Biological Sciences Division, Pacific Northwest National Laboratory, 3300 Stevens Dr., Richland, WA 99354, United States.
Department of Environmental Health and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686, United States; Department of Civil and Environmental Engineering, The University of Texas at San Antonio, 1 UTSA Cir, San Antonio, TX 78249, United States.
Bioresour Technol. 2018 Dec;269:210-220. doi: 10.1016/j.biortech.2018.08.085. Epub 2018 Aug 21.
This study investigated enhancing methane production from algal-bacteria biomass by adjusting the C/N ratio through co-digestion with a nitrogen-poor co-substrate - cellulose. A biomethane potential test was used to determine cumulative biogas and methane production for pure and co-digested substrates. Four kinetic models were evaluated for their accuracy describing experimental data. These models were used to estimate the total energy output and net energy ratio (NER) for a scaled AD system. Increasing the algal C/N ratio from 5.7 to 20-30 (optimal algae:cellulose feedstock ratios of 35%:65% and 20%:80%) improved the ultimate methane yield by >10% and the first ten days production by >100%. The modified Gompertz kinetic model demonstrated highest accuracy, predicting that co-digestion improved methane production by reducing the time-lag by ∼50% and increasing rate by ∼35%. The synergistic effects increase the AD system energy efficiency and NER by 30-45%, suggesting potential for substantial enhancements from co-digestion at scale.
本研究通过用贫氮共底物——纤维素进行共消化来调整 C/N 比，从而提高藻类-细菌生物质的甲烷产量。采用生物甲烷潜力测试来确定纯底物和共消化底物的累积沼气和甲烷产量。评估了四个动力学模型，以确定它们在描述实验数据方面的准确性。这些模型用于估算规模化 AD 系统的总能量输出和净能量比 (NER)。将藻类的 C/N 比从 5.7 增加到 20-30（最佳藻类：纤维素进料比为 35%:65%和 20%:80%），可将最终甲烷产量提高 10%以上，并将前十天的产量提高 100%以上。修正的 Gompertz 动力学模型显示出最高的准确性，预测共消化通过将滞后时间减少约 50%并将速率提高约 35%来提高甲烷产量。协同作用提高了 AD 系统的能源效率和 NER 约 30-45%，表明在规模化共消化方面具有显著提高的潜力。
