Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Kinetics

1,050 views

Published on

Project from Chemical Reaction Engineering

Published in: Education
  • If you going to start a essay then you have to make a great study on your essay topic. InHelpWriting.net my academical essay. I had taken a online essay writing service to complete my essay. Because they can write a best essay as our specifications. I kept the service link in the source. HelpWriting.net Good luck!
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • DOWNLOAD FULL BOOKS INTO AVAILABLE FORMAT ......................................................................................................................... ......................................................................................................................... 1.DOWNLOAD FULL PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Be the first to like this

Kinetics

  1. 1. Kraft Process <ul><li>Jennifer Pratt </li></ul><ul><li>Chemical Reaction Engineering </li></ul><ul><li>5/1/06 </li></ul>
  2. 2. Outline <ul><li>Intro </li></ul><ul><li>Overview </li></ul><ul><li>Theory </li></ul><ul><li>Applications </li></ul><ul><li>Conclusions </li></ul>
  3. 3. Introduction <ul><li>Paper making began in China 2000 years ago </li></ul><ul><li>-originally used old rags  fibers </li></ul><ul><li>Today: trees/ recycled materials  fibers by pulping </li></ul><ul><li>Kraft process is main chemical method for tree  pulp </li></ul><ul><li>“ Kraft”=strong in German. Strong paper is made from Kraft pulped paper </li></ul><ul><li>Also “Sulfate Process” because sulfates are produced as a byproduct </li></ul><ul><li>Goal = remove lignin from the wood and obtain individual fibers </li></ul><ul><li>Lignin=strong polymer in plant cell walls for support and structure </li></ul>
  4. 4. Paper Making Process
  5. 5. Source: http://www.epa.gov/ttn/chief/ap42/ch10/final/c10s02.pdf
  6. 6. Overview <ul><li>Begins in Digester </li></ul><ul><ul><li>White liquor= Na 2 s+NaOH </li></ul></ul><ul><ul><li>Chips=logs chopped up into cornflake sized pieces </li></ul></ul><ul><li>Reaction of White liquor and chips </li></ul><ul><ul><li>Yields Black Liquor/Pulp mixture </li></ul></ul><ul><li>Blow Tank then Filter </li></ul><ul><ul><li>Contents separated into Black Liquor and Pulp Slurry </li></ul></ul><ul><ul><li>Pulp eventually becomes paper </li></ul></ul><ul><li>Chemical Recovery </li></ul><ul><ul><li>Black Liquor diluted and burned  energy and smelt </li></ul></ul><ul><ul><li>Smelt diluted  Green Liquor </li></ul></ul><ul><ul><li>Green Liquor converted back to White Liquor with Calcium Oxide </li></ul></ul>
  7. 7. Theory <ul><li>In the Digester </li></ul><ul><ul><li>Na 2 S + NaOH + wood chips —>Na 2 SO 4 + Na 2 CO 3 + pulp </li></ul></ul><ul><li>Five steps in Digester </li></ul><ul><ul><li>transportation of liquor ions to wood surface </li></ul></ul><ul><ul><li>diffusion of the ions into the wood fibers </li></ul></ul><ul><ul><li>chemical reaction between the wood and the ions </li></ul></ul><ul><ul><li>diffusion of the products back to the surface of the wood fibers </li></ul></ul><ul><ul><li>movement of the products into the bulk liquor. </li></ul></ul>
  8. 8. Theory <ul><li>Residence time is important </li></ul><ul><ul><li>More time=more lignin removal </li></ul></ul><ul><ul><li>Too much time=cellulose in fibers breaks down </li></ul></ul><ul><li>Kappa Number </li></ul><ul><ul><li>Degree of Lignification </li></ul></ul><ul><ul><li>Goal=maximize Kappa Number with least amount of chemicals </li></ul></ul>
  9. 9. Theory <ul><li>Rate of Delignification </li></ul><ul><ul><li>Initial-extraction of low MW lignin, turpentine and tall oil </li></ul></ul><ul><ul><li>Bulk-most lignin removed </li></ul></ul><ul><ul><li>Residual-last remnants of lignin removed </li></ul></ul>
  10. 10. Bulk Delignification Kinetics <ul><ul><li>-dL/dt=k 1 (OH - )(L) </li></ul></ul><ul><ul><li>Constant white liquor input  ln(Lo/L)=(k o )(t) </li></ul></ul><ul><ul><li>k o =Ae (-Ea/RT) </li></ul></ul><ul><ul><li>Activation energy for each wood is ultimately determined from experiment </li></ul></ul>
  11. 11. Conclusion <ul><li>Industry needs to know activation energy for pulp reaction to optimize process </li></ul><ul><li>Different parts of tree have different lignin content and uses </li></ul><ul><li>Trees from different geographical regions have different lignin content </li></ul><ul><li>Wood type chosen based on paper product produced, wood’s resistivity to delignification, & integrity of wood fibers produced in pulping </li></ul>
  12. 12. References <ul><li>Andersson, N., Wilson, D., and Germgard, U. (2002). Validating Continuous Kraft Digester Kinetic Models with Online NIR Measurements. Anchorage, AK. Proceedings for the American Control Conference. </li></ul><ul><li>Helm, R. (2000). Kraft Pulping . Retrieved April 25, 2006, from http://dwb.unl.edu/Teacher/NSF/C06 /C06Links /www.chem.vt.edu/chem- dept/helm/3434WOOD/notes2/kraft.html. </li></ul><ul><li>Wong, B.M., Deka, G.C., and Roy, D.N. (1995). Bulk Delignification Kinetics at Selected Vertical Heights With Jack Pine Plus Trees. Wood Science and Technology, 29, 11-18. </li></ul>
  13. 13. Questions?

×