Product and Operation Valorization

October 27 - 30, 2019 | St. Louis, Missouri

Session 2: Product and Operation Valorization

Tuesday, October 29, 2019
10:30am - 12:00pm


Featured Presentation

“Techno-economic Assessment of Supercritical Water Treatment of Black Liquor, Impact of Recovery Cycle Integration.” 

Presenter:  Mohamed Magdeldin, Aalto University

Supercritical water is an interesting processing medium for the treatment of black liquor in pulp mill operation. The advantageous thermophysical properties of water near to or beyond the critical point allow for the valorization of the organic residue into fuel gas while enabling the efficient recovery of the inorganic cooking chemicals.

Hear the results of a study that examined the impact of an integrated supercritical water system on the black liquor recovery cycle. A process flowsheet was developed on Aspen Plus software for the stand-alone black liquor treatment unit. The thermal efficiency of the process was found to be 79 and 69 % for the two gasification case studies at 450 °C and 600 °C respectively. Alkali recovery in the recycle aqueous stream was 55 and 39% for sodium and potassium respectively, with the balance found in the byproduct solid char (12 wt.%) –inorganic mixture. Inorganic nature in the solid mixture was primarily in the form of carboxylic salts, as well as alkali sulfate and carbonate hydrates. The carbon recovery in fuel gas was 68%, while sulfur primarily partitioned into the solid by product at 87%.


During this presentation you will learn:

1. How an integrated supercritical water system can impact your black liquor recovery cycle

2. The thermal design trade-offs between the existing evaporation train technology and that of the integrated system

3. The costs associated with the partial replacement of a standard industrial evaporator train by a  supercritical water treatment unit.


Additional Session Presentations