THE EFFECT OF IMPERFECT MIXING ON POLYMER QUALITY IN LOW DENSITY POLYETHYLENE VESSEL REACTORS

Abstract

A mathematical model is developed for the calculation of polymer quality in low density polyethylene vessel reactors, taking into account mixing limitations at the initiator feed point. Model predictions show that imperfect mixing in the reactor can produce considerable variations in polymer molecular weight distribution. The effect of the most important process conditions, input feed temperature, solvent concentration, monomer flow rate and initiator type, on the final polymer quality is analyzed. The advantages of the design solution which divides the reactor in more compartments in series are also discussed.

KEYWORDS:

• Mixing
• Polymer
• Polyethylene

Notes

† On leave from the Donegani Research Institute, Montedison Co., Via Fauser, Novara, Italy.

‡ To whom correspondence should be addressed: Department of Chemical Engineering, Lehigh University, Bethlehem, PA 18015.