Development and performance evaluation of a novel industrial-scale fixed bed dryer for alkali-treated eucheuma cottonii chips

Drying alkali-treated Eucheuma cottonii chips (ATCC) in the seaweed industry demands significant resources, particularly energy, and generates substantial CO₂ emissions, especially when fossil fuels serve as the primary energy source. Simultaneously, the global seaweed industry has become increasingly competitive, which demands technological advancements across processing stages, especially in drying. Here, we developed a novel industrial-scale fixed-bed dryer (FBD) for ATCC and assessed its feasibility to address these issues. Several critical parameters, including product quality, drying performance, and CO₂ emission reduction, were evaluated to determine the novel FBD's viability compared to a conventional FBD. Drying kinetics were also analyzed using 24 thin-layer drying models to identify the most appropriate model for describing ATCC drying behavior with the novel FBD. The results of this study indicated that the novel FBD effectively dried ATCC to a quality suitable for milling. The Improved Midilli-Kucuk and Hii et al. models provided the best fit for describing the drying kinetics. Additionally, the novel FBD reduced drying time by one hour, decreased specific energy consumption by 60%, improved drying efficiency by over 150%, and lowered drying costs by 55%. Consequently, it emitted 60% less CO₂ than the conventional FBD. In conclusion, this study successfully developed a novel FBD that addresses the critical challenges of high energy consumption and CO₂ emissions in ATCC drying and also offers multiple benefits for the global seaweed industry, aligning with the objectives of SDG 7, SDG 9, and SDG 13.