Benefit analysis of multi-approach biomass energy utilization toward carbon neutrality

To reduce greenhouse gas (GHG) emissions, biomass has been increas-ingly developed as a renewable and clean alternative to fossil fuels because of its carbon-neutral characteristics. China has been investi-gating the rational development and use of bioenergy for developing its clean energy and achieving carbon neutrality. Substituting fossil fuels with multi-source and multi-approach utilized bioenergy and correspond-ing carbon reduction in China remain largely unexplored. Here, a compre-hensive bioenergy accounting model with a multi-dimensional analysis was developed by combining spatial, life cycle, and multi-path analyses. Accordingly, the bioenergy production potential and GHG emission reduc-tion for each distinct type of biomass feedstock through different conver-sion pathways were estimated. The sum of all available organic waste (21.55 EJ yr-1) and energy plants on marginal land (11.77 EJ yr-1) in China produced 23.30 EJ of bioenergy and reduced 2,535.32 Mt CO2-eq emissions, accounting for 19.48% and 25.61% of China's total energy production and carbon emissions in 2020, respectively. When focusing on the carbon emission mitigation potential of substituting bioenergy for conventional counterparts, bioelectricity was the most effective, and its potential was 4.45 and 8.58 times higher than that of gaseous and liquid fuel alternatives, respectively. In this study, life cycle emission re-ductions were maximized by a mix of bioenergy end uses based on biomass properties, with an optimal 78.56% bioenergy allocation from bio-diesel, densified solid biofuel, biohydrogen, and biochar. The main regional bioenergy GHG mitigation focused on the Jiangsu, Sichuan, Guangxi, Henan, and Guangdong provinces, contributing to 31.32% of the total GHG mitigation potential. This study provides valuable guidance on ex-ploiting untapped biomass resources in China to secure carbon neutrality by 2060.

Automated summary

To reduce greenhouse gas emissions, China has been developing and utilizing biomass as a renewable and clean alternative to fossil fuels. This study estimates the potential and emission reduction of different types of biomass feedstock through various conversion pathways, and finds that bioelectricity is the most effective bioenergy option. The research provides valuable guidance on exploiting the untapped biomass resources in China to achieve carbon neutrality by 2060.