Hl. Schubert et al., THE ASAM-PROCESS - A PULP TECHNOLOGY READ Y FOR INDUSTRY - EXPERIENCES GAINED THROUGH 3 YEARS OPERATION OF THE PILOT-PLANT, Das Papier, 47(10A), 1993, pp. 220000006-220000015
The ASAM-process makes it possible to procude pulps of high strength a
nd whiteness from the usual varieties of pulpwood, without the use of
chlorine and chlorine containing bleaching chemicals. Apart from defib
ering and bleaching the recovery of chemicals was also tested on a tec
hnical scale. The removal of lignins from Spruce during pulping can be
carr ed out up to Kappa numbers of 16. No troubles are encountered du
ring the bleaching of pulps by the O-Z-P sequence to whiteness degrees
of over 88% ISO. The strength properties of ASAM-TCF pulps correspond
to those of conventional kraft pulps. The methanol recovery system ha
s been used in the pilot plant for over 3 years and recovery rates exc
eeding 99% have been achieved. Thickening of the spent liquor from ASA
M pulping is possible to high solids contents at low viscosities. The
possibility of utilizing a normal kraft pulping liquor boiler for inci
nerating ASAM spent liquor was proven by an incineration trial. The su
itability of existing conversion processes for the inorganic chemicals
could be further confirmed and it is possible to simplify this proces
s. Small water consumption and a low burden in the effluent are assure
d by the almost complete system closure.