Black liquor gasification is a thermochemical conversion process in which black liquor—the aqueous, alkaline spent cooking liquor generated during chemical pulping and containing dissolved lignin-derived organic matter together with inorganic sodium- and sulfur-containing pulping chemicals—is converted under substoichiometric oxidizing conditions into a combustible product gas and an inorganic recovery stream [1][2]. Unlike conventional black-liquor recovery-boiler operation, which primarily combusts the organic fraction, gasification uses controlled partial oxidation, with oxygen, air, steam, or their combinations as gasifying agents, to form a synthesis-gas mixture principally containing carbon monoxide, hydrogen, carbon dioxide, water vapor, and, depending on process conditions, methane and sulfur-bearing gases [1]. The concept encompasses gasifier configurations that process concentrated liquor at elevated temperature, including entrained-flow, fluidized-bed, and supercritical-water systems, provided that conversion of the liquor’s organic fraction to gas is coupled with retention or recovery of its inorganic chemical constituents [2][3]. It excludes simple combustion and gasification of solid biomass not derived from pulping liquor.
- gasification
- kraft pulping
- synthesis gas
- black liquor
References
- Patrick D. Kiely; Geoffrey Rader; John M. Regan; Bruce E. Logan; Long-term cathode performance and the microbial communities that develop in microbial fuel cells fed different fermentation endproducts. Bioresour. Technol. 2011, 102, 361-366, 10.1016/j.biortech.2010.05.017.
- Michal Hruška; Miroslav Variny; Juma Haydary; Ján Janošovský; Sulfur Recovery from Syngas in Pulp Mills with Integrated Black Liquor Gasification. For. 2020, 11, 1173, 10.3390/f11111173.
- Mohamed Magdeldin; Mika Järvinen; Supercritical water gasification of Kraft black liquor: Process design, analysis, pulp mill integration and economic evaluation. Appl. Energy 2020, 262, 14558, 10.1016/j.apenergy.2020.114558.