In the PRENFLO plant in Furstenhausen, Germany, experience of material
s exposure was acquired over more than 10000 operating hours. The PREN
FLO process is based on the entrained-flow principle with dry fuel dus
t feeding. The PRENFLO development - based on the Koppers-Totzek proce
ss - received funding from the Federal Ministry of Research and Techno
logy (BR IFT) and the Commission of the European Communities (CEC). Wi
thin the operating time we elaborated two special materials programmes
together with the Electric Power Research Institute (EPRI, USA). In t
he second materials programme KEMA (The Netherlands) was also involved
to a large extent. This paper mainly describes some results from the
second test series with uncooled samples.