1 Department of Food Engineering, Faculty of Animal Science and Food Engineering, University of Sao Paulo, Brazil.
2 Laboratory of Environment-Enhancing Energy (E2E), Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing, People's Republic of China.
Waste Manag Res. 2019 Jan;37(1):74-82. doi: 10.1177/0734242X18806998. Epub 2018 Nov 9.
Vegetable crop residues, such as sugarcane bagasse (SCB), despite their limited biodegradability, are potential materials for anaerobic processes because of their low cost, high availability, and sugar content. The difficulty of biodegrading this type of material is primarily related to its chemical composition and to the complex interactions between its compounds (cellulose, hemicelluloses, and lignin). Thus, the following supercritical and near critical carbon dioxide (CO) pre-treatments were evaluated with and without the addition of sodium hydroxide (NaOH): (i) 40°C/70 kgf·cm; (ii) 60°C/200 kgf·cm; and (iii) 80°C/200 kgf·cm, aiming to enhance the anaerobic biodegradability of SCB. The methanogenic production of SCB increased in all cases in which the material was pre-treated, except the case in which NaOH was used together with a high temperature. The condition using CO at 60°C/200 kgf·cm was highlighted with a lignin removal of 8.07% and an accumulated methane production of 0.6498 ± 0.014 L (273.15K, 1.01325 × 10 Pa), 23.4% higher than the value obtained with the untreated material. This condition also showed the highest net energy at the energy balance that was calculated for comparison with the tested conditions. The results showed that pre-treatments with near critical and supercritical fluids have the potential to reduce structural obstacles of lignocellulosic materials and to enhance their anaerobic biodegradability.
尽管蔬菜作物残余物（如甘蔗渣）的生物降解能力有限，但由于其成本低、可用性高且含糖量高，它们仍是厌氧过程的潜在材料。这种类型的材料难以生物降解，主要与其化学成分以及其化合物（纤维素、半纤维素和木质素）之间的复杂相互作用有关。因此，评估了以下超临界和近临界二氧化碳（CO）预处理方法，分别在添加和不添加氢氧化钠（NaOH）的情况下进行：（i）40°C/70 kgf·cm；（ii）60°C/200 kgf·cm；和（iii）80°C/200 kgf·cm，旨在提高甘蔗渣的厌氧生物降解性。在所有进行预处理的情况下，甘蔗渣的产甲烷量均有所增加，除了在高温下同时使用 NaOH 的情况。在 60°C/200 kgf·cm 下使用 CO 的条件下，木质素去除率为 8.07%，累积甲烷产量为 0.6498 ± 0.014 L（273.15K，1.01325 × 10 Pa），比未处理材料的产量高 23.4%。该条件还在能量平衡计算中显示出最高的净能量，与测试条件进行了比较。结果表明，近临界和超临界流体预处理具有降低木质纤维素材料结构障碍并提高其厌氧生物降解性的潜力。
