2025 年 16 巻 2 号 p. 25-31
Blending different agricultural residues for pellet production can address the problem of seasonal availability of materials and improve biomass pellet quality and efficiency. With widely available agricultural residues in Thailand, our previous research took the blending approach to produce biomass pellets from five residue types, including Rice Stubble (RB), Rice Straw (RW), Sugarcane Leaves (SL), Cassava Leaves (CL), and Cassava Rhizome (CR). By combining high and low energy residues, it is possible to enhance the energy density, durability, and other desirable properties of the pellets. To gain a better understanding of agricultural residue availability, this study investigated farming practices and crop/residue characteristics by considering several factors, including the plantation process (site, area, growing crops, production, and harvesting), crop residue production, and crop residue utilization and the management. Using a sub-district in Mahasarakham Province as a case study, a questionnaire survey was conducted on 100 households to collect data on rice, sugarcane, and cassava crops and their associated residues. The Surplus Availability Factor (SAF) was estimated using survey data to assess the ratio of residues available for energy use to the total residue produced. This factor indicates the portion of the residue that can be collected for energy as a surplus after basic local usage. The study showed that RB and RW are the most commonly produced residues in Mahasarakham Province, but only RB has the greatest potential for energy use. SL and CR exhibited substantial volumes in the area despite the lower production of cassava and sugarcane. Regarding seasonal availability, RB and RW are available for a longer duration, whereas SL, CL, and CR are only available for four to five months. The results show that SL and CL were not used at all, and their SAFs were 1.00. Meanwhile, CR and RB had relatively lower SAF values (0.913 and 0.875, respectively). As rice straw may be sold and utilized for various applications, it had the lowest SAF (0.134). An estimated 5,509 tons of biomass pellets could be produced annually in Mahasarakham Province using the agricultural residues that are currently available. The biomass blending technique can offer an alternative use of agricultural waste to generate energy and value-added products. Using agricultural waste as an energy source has numerous environmental benefits, including minimizing harvesting burning, providing a carbon-neutral fuel supply, and encouraging the circular economy by using waste as an input for new products.
