The hydrothermal carbonization (HTC) technique is known for its advantages in producing hydrochar from biomass samples with high water content compared to conventional pyrolysis techniques. This study utilized HTC to produce an activated carbon catalyst from renewable mesocarp fiber derived from palm oil processing. The introduction of K₂CO₃ and Cu(NO₃)₂ produced a bifunctional catalyst suitable for conversion of used cooking oil to biodiesel. The catalyst possessed a mesoporous structure with a BET surface area of 3909.33 m²/g. An optimum treatment ratio of 4:1 (K₂CO₃: Cu(NO₃)₂) provided elevated basic (5.52 mmol/g) and acidic (1.68 mmol/g) concentrations on the catalytic surface, which promoted esterification and transesterification reactions. Maximum yield (96.4%) of biodiesel was obtained at 70 °C for 2 h with 5 wt% catalyst and a 12:1 molar ratio of methanol to oil. The catalyst endured up to 5 reaction cycles while maintaining biodiesel yields of more than 80%. These findings indicated that HTC pretreatment yielded a high-quality bifunctional catalyst for conversion of low-quality used cooking oil for production of biodiesel.

与传统的热解技术相比，水热碳化 (HTC) 技术以其在从含水量高的生物质样品中生产水炭方面的优势而闻名。本研究利用 HTC 从棕榈油加工中提取的可再生中果皮纤维生产活性炭催化剂。K ₂ CO ₃和Cu(NO ₃ ) ₂的引入产生了适用于将用过的食用油转化为生物柴油的双功能催化剂。该催化剂具有介孔结构，BET表面积为3909.33 m ² /g。最佳处理比例为 4:1 (K ₂ CO ₃ : Cu(NO ₃ ) ₂) 在催化表面提供升高的碱性 (5.52 mmol/g) 和酸性 (1.68 mmol/g) 浓度，促进酯化和酯交换反应。生物柴油的最大产率 (96.4%) 在 70 °C 下使用 5 wt% 催化剂和 12:1 的甲醇与油的摩尔比在 2 小时内获得。该催化剂可承受多达 5 个反应循环，同时保持生物柴油产率超过 80%。这些发现表明，HTC 预处理产生了一种高质量的双功能催化剂，用于将低质量的食用油转化为生物柴油的生产。