1 / 12

Reactions :

Reactions :. BASIC DATA (Ullmann’s Encyclopedia of Industrial Chemistry). “In all conventional processes, reaction takes place in the liquid phase, ...”. “The reaction of ethylene oxide with ammonia takes place slowly and is accelerated by water.”.

zonta
Download Presentation

Reactions :

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Reactions:

  2. BASIC DATA (Ullmann’s Encyclopedia of Industrial Chemistry) “In all conventional processes, reaction takes place in the liquid phase, ...” “The reaction of ethylene oxide with ammonia takes place slowly and is accelerated by water.” “The reaction is highly exothermic; the enthalpy of reaction is about 125 kJ per mole of ethylene oxide. ” “All the reaction steps have about the same activation energy and show a roughly quadratic dependence of the reaction rate on the water content of the ammonia – water mixture used. ”

  3. PERFORMANCE Type of reaction? Mixed reactions: NH3, MEA: Multiple in series EO: Multiple in parallel Performance choice? Maximum selectivity Conversion target? Multiple in series reactions: low conversion (50%?)

  4. Product Feed PF CSTR CONCENTRACIÓN CONCENTRATION Product Feed For safety reasons, ethylene oxide must be metered into the ammonia stream ; in the reverse procedure, ammonia or amines may cause ethylene oxide to undergo an explosive polymerization reaction. FLOW PATTERN

  5. CONCENTRATION Performance choice: maximum selectivity Stoichiometric ratio? NH3 >> EO

  6. TEMPERATURE Performance choice: maximum selectivity “All the reaction steps have about the same activation energy and show a roughly quadratic dependence of the reaction rate on the water content of the ammonia – water mixture used. ” Selectivity does not depend on temperature: maximum T (reduces reactor volume). “The reaction is highly exothermic ; the enthalpy of reaction is about 125 kJ per mole of ethylene oxide. ” Intensive cooling required.

  7. PRESSURE Objetivo: máxima selectividad “All the reaction steps have about the same activation energy and show a roughly quadratic dependence of the reaction rate on the water content of the ammonia – water mixture used. ” “In all conventional processes, reaction takes place in the liquid phase, ...” Selectivity does not depend on pressure: minimum P required to keep liquid phase (temperature depending).

  8. PRACTICAL REACTOR • Liquid phase reaction. • Homogeneous catalytic. • Flow pattern: PF (NH3 and MEA) and CSTR (EO). • Highly exothermic: cooling required • High pressure. “The reaction of ethylene oxide with ammonia takes place slowly and is accelerated by water.” • High residence time. Multi-tubular cooled reactor, with multiple intermediate EO feed points.

  9. SEPARADOR DIAGRAM

  10. Ullmann’s Encyclopedia of Industrial Chemistry “All the reaction steps have about the same activation energy and show a roughly quadratic dependence of the reaction rate on the water content of the ammonia – water mixture used. Therefore, product composition depends solely on the molar excess of ammonia and not on water content, reaction temperature, or pressure. The product distribution as a function of the molar ratio of the reactants is shown in Figure.”

  11. Ullmann’s Encyclopedia of Industrial Chemistry “Today, ethanolamines are produced on an industrial scale exclusively by reaction of ethylene oxide with excess ammonia, this excess being considerable in some cases ” “In all conventional processes, reaction takes place in the liquid phase, and the reactor pressure must be sufficiently large to prevent vaporization of ammonia at the reaction temperature.” “In current procedures, ammonia concentrations in water between 50 and 100 % , pressures up to 16 MPa (160 bar), reaction temperatures up to 150 °C, and an excess up to 40 mol of ammonia per mole of ethylene oxide are used. ”

  12. Ullmann’s Encyclopedia of Industrial Chemistry

More Related