The main purpose of this work is to identify the hygroscopic equilibrium and also determine the product–water relationship in olive pomace. In this context, experimental, modeling and thermodynamic analysis of adsorption isotherms of four types of agricultural wastes (olive pomace), have been carried out. Two samples were separately de-oiled by the maceration method and the hydrothermal carbonization process. Besides, adsorption isotherms of these biomass samples were obtained experimentally at three oven temperatures (30, 40 and 50 °C). The findings showed that the de-oiled samples are more hydrophobic than those containing residual oil, especially when water activity (a_w) values are higher than 0.4. Moreover, adsorption isotherms were modeled by five mathematical models available in the literature. In the thermodynamic point of view, the net isosteric heat and the differential entropy of adsorption were estimated for each sample. The highest value of the net isosteric heat (around 65 kJ mol⁻¹) is obtained for no de-oiled samples. Also, it has been found that the development of monolayer adsorption requires more net isosteric heat to ensure the water molecules adhesion to the biomass surface unlike the formation of multilayer adsorption. In addition, the enthalpy/entropy compensation theory for all examined biomasses was confirmed, and their free energy values are positive (between 3479.8 and 4155.6 J mol⁻¹). Finally, optimal water activity values were also estimated and ranged from 0.35 to 0.49.

这项工作的主要目的是确定吸湿平衡并确定橄榄果渣中的产品-水关系。在此背景下，对四种农业废弃物（橄榄果渣）的吸附等温线进行了实验、建模和热力学分析。两个样品分别通过浸渍法和水热碳化工艺脱油。此外，这些生物质样品的吸附等温线是在三个烘箱温度（30、40 和 50 °C）下通过实验获得的。研究结果表明，脱油的样品比含有残留油的那些更疏水，尤其是当水活度（一_瓦特) 值高于 0.4。此外，吸附等温线由文献中可用的五个数学模型建模。从热力学的角度来看，对每个样品的净等量热和吸附的微分熵进行了估计。净等量热的最高值（大约 65 kJ mol ^-1）是在未脱油样品的情况下获得的。此外，已经发现单层吸附的发展需要更多的净等量热以确保水分子粘附到生物质表面，这与多层吸附的形成不同。此外，所有生物质的焓/熵补偿理论得到证实，它们的自由能值为正（在 3479.8 和 4155.6 J mol ^-1）。最后，还估计了最佳水分活度值，范围为 0.35 至 0.49。