Date of Award


Degree Name

Master of Science


Chemical and Paper Engineering


Paper Engineering, Chemical Engineering and Imaging

First Advisor

Dr. John Cameron

Second Advisor

Dr. Raja Aravamuthan

Third Advisor

Dr. Jan Pekarovic

Access Setting

Masters Thesis-Open Access


The original Neutral Sulfite Semi-Chemical (NSSC) pulping process used sodium sulfite as the principle cooking chemical and had the disadvantage of sulfur emission problems. Considerable research was conducted to investigate the use of other chemicals including sodium hydroxide, but was not completely satisfactory. Several mills adapted a sodium carbonate based process but experienced slower pulping and reduced physical properties. The objective of this research is to study the use of borate as a pulping chemical in sodium carbonate semi-chemical pulping. The experimental plan included digester cooks; controls with pure sodium carbonate, and the other with partially borate autocausticized sodium carbonate.

It was found that without heating the borate and sodium carbonate, the effect of borate was similar to that of sodium carbonate. When the mixtures were heated to simulate the processes occurring in a fluidized bed reactor ( a common recovery system in sodium carbonate semi-chemical pulping), there was a slight reaction between sodium carbonate and sodium borate resulting in the production of sodium hydroxide, which tended to increase the pulping rates and the resulting paper strength properties.