A review.Black liquor made in the kraft pulping process contains various surfactants derived from modified lignin.That means black liquor tends to make foam so easily that the process is troubled with foam at any time.If amount of foam was broken out, the efficiency of brown stock washer would decrease and the whiteness of pulp would be under the standard level.Furthermore, operation speed of brown stock washer would lower, which means the efficiency of pulp manufacturing would decrease.Though the foam trouble can also be prevented mech., chem. method using the defoamer is mainly adopted in the kraft pulping process.We present the characteristics of new silicone type defoamers, and their applications.
