State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Bioresour Technol. 2018 Dec;269:57-66. doi: 10.1016/j.biortech.2018.08.072. Epub 2018 Aug 20.
Biochemical biogas upgrading retaining more CO from biogas to form biomethane opens new avenues for sustainable biofuel production. For developing this technology, maintaining sustain pH for CO·HO is fundamental. This study proposes an innovative control strategy for in-situ biogas upgrading retaining and converting the CO in the biogas into CH, via hydrogenotrophic methanogenesis without external agent. The Biogas-pH strategy limited pH drop over 7.4 by stop feeding and maintained the methanogenesis activity by biogas flow rate over 98 ml·h. Low pH (7.37-7.80) decrease CO·HO as a substrate in stage-I, higher pH (7.40-8.41) enhances CO to CO·HO transfer by 6.29 ± 2.20% in stage-II. Because of that 95% CO·HO converts to HCO and CO when pH > 7.9, higher pH > 7.9 did not further upgrading the biogas. The carbonate buffer system shown open and close system characteristics in gas and liquid phase. The biogas CH was upgraded from 67.27 ± 5.21% to 73.56 ± 5.01%.
生物化学沼气升级保留更多的 CO 从沼气中形成生物甲烷，为可持续生物燃料生产开辟了新途径。为了开发这项技术，维持 CO·HO 的持续 pH 值是基础。本研究提出了一种创新的控制策略，用于原位沼气升级，通过氢营养型产甲烷作用将沼气中的 CO 保留并转化为 CH，无需外部试剂。沼气-pH 策略通过停止进料将 pH 值的下降限制在 7.4 以上，并通过沼气流量维持产甲烷活性超过 98ml·h。低 pH 值（7.37-7.80）在第一阶段降低 CO·HO 作为底物，高 pH 值（7.40-8.41）通过 6.29±2.20%增强 CO 向 CO·HO 的转移。由于当 pH 值大于 7.9 时 95%的 CO·HO 转化为 HCO 和 CO，因此 pH 值大于 7.9 不会进一步升级沼气。碳酸盐缓冲系统在气相和液相中表现出开放和关闭系统的特性。沼气中的 CH 从 67.27±5.21%升级到 73.56±5.01%。
