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

Edi Iswanto Wiloso,Subyakto ,I Made Sudiana,Dede Hermawan,Adisa Ramadhan Wiloso,Satya Nugroho,Reinout Heijungs,Arief Ameir Rahman Setiawan,Reni Lestari,Muryanto ,Kai Fang,Hafiizh Prasetia

doi:10.18331/brj2020.7.3.2

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.

Highlights

Edi Iswanto Wiloso 1,2,*, Arief Ameir Rahman Setiawan1, Hafiizh Prasetia3, Muryanto3, Adisa Ramadhan Wiloso2, Subyakto4, I
➢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%
The global warming impacts of electricity generation were evaluated for the single-firing of coal (SFC), CF, and single-firing of pellets (SFP) product systems

Summary

Introduction

Edi Iswanto Wiloso 1,2,*, Arief Ameir Rahman Setiawan, Hafiizh Prasetia, Muryanto, Adisa Ramadhan Wiloso, Subyakto, I. 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 These results changed when reduced biomass yield of 24 ton/ha·yr, biomass loss, field emissions, and incomplete combustion were considered in the model. 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 discussed . According to the Ministry of Environment and Forestry, Indonesia has approximately 14 million ha of marginal land in total (MoEF, 2018)

Objectives

Methods

Results

Conclusion