In this study, activated carbon (AC) based adsorbents were synthesized from biomass-derived hydro-char (HC) through modified hydrothermal carbonization (HTC) process coupled with H₃PO₄ (PA), ZnCl_2, (ZnCl), and KOH thermochemical activation with a specific impregnation ratio of 1:3 (HC/activating agent) at 600 °C. The prepared ACs were characterized through CHN-S analyser, XRD, SEM/EDS, BET, TGA, and FTIR analysis. The modification in textural and surface morphology has been observed. Thermochemical activation results in surface modification of AC samples with a higher specific (S_BET) surface area having a range of 650−1225 m²/g, large microporous volume (V_μD-A, V_μD–R) up to 0.624 and 0.642 cm³/g with 68–90 % micro-porosity. The CO₂ adsorption capacity was examined through a high-pressure gas sorption analyser at a pressure of 0−16 bar and temperature of 15 °C, 30 °C, and 45 °C. At 15 °C of temperature, AC-PA showed the adsorption capacity of 130 and 958 mg/g, while AC-ZnCl exhibited 160 and 836 mg/g of adsorption at 1 and 16 bar of pressure respectively. Whereas AC-KOH exhibited a notable CO₂ adsorption capacity of 198 and 1560 mg/g at 1 and 16 bar of pressure (15 °C). Furthermore, experimental equilibrium data of CO₂ adsorption were analysed by applying Freundlich, Langmuir, Redlich-Peterson, Sips, and Toth isotherm models and validate these models by calculating the regression coefficient (R²), and standard deviation Δq (%). Finally, the thermodynamics parameters (ΔH°, ΔS°, ΔG°, and ΔH_Isosteric) were evaluated and concluded that the adsorption of CO₂ (adsorbate) on adsorbent is spontaneous and exothermic.

在这项研究中，活性炭（AC）为基础的吸附剂是由生物质衍生的碳氢化合物（HC）通过改进的水热碳化（HTC）工艺与H ₃ PO ₄（PA），ZnCl ₂（ZnCl）和KOH合成的在600°C下以1：3的特定浸渍比（HC /活化剂）进行热化学活化。通过CHN-S分析仪，XRD，SEM / EDS，BET，TGA和FTIR分析对制备的AC进行表征。已经观察到纹理和表面形态的改变。热化学活化导致具有较高比_表面积（S _BET）的AC样品的表面改性，比_表面积（S _BET）范围为650-1225 m ² / g，微孔体积较大（_VμD-A，V _μD–R）高达0.624和0.642 cm ³ / g，微孔率为68–90％。通过高压气体吸附分析仪在0-16 bar的压力和15°C，30°C和45°C的温度下检查了CO _2的吸附能力。在15°C的温度下，AC-PA的吸附容量为130和958 mg / g，而AC-ZnCl在1 bar和16 bar的压力下分别显示160和836 mg / g的吸附量。而AC-KOH在1和16 bar的压力（15°C）下表现出明显的198和1560 mg / g的CO ₂吸附容量。此外，通过使用Freundlich，Langmuir，Redlich-Peterson，Sips和Toth等温线模型分析了CO ₂吸附的实验平衡数据，并通过计算回归系数（R²）和标准偏差Δq（％）。最后，评估了热力学参数（ΔH°，ΔS°，ΔG°和_ΔHIsosteric），并得出结论，吸附剂对CO ₂（被吸附物）的吸附是自发的且放热的。