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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
Study of a model of cellulose depolymerization in the hypochlorite bleaching stage, TAPPI JOURNAL April 1988 88APR157
Study of a model of cellulose depolymerization in the hypochlorite bleaching stage, TAPPI JOURNAL April 1988
Journal articles
DTPMPA: polyamino polyphosphonic acid and its use in paper related processes-Part 2: paper production from silicate-free pulp bleached with DTPMPA as a stabilizer, TAPPI JOURNAL August 1988
DTPMPA: polyamino polyphosphonic acide and its use in paper related processes-Part 2: paper production from silicate-free pulp bleached with DTPMPA as a stabilizer, TAPPI JOURNAL August 1988
Journal articles
Acid-insoluble and acid-soluble lignin characteristics in kraft pulping of hybrid salix clones, TAPPI JOURNAL August 1988
Acid-insoluble and acid-soluble lignin characteristics in kraft pulping of hybrid salix clones, TAPPI JOURNAL August 1988
Journal articles
Nonwood fiber: Number 2, and trying harder-An interview with Dr. Joseph E. Atchison, TAPPI JOURNAL August 1988
Nonwood fiber: Number 2, and trying harder-An interview with Dr. Joseph E. Atchison, TAPPI JOURNAL August 1988
Journal articles
A wet-laid process for the preparation of random fiber-reinforced composites, TAPPI JOURNAL August 1988
A wet-laid process for the preparation of random fiber-reinforced composites, TAPPI JOURNAL August 1988
Journal articles
A fast-track approach through the design and permit phases for an ash landfill, TAPPI JOURNAL August 1988
A fast-track approach through the design and permit phases for an ash landfill, TAPPI JOURNAL August 1988
Journal articles
Significance of PM10 regulations for the forest products industry, TAPPI JOURNAL August 1988
Significance of PM10 regulations for the forst products industry, TAPPI JOURNAL August 1988
Journal articles
Fibers properties and tearing resistance, TAPPI JOURNAL February 1988 88FEB103
Fibers properties and tearing resistance, TAPPI JOURNAL February 1988
Journal articles
Using the Drainage Time to evaluate Mechanical Pulps, February 1988, TAPPI Journal 88FEB115
Using the drainage time to evaluate mechanical pulps, TAPPI JOURNAL February 1988