Intraparticle Connectivity in Sugarcane Bagasse Unveiled by Pore Network Modeling

Sugarcane bagasse is a vast, inexpensive lignocellulosic feedstock that can be industrially converted into renewable materials, chemicals and biofuels. Bagasse, which results from the shredding and crushing of the sugarcane stalks, has a pore structure that is inherited from the native plant tissues and is partly disrupted due to the applied mechanical processes. The connectivity in the bagasse pore space can be critical for mass transport in industrial processes requiring liquid or solute extraction from the solid or impregnation of catalysts and reactants into the biomass. In this work, we pioneer the construction of pore network models (PNMs) to investigate intraparticle connectivity in lignocellulosic biomass. X-ray microtomograms of sugarcane bagasse are employed to extract the PNMs, which are then analyzed with support from hydraulic, diffusion, and graph theory-based methods. The analysis determines the characteristic sizes and anisotropies of the bagasse pore space. Moreover, it reveals that a relatively small number of pores are critical for the intraparticle connectivity. The critical pores can be in tissue cracks and xylem vessels as well as in ruptured parenchyma and fiber cells. The relative importance of each of these regions depends on the specifics of the bagasse particle.