Integrated biorefinery concept for grass silage using a combination of adapted pulping methods for advanced saccharification and extraction of lignin.
An integrated refining and pulping process for ensiled biomass from permanent grassland was established on laboratory scale. The liquid phase, containing the majority of water-soluble components, including 24% of the initial dry matter (DM), was first separated by mechanical pressing. The fiber fraction was subjected to high solid load saccharification (25% DM) to enhance the lignin content in the feed for subsequent organosolvation. The saccharification enzymes were pre-selected applying experimental design approaches. Cellulose convertibility was improved by a secondary pressing step during liquefaction. Combined saccharification and organosolvation showed high degree of saccharide solubilization with recovery of 98% of the glucan and 73% of the xylan from the fiber fraction in the hydrolysates, and enabled the recovery of 41% of the grass silage lignin. The effects of the treatment were confirmed by XRD and SEM tracking of cellulose crystallinity and fiber morphology throughout the pulping procedure.
Technische Universität München, Chair of Chemistry of Biogenic Resources, Schulgasse 16, 94315 Straubing, Germany.
Dominik
D
Schwarz
Technische Universität München, Biogenic Polymers, Schulgasse 16, 94315 Straubing, Germany.
Jörg
J
Dörrstein
Technische Universität München, Biogenic Polymers, Schulgasse 16, 94315 Straubing, Germany.
Sabine
S
Kugler
Technische Universität München, Chair of Chemistry of Biogenic Resources, Schulgasse 16, 94315 Straubing, Germany. Electronic address: doris.schieder@tum.de.
Doris
D
Schieder
Technische Universität München, Biogenic Polymers, Schulgasse 16, 94315 Straubing, Germany.
Cordt
C
Zollfrank
Technische Universität München, Chair of Chemistry of Biogenic Resources, Schulgasse 16, 94315 Straubing, Germany.
Volker
V
Sieber
D018533:Biomass; D002482:Cellulose / Q000737:chemistry; D006868:Hydrolysis; D008031:Lignin / Q000302:isolation & purification*; D006109:Poaceae / Q000737:chemistry*; D012820:Silage
D002482:Cellulose; D008031:Lignin
Biorefinery; Enzymatic hydrolysis; Grass silage; Integrated pulping; Organosolvation