Anaerobic digestion of low-strength dairy waste water was used for the production of biogas which is aimed at serving as a concentrated carbon dioxide (CO₂) source for further methanation. Using hydrogen (which can be produced via electrolysis using renewably sourced electricity), the CO₂ fraction of the produced biogas can be used as a mechanism to store surplus electricity by the Sabatier process, which converts the CO₂ fractions to methane (CH₄), i. e. synthetic natural gas. This study investigates the use a combined reactor scheme for the anaerobic digestion of dairy waste water, and the further upgrading of the biogas products from the process. A combination pilot scale process was established with a 90 d start-up time using a 1 m³ continuous stirred tank reactor (CSTR) and a 0.2 m³ baffled reactor (ABR) in series. The system was fed at constant retention time in the ABR of 1.6 d and with varying substrate organic loading rates between 1.25 and 4.50 kg m⁻³ d⁻¹. The average chemical oxygen demand (COD) removal was 82% with a biogas yield of 0.26 m³ kg⁻¹. The use of the derived biogas for the Sabatier process to convert hydrogen into CH₄ showed no disadvantages compared to synthetic gas mixtures. The combination of CSTR and ABR overcame the individual disadvantages of both reactor types. The investigated anaerobic digestion system can be further optimized and adopted to replace conventional waste water treatment systems.

低强度乳制品废水的厌氧消化用于生产沼气，旨在用作进一步甲烷化的浓二氧化碳（CO ₂）源。使用氢气（可通过使用可再生能源通过电解产生的氢气），产生的沼气的CO ₂馏分可以用作通过Sabatier工艺存储剩余电量的机制，该过程将CO ₂馏分转化为甲烷（CH ₄），即合成天然气。这项研究调查了使用联合反应器方案厌氧消化乳制品废水，以及进一步提纯过程中的沼气产品。使用串联的1 m ³连续搅拌釜反应器（CSTR）和0.2 m ³折流板反应器（ABR），在90 d的启动时间建立了组合中试规模工艺。以恒定的保留时间在1.6 d的ABR中进料系统，并在1.25至4.50 kg m ^-3  d ^-1之间改变底物有机负载率。平均化学需氧量（COD）去除率为82％，沼气产量为0.26 m ³  kg ^-1。与合成气体混合物相比，将衍生的沼气用于Sabatier工艺以将氢气转化为CH ₄并未显示出任何缺点。CSTR和ABR的组合克服了两种反应器类型各自的缺点。可以进一步优化研究的厌氧消化系统，并取代传统的废水处理系统。