Maleic Anhydride TMP dosing system

TMP dosing system – Extends catalyst life cycle

From Start-of-Run till End-of-Run Maleic Anhydride (MA) catalyst activity is continuously decreasing. To lengthen the life-cycle of catalyst Trimethyl-Phosphate (TMP) must be added to the feed. Important role of TMP is activation procedure of catalyst for achieving of full selectivity of catalyst.


General description of the system:

Selectivity/Activity Stabilizer (SAS) dosing system is placed into the reactor section and it is supplied as a package that contains stainless steel tank for TMP storage, dosing pump, control system, safety relief valve, and TMP drum pump with hose for safe and fast unloading of TMP from the drum into the tank. The dosing system is installed into a heated cabinet. A special atomizer/distributor is located at TMP / feed gas line connection point.

TMP is supplied by the TMP dosing pump from TMP tank and is then injected to feed-gas line through special atomizer/distributor. On TMP line a shut-off valve is installed to prevent feed-gas back flowing to TMP system. Dosing pump is equipped with capacity regulation and discharge pressure protection.


Main Advantages of TMP dosing system:

  • constant flow and perfect distribution of TMP in reactor;
  • better control of the catalyst operation – stabile catalyst hot-spot;
  • higher yields and plant productivity;
  • longer catalyst lifecycle;
  • system is also capable of dosing Triethyl-Phosphate (TEP).