Bioenergy in China: Evaluation of domestic biomass resources and the associated greenhouse gas mitigation potentials

Abstract

As bioenergy produces neutral or even negative carbon emissions, the assessment of biomass resources and associated emissions mitigation is a key step toward a low carbon future. However, relevant comprehensive estimates lack in China. Here, we measure the energy potential of China's domestic biomass resources (including crop residues, forest residues, animal manure, municipal solid waste and sewage sludge) from 2000 to 2016 and draw the spatial-temporal variation trajectories at provincial resolution. Scenario analysis and life cycle assessment are also applied to discuss the greenhouse gas mitigation potentials. Results show that the collectable potential of domestic biomass resources increased from 18.31 EJ in 2000 to 22.67 EJ in 2016 with overall uncertainties fluctuating between (-26.6%, 39.7%) and (-27.6%, 39.5%). Taking energy crops into account, the total potential in 2016 (32.69 EJ) was equivalent to 27.6% of China's energy consumption. If this potential can be realized in a planned way to displace fossil fuels during the period 2020-2050, cumulative greenhouse gas emissions mitigation would be in the range of 1652.73-5859.56 Mt CO₂-equivalent, in which the negative greenhouse gas emissions due to the introduction of bioenergy with carbon capture and storage would account for 923.78-1344.13 Mt CO₂-equivalent. Contrary to increasing bioenergy potentials in most provinces, there are declining trends in Tibet, Beijing, Shanghai and Zhejiang. In addition, Yunnan, Sichuan and Inner Mongolia would have the highest associated greenhouse gas mitigation potentials. This study can provide valuable guidance on the exploitation of China's untapped biomass resources for the mitigation of global climate change.

Keywords: Bioenergy potential; Biomass resources; China; GHG mitigation Potentials; Spatial-temporal variation; Uncertainty analysis.

Fig. 1

The framework for evaluating biomass resources and associated GHG mitigation potentials in China.

Fig. 2

Changes in China's domestic bioenergy potential.

Fig. 3

Percentages of the sub-types of crop residues (a), forest residues (b) and animal manure (c). (The inner ring depicts the percentages in 2000 and the outer ring represents that in 2016).

Fig. 4

China's provincial bioenergy potential in 2000 (a), 2007 (b) and 2016 (c), as well as the relative changes between 2000 and 2016 (d).

Fig. 5

The total potential of China's biomass resources including energy crops (a) and their density (b) in 2016.

Fig. 6

GHG mitigation potentials of the bioenergy sector in China. (S1, S2, S3 and S4 represent scenario 1, scenario 2, scenario 3 and scenario 4, respectively).

Fig. 7

Avoided GHG emissions and life-cycle GHG emissions of bioenergy in China.

Fig. 8

China's provincial cumulative GHG mitigation potentials of bioenergy from 2020 to 2050 in the four scenarios.

Fig. 9

Ranges of residue to product ratio (RPR) and animal excretion coefficient for each sub-type of crop residues (a) and animal manure (b). (Diamonds and centre lines represent mean values and 50th percentile, respectively. Boxes represent 25th to 75th percentiles, and bars represent 5th to 95th percentiles of 5000 Monte Carlo simulations).

Fig. 10

Uncertainties of the collectable potential of China's domestic biomass resources in this study and comparisons with existing studies. Data sources are Liu et al. [44], Yang et al. [20], Zhou et al. [21], and Zhang [40].