NEW NORIT GCN 48 SUPERIOR LOW ATTRITION CATALYST CARRIER FOR TEREPHTHALIC ACID (PTA) PRODUCTION


PTA is used as monomer in the production of polyethylene terephthalate (PET), a fast growing plastic for packing of food and drinks. In the production process of PTA the hydrogenation of crude TPA (C-TPA) to TPA is an important process step. For this continuous process a granular activated carbon based Pd catalyst is used. The type and properties of the GAC carrier are of utmost importance for a continuous, problem free process and strongly influence the activity, the selectivity and the lifetime of the catalyst.

The required properties for a GAC carrier are:

o Consistency for an ongoing and stable production of the catalyst
o A low the pressure drop
o A large internal surface area and an optimal micro, meso and macro pores structure for a Pd dispersion of small, stable and anchored particles.
o A high density for a large weight amount of catalyst in a fixed volume reactor
o A high purity: to prevent poisoning of the Pd and side reactions
o An exceptional low attrition

A very hard, low attrition carbon is one of the most important properties, beneficial to avoid losses of Pd and to avoid decrease of lifetime of the catalyst. The attrition is measured according to ASTM D4058/87 (NSTM2.24)

General characteristics:

Standard coconut based PTA carbon 2-2.9 Attrition (mass %)
NORIT GCN 48 (present generation) <1.5 Attrition (mass %)

The new GCN 48 combines a very low attrition with a very high internal surface area. Because of the fact that the Pd is situated in the outer shell of the particles a decrease in attrition of 25% compared to competitors, means a substantial saving in Pd and a much longer catalyst life time.

The NORIT GCN 48 grades can also be used as catalysts carrier for precious metals in other applications as well, where a granular high activated carbon with low sulphur, iron and copper, a superior hardness and extreme low attrition is required.