Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

Chemical Technology

Chemical Engineering : Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

The document Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev is a part of the Chemical Engineering Course Chemical Technology.
All you need of Chemical Engineering at this link: Chemical Engineering

Nylon 6 

Nylon 6 is produced from polymerisation of caprolactam. Process steps involved in production of Nylon 6 involve the following steps

  • Caprolactam melting and addition of additives
  • Polymerisation: Batch/continuous and chips production
  • Chips washing and drying
  • Spinning of nylon
  • Recovery section

Caprolactam is polymerised to Nylon 6 polymer by ring opening polymerisation at 240-270 0C in presence of water, which opens the ring structure of the caprolactam to give amino caproic acid. Reacting SO2 with ammonium nitrite & ammonium carbonate which results in production of hydroxylamine disulphonate finally hydrolysis of hydroxylamine disulphonate at 95 oC to yield hydroxylamine sulphate & ammonium sulphate as by-product. Process flow diagram for nylon 6 manufacturing is shown in Figure M-VIII 5.4.  

Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

Figure M-VIII 5.4: Manufacture of Nylon 6 

Nylon 66 

Nylon 66 is produced by polymerisation of adipic acid & hexamethylene diamine. Manufacturing process flow diagram for nylon 66 is shown in Figure M-VIII 5.5. Process step involved in manufacture of Nylon 66  

  • Production of nylon salt (hexamethylene diammonium adipate) by reaction of adipic acid & hexamethylene diamine
  • Concentration of nylon salt
  • Polymerisation of nylon salt into a jacketed vessel equipped with internal coils and heated by dowtherm
  • Cooling and chips production
  • Spinning of nylon 66 chips · Recovery section
  • Nylon salt (hexamethylene diammonium adipate) is prepared by mixing adipic acid and hexamethylene diamine in 1:1 molar ratio.  

Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

Figure M-VIII 5.5: Process of Nylon 66 manufacture  

  • Adipic acid is the basic raw material for the manufacture of Nylon 66
  • World overall demand for adipic acid is growing by 3.6% during 2000-2010.
  • Adipic acid is manufactured from number of starting raw materials like phenol, cyclohexane, tetrahydrofuran, etc. Various routes for adipic acid manufacture 

Adipic Acid  

Various routes of adipic acid manufacturing is shown in Figure M-VIII 5.6 

Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

 Adipic acid Hexamethylenediamine Hexamethylene diammonium adipate  

 (Nylon salt)

 [-HN(CH2)6NHOC(CH2)4co-] + 2x.H2

 Poly (Hexamethylene Adipamide) or Nylon 

Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

Figure M-VIII 5.6: Various Routes for Manufacture of Adipic Acid  

Process 

Cyclohexane is oxidised by air to form cyclohexanol &cyclohexanone in presence of cobalt naphthenate catalyst at temperature of 145-150 oC. The cyclohexanol and cyclohexanone mixture is oxidised to adipic acid in presence of nitric acid using ammonium metavanadate and copper scrap at 60-80 oC. The adipic acid formed is crystallised, centrifuged and finally dried with hot air.  

Hexamethylene diamine is another intermediate for the manufacture of Nylon 66.  Hexamethylene diamine is manufactured by the catalytic hydrogenation of adiponitrile. Hexamethylene diamine is manufactured by catalytic hydrogenation of adiponitrile in presence of catalyst either by high pressure process (60-65 MPa) or low pressure process (3 MPa).   Catalyst in low pressure is nickel whereas in case of high pressure process it is cobalt and copper. Process flow diagram for the manufacture of  Hexamethylene diamine  is given in Figure M-VIII 5.7 

 NC(CH2)4CN + 2 H2    →HN=CH(CH2)4CH=NH  

Cyclohexane, Caprolactam, Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

Figure M-VIII 5.7: Process flow diagram for Hexamethylene diamine 

Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Related Searches

Summary

,

shortcuts and tricks

,

Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

,

Objective type Questions

,

Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

,

video lectures

,

pdf

,

Sample Paper

,

mock tests for examination

,

Nylon 6 Adipic Acid (Part - 2) Chemical Engineering Notes | EduRev

,

Caprolactam

,

MCQs

,

Viva Questions

,

Cyclohexane

,

Free

,

Semester Notes

,

Extra Questions

,

past year papers

,

study material

,

Cyclohexane

,

Caprolactam

,

practice quizzes

,

ppt

,

Important questions

,

Previous Year Questions with Solutions

,

Cyclohexane

,

Caprolactam

,

Exam

;