This work conducts a single-factor experiment to study the effects of biomass types on the relax density, volume expansion, durability, hydrophobicity, and processing energy consumption. We analyze the differences in the quality of the pellets, and optimize the compaction conditions suitable for different biomass types including straw, hardwood, shell, and herbaceous plant. The results indicated that with a compressing force of 60~1500 N, compressing time of 10 s, powder size of less than 0.5 mm, and moisture content of 10%, the relax densities of corn straw, rice straw, selenium-rich rice straw, weigela japonica branches, and camphor leaves range from 360 to 820 kg/m³, with a processing energy consumption of 17,360 to 28,740 J/kg; meanwhile, the relax densities of argy wormwood, forage grass, green grass, and peanut shells range from 340 to 840 kg/m³, with a processing energy consumption of 33,510 to 73,700 J/kg. Therefore, the compaction pretreatment effectively regulates the density of biomass pellets and reduces the processing energy consumption. This study analyzed the differences in the quality of pellets caused by the inherent characteristics of biomass, providing strong support for the directional depolymerization and enhanced pretreatment technology for the scaled production of biomass alcohol fuels.

To progress towards the “dual carbon” goal and reduce the cost and increase the efficiency of solid oxide fuel cells, this study conducts a full life cycle analysis of solid oxide fuel cells, in which the environmental impact caused by the operating devices’ manufacturing, fuel gas catalyst reforming, single-cell manufacturing, cell stack manufacturing, and energy consumption and emissions are systematically analysed. In this study, we establish an assessment model for solid oxide fuel cells by using the cut-off criterion. The results show that 96.5% of the global warming potential in the use of solid oxide fuel cells comes from the stack operating subsystem. The stack manufacturing subsystem, operating device manufacturing subsystem, and waste stack processing subsystem all contribute greatly to acidification, accounting for 32.89%, 44%, and 35.82% of the total acidification, respectively. These three subsystems also contribute significantly to eutrophication, contributing 23.11%, 22.03%, and 42.15%, respectively. Compared with traditional thermal power generation systems, solid oxide fuel cell power generation systems have slightly higher overall environmental benefits, and the reductions in greenhouse gas emissions and acidification potential reach 6.22% and 18.52%, respectively. The research results have guiding significance and reference value for subsequent energy-saving and emission reduction design and improvement efforts for solid oxide fuel cells.

This study assesses the relationship between the color changes and physicochemical properties of thermally treated biomass feedstocks, using colorimetric measurements to study the color difference values of straw, forest, and grass undergoing thermal treatments at 120~200 °C. We establish a multiple linear regression model to correlate the physicochemical properties of the treated solid products with three-dimensional color coordinates (L*, a*, b*). The results indicate that as the treatment temperature increases, the color difference ($∆E_{ab}^{\mathrm{*}}$) value also increases. Meanwhile, the number of conjugated structures in the chromophore groups increases, causing the color of the solid products to tend toward black. The ash, volatile, fixed carbon, carbon, hydrogen, oxygen, nitrogen, higher calorific value, solid yield, energy yield, bulk density, and water contact angle of the thermally treated biomass feedstocks have a statistical measure of R² ≥ 0.90 with the three-dimensional color coordinates, indicating a good correlation. Therefore, it is possible to quickly predict the basic physicochemical properties of thermally treated biomass feedstocks based on their surface color, providing a theoretical basis for the rapid quality assessment of solid products using CIELAB color changes in industrial applications.