• The Phthalic Anhydride (PA)is today produced from two main sources:
• production from o-xylene
• production from benzene – some old plants
  

Both main technologies involve specific catalyst  for selective oxidation of raw material to product.

• Basically the technology consist of 3 main phases:
• oxidation (performed in reactor block),
• recuperation of Phthalic Anhydride from reactor off-gases (performed in switch condensing section) and
• refining to commercial product (performed in distillation unit).
  

• Any of Phthalic Anhydride production technologies include sub sections as:
• Steam system – energy recuperation
• Waste gases incineration
  

• Is possible to recover Maleic anhydride from off gases of switch condensers in quantity of about 4% calculated on PA