• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Chemicals based on ethylene
 

Chemicals based on ethylene

on

  • 1,061 views

 

Statistics

Views

Total Views
1,061
Views on SlideShare
1,060
Embed Views
1

Actions

Likes
0
Downloads
36
Comments
1

1 Embed 1

http://www.linkedin.com 1

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

11 of 1 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • good
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Chemicals based on ethylene Chemicals based on ethylene Presentation Transcript

    • COMSATS Institute of Information Technology Defence Road, Off Raiwind Road, Lahore, Pakistan
    • Chemistry of Petrochemical Processes Chemicals based on Ethylene
    • Presented by Group #7 • Hafiz Annus Mahmood CIIT/SP10-BEC-015/LHR • Mohammad Abubakar CIIT/SP10-BEC-022/LHR • Noaman Ahmed CIIT/SP10-BEC-037/LHR • Saim Khan CIIT/SP10-BEC-044/LHR
    • Outline • Brief introduction of ethylene • Properties of ethylene • List of major products of ethylene • Discussion of products obtained from ethylene ▫ Ethylene Glycol ▫ Acetaldehyde • Conclusion • References
    • Ethylene – An Introduction • Ethylene is a hydrocarbon with a chemical formula C2H4
    • Ethylene – Properties • Colorless, flammable gas with a sweet and musky odor in its pure form • Simple structure • High reactivity • Relatively inexpensive • Produces less by-products, during reactions with other compounds, as compared to other olefins
    • Ethylene – Properties (contd.) • Raw material for various chemicals and polymers e.g., ethanol and polyethylene • Easily produced from any hydrocarbon source through steam-cracking • Molecular weight – 28.05 g/mol • Density - 1.178 kg/m3 at 15 °C, gas • At standard conditions, ▫ Melting point is −169.2 °C or 104.0 K ▫ Boiling point is −103.7 °C or 169.5 K
    • Major Chemicals & Polymers produced form Ethylene
    • Products of Ethylene ETHYLENE OXIDE
    • Ethylene Oxide • A precursor for many important commercial chemicals such as, ▫ Ethylene glycol ▫ Ethanolamines ▫ Polyesters
    • Ethylene Oxide - Production • Main reaction is controlled oxidation (either using oxygen or air) of ethylene over a silver catalyst • Reaction is exothermic and heat content should be controlled • Excessive temperature increase and over-oxidation causes complete combustion of ethylene liberating water and carbon dioxide • Catalyst deteriorates at high temperature
    • Ethylene Oxide - Production (contd.) Ethylene Oxide
    • Ethylene Oxide - Production (contd.) • Why use oxygen instead of air ? • Oxygen (> 95% purity) is preferred for several reasons such as, ▫ Higher molar yield of ethylene oxide (75–82% for oxygen vs. 63–75% for air) ▫ Higher reaction rate (no gas dilution) ▫ No need of separating nitrogen in the reaction products
    • Ethylene Oxide - Production (contd.)
    • Ethylene Oxide - Production (contd.) • Compressed oxygen, ethylene, and recycled gas are fed to a multi-tubular reactor • The temperature of oxidation is controlled by boiling water in the shell side of the reactor • Effluent gases are cooled and passed to the scrubber where ethylene oxide is absorbed as a dilute aqueous solution • Un-reacted gases are recycled • Epoxidation reaction occurs at approximately 200–300°C with a short residence time of one second
    • Ethylene Oxide - Production (contd.) • A selectivity of 70–75% can be reached for the oxygen based process • Ethylene oxide selectivity can be improved when the reaction temperature is lowered and the conversion of ethylene is decreased (higher recycle of un- reacted gases)
    • Products of Ethylene ACETALDEHYDE
    • Acetaldehyde • A colorless liquid with a pungent odor • A reactive compound with no direct use except for the synthesis of other compounds e.g., raw material for production of acetic acid
    • Acetaldehyde - Production • Old Technique: Silver-catalyzed oxidation or chromium activated copper- catalyzed dehydrogenation of ethanol (reaction temperature for oxidation is approximately 500 °C whereas for dehydrogenation is approximately 250 °C ) • New Technique: Oxidation of ethylene using a homogeneous catalyst (Wacker catalyst and reaction temperature of 130 °C )
    • Acetaldehyde – Production (contd.) • Ethylene oxidation is carried out through redox reactions • The overall reaction is exothermic Acetaldehyde
    • Acetaldehyde – Production (contd.) The Wacker Process • The process employs an aqueous solution of palladium(II) chloride, copper(II) chloride catalyst system • Pd2+ ions are reduced to Pd metal, and ethylene is oxidized to acetaldehyde
    • Acetaldehyde – Production (contd.) The Wacker Process (contd.) • Pd° is re-oxidized by action of Cu(II) ions, which are reduced to Cu(I) ions • The reduced Cu(I) ions are re-oxidized to Cu(II) ions by reaction with oxygen and HCl
    • Acetaldehyde – Production (contd.) • The oxidation reaction may be carried out in a single- stage or a two stage process ▫ In the single-stage, ethylene, oxygen, and recycled gas are fed into a vertical reactor containing the catalyst solution. Heat is controlled by boiling off some of the water. The reaction conditions are approximately 130°C and 3 atmospheres ▫ In the two-stage process, the reaction occurs under relatively higher pressure (approximately 8 atmospheres) to ensure higher ethylene conversion. The reaction temperature is approximately 130°C
    • Acetaldehyde – Production (contd.) • The yield of acetaldehyde from either process is about 95% • By-products from this reaction include acetic acid, ethyl chloride, chloroacetaldehyde, and carbon dioxide
    • Conclusion
    • Conclusion • Ethylene is indeed one of the most important raw materials for manufacturing of various chemicals and polymers • It is sometimes referred to as the “king of petrochemicals” • It has great commercial importance and thus improvements should be continuously made in its manufacturing, in order to increase production of various other petrochemicals
    • References 1. S. Matar, Ph.D., Chemistry of Petrochemical Processes, 2nd Ed., Gulf Publishing Company, Houston, Texas 2. http://en.wikipedia.org/wiki/Ethylene_oxide 3. http://en.wikipedia.org/wiki/Acetaldehyde
    • HAVE A NICE DAY ! 