Theses of Ph.D. dissertation PREPARATION AND INVESTIGATION OF DETERGENT DISPERSANT ADDITIVES OF GAS OIL

Transcription

1 PREPARATION AND INVESTIGATION OF DETERGENT DISPERSANT ADDITIVES OF GAS OIL Prepared by: Márk Bubálik Theme leader: Dr. Jenő Hancsók Doctoral School in Chemical Engineering and Materials Sciences Department of Hydrocarbon and Coal Processing University of Pannonia Veszprém 2009

2 I. Introduction and aims Theses of Ph.D. dissertation Engine fuels are comprised of high quality blending components and highly efficient additives. Nowadays, application of high performance additives is essential to meet the required fuel properties and to protect the engine and environment. Out of the numerous additive types, Deposit Control Additives (DCAs) are applied in the highest amount. Deposits may form in the fuel injector system of the engine. These deposits influence the emission, fuel economy, cold start behaviour, driveability and performance, too. DCAs are generally long chain hydrocarbons attached to a polar head group. Deposit precursors are attracted to the deposit control molecule, and become bounded into the dispersant micelles. At normal operating temperatures the DCA is a liquid that forms a thin film on the surface of the inlet system. The thin film is driven forward by air and fuel vapour flow, but forms a first line barrier to deposit precursors as well as a dispersant/neutraliser of the precursors protecting the metal surface. In the case of deposits on the metal surface, the liquid film slowly removes deposits by a detergent action. Diesel fuel detergents are predominantly based on polyisobutylene (PIB-amine, -succinimide, etc.) and other ashless polymeric products. Diesel fuel injector pumps often rely on the fuel itself to lubricate. Wear occurs on the parts of the fuel pump moving on each other. Therefore, it is very important to ensure the formation of a cover film either by physical adsorption or chemisorptions, in order to reduce the number of metal to metal contact points. Formerly the lubrication function was provided by natural components in the diesel fuel (sulphur, aromatics and other heterocyclic, polar compounds). Due to environmental protection and human health reasons, the sulphur content of Diesel fuels was reduced in the last years. As a result, the lubricity of diesel fuels decreased. Lubricity improving additives are polar compounds with long carbon chain, i.e. they are able to form a protective layer on the surface. Many types of compounds are used as diesel fuel lubricity improving additives. These may be alkenyl succinics, alcohols, C 8-19 carboxylic acids, esters (esters of fatty acids and alcohols, bis-alkenyl-succinic ester, etc.), carboxylic acid amides, mixtures of fatty acids and tertiary amines. Diesel fuels contact with the metal equipment of the fuel system. The fuel should not have any negative effect on these materials. Hydrocarbons do not cause corrosion, but the acidic compounds (i.e. naphthenic acid) and sulphur molecules in the diesel fuel are very aggressive to copper and their alloy and can cause important wear, especially in case of long term stand-down. Solid and/or gel materials are formed in these reactions can deposit on different parts of the engine and can cause faults. Corrosion may develop on the wall of storage tanks during long term storage, especially in the presence of water. Nowadays, these corrosion effects can be prevented with suitable corrosion inhibitors. These additives build up a cover film on the metal surface. Typical corrosion inhibitors are carboxylic acids, amines and amine salts of carboxylic acids. For example: alkyl- or polyalkyl-succinics, their esters, dimeric acids and amine-salts. Among the fuel additives discussed above the derivatives of different alkene-, alkyl-, polyalkene-, polyalkyl-succinic anhydrides are applied in highest amount. The derivatives of succinic anhydrides are usually produced in two steps: the first step is the preparation of alkenyl succinic anhydrid by ene-reacton between olefins and/or polyolefines and maleic anhydride. In the second step, the intermediates synthesized through the first step are used to acylate amines, amino alcohols, alcohols etc. Possibilities for the next reactions and the properties of final products significantly depend on the structure and purity of the resultant intermediate as well as the conversion of MA- and olefin. The main research ways targeting

3 the improvement of the reaction parameters are the thermal or radical initiation, catalytic synthesis or their combinations. Fatty acid methyl esters (FAME) and/or their derivatives are able to substitute diesel fuels and/or their additives. The use of FAMEs can moderate the agricultural overproduction crises and/or reduce the import dependence of crude oil and its products. The application of esters based on vegetable oils in premium quality diesel fuels ensures environmental advantages (lower CO2-emission, biodegradability, non-toxic, etc.). Many vegetable oils can be used as a source of methyl ester production; however the application of the rapeseed- and the sunflower-oils is the most wide-spread because their properties are the most similar to those of diesel fuel. Their advantage is the good lubricity and the smaller emission of particulate matter. A more and more significant utilization option of vegetable oils resulting in substantial value addition is the production of additives that are useful for various industrial purposes. This utilization option is not only motivated by their renewable nature and their superior biodegradability compared to synthetic products but also by their applicability in various chemical reactions or structural modifications because of the unique distribution of their unsaturated bonds and their reactive functional groups. Based on the environmental regulation and the market demands described above the aim of research work was the development of polyisobutylene-based, ash-free detergent dispersant additives of Diesel oil. Our main purpose was the elimination of the disadvantages of the thermic PIBSA-synthesis (high energy demand and reaction time, not too bright color etc.) and the demand of distinguishable product (new product-structure) Besides of these the other objective of our work was the development of a multifunctional (DD, lubricity-improver and corrosion inhibiting effects) fuel additive containing bio-component as molecular-constituent, which has a new, non-published molecular structure, hereby the antagonism effect of the surfactant type additives can be eliminated. II. Experimental and test methods The synthesis was carried out in two steps. Polyisobutylenes, maleic anhydride and rapeseed oil methyl ester, aromatic solvent and radical initiator were used in the first step. Polyethylene polyamine and base oil was applied for the preparation of final products. Additive-free middle distillates were used to characterize the performance properties of the additives. The base fuels (sulphur content: 4 mg/kg) have met the requirements of EN 590:2004 standard, except the corrosion and lubricity properties. The analytical and performance test of the intermediates and the final products were carried out according to international and local standards or proprietary methods. The molecular structure of intermediers and products was investigated by GPC, IR, 1 H and 13 C spectroscopy. III. New scientific results 1. For the sake of accurate screening evaluation of lubricity efficiency of the synthesized diesel fuel additives, the author has further developed the four-ball test method. As a result, the antiwear efficiency of diesel fuel lubricity impover additives can be characterized with suitable precision by applying this developed method [10; 11; 12; 13].

4 2. The author has synthesized succinic anhydride derivatives from polyisobutene ( M npib 1000) and maleic anhydride in the presence of radical initiator, which were found to be suitable for producing diesel fuel additives [9]. a. In the view point of additive production the most advantageous reaction parameters and molar ratio of the component were determined based on laboratory and pilot plant experiment. By applying temperature of 140±1 C, reaction time of ca. 8 hours intermediate products (PIBBAI) could be synthesized from PIB having M n ~1000.Using these parameters intermedier products having different succinic anhydride PIB connection ratio can be produced (i.e. 0.8 and 1.4). b. The author has determined that the properties of the product of radical initiating reaction was similar to the properties of the thermal reaction product, moreover some characteristic, like colour and MA-content were better. By radically initiated method 10% higher MA conversion could be achieved than by the thermal way. This higher conversion can be reach under economically more advantageous circumstances (lower temperature with C). c. By using IR, GPC, 13 C and 1 H NMR techniques, the difference of the molecular structure between the PIBSA produced by radically initiated method and thermal way has been demonstrated. The PIBSA synthesised by thermal way mainly contains molecules having 1:1 PIB-SA connection ratio. The PIBSA produced by radical initiated method consist of in addition of the above mentioned molecule succinic anhydride substituted with two PIB molecules (in ratio of 2/3), which ensures the dispersant effect, and there are some polyisobutylene molecules connected with two or more succinic anhydride rings, which can improve the detergent effect due to the formation of more polar molecules. d. The author has determined that in case of PIBDISA (BA PIB molar ratio 2:1) production the reaction time of the second BA ring connecting to the PIB chain is much longer, therefore the longer time of the synthesis is preferred to produce this intermedier, meanwhile increasing the number of raw material portions (thus decreasing the unreacted MA ratio in the mixture at given time) results in less PIBDISA type molecules. 3. It was determined that fuel additives with improved DD efficiency can be produced from reaction of intermediers described above and polyethylene-polyamine according to well known methods in the synthesis of PIB-succinimides. The synthesized additive blended in diesel fuel can maintain cleanness of the injector nozzles of diesel engines more efficiently than traditional polyisobutene-succinimides most frequently used as commercial deposit control additives [9; 19]. 4. It was realised that with an original structure, alkyl-succinic anhydride containing biocomponent as molecular-constituent can be synthesised from fatty acid methyl ester (FAME), polyisobutylene and maleic anhydride in the presence of radical initiator [6; 8; 14; 15; 16]. a. The author has demonstrated that excellent intermediers of fuel additives can be synthesised in a reproducible way with the determined dosage sequence of reactants under the established reaction parameters. In case of inadequate dosage sequence polymerization reactions can take place.

5 b. The reaction between the MA and PIB is faster than between MA and FAME in the presence of radical initiator, that is why the accurate amount of initiator (10% based on MA) is necessary to be applied to produce succinic anhydride derivative substituated with FAME and PIB. c. Based on the IR, GPC, 13 C and 1 H NMR analytical tests it was confirmed that the fatty acid methyl ester can be built into the PIB-succinic anhydride structure, thus producing a novel compound having original structure. 5. The selected intermediates containing bio-component as molecular-constituent were used to acylate polyethylene polyamines according to the investigated method applied for the synthesis of polyalkylene succinimides and the products were examined by analytical and performance tests [8; 9; 17; 18 ; 19]. a. Based on the test results the author has established, that the DD efficiency of traditional succinimides producing in thermal way could be achieved moreover in some cases exceeded. The author has confirmed that the polar end-group of FAME has an active role in the mechanism of detergent action. b. The author has demonstrated that the synthesized fuel additives had excellent corrosion inhibiting- and lubricity improving effects. c. The author has determined that the purposive choose of polyethylene polyamine type enables the additive to satisfy different demands: for increasing the DD effect the use of smaller molecular weight polyethylene polyamine is favourable and for the lubricity improving effect the use of higher molecular weight polyethylene polyamines (TEPA, PEHA) are preferred. d. Based on the IR, GPC tests nearly total conversion of polyethylenepolyamine and the conformation of imide s structure was confirmed. IV. Industrial application of the results The MOL LUB Ltd. and predecessors in title has been using the succinimides in their different motor-oil formula since the 70 s. Since 1988 chloride-free additive-production technology claimed by several national and international patents [93, ] has been developed by MOL LUB Ltd. together with the researchers of the Department of Hydrocarbon- and Coal Processing. This technology is able to produce 14 different structures of succinimide type additives. The development of diesel fuel additives is the subject-matter of this thesis which is attached to the systematic research series of the polyisobuthylene-based succinic anhydride derivatives development carried out by cooperation of the above mentioned institutes since The scale up experiments and the further structural tests are on the way now for purpose of implementation of a new additive-technology.

6 V. List of publication and conference presentation Publications [1] Hancsók, J., Bubálik, M.: Motorhajtóanyagok korszerű adalékai. I. Motorbenzinek adalékai, MOL Szakmai Tudományos Közlemények, 2003 (2), [2] Hancsók, J., Bubálik, M., Kovács, F.: Motorhajtóanyagok korszerű adalékai II. Dízelgázolajok adalékai, MOL Szakmai Tudományos Közlemények, 2004 (1), [3] Hancsók, J., Auer, J., Baladincz, J., Kocsis, Z., Bartha, L., Bubálik, M., Molnár, I.: Interactions between Modern Engine Oils and Reformulated Fuels, Petroleum and Coal, 2005, 47(2), [4] Baladincz, J., Szirmai, L., Bubálik, M., Hancsók, J.: A motorbenzinek korszerű adalékai, Magyar Kémikusok Lapja, 2005, 60(11), [5] Baladincz, J., Szirmai, L., Hancsók, J., Bubálik, M.: Dízelgázolajok korszerű adalékai, Magyar Kémikusok Lapja, 2006, 61(4), [6] Hancsók, J., Bubálik M., Törő, M., Baladincz, J.: Synthesis of fuel additives on vegetable oil basis at laboratory scale, European Journal of Lipid Science and Technology, 2006, 108(8), [7] Hancsók, J., Bubálik, M., Bartha, L., Baladincz, J., Kocsis, Z.: Dízelgázolajok és motorolajok kölcsönhatásai, azok következményei, Magyar Kémikusok Lapja, 2007, 62(8-9), [8] Hancsók, J., Bubálik, M., Beck, Á., Baladincz, J.: Development of multifunctional additives based on vegetable oils for high quality diesel and biodiesel, Chemical Engineering Research & Design, 2008, 86, [9] M. Bubálik, Á. Beck, J. Baladincz, J. Hancsók: Development of deposit control additives for Diesel fuel, Petroleum and Coal, - accepted Conference presentations published in proceedings [10] Bubálik, M., Hancsók, J., Molnár, I.: Dízelgázolaj adalékok kenőképesség-javító hatásának vizsgálata Stenhope-Seta négygolyós készüléken, Műszaki Kémiai Napok 04, Veszprém, április , in Proceedings, (ISBN ), [11] Bubálik, M., Hancsók, J.: Characterization of the AF/AW properties of diesel fuel, Motor Fuels 2004, Vyhne, Szlovák Köztársaság, június , In Conference CD 12pp, MF-2218 [12] Bubálik, M., Hancsók, J., Molnár, I., Holló, A.: Characterization of the AF/AW properties of diesel fuel, 5th International Colloquium on Fuels 2005, Technische Akademie Esslingen, Ostfildern Németország, január 12-13, in Proceeding [Bartz, W. J. (editor)] (ISBN ), [13] Bubálik, M., Hancsók, J., Csordás, E., Molnár, I., Holló, A.: Development of methods used for examination of Diesel fuel additives INTERFACES 05, Magyarország, Sopron, szeptember , in Proceedings, (ISBN ),

7 [14] Bubálik, M., Hancsók, J., Törő, M.: Növényolaj alapú motorhajtóanyag-adalékok előállítása és vizsgálata, Műszaki Kémiai Napok 06, Veszprém, április 25-27, in Proceedings, (ISBN ), [15] Hancsók, J., Bubálik, M., Törő, M., Baladincz, J., Holló, A.: Synthesis of Fuel Additives Based on Vegetable Oil Derivative, International Conference, Tribology of Alternative Fuels and Ecolubricants, Ausztria, Bécs, május In Proceedings (ISBN ), 4 oldal [16] Bubálik, M., Hancsók, J., Törő, M., Baladincz, J.: New fuel additives based on vegetable oil, 7th International Symposium MOTOR FUELS 2006, Szlovákia, Tatranské Matliare, junius , in Proceedings (ISBN ), [17] Hancsók, J.; Bubálik, M.; Beck, Á.: Development of multifunctional additives based on vegetal oils for high quality diesel and biodiesel, European Congress of Chemical Engineering 6, Dánia, Koppenhága, szeptember , In ECCE-6 Book of Abstracts Vol(1), , In Conference CD 11pp [18] Beck, Á., Hancsók, J., Bubálik, M.: Repceolaj zsírsav-metil-észter alapú többfunkciós dízelgázolaj és motorolaj adalékok előállítása és vizsgálata, Műszaki Kémiai Napok 08, Veszprém, április , in Proceedings (ISBN ), [19] Bubálik, M., Beck, Á., Hancsók, J.: Gázolaj adalékok detergens-diszegens vizsgálata motorkísérletekkel, Műszaki Kémiai Napok 09, 2009 április , in Proceedings (ISBN: ), Conference presentation [1] Bubálik M., Bartha L.: Motorolajok súrlódáscsökkentő hatékonyságának vizsgálatára használt mérési módszer továbbfejlesztése, Intézményi Tudományos Diákköri Konferencia, Veszprémi Egyetem, Veszprém, [2] Bubálik M., Bartha L.: Motorolajok súrlódáscsökkentő hatékonyságának vizsgálatára használt mérési módszer továbbfejlesztése, XXVI. Országos Tudományos Diákköri Konferencia, ELTE, Budapest, [3] Bubálik, M., Hancsók, J., Molnár, I., Csordás, E.: Különböző kén-, nitrogén- és aromásváltozó adaléktartalmú dízelgázolajok korróziós hatásának vizsgálata, Műszaki Kémiai Napok 05, Veszprém, április , Kiadvány, (ISBN ), 271 [4] Kocsis, Z., Baladincz, J., Bartha, L., Bubálik, M., Hancsók, J., Sági, R.: Poliisobuthylene-Dycarboxylic Acids and Their Additive Derivates, 15th International Colloquim Tribology, Technische Akademie Esslingen, január Proceedings (ISBN: ), 291. [5] Bubálik, M. Hancsók, J. Beck, Á. Sági, R. Baladincz, J.: Development of multifunctional additives based on vegetable oils for high quality lube oil and diesel fuel, 16th International Colloquium Tribology, Németország, Stuttgart/Ostfildern, január

8 Other publications and conference presentations [1] Hancsók, J., Bubálik, M., Almási, M.: Energiatelepek, az újból felfedezett alternatív energiaforrás, MOL Szakmai Tudományos Közlemények, 2004 (1), [2] Hancsók, J., Bubálik, M.: Fémek visszanyerése használt katalizátorokból, I. Nemesfémek visszanyerése, MOL Szakmai Tudományos Közlemények, 2006, (2), [3] Hancsók, J., Bubálik, M., Nagy, G.: Fémek visszanyerése használt katalizátorokból II. Átmeneti fémek visszanyerése és FCC-katalizátorok feldolgozása, MOL Szakmai Tudományos Közlemények, 2007, 1, [4] M. Bubálik, L, Leveles, I, Valkai, M, Balassa, Zs, Császár: Development opportunities for Fluid Catalytic Cracking units, INTERFACES 08, Magyarország, Sopron, szeptember , in Proceedings of Interfaces 08, (ISBN ), 38. Reference To Hancsók, J., Bubálik M., Törő, M., Baladincz, J.: Synthesis of fuel additives on vegetable oil basis at laboratory scale, European Journal of Lipid Science and Technology, 2006, 108(8), publication [1] Ayhan Y ld r m, Mehmet Çetin: Synthesis of undecanoic acid phenylamides as corrosion inhibitors European Journal of Lipid Science and Technology, 2008, 110(6), Impact factor of publications: 2,021