Evaluation of APMP and BCTMP Processes for Market Pulp Properties from South American Eucalyptus Species, 1996 Pulping Conference Proceedings

Eric C. Xu

Marc J. Sabourin

J. Brad Cort

Andritz Sprout-Bauer, Inc.

The possibility of the utilization of three South American eucalyptus species: E.grandis from Argentina, E.grandis and E.saligna from Paraguay were investigated for high brightness grade applications using APMP and conventional CTMP processes. A detailed comparison between APMP and CTMP processes was made in terms of energy consumption, Pulp property development, process effluent characteristics, and post bleachability. Results from this study demonstrated that (1)the three species were very similar in their responses to process condition changes, and post bleachability; (2) all three eucalyptus species demonstrated a good potential for both tissue and printing/writing grade applications; (3) APMP and CTMP are comparable in their ability to control process energy consumption, pulp physical property development, and effluent discharge; (4) a major drawback from CTMP was its

limitation on post bleachability, while APMP pulps were capable of being post-bleached to 89% ISO; (5) for a two stage impregnation APMP process, the distribution of chemicals between the stages not only affected process chemical efficiency, but post-bleachability as well.