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Journal articles
Towards closed water systems in chemical pulp mills: Evaporation of acidic filtrate from ECF bleaching with high chloride content, TAPPI Journal January 2026
ABSTRACT: In modern bioproducts mills utilizing elemental chlorine-free (ECF) bleaching, the bleaching process is the primary effluent source. The pulp bleaching typically generates 10 m³/a.d. metric ton of acidic filtrate. Despite extensive studies on recycling methods, the acidic filtrate is still typically directed to wastewater treatment plants due to the challenges created by its volume and chloride content. Recently, the volume of acidic filtrate has significantly decreased to 5 m³/a.d. metric ton, reducing the capacity required for the recycling process closer to a feasible level. In this study, we investigated recycling of acidic filtrate by evaporation from the D0 stage of a D0-Eop-D1 bleaching sequence. In the mill, hydrochloric acid (HCl) was used for pH control instead of sulfuric acid (H2SO4) due to better control of precipitation. This arrangement substantially changes the composition of the acidic filtrate, increasing the chloride (Cl-) and decreasing the sulfate (SO4 2-) ionic content. For the above reasons, it is necessary to study the effect of evaporation on the quality of the resulting condensate and concentrate. The results provide new information on how to close water loops in a modern bioproducts mill with higher Cl- content as one option. The results show that the evaporation of the high-chlorine D0 filtrate produces a pure condensate with methanol as the main component. Only small amounts of Cl- were observed in the condensate. The majority of chlorine (Cl) compounds remains as dissolved compounds in the evaporated concentrate when the dry solids content of the concentrate is ~10%. The Cl compounds in the concentrate can be converted to sodium chloride (NaCl) by incineration.
Journal articles
Recent Advances in the Application of Acoustic Leak Detectio
Recent Advances in the Application of Acoustic Leak Detection to Process Recovery Boilers, 1995 Engineering Conference Proceedings
Journal articles
Black Liquor Recovery by Pressurized, Oxygen-Blown Gasificat
Black Liquor Recovery by Pressurized, Oxygen-Blown Gasification, 1996 Engineering Conference Proceedings
Journal articles
Qualification of Welding Procedures for Duplex Stainless Ste
Qualification of Welding Procedures for Duplex Stainless Steels, 1999 Engineering Conference Proceedings
Journal articles
Electrochemical Removal of Color and Toxicity from Bleached
Electrochemical Removal of Color and Toxicity from Bleached Kraft Effluents, 1994 Environmental Conference Proceedings
Journal articles
Abitibi consolidated's mill in snowflake, az, converts to 100% recycling, TAPPI JOURNAL, April 2000, Vol. 83(4)
Abitibi consolidated's mill in snowflake, az, converts to 100% recycling, TAPPI JOURNAL, April 2000, Vol. 83(4)
Journal articles
A six-year review of the TAPPI research funding program, TAPPI JOURNAL, April 2000, Vol. 83(4)
A six-year review of the TAPPI research funding program, TAPPI JOURNAL, April 2000, Vol. 83(4)
Journal articles
Performance evaluation of two simple causticizing control systems, TAPPI JOURNAL, April 2000, Vol. 83(4)
Performance evaluation of two simple causticizing control systems, TAPPI JOURNAL, April 2000, Vol. 83(4)
Journal articles
Dynamic behavior of a pulp processing and reject refining plant, TAPPI JOURNAL, April 2000, Vol. 83(4)
Dynamic behavior of a pulp processing and reject refining plant, TAPPI JOURNAL, April 2000, Vol. 83(4)
Journal articles
Chip size distribution for an ultra-high-yield sulfite process, TAPPI JOURNAL, April 2000, Vol. 83(4)
Chip size distribution for an ultra-high-yield sulfite process, TAPPI JOURNAL, April 2000, Vol. 83(4)