. Increasing of the desulfurization activity can be explained with at higher temperature the triglycerides are quickly hydrogenated to paraffins, so the active sites can be free for sulphur containing compounds. 4. Based on the investigation of freezing points of target product obtained on different transition metal/support catalysts I found products obtained on sulphided CoMo/Al 2 O 3 catalyst have lower freezing point (-44 C) compared to products obtained with sulphided NiMo/Al 2 O 3 catalyst (-41 C). The reason is the (decarbonylation/decarboxylation) reactions were in higher rate in case of CoMo/Al 2 O 3 catalyst compared to NiMo/Al 2 O 3 containing catalytic system, so this means lower carbon number products what leads to lower freezing point. 5. I found mainly the formed bioparaffins from special hydrocracking of triglycerides and formed cycloparaffins from the saturation of aromatic hydrocarbons of the kerosene part result higher smoke points (> 30 mm at the favourable process 4

6 parameters and above). The reason is bioparaffins burn with less smoking flame because their higher energy content compared to aromatic hydrocarbons. 6. I found kerosene carbon number hydrocarbon products (40.9 %) formed from gas oil at the special hydrocracking of sunflower oil/kerosene mixture on Pt/H-mordenite catalyst and the formed kerosene products do not crack to lighter hydrocarbons at the favourable process parameters (T= 320 C, P= 50 bar, LHSV= 2,0 h -1, H 2 /alapanyag térfogatarány= 600 Nm 3 /m 3 ). 5

7 4. INDUSTRIAL APPLICABILITY OF THE RESULTS Based on the experimental results I determined mainly transition metal/support catalysts are suitable to produce alternative jet fuel with special hydrocracking mixtures of technical grade coconut oil and crude oil based kerosene. Mixtures of kerosene carbon number and boiling range paraffins forms with high yield but different composition on sulphided and nonsulphided forms of CoMo/Al 2 O 3 and NiMo/Al 2 O 3 catalysts. I conclude based on the jet fuel producing experiments hydrogen sulphide containing hydrogen gas what is forming during the desulphurization of middle distillates, is favourable applicable in crude oil refineries for maintaining the sulphide state of the catalyst. Other advantage is H 2 S removal is not necessary with absorption/desorption. This means significant chemical energy demand, harmful material emission and operation cost decreasing. This solution can be integrated easily in a crude oil refinery. I found during the sulphur and aromatic containing feedstock transformations in different catalytic systems CoMo/Al 2 O 3 and NiMo/Al 2 O 3 catalysts are able to significant desulphurization and aromatic saturation independently from actual concentration of triglycerides. Pt/H-mordenite catalyst is able to desulphurization of low sulphur content feedstocks (< 50 mg/kg) due its noble metal content, but it has high degree saturation activity in in case of sunflower oil/kerosene feedstock. Production of bioparaffin containing jet fuel from triglyceride containing kerosene feedstock can be carried out in an existing jet fuel hydrotreater plant. The applied catalyst and process parameters are very similar ( C temperature, 30 bar pressure, h -1 liquid hourly space velocity, Nm 3 /m 3 H 2 /feedstock volume ratio), only the pretreatment of bioorigined feedstock must be solved (mainly filtration and clarification are enough). Significant advantage of technical grade coconut oil is its high saturated fatty acid content (> 90 %) because the hydrogen demand of the deoxygenation is lower compared to other triglyceride feedstocks. This could be source of significant profit. The needed analytical and performance property tests are given, moreover the safety technology and special handling experiences of jet fuels are given too. 6

8 5. PUBLICATIONS IN THE FIELD OF THE PHD THESIS 5.1. Base publications of the PhD thesis Publications in foreign journals: 1. Eller, Z., Varga, Z., Varga, G., Hancsók, J.: Biocomponent Containing Jet Fuel Production with Using Coconut Oil,Chemical Engineering Transactions, 2014, 39(Part1), Eller, Z., Varga, Z., Hancsók, J.: Advanced production process of jet fuel components from technical grade coconut oil with special hydrocracking, Fuel, 2016, 182., (IF= 3,611 (2015)) Publication in foreign language Hungarian journal: 3. Eller, Z., Hancsók, J.: Reduced aromatic jet fuels, Hungarian Journal of Industrial Chemistry (ISSN ), 2011, 39 (3), International, foreign language conference presentations with full-text publication: 4. Eller, Z., Holló, A., Hancsók, J.: Production of Reduced Aromatic Jet Fuel From Sunflower oil Kerosene Mixture, 20th Biomass Conference and Exhibition, június , Milánó, Olaszország, (ISBN ), Eller Z., Papp A., Hancsók J.: Production of Jet Fuel from Alternative Source, 9th International Colloquium Fuels, január , Stuttgart/Ostfildern, Németország, (ISBN-Nr ), Eller Z., Varga G., Hancsók J.: Alternative Components of Jet Fuels, 10th International Colloquium Fuels, január , Stuttgart/Ostfildern, Németország, (ISBN-Nr ), Publications in the field of PhD dissertation Publication in foreign journal: 7. Eller Z., Varga Z., Hancsók J.: Production of Jet Fuel from Renewabe Source Material, Chemical Engineering Transactions, 2013, 35(2), Hancsók, J., Eller, Z.; Pölczmann, Gy.; Varga, Z.; Holló, A.; Varga, G.: Sustainable production of bioparaffins in a crude oil refinery, Clean technologies and Environmental Policy, 2014, 16(7), (IF: 1,934 (2014)) 9. Szarvas, T., Eller, Z., Kasza, T., Ollár, T., Tétényi, P., Hancsók, J.: Radioisotopic investigation of the oleic acid-1-14c HDO reaction pathways on sulfided Mo/P/Al 2 O 3 and NiW/Al 2 O 3 catalysts, Applied Catalysis B: Environmental, 2015, 165, (IF= 8,328 (2015)) 7

9 International, foreign language conference presentations with full-text publication: 10. Eller, Z., Hancsók, J.: Possibilities of quality improving of jet fuels, International Symposium on Motor Fuel 2010, Szlovákia, Tatranské Matliare, június In CD Proceedings (ISBN ), MF-2506, 11 oldal 11. Eller, Z., Hancsók, J.: Reduced aromatic Jet fuel, 8 th International Colloquium Fuels 2011, Németország, Stuttgart/Ostfildern, január , In Proceedings (ISBN ), Eller, Z., Hancsók, J.: Effects of blending bioparaffins to jet fuel products, 45 th International Petroleum Conference, Szlovákia, Pozsony, június , In Conference CD, ISBN Eller, Z., Hancsók, J.: Isomerization of petroleum fraction on Pt/SAPO-11 catalyst, Interfaces 11, (MKE) Sopron, szeptember , pp Eller, Z., Solymosi, P., Kasza, T., Varga, Z., Hancsók, J.: Production of biocomponent containing jet fuels, 2nd Eurpoean Conference of Chemical Engineering (ECCE 11), december , Puerto de La Cruz, Tenerife, Spanyolország, Proceedings (ISBN ), Hancsók J., Varga Z., Eller Z., Pölczmann Gy., Kasza T.: Liquid Alternative Diesel Fuels with High Hydrogen Content 9th International Colloquium Fuels, január , Stuttgart/Ostfildern, Németország, (ISBN-Nr ), Eller Z., Varga Z., Hancsók J.: "Conversion of coconut oil/kerosene mixture to JET fuel", 46th International Conference on Petroleum Processing, Pozsony, június 7., CD Proceedings (ISBN: ) 10pp. 17. Hancsók J., Eller Z., Pölczmann Gy., Varga Z.: Sustainable Production of Bioparaffins, in Proceedings of 16th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 2013 szeptember 29 - október 2., Rodosz, Görögország 18. Eller Z., Varga Z., Hancsók J.: Production of Jet Fuel from Renewabe Source Material, in Proceedings of 16th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 2013 szeptember 29 - október 2., Rodosz, Görögország 19. Eller, Z., Varga, Z., Varga, G., Hancsók, J.: Biocomponent Containing Jet Fuel Production with Using Coconut Oil, 17th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction PRES 2014, Prague, Czech Republic, August 2014,Conference CD, ISBN: , Serial Number: 0560, P7.42 International, foreign language conference presentations with abstract publication: 20. Eller Z., Noé I., Hancsók J.: Biojet fuel from Kerosene/Coconut Oil Mixtures, XXI. International Conference on Chemical Reactors, Delft, Hollandia, Book of Abstracts

10 Hungarian conference presentations with full-text publication: 21. Eller, Z., Hancsók, J.: Csökkentett aromástartalmú sugárhajtómű üzemanyagok, Műszaki Kémiai Napok 2011, Veszprém, április , Kiadvány (ISBN ), Eller, Z., Hancsók, J.: Biokomponens-tartalmú sugárhajtómű üzemanyag előállítása, Műszaki Kémiai Napok, Veszprém, április , (ISBN ), Eller, Z., Hancsók, J.: Sugárhajtómű üzemanyag előállítása alternatív forrásból, Műszaki Kémiai Napok, Veszprém, április , (ISBN ), Eller, Z., Hancsók, J.: Biokomponenstartalmú sugárhajtómű üzemanyag előállítása katalitikus úton, Műszaki Kémiai Napok 2016, Veszprém, április , Kiadvány, ISBN ,

11 6. SCIENTIMETRIC DATAS Number of publications which are the bases of the PhD thesis: 6 total impact factor: Number of other publications in the field of the PhD thesis: 18 total impact factor: Publications in journals: 6 - foreign language, peer-reviewed, in foreign journal: 5 - foreign language, peer-reviewed, in Hungarian journal: 1 Publications in conference proceedings: 18 - foreign language, in international conference proceedings: 13 - abstract in international conference proceedings: 1 - Hungarian language, in Hungarian conference proceedings: 4 Total number of publications: 24 Total impact factor of publications: Number of independent citations: 16 SCI: 5 Veszprém, February

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