The carbon dioxide (CO₂) torrefaction of oil palm empty fruit bunch (OPEFB) pellets was investigated at various temperatures from 250 to 300 °C and residence times from 15 to 60 minutes. The objective was to investigate the effects of CO₂ torrefaction on the yield and characteristics of the torrefied products. The optimal conditions for maximum mass yield (M_Y) of CO₂ torrefaction were also examined by response surface methodology (RSM) using full factorial design. Results revealed that temperature and time significantly influenced the mass (M_Y), liquid (L_Y) and gas (G_Y) yields. The M_Y and energy yield (E_Y) decreased with increasing severity of torrefaction, whereas the L_Y, G_Y, energy density (D_E) and higher heating value (HHV) increased during the process. Characterisation revealed substantial improvements in the microstructure, pH, hydrophobicity and grindability of the torrefied pellets compared with the raw pellets. The thermal ignition and degradation characteristics of the OPEFB pellets were also significantly transformed after torrefaction. The liquid torrefaction products contained an acidic, turbid and pungent mixture of water and organic compounds. RSM optimisation revealed the optimal conditions: temperature of 275 °C and residence time of 35 minutes with the predicted M_Y of 50.54%, mass loss of M_L = 49.46% and HHV = 24.47 MJ/kg. The findings revealed that CO₂ torrefaction is a practical approach to clean energy recovery.

在250至300°C的不同温度和15至60分钟的停留时间下研究了油棕空果束（OPEFB）颗粒的二氧化碳（CO ₂）烘焙。目的是研究CO ₂焙干对焙干产品的产率和特性的影响。还通过使用全因子设计的响应面方法（RSM）检验了CO ₂焙烧的最大质量产率（M _Y）的最佳条件。结果表明，温度和时间显着影响质量（M _Y），液体（L _Y）和气体（G _Y）的产率。M _Y和能量产率（E _Y）随焙烧强度的增加而降低，而在此过程中L _Y，G _Y，能量密度（D _E）和较高的热值（HHV）升高。表征显示，与原始粒料相比，焙烤粒料的微观结构，pH，疏水性和可磨性有了显着改善。焙烧后，OPEFB颗粒的热着火和降解特性也发生了显着变化。液体烘焙产品包含水和有机化合物的酸性，浑浊和刺激性混合物。RSM优化揭示的最佳条件：35分钟与预测M的275℃温度和停留时间_ÿ的50.54％，M的质量损失_大号= 49.46％，HHV = 24.47 MJ / kg。研究结果表明，CO ₂焙干是清洁能源回收的实用方法。