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Contents contributed and discussions participated by Amy Chern

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Amy Chern

Case Study: The Haber Process - ChemWiki - 3 views

chemwiki.ucdavis.edu/...Haber_Process

shared by Amy Chern on 14 Feb 13 - No Cached
  • used in order to produce food, so that in WWI people could continue to fight. It only requires 1 percent of the world's energy to make 500 million tons of artificial fertilizer per year, which, in turn, helps feed 40 percent of the world's population.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Origins of the Haber process - needed during World War I. Ammonia for use in fertilizer is effective and economical
  • exothermic reaction,
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Equilibrium - desirable to have lower temperature to shift equilibrium to the right Kinetics - higher temperature would result in faster reaction Must reach a compromise between the two.
Amy Chern

Haber Process - 4 views

go.galegroup.com/ps/retrieve.do?sgHitCountType=None&sort=DA-SORT&inPS=true&prodId=GPS&userGroupName=lom_inac&tabID=T003&searchId=R1&resultListType=RESULT_LIST&contentSegment=&searchType=BasicSearchForm&currentPosition=2&contentSet=GALE%7CA273242152&&docId=GALE|A273242152&docType=GALE&role=ITOF

shared by Amy Chern on 14 Feb 13 - No Cached
  • For the past 100 years, the Haber-Bosch process has been used to convert atmospheric nitrogen into ammonia, which is essential in the manufacture of fertilizer.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Ammonia is essential for the production of fertilizer, and the Haber process provides an efficient and effective way to produce ammonia.
  • iron catalyst at extremely high pressures and high temperatures to break those bonds and produce ammonia
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Iron catalyst - speeds up reaction, but doesn't increase yield High Pressure - increase yield by shifting equilibrium to the right. High temperature - doesn't this push the equilibrium to the left?
  • eaction occurs only on a solid catalyst,
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Does it only occur on a solid catalyst because it needs a surface to react on?
  • ...4 more annotations...
  • They discovered that an iron complex combined with potassium was capable of breaking the strong bonds between the nitrogen (N) atoms and forming a complex with an Fe3N2 core, which indicates that three iron (Fe) atoms work together in order to break the N-N bonds.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Iron catalyst speeds up reaction by helping to break the strong nitrogen bonds.
  • Holland points out that the catalyst used in Haber-Bosch is considerably less expensive than what was used by his team.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      While other methods of forming ammonia exist, the Haber process is the most economical and efficient process.
  • one that would allow ammonia to be produced at lower temperatures and pressures.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      By decreasing temperature, the yield would increase as the production of ammonia is an exothermic reaction. If a catalyst could compensate for this decrease in temperature, then the efficiency of the production of ammonia would be maximized.
  • their strong triple bonds are difficult to break, making them highly unreactive.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Because bonds are difficult to break, must use a catalyst to speed up reaction.
  • Amy Chern on 14 Feb 13
     
    Amy Chern
Amy Chern

Gale Science In Context - Document - 2 views

ic.galegroup.com/...DocumentToolsPortletWindow

shared by Amy Chern on 14 Feb 13 - No Cached
  • German chemists Fritz Haber and Carl Bosch learned how to make ammonia in large quantities by high-pressure catalytic reactions of nitrogen (from air) with hydrogen.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Shift equilibrium as far to the right as possible to increase yield and to speed up production - high pressure and catalyst
  • The mixed gases circulate through the catalyst, ammonia is formed and removed, and the unconverted reactants are recirculated.
  • nited
  • ...3 more annotations...
  • United States production of ammonia reached 17 million tons in 1991, and demand was even larger than U.S. production, leading to about two million tons of imports.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Haber Process is important because ammonia is in high demand - need to have the most efficient and economical process for producing ammonia
  • New uses may develop, particularly for ammonia as a relatively inexpensive base with unique properties, for liquid ammonia as a solvent, and as a storage medium for hydrogen, as the nations evolve toward alternative fuels.
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      New uses of Ammonia are continously being discovered
  • earned to generate ammonia from animal parts such as deerhorn, and obtained ammonial preparations
    • Amy Chern
      Amy Chern on 14 Feb 13
       
      Ammonia has long been used for various purposes.
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