Circular approaches to revalorise waste biomass from agriculture and food production sectors are crucial for developing a sustainable bioenergy strategy. For instance, while the demand for edible mushroom cultivation has increased globally, the production generates a substantial amount of waste biomass, known as Spent Mushroom Substrate (MS). Thermochemical biomass conversion technologies such as hydrothermal carbonisation offers a robust strategy to produce “hydrochar” from the wet biomass and can be used downstream for various environmental applications. In this study, we assess the feasibility of MS-derived hydrochar for energy application, specifically as a blend with coal. The key parameters for the hydrochar production such as temperature, time and moisture content were optimised (205 °C, 3.65 h, and 73.18 %, respectively) using a statistical tool “Response Surface Methodology (RSM)” to obtain a carbon material with higher yield and calorific value. The hydrochar from MS exhibited an acidic pH (4.42), increased fixed carbon content (23.7 %), reduced sulphur content (0.26 %), coarser porous surface, enhanced oxygenated functional groups (hydroxyl, carboxyl and ketonic) and the formation of minerals like Sodium Carbonate (NaCO), whewellite (CaCO·HO) and gypsum (CaSO). Combustion behaviour of hydrochar was also assessed using calorimetry and thermogravimetry, specifically to test different coal and hydrochar blends on the feasibility of using hydrochar as a supplement to conventional solid fuels. Our results suggest that a blend of 20 % hydrochar with 80 % coal as an ideal blending ratio (with a calorific value of 27.65 MJ kg) highlighting the use of hydrochar as supplement with conventional fuel like coal.

中文翻译：

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农业废弃物水炭的热化学表征及其作为固体燃料补充的效率


重新利用农业和粮食生产部门废弃生物质的循环方法对于制定可持续生物能源战略至关重要。例如，虽然全球对食用菌种植的需求不断增加，但生产过程中却产生了大量废弃生物质，即废蘑菇基质 (MS)。热化学生物质转化技术（例如水热碳化）提供了一种从湿生物质生产“水炭”的强大策略，并且可以在下游用于各种环境应用。在这项研究中，我们评估了 MS 衍生的氢炭用于能源应用的可行性，特别是作为与煤的混合物。使用统计工具“响应面方法（RSM）”对水热炭生产的关键参数（例如温度、时间和水分含量）进行了优化（分别为205℃、3.65h和73.18％），以获得具有更高性能的碳材料。产量和热值。来自 MS 的水炭表现出酸性 pH 值 (4.42)、固定碳含量增加 (23.7%)、硫含量降低 (0.26%)、多孔表面更粗糙、含氧官能团（羟基、羧基和酮基）增强以及矿物质的形成，例如碳酸钠 (NaCO)、角钙石 (CaCO·H2O) 和石膏 (CaSO)。还使用量热法和热重分析法评估了水热炭的燃烧行为，特别是测试不同的煤和水热炭混合物，以了解使用水热炭作为传统固体燃料的补充的可行性。我们的结果表明，20% 水热炭与 80% 煤的混合物是理想的混合比例（热值为 27.65 MJ kg），强调使用水热炭作为煤炭等传统燃料的补充。