July 14, 2024， teams of Dr. Tao Luo (Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, China) and Prof. Bo Shen (Lawrence Berkeley National Laboratory, Berkeley, USA) as the main researchers have published their latest research. On-site conversion of organic waste into biogas to satisfy consumer energy demand has the potential to realize energy equality and mitigate climate change reliably. However, existing methods ignore either real-time full supply or methane escape when supply and demand are mismatched. Researchers show an improved design of community biogas production and distribution system to overcome these and achieve full co-benefits in developing economies. They take five existing systems as empirical examples. Mechanisms of synergistic adjusting out-of-step biogas flow rates on both the plant-side and user-side are defined to obtain consumption-to-production ratios of close to 1, such that biogas demand of rural inhabitants can be met. Furthermore, carbon mitigation and its viability under universal prevailing climates are illustrated. Coupled with manure management optimization, Chinese national deployment of the proposed system would contribute a 3.77% reduction towards meeting its global 1.5°C target. Additionally, fulfilling others’ energy demands has considerable decarbonization potential. These findings are published in the journal Nature communications.

Recognizing specifically the significant role that emissions of methane play in increasing temperatures, both countries consider increased action to control and reduce such emissions to be a matter of necessity. To this end, China intends to develop a comprehensive and ambitious National Action Plan on methane, aiming to achieve a significant effect on methane emissions control and reductions in the 2020s. Particularly, the waste sector account for around 20% of global human-caused methane emissions. On one hand, high-quality biogas systems have been recognized as the most efficient strategy to reduce methane emission of organic waste treatment; on other hand, biogas is considered a feasible and essential technology to produce sustainable energy to cover the shortage of nature gas. In these circumstances, identifying the most efficient biogas system and the deploying strategy it in developing areas have become hot topics. On-site generation and direct supply biogas to consumers would result in significant advantages to the supply chain of exploitation, conversion, and distribution. Most of all, it is possible to acquire the best co-benefits of sustainable energy production and greenhouse gas (GHG) emission mitigation, on the prerequisites of on-demand biogas supply and close-to-zero methane leakage.

Authors provide a quantitative demonstration to analyze the dynamic changes of biogas flow depending on the user side and production side. Its general form includes fitting the biogas supply rate curve based on the characteristics of user-side consumption, establishing a self-adjusting platform, and building the mechanism of biogas flow modulation. They also show that an upgraded CBPD is a viable method for realizing the full co-benefits of transforming organic waste into biogas under prevailing climate conditions. Further, upgraded CBPD would not only be carried out in rural communities in a decentralized manner, but also could be conducted to store and supply organic fertilizer on-site for distribution distances minimization, to decrease direct nitrous oxide emissions by avoiding denitrification processes, and reduce synthetic fertilizer inputs, because more manure nitrogen is recycled back to farmland instead of being released into the open air. These could facilitate ecological utilization of an anaerobically digested fertilizer to nearby farms.

There is a huge energy demand of clean energy in China, such as biogas. Firstly, the methane production potential of manure is 2,467.7 billion MJ yr-1, which only covers 26.3% of current direct residential energy consumption in rural areas. Secondly, rural manufacturing industries would provide an exponential of energy consumption due to China’s rural revitalization strategy. Thirdly, the clean energy renovation of solid fuel substituting also requires more upgraded CBPD deployment for converting various agricultural wastes to satisfy time-use demand in rural areas.

Except for upgraded CBPD design and skillful manipulation, a potential strategy leading to a more resilient system is to dynamically adjust biogas usage by kinetic parameters learned from detailed applications. Further research should focus on auxiliary measures to minimize the requirement of biogas storage volume and the negative impact of undesirable processes (for example, temporal congestion caused by inaccurate feeding time points or amount selections without intervention), which contain the policy of time-of-use pricing at peak and trough biogas usage. On one hand, energy usage in future scenarios can be accurately predicted, and biogas supply can be planned for another usages, such as, manufacturing industries. Upgraded CBPD illustrates a way to stable supply biogas in dynamic situations with full utilization, and its broad feasibility could acquire an important contribution of climate change mitigation. On other hand, upgraded CBPD deployment in combination with other renewable energy systems, such as solar energy, heat pumps, etc., could develop superior synergistic systems for more stand-alone energy supply. It could acquire a higher primary energy use ratio by more efficiently applying the characteristics of upgraded CBPD’s flexible energy production.

The collaboration team also includes Professor Zili Mei from Biogas Institute of Ministry of Agriculture and Rural Affairs, Dr. Anders Hove from Lawrence Berkeley National Laboratory and Dr. Keyi Ju from Jiangsu University of Science and Technology. Financial support of the study is from the Sichuan Science and Technology Program (Nos. 23ZDYF0252 and 2023YFS0386), the Central Public-interest Scientific Institution Basal Research Fund (No. 1610012022008_03102), and the Agricultural Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2021-BIOMA).

Please cite this article as

Luo, T., Shen, B., Mei, Z. et al. Unlocking the potential of biogas systems for energy production and climate solutions in rural communities. Nat Commun 15, 5900 (2024). https://doi.org/10.1038/s41467-024-50091-9