Production of sorghum pellets for electricity generation in Indonesia: A life cycle assessment

Document Type: Research Paper

Authors

1 Research Center for Science, Technology and Innovation Policy and Management, Indonesian Institute of Sciences, Jakarta 12710, Indonesia.

2 Pamulang University, South Tangerang 15435, Indonesia.

3 Research Center for Chemistry, Indonesian Institute of Sciences, South Tangerang 15343, Indonesia.

4 Research Center for Biomaterials, Indonesian Institute of Sciences, Bogor 16911, Indonesia.

5 Research Center for Biology, Indonesian Institute of Sciences, Bogor 16911, Indonesia.

6 Research Center for Plant Conservation and Botanic Gardens, Indonesian Institute of Sciences, Bogor 16911, Indonesia.

7 Research Center for Biotechnology, Indonesian Institute of Sciences, Bogor 16911, Indonesia.

8 Bogor Agricultural University, Bogor 16680, Indonesia.

9 School of Public Affairs, Zhejiang University, Hangzhou 310058, China.

10 Center of Social Welfare and Governance, Zhejiang University, Hangzhou 310058, China.

11 School of Business and Economics, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.

12 Institute of Environmental Sciences, Leiden University, 2300 RA Leiden, The Netherlands.

Abstract

The current study makes use of life cycle assessment to evaluate the potential greenhouse gas (GHG) savings in coal electricity generation by 5% co-firing with sorghum pellets. The research models the utilization of 100 thousand hectares of under-utilized marginal land in Flores (Indonesia) for biomass sorghum cultivation. Based on equivalent energy content, 1.12 tons of pellets can substitute one ton of coal. The calculated fossil energy ratio of the pellets was 5.8, indicating that the production of pellets for fuel is energetically feasible. Based on a biomass yield of 48 ton/ha·yr, 4.8 million tons of pellets can be produced annually. In comparison with a coal system, the combustion of only pellets to generate 8,300 GWh of electricity can reduce global warming impacts by 7.9 million tons of CO2-eq, which is equivalent to an 85% reduction in GHG emissions. However, these results changed when reduced biomass yield of 24 ton/ha·yr, biomass loss, field emissions, and incomplete combustion were considered in the model. A sensitivity analysis of the above factors showed that the potential GHG savings could decrease from the initially projected 85% to as low as 70%. Overall, the production of sorghum pellets in Flores and their utilization for electricity generation can significantly reduce the reliance on fossil fuels and contribute to climate change mitigation. Some limitations to these conclusions were also discussed herein. The results of this scenario study can assist the Indonesian government in exploring the potential utilization of marginal land for bioenergy development, both in Indonesia and beyond.

Graphical Abstract

Production of sorghum pellets for electricity generation in Indonesia: A life cycle assessment

Highlights

  • Utilization of marginal land to produce sorghum pellet electricity is modeled.
  • Energy content of 1.12 tons of sorghum pellets is equivalent to 1 ton of coal.
  • Burden shifting is avoided by considering a comprehensive system boundary.
  • The pellet processing stage contributes the most to global warming impacts.
  • A sensitivity analysis shows greenhouse gas savings ranging between 70% and 85%.

Keywords


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