Caustic Corrosion in Black Liquor Evaporators, 1996 Engineering Conference Proceedings

Today, the dry solid content of black liquors before combustion has been increased from 70 wt.% of d.s. to almost 80 wt.% of d.s., sometimes even above that. In many cases this means that the evaporation temperatures of kraft black liquors increase, too. The corrosion of ten different grades of stainless steel and nickel compounds was measured at the temperatures of 150°C and 170°C for periods of 14 and 40 days. The high testing temperatures were reached by installing the test coupons and the black liquor in 4 cylinders that were rotated in hot oil during the test. For some of the tests, black liquors from two different mills were modified by adding NaOH or H2 S04 . The black liquors used in the tests were chemically analyzed before and after the corrosion tests. It can be concluded that duplex stainless steels are more resistant to caustic grain boundary corrosion than normal grades of stainless steel. At high levels of NaOH, depending on the test temperature, grain boundary corrosion of stainless steels became evident. So, if the rate of corrosion should not exceed the level of 0.1 mm/y, a temperature increase from 150°C to 170°C means that the critical concentration of NaOH should be decreased by almost 50 %.

Author: Klarin, A., Kottila, M.
Caustic Corrosion in Black Liquor Evaporators, 1996 Engineer
Caustic Corrosion in Black Liquor Evaporators, 1996 Engineering Conference Proceedings
35.00

New Releases

TAPPI PRESS Catalog eBook 2024


Experience the Power of Publications in the 2024 TAPPI Press Catalog


Open


 

Kraft Recovery Boilers, Third Edition  


Sponsored by the Recovery Boiler Program R&D Subcommittee of the American Forest & Paper Association (AF&PA) and published by TAPPI Press.


Purchase


 

Handbook For Pulp and Paper Technologists (The SMOOK Book), Fourth Edition

The best-selling text to introduce the entire technology of pulp and paper manufacture.

Purchase

 

Guidelines for Safe Assessment and Operation of Yankee Dryers  


A project of the Yankee Dryer Safety & Reliability Committee.

Purchase

 

Check our newest additions.


TAPPI Press offers some of the most in-depth resources and references for the forest products and related industries. 

See More

   
 

Available for Purchase – Conference Proceedings


TAPPI maintains a record of key conference papers, presentations, and other conference publications, available for purchase in a variety of formats.

See More