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CATALYSTS Sammy Tran

CATALYSTS Sammy Tran. Catalytic Converter used on automobiles in Europe: Converts CO, Hydrocarbons, and oxides of nitrogen into Water, Carbon Dioxide, and Nitrogen. Reduces the emissions of these harmful gases. What is a Catalyst?.

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CATALYSTS Sammy Tran

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  1. CATALYSTS Sammy Tran Catalytic Converter used on automobiles in Europe: Converts CO, Hydrocarbons, and oxides of nitrogen into Water, Carbon Dioxide, and Nitrogen. Reduces the emissions of these harmful gases.

  2. What is a Catalyst? A Catalyst is a substance that initiates or accelerates a chemical reaction without itself being affected.Catalysts provide an alternative reaction mechanism with a lower activation energy.

  3. Introduction to Catalysts • Catalysts increase the rates of both the forward and reverse reactions equally. Thus, they reduce the time to reach the equilibrium. They have no effect on either the yield of the reaction or the equilibrium constants. • Reaction with Catalyst Vs. without Catalyst>>>

  4. General Uses Of Catalysts • Meat products • Catalytic Converters help reduce pollution • Antibiotics • “Biological” Detergents • Manufacturing of Petroleum • Different types of Motors (thrusters)

  5. Recyclable Catalysts • Replacing hazardous solvents with water and being more efficient with resources are methods that chemists use to reduce the environmental impact of their reactions—a central goal of the ‘green chemistry’ movement. Yasuhiro Uozumi from the RIKEN Advanced Science Institute in Wako has developed recyclable catalysts that selectively generate chiral organic molecules in water, considered a nearly ideal green chemical process.

  6. Goal: Improve quality of loading of reformer catalyst • Goal: Improve quality of loading of reformer catalystTools: PETROVAL uses the UNIDENSE technology to load reformer tubes in ammonia, methanol and hydrogen plants. gives improved homogeneity and density, and shorter loading time, than pre-socked catalystBenefits: • · Quick loading • · No pre-socking required • · No or very little tube vibration • · Uniform dPs (PETROVAL guarantees ±5%) • · No bridging or gaps in catalyst inside the tubes

  7. catalysts improve yields in petrochemical plants.

  8. Homogeneous Catalysts ---Catalyst is in the same phase as reactants ---Increase rate of reaction caused by catalyst allowing for reaction to occur with alternative mechanism with lower activation energy ---Catalyst is consumed at one stage in the mechanism and reformed at a later stage ---Liquid Phase *Source-Green Damji- Chemistry 2nd Edition p.241 Heterogeneous Catalysts ---Catalyst is in different phase to reactants ---Catalyst provides reactive surface where reaction can take place; reactants are absorbed onto the surface ---This process weakens the bonding in molecules and brings them into close contact; reaction occurs on the surface and the products are desorbed; this frees the surface for further reaction ---Solid/Gas Phase *Source-Green Damji- Chemistry 2nd Edition p.241 Types of Catalysts

  9. HOMOGENEOUS CATALYSIS WORKFLOW • The Homogeneous Catalysis Workflow uses liquid and solid handling robotics, parallel pressure reactors, and standard analytical screens to study up to hundreds of reactions every day under different temperature/pressure conditions

  10. Homogeneous Catalysts Advantages---all the catalyst is exposed to the reactant, easily modified, reaction mechanisms are well understood by scientists, easy process of diffusion and heat transfer, well defined active site Disadvantages--- can be difficult to remove from the products for reuse Heterogeneous Catalysts Advantages---easily removed from products by filtration, easily recycled Disadvantages---only effective on the surface, reaction mechanisms are poorly understood in general, poorly defined active site Advantages and Disadvantages

  11. Low Temp. Oxidation Catalyst • <<<Low Temperature Oxidation Catalyst—reduces CO emissions as well as formaldehydes and other lightweight hydrocarbons

  12. Heterogeneous One or more of reactants adsorbed(stick to surface) onto surface in the active site, Product molecules are desorbed, or break away. Homogeneous Catalyst in same phase as reactants transition metal compounds as catalysts is convenient- their ability to change oxidation state-avoids problem of wrong collisions for reaction to occur MODES OF ACTION

  13. CatCart Immiscible phases • The CatCart® - created to make the process of hydrogenation easier and more efficient., steel tube packed with heterogeneous catalyst, filter system at both ends of tube allows liquid to pass through the column and prevents catalyst from leaking out • two immiscible aqueous-organic phases investigated for different organic transformations =the onium salt forms a distinct liquid phase which is catalyst-philic, and contains - or coats - the metal catalyst methods of catalyst separation and product recovery, as well as advantages on catalytic efficiency, have been demonstrated.

  14. Factors that determine choice of catalysts selectivity (produce only the desired product) efficiency ability to work under mild/severe conditions environmental impact problems caused by catalysts becoming poisoned by impurities.

  15. RTM is a low pressure moulding process, where a mixed resin and catalyst are injected into a closed mould containing a fibre pack or preform. When the resin has cured the mould can be opened and the finished component removed. • The Advantages and Benefits of using RTM: • Components will have good surface finish on both sides • Selective reinforcement and accurate fibre management is achievable • Ability to build-in fibre volume fraction loadings up to 65% • Uniformity of thickness and fibre loading, resulting in uniform shrinkage • Tooling costs comparatively low compared to other manufacturing processes • Uses only low pressure injection • Low volatile emission during processing • Ability to produce near net shape mouldings, reducing material wastage • Process can be automated, resulting in higher production rates with less scrap • Ability to mould complex structural and hollow shapes

  16. Bibliography of Photos http://www.nasa.gov/centers/langley/images/content/351625main_low-temp-ox-catalyst_516-387.gif http://www.plastech.co.uk/Images/JEC%20RTM%20Diagram.jpg http://www.vajdagroup.com/images/stories/industry/our%20offer/production/RTM_1.jpg http://www.symyx.com/products/images/homogeneous_catalysis_4.jpg http://www.thalesnano.com/files/image/products/catcarts.jpg http://www.rikenresearch.riken.jp/images/figures/hi_3392.jpg http://www.basf.com/group/corporate/en/function/conversions:/publish/content/innovations/innovation-award/2007/images/2007-catalysts-170x170.jpg http://www.petroval.fr/image/tubeloading_250.gif http://ene.web.psi.ch/Combustion/comchem/Fig1a.gif http://www.unive.it/media/allegato/dipartimenti/Dip%20SA/Selva_image037.jpg http://www.ace.mmu.ac.uk/Resources/Fact_Sheets/Key_Stage_4/Transport/images/06a.jpg

  17. Other Sources http://gcserevision101.files.wordpress.com/2009/02/energy-level-diagram-activation-energy.jpg Green, Damji Chemistry: For Use With The International Baccalaureate Diploma Programmme http://www.essortment.com/all/howenzymeswork_rkyf.htm file:///C:/DOCUME~1/SAMMYT~1/LOCALS~1/Temp/chemistry_hl_paper_2a.pdf http://www.ibo.org/diploma/curriculum/examples/samplepapers/documents/gp4_chemistyhl3.pdf http://web.uvic.ca/~mcindoe/423/homovshet.pdf http://www.chemguide.co.uk/physical/catalysis/introduction.html

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