Dilute acid hydrolysis was employed to generate lipid-dense post-hydrolyzed rice bran (PHRB) which was utilized as feedstock in biodiesel production. Upon drying of the wet PHRB with the entrained dilute acid solution, subsequent carbonization and sulfonation occurred with the material, incorporating significant amounts of sulfur in PHRB as sulfonic acid. The collected dry PHRB was utilized as feedstock in the in-situ (trans)esterification (ISTE) of its lipids to fatty acid methyl esters (FAME), whereby the available acid sites reduced the acid catalyst to be loaded in the reaction system. The optimum reaction conditions under ambient pressures were determined via the Taguchi method and the highest yield achieved was 22.38 ± 0.28 g FAME/100 g PHRB (82.31% conversion or reaction yield), and was achieved at 65 °C, SSR of 20 mL methanol/g dried PHRB, 12 h reaction time, and 5 wt% H₂SO₄ of the PHRB processed. The post-ISTE PHRB was found to still possess the catalytic activity and could be used for the esterification of oleic acid and methanol and appreciable stability. Finally, the FAME-rich product also exhibits free-radical scavenging activity, owing to the presence of bioactive components, which may provide better oxidative stability or could be further recovered as high-value by-products.

采用稀酸水解生成高脂后水解米糠 (PHRB)，用作生物柴油生产的原料。在用夹带的稀酸溶液干燥湿 PHRB 后，材料发生随后的碳化和磺化，在 PHRB 中以磺酸的形式引入大量的硫。收集的干燥 PHRB 用作其脂质原位（转）酯化（ISTE）为脂肪酸甲酯（FAME）的原料，由此可用的酸位点减少了要加载到反应系统中的酸催化剂。通过田口法确定了环境压力下的最佳反应条件，获得的最高产率为 22.38 ± 0.28 g FAME/100 g PHRB（转化率或反应产率 82.31%），并在 65 °C、20 mL 甲醇的 SSR 下实现/g 干 PHRB，处理过的PHRB的₂ SO ₄。发现后ISTE PHRB仍具有催化活性，可用于油酸和甲醇的酯化反应，并具有可观的稳定性。最后，由于生物活性成分的存在，富含 FAME 的产品还表现出自由基清除活性，这可以提供更好的氧化稳定性或可以作为高价值副产品进一步回收。