Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Bioresour Technol. 2022 Jan;344(Pt B):126412. doi: 10.1016/j.biortech.2021.126412. Epub 2021 Nov 24.
Biogas upgrading is an essential process for efficient and safe utilization of biogas produced from anaerobic digestion (AD), a cost-effective and environmentally friendly technology for bioenergy recovery from organic wastes. Biogas recirculation in AD reactors has been recently reported as a cost-effective and promising method to enhance methane content in biogas. This review aimed to summarize the state-of-the-art of biogas recirculation-based AD systems to better understand the possible mechanisms and main factors relating to in-situ biogas upgrading. It shows that biogas recirculation in the AD reactor can not only enhance methane content via both physicochemical and biological effects, but also help establish a robust AD system with high buffering capacity for highly efficient treatment of various organic wastes. More research works are demanding for a better understanding of the mechanisms and the optimization of the whole AD system, targeting its further development for high-calorie bioenergy production.
沼气升级是高效、安全利用厌氧消化（AD）产生的沼气的必要过程，AD 是从有机废物中回收生物能源的一种具有成本效益和环保效益的技术。最近有报道称，在 AD 反应器中进行沼气再循环是一种经济有效的提高沼气中甲烷含量的有前途的方法。本综述旨在总结基于沼气再循环的 AD 系统的最新进展，以便更好地了解与原位沼气升级相关的可能机制和主要因素。结果表明，AD 反应器中的沼气再循环不仅可以通过物理化学和生物效应来提高甲烷含量，还可以帮助建立一个具有高缓冲能力的稳健 AD 系统，从而高效处理各种有机废物。需要更多的研究工作来更好地理解其机制，并对整个 AD 系统进行优化，以进一步开发用于生产高热值生物能源的技术。
