Presentación del tema: "CATÁLISIS EN LA INDUSTRIA QUÍMICA relevancia industrial"— Transcripción de la presentación:
1CATÁLISIS EN LA INDUSTRIA QUÍMICA relevancia industrial Y EN LA VIDA COTIDIANAProcesos catalíticoshomogéneos yheterogéneos derelevancia industrialJ. Carles BayónUniversitat Autònoma de Barcelona
2ESTRUCTURA DE LA PRESENTACIÓN Definiciones y conceptos importantesAplicaciones visibles de la catálisisPerspectiva histórica
3CATALISIS QUÍMICALa catálisis química es una ciencia central en una sociedad tecnológicamente avanzadaMás del 80% de los productos químicos manufacturados requieren por los menos una etapa catalítica (es decir, emplean al menos un catalizador)La investigación en catálisis es indispensablepara el desarrollo sostenible del planeta
4Catálisis: Energía y petroquímica La catalisis es una disciplina crucial en el desarrollo de la industria quimica actualmas del 80% de los productos quimicos manufactarados requiren por lo menos una etapa catalitica en su sintesis
5Catálisis: Abonos y agroquímicos La preparacion de abonos y productos agriquimicos (herbicidas, insecticidas, etc) es crucial en la sociedad actual.Se inica con la sintesis catalitica del amoniaco hace mas de 100 años.Por primera vez en al historia el hombre dispone de tecnologia para alimentar a toda la población del planeta. El hambre es un problema politico, no tecnico.
6Tratamiento de residuos y contaminates Catálisis:Tratamiento de residuosy contaminatesLa preparacion de abonos y productos agriquimicos (herbicidas, insecticidas, etc) es crucial en la sociedad actual.Se inica con la sintesis catalitica del amoniaco hace mas de 100 años.Por primera vez en al historia el hombre dispone de tecnologia para alimentar a toda la población del planeta. El hambre es un problema politico, no tecnico.
111890 Pf= -25ºC Peb= 43ºC Ludwig Mond (1839-1909) Pf= -25ºCPeb= 43ºCChemist and industrialist, Mond invented a process for recovering sulphur during the manufacture of alkali and also developed a producer gas known by his name. He was cofounder and director of Brunner-Mond (1872), which became the world's largest producer of alkalies. Another outstanding discovery of his was nickel carbonyl, a gas formed from carbon monoxide and metallic nickel. He developed one of the first hydrogen-oxygen fuel cells.Ludwig Mond was born in Kassel, Germany, and studied chemistry at Marburg under suporvision of Prof. Hermann Kolbe and then at Heidelberg under supervision of Prof. Robert Bunsen. In 1859, working in a small soda works near Kassel, he initiated the new process for the recovery of sulphur. This gained him an invitation from a Lancashire industrial chemist, and Mond moved to the UK in 1862.In England Mond obtained a position in a chemical works at Widnes, where he elaborated the practical application of a method he had devised for recovering the sulphur lost as calcium sulphide in the black ash waste of the Leblanc alkali process. He became a naturalized British subject in In 1873 he entered into partnership with Sir John Tomlinson Brunner, whom he had met when he was at Widnes, and thus founded the great chemical manufacturing firm of Brunner, Mond & Co. They began to make alkali by the ammonia-soda process, under licence from the Belgian chemist, Ernest Solvay, but at first the venture threatened to prove a failure. Gradually, however, the technical difficulties were overcome and success assured. The Brunner, Mond & Co eventually became the international giant, Imperial Chemical Industries (ICI). A son of Ludwig Mond, Alfred Mond, 1st Baron Melchett ( ), continued as a director of the father's companies but was more interested in politics, becoming a member of Lloyd George's cabinet.In 1879, Mond became interested in the production of ammonia. He began experiments in the economical utilization of fuel, and his efforts led him to the system of making producer-gas, known by his name. One outcome was the development of the Mond producer gas process, in which carbon monoxide and hydrogen are produced by alternately passing air and steam over heated coal or coke (and the hydrogen used to convert nitrogen into ammonia). By the early 1900s, Mond's Dudley Port Plant in Staffordshire was using 3 million tonnes of coal each year to make producer gas (Mond gas).In 1889, Mond and his assistant Carl Langer described their experiments with a hydrogen-oxygen fuel cell that attained 6 amps per square foot (measuring the surface area of the electrode) at 0.73 volts. Mond and Langer's cell used electrodes of thin, perforated platinum. They noted difficulties in using liquid electrolytes, saying "we have only succeeded by using an electrolyte in a quasi-solid form, viz., soaked up by a porous non-conducting material, in a similar way as has been done in the so-called dry piles and batteries." An example given is an earthenware plate "impregnated by dilute sulfuric acid." The term "fuel cell" was coined (or at least popularized) in 1889 by Ludwig Mond and Charles Langer, when they attempted to use air and coal gas to generate electricity. Nickel carbonylLater, while attempting to utilize the gas for the production of electricity by means of a Grove gas battery, he noticed that the carbon monoxide contained in it combined with nickel. The resulting compound, nickel carbonyl, which was described to the Chemical Society in 1890, is both formed and decomposed within a very moderate range of temperature. Lord Kelvin described nickel carbonyl molecules as "metals with wings". Mond developed a valuable method known as the Mond process for extracting nickel from its ores by use of this carbonyl. In the process, carbon monoxide passing over the crushed and smelted ore containing nickel produces the volatile nickel carbonyl; this is decomposed to yield metallic nickel.A liberal contributor to the purposes of scientific research, Mond founded in 1896 the Davy-Faraday Research Laboratory in connexion with the Royal Institution. He donated for this laboratory costing £100,000. On his death, which occurred in London on the 11th of December 1909, he bequeathed a large part of his collection of pictures to the nation. Mond was buried on the Saint Pancras Cemetery, East Finchley, London, England (see a picture of his burial at left).Ludwig Mond ( ) desceple de Bunsen a Heilderberg. Va viure i treballar a UK on va descubrir el Ni(CO)4 quan treballava amb amb valvules de Ni en les que va observar corrossio per CO. Va descubrir el Ni(CO)4 al 1890 i patentar un metode per purificar el Ni (especialment del Co) per “extraccio” del Ni en forma de carbonil i reciclatge de CO. Un dels fundadors d’ICILudwig Mond( )
13DEFINICIÓN:Catalizador es una sustancia que aumenta la velocidad con la que una reacción alcanza el equilibrio, sin consumirse esencialmente en esta reacciónWilhem Ostwald (1895)Catálisis es una habilidad de las substancias para exaltar, por mero contacto, la afinidad latente de los reactivos para producir una reacción, que de otra forma no tendría lugarJakob Berzelius (1835)Berzelius insisted categorically that it had not been his intention with this terminology to give an explanation of the group of phenomena. On the contrary he defined: The catalytic force actually appears to consist in the ability of substances to arouse the affinities dormant at this temperature by their mere presence and not by their affinity and so as a result in a compound substance the elements become arranged in another way such that a greater electrochemical neutralization is brought about.
15G‡ H2C=CH2 G + H2 H3C- CH3 + Ni Reacción catalizada El segundo aspecto importante: catalizador no se consume+ NiH3C- CH3
16Catalizada versus no catalizada El primer aspecto y fundamental es que permite llevar a cabo reacciones que serian inviables en ausencia de catalizador.
17ABONOS 1909 1/2 N2 + 3/2 H2 NH3 H= - 309 kJ·mol-1 El problema de alimentar a la población mundial es hoy dia “solo” una cuestion politica (compleja: mantener precios, tratamiento de excedentes, etc) ya que el problema tecnologico esta resuelto. Quizas el problema politico de la distribucion de aliementos no es mas facil de resolver que el tecnologico, pero es mejor enfrentarse a uno que a dos problemas.
18ABONOS Abono natural (mineral): NaNO3 (KNO3) Abono sintético: 25% NO3- 8 % NH4+P, S, K, Mg,Nitrato de Chile junto con el abono natural (guano, estiercol) fue la fuente de nitrogeno para el abono hasta el 1920 aproximadamente.Catalizador: malla de 4 m diametro , hilo e 0.06 mm seccion, 1024 meshes/cm2Reactor contiene hasta 50 mallas
19ABONOS Wilhem Ostwald 1853-1932 Premio Nobel 1909 Wilhem Ostwald Catalizador actualNH3 + 2 O HNO3 + H2O H= kJ·mol-1Catalizador: malla de Pt, 5% Rh, 5% Pd1902Wilhelm Ostwald was born on September 2, 1853, in Riga, Latvia, as the son of master-cooper Gottfried Wilhelm Ostwald and Elisabith Leuckel. In 1909 Ostwald was awarded the Nobel Prize for Chemistry for his work on catalysis, chemical equilibria and reaction velocities.Ostwald: definicion de catalizadorEl amoniaco solo se obtenía como subproducto de la gasificación de la hullaCatalizador: malla de 4 m diametro , hilo e 0.06 mm seccion, 1024 meshes/cm2Reactor contiene hasta 50 mallasProceso industrial en 1908
20ABONOS F. Haber (1868-1934) C. Bosch (1874-1940) Proceso industrial en 191319091/2 N2 + 3/2 H NH3 (15-25% conversión!)400ºC200 barCatalizador:90% Fe() y promotores (K2O, Al2O3, MgO, SiO2)Mittasch (BASF)20,000 catalizadoresFritz Haber was born on December 9, 1868 in Breslau, Germany, in one of the oldest families of the town, as the son of Siegfried Haber, a merchant. He went to school at the St. Elizabeth classical school at Breslau and he did, even while he was at school, many chemical experiments. From 1886 until 1891 he studied chemistry at the University of Heidelberg under Bunsen, at the University of Berlin under A.W. Hoffmann, and at the Technical School at Charlottenberg under Liebermann. After completing his University studies he voluntarily worked for a time in his father's chemical business and, being interested in chemical technology, he also worked for a while under Professor Georg Lunge at the Institute of Technology at Zurich. He then finally decided to take up a scientific career and went for one and a half years to work with Ludwig Knorr at Jena, publishing with him a joint paper on diacetosuccinic ester. Still uncertain whether to devote himself to chemistry or physics, he was offered in 1894, and accepted, an assistantship at Karlsruhe by the Professor of Chemical Technology there, Hans Bunte. Here he remained until Bunte was especially inlterested in combustion chemistry and Carl Engler, who was also there, introduced Haber to the study of petroleum and Haber's subsequent work was greatly influenced by these two colleagues. In 1896 Haber qualified as a Privatdozent with a thesis on his experimental studies of the decomposition and combustion of hydrocarbons and in 1906 he was appointed Professor of Physical Chemistry and Electrochemistry and Director of the Institute established at Karlsruhe to study these subjects. In 1911 he was appointed to succeed Engler as Director of the Institute for Physical and Electrochemistry at Berlin-Dahlem, where he remained until, in 1933, the Nazi race laws compelled nearly all his staff to resign and Haber, rather than agree to this, himself resigned. He was then invited by Sir William Pope to go to Cambridge, England and there he remained for a while. He had, however, been suffering for some time from heart disease and, fearing the English winter, he moved to Switzerland. Haber's early work on the decomposition and combustion of hydrocarbons has already been mentioned. In 1898 Haber published his textbook on Electrochemistry, which was based on the lectures he gave at Karlsruhe. In the preface to his book he expressed his intention to relate chemical research to industrial processes and in the same year he reported the results of his work on electrolytic oxidation and reduction, in which he showed that definite reduction products can result if the potential at the cathode is kept constant. In 1898 he explained the reduction of nitrobenzene in stages at the cathode and this became the model for other similar reduction processes. There followed, during the next ten years, many other electrochemical researches. Among these was his work on the electrolysis of solid salts (1904), on the establishment of the quinone-hydroquinone equilibrium at the cathode, which laid the foundations for Biilmann's quinhydrone electrode for determining the acidity of a liquid; but Haber invented, in collaboration with Cremer, the glass electrode for the same purposes which is now widely used. This led Haber to make the first experimental investigations of the potential differences that occur between solid electrolytes and their aqueous solutions, which were of great interest to physiologists. During this period Haber also studied the loss of energy by steam engines, turbines and motors driven by fuels, and sought methods of limiting their loss by electrochemical means. He did not succeed in finding a solution of this problem that was commercially applicable, but he did succeed in finding a fundamental solution for the laboratory combustion of carbon monoxide and hydrogen. He then turned to the study of flames and did fundamental researches on the Bunsen flame, showing that, in the luminous inner cone of this flame, a thermodynamic water-gas equilibrium is established and that, in its outer mantle, there is combustion of water-gas. This led to a chemical method of determining flame temperatures. Haber then undertook the work on the fixation of nitrogen from the air for which he was given the Nobel Prize in Chemistry for 1918 (awarded in 1919). In 1905 he had published his book on the thermodynamics of technical gas reactions, in which he recorded the production of small amounts of ammonia from N2 and H2 at a temperature of 1000° C with the help of iron as a catalyst. Later he decided to attempt the synthesis of ammonia and this he accomplished after searches for suitable catalysts, by circulating nitrogen and hydrogen over the catalyst at a pressure of atmospheres at a temperature of about 500° C. This resulted in the establishment, with the cooperation of Bosch and Mittasch, of the Oppau and Leuna Ammonia Works, which enabled Germany to prolong the First World War when, in 1914, her supplies of nitrates for making explosives had failed. Modifications of this Haber process also provided ammonium sulphate for use as a fertilizer for the soil. The principle used for this process and the subsequent development of the control of catalytic reactions at high pressures and temperatures, led to the synthesis of methyl alcohol by Alwin Mittasch and to the hydrogenation of coal by the method of Bergius and the production of nitric acid. During the years between the two World Wars Haber produced his firedamp whistle for the protection of miners, his quartz thread manometer for low gas pressures and his observation that adsorption powers can be due to unsaturated valence forces of a solid body, on which Langmuir founded his theory of adsorption. When the First World War broke out he was appointed a consultant to the German War Office and organised gas attacks and defences against them. This and other work undermined his health and for some time he was engaged in administrative work. He helped to create the German Relief Organisation and served on the League of Nations Committee on Chemical Warfare. From 1920 until 1926 he experimented on the recovery of gold from sea water, his idea being to enable Germany to meet her war reparations. Greatly depressed by the failure of this project, which he attributed to his own deficiency, he devoted himself to the reorganisation of his Institute, to which he appointed sectional directors with complete freedom in their work. Among these were James Franck, Herbert Freundlich, Michael Polanyi and Rudolf Ladenburg; from the Institute came much work on colloid chemistry and atomic physics. Haber himself, at this time, made great efforts to re-establish the scientific relationships of Germany with other countries and the colloquia which he held every fortnight did much to establish the international repute of his Institute. During his last years he worked on chain reactions and on mechanisms of oxidation and on hydrogen peroxide catalysis. Haber lived for science, both for its own sake and also for the influence it has in moulding human life and human culture and civilization. Versatile in his talents, he possessed an astonishing knowledge of politics, history, economics, science and industry and he might have succeeded equally well in other fields. The hesitation with which he finally decided to be a chemist has already been mentioned. He welcomed administrative responsibilities in addition to research work. Always approachable and courteous, he was interested in every kind of problem. His ability to clarify, in a few sentences, the obscurities of a scientific discussion, was a valuable feature of the colloquia he held at his Institute and his organising talent made him a model Director of a large establishment in which he allowed complete freedom, to the workers under him, maintaining, nevertheless, a remarkable control over the activities of the Institute as a whole. A man of forceful personality, he left a lasting impression on the minds of all his associates. Apart from the Nobel Prize, Haber received many honours during his life. At Max von Laue's instigation, the Institute for Physical and Electrochemistry at Berlin-Dahlem was renamed the Fritz Haber Institute after his death. After a grave illness, Haber died on January 29, 1934, at Basle, on his way from England to convalesce in Switzerland, his spirit broken by his rejection by the Germany he had served so well.From Nobel Lectures, Chemistry , Elsevier Publishing Company, AmsterdamHaber dirigio personalmente el primer ataque con agentes quimicos (Cl2) en la guerra de trincheras durante la primera guerra mundial, Su esposa se suicido, probablemnte por este motivo.Aunque el 80% del amoniaco que se produce se utiliza en la industria de los abonos, una pequeña parte se emplea en la industria de explosivos (nitroderivados).Estos dos hechos dan un perfil belicista de Haber. No obstante, la disponibilidad de abonos casi ilimitada (si se dispone de la energía suficiente) y por tanto de alimentos, que debemos a su descubrimiento de la síntesis de del amoniaco sin duda ha evitado y evitara muchas guerras en el futuro.Premio Nobel 1918Premio Nobel 1931
22MOTOR DE COMBUSTIONCombustión estequiométricaC6H O CO2 + 6 H2OConvertidor catalíticoCxHy + COO2PtCO2 + H2OMódulo de oxidaciónCombustión en defecto de O2C6H O CO + 6 H2ONOxRh1/2 N2 + x/2 O2Módulo de reducciónCombustión en exceso de O2C6H O CO2 + 6 H2ON2 + O NOx
23Fotocatálisis sobre TiO2 Purificación de aguas residuales con bajaconcentración de contaminantesbanda devalenciaconducción
24APLICACIONES ACTUALES Hidrogenación de las olefinas de la naftaObtención de margarinas
25Aceite vegetal H2 Ni Margarina Triglicerido Acidos grasos: oleico (monoinsaturado) y linaloico (polinsaturado)
26disuelto en EtOH ivermictina H2 RhCl(PPh3)3 disuelto en EtOH Ivermictina infecciones por parasitos (tambien en animales) antihelmintico= gusanos parasitos)
27DEFINICIÓN:Catalizador homogéneo es el que se encuentra en la misma fase (normalmente en disolución) que los reactivosCatalizador heterogéneo es el que se encuentra en una fase distinta a la de los reactivos. Normalmente el catalizador es sólido y los reactivos son gases o líquidos
31las reacciones mediante el catalizador Bcontrol sobre laselectividad delas reacciones mediante el catalizadorSi aceptamos que la energia de activacion esta relacionada con la estabilidad del intermedio de reaccion
33El papel de los ligandos HidroformilaciónO. RoelenRuhrchmie AG, 1938300 bar160ºC20 bar100ºCUnion Carbide, 1976O. RoelenSelectividad 80%Selectividad 95%
34El papel de los ligandos Polimerización de olefinasPremio Nobel 1963K. Ziegler, G. NattaMontecatini, 1955Exxon, Dow, etc 1990-Acabando estamos acabando la edad de hierro de los polimeros (aunque el hiero este ausente con alguna excepcion en los catalizasoresCrecimiento exponencial de las publicaciones sobre polimerizacion de etilenoPolipropilenoisotácticoControl del Mw,copolimerización
35W.S. Knowles R. Noyori K.B. Sharpless Premio Nobel 2001 El papel de los ligandosW.S. KnowlesR. NoyoriK.B. SharplessPremio Nobel 2001Catálisis asimétrica
36Objeto quiral: No contiene un eje impropio de simetría DEFINICIÓN:Objeto quiral: No contiene un eje impropio de simetría( no tiene plano de simetría)S-asparaginaamargantRdolça+C-ONH32amargadulceLos dos isomeros saben diferente porque el material biológico de las papilas gustativas es quiral
37Productos enantioméricamente puros Fármacos100 más vendidos en 199450 quirales199833 fármacos quirales aprobados FDA:32 enantiómero puro1 mezcla de enantiómeros25enantiómeropuro25mezclaenantiómeros
38tratamiento sintomático Síntesis de la LEVODOPARh-DIPAMPL-DOPA (Monsanto)tratamiento sintomáticode la enfermedadde Parkinson
39DEFINICIÓN:Selectividad de un catalizador (en un producto) es el cociente entre los moles de producto obtenidos y los moles de reactivo consumidosActividad de un catalizador es una medida de la velocidad de la reacción en relación al catalizador utilizado:Estabilidad de un catalizador es una medida de su capacidad de convertir reactivos en productos durante su “tiempo de vida”:
40ECONOMÍA ATÓMICA Ruta catalítica Ruta clásica El catalizador de plata es selectiva para esta oxidación y no para la combustión completa a CO2 o a otros productos de oxidación.El oxido de etileno se emplea fundamentralment en en la sintesis de etilenglicol (componete del PET, disolvente para pinturas), acrilonitrilo (base de las fibras acrilicas) y de los polietilenglicoles que son tensoactivos no ionicos.
41EL PROBLEMA DE LOS RESIDUOS Procesos sin residuos:SelectividadEconomía atómicaDisolvente aceptable (o sin disolvente)Un proceso totalmente selectivo y con perfecta economia atómica es un procesos sin residuos, es decir es "quimica verde"
42EL PROBLEMA DE LOS RESIDUOS Segmento Producción kg subproductosindustrial Tm/año kg productoProductos de <1 a 5básicosQuímica de 5 a < 50FinaFarmacéutica de 25 a 100
43ECONOMÍA ATÓMICA EN FARMACOS Ruta BootsDespilfarro atómicoRuta HoeschtEconomía atómica
45ZSM-5 Nan[AlnSi96-nO192] ~ 16 H2O (n < 27) Características: Carácter de ácido fuerteCatalizador heterogéneo selectivoPatente US 1972Estructura molecular porosaK1
46Proceso Amoco (oxidación p-xileno a diácido) Producción mundial:millones de Tmmillones de Tm
47Electrocatálisis (oxidación tolueno a benzaldehído)
48(Clean Urban Tranport for Europe) Proyecto CUTE(Clean Urban Tranport for Europe)H2 - 2 e H+1/2 O2 + 2H+ + 2e H2OH2 + 1/2 O H2O
49PEMFC H2 - 2 e- 2H+ 1/2 O2 + 2H+ + 2e- H2O H2 + 1/2 O2 H2O H2 O2 catcátodoánodoPEMFC- 2 e-+ 2 e-O2H2+ 2 e-2H+Celdas de combustible en centrales d energía , en pequeñas aplicaciones que requieren energía eléctrica (ordenadores portátiles, teléfonos móviles, etc).H2OE= 0.7 V
50COCHE: un problema más complicado CH3OH + H2O CO2 + 3 H H> 0CH3OH + O CO2 + 2 H H< 0Catalizadores: óxidos mixtos de Cu, Zn, Al etcLa densidad del H2 liquido es 79 g/l , es decir un décimo de la del metanol. Asi, un l de metanol contiene 10 veces mas masa que 1 l de H2.La densidad del H2 gas es 0.09 g/l