Biogas and nutrient recovery potential: A spatially explicit analysis of China’s county-level livestock and poultry manure

Abstract

Livestock and poultry manure is increasingly recognized as a critical renewable resource for reducing carbon emissions and producing carbon–neutral biofuel, owing to its capacity to undergo anaerobic digestion into biogas and nutrient-rich digestate. Optimizing the utilization of these manure resources requires high-resolution spatial data; however, previous studies have predominantly relied on analyses at the provincial level. To bridge this gap, the study offers a comprehensive county-level assessment of China’s livestock and poultry manure resources for 2020. It systematically quantifies the biogas energy potential of these resources and the nutrient profiles of the resulting digestate. The analysis reveals an annual recoverable volume of 840.40 million tons (Mt) of livestock and poultry manure, containing 207.04 Mt of total solids. This biomass could generate an estimated 69.23 billion cubic meters of biogas. The resulting digestate contains substantial nutrient reserves: 2.86 Mt of nitrogen (N), 5.13 Mt of phosphorus (P), and 1.78 Mt of potassium (K). At the county level, Guangze County exhibits the highest biogas potential of 4,981.26 GWh, and it also leads in N production at 21.43 kilo tons (kt) and in K production at 30.64 kt, while Fuxin Mongolzu Autonomous County tops P production at 39.56 kt. These results provide a critical foundation for policymakers to develop spatially differentiated biomass utilization strategies, thereby addressing localized energy constraints through targeted interventions.