Evaluation of Filter Cloths Properties for Extracting Lignin from Black Liquor by Filter Press

Lignin is the second most abundant natural biopolymer on Earth and is considered a potential alternative to replace petroleum-based compounds due to its aromatic polymeric structure. As the demand for lignin as a feedstock for commercial usage increases, a robust lignin extraction technique from black liquor is essential. This study explores the properties of filter cloth to improve filter press performance for extracting lignin from acidified black liquors by increasing dewatering under high pressure. Although the nylon filter cloth has a higher tensile strength (4,400 N and 3,800 N) than the polypropylene filter cloth, the tensile strength of TSP-106 filter cloth made of polypropylene shows that it has the potential to withstand the high pressures during the filter pressing process. TSP-106 filter cloth also has a low air permeability, which increases the efficiency of filtering black liquor to collect lignin, suggesting that TSP-106 is applicable as a filter press filter cloth. © 2024 Korean Technical Assoc. of the Pulp and Paper Industry. All rights reserved.