Life cycle assessment of sugarcane ethanol production in India in comparison to Brazil

• Published in: The international journal of life cycle assessment 2014-05, Vol.19 (5), p.1049-1067
• Main Authors: Tsiropoulos, Ioannis, Faaij, André P. C, Seabra, Joaquim E. A, Lundquist, Lars, Schenker, Urs, Briois, Jean-François, Patel, Martin K
• Format: Article
• Language: English
• Subjects: Agricultural production; Air pollution; Allocations; Biofuels; Brazil; Carbon dioxide; Carbon dioxide emissions; Comparative analysis; coproducts; correlation; crops; Distilleries; Earth and Environmental Science; Economics; ecosystems; Electricity; Emissions; energy; Energy consumption; Energy requirements; Energy use; Environment; Environmental assessment; Environmental Chemistry; Environmental Economics; Environmental Engineering/Biotechnology; Environmental impact; Environmental performance; Ethanol; ethanol production; Ethyl alcohol; Eutrophication; exports; freshwater; Freshwater ecosystems; Greenhouse effect; greenhouse gas emissions; Greenhouse gases; Groundwater; Groundwater irrigation; human health; India; irrigation requirement; Irrigation water; Lca for Energy Systems and Food Products; Life cycle analysis; life cycle assessment; Life cycles; materials life cycle; mixing; Molasses; Pesticides; Product life cycle; Renewable energy; Sensitivity analysis; Sugar; Sugarcane; sugars; Water use
• ISSN: 0948-3349; 1614-7502
• DOI: 10.1007/s11367-014-0714-5

PURPOSE: India’s biofuel programme relies on ethanol production from sugarcane molasses. However, there is limited insight on environmental impacts across the Indian ethanol production chain. This study closes this gap by assessing the environmental impacts of ethanol production from sugarcane molasses in Uttar Pradesh, India. A comparative analysis with south-central Brazilian sugarcane ethanol is also presented to compare the performance of sugarcane molasses-based ethanol with sugarcane juice-based ethanol. METHODS: The production process is assessed by a cradle-to-gate life cycle assessment. The multifunctionality problem is solved by applying two variants of system expansion and economic allocation. Environmental impacts are assessed with Impact 2002+ and results are presented at the midpoint level for greenhouse gas emissions, non-renewable energy use, freshwater eutrophication and water use. Furthermore, results include impacts on human health and ecosystem quality at the damage level. Sensitivity analysis is also performed on key contributing parameters such as pesticides, stillage treatment and irrigation water use. RESULTS AND DISCUSSION: It is found that, compared to Brazilian ethanol, Indian ethanol causes lower or comparable greenhouse gas emissions (0.09–0.64 kgCO₂ₑq/kgₑₜₕₐₙₒₗIN, 0.46–0.63 kgCO₂ₑq/kgₑₜₕₐₙₒₗBR), non-renewable energy use (−0.3–6.3 MJ/kgₑₜₕₐₙₒₗIN, 1–4 MJ/kgₑₜₕₐₙₒₗBR), human health impacts (3.6 · 10⁻⁶ DALY/kgₑₜₕₐₙₒₗIN, 4 · 10⁻⁶ DALY/kgₑₜₕₐₙₒₗBR) and ecosystem impairment (2.5 PDF · m² · year/kgₑₜₕₐₙₒₗIN, 3.3 PDF · m² · year/kgₑₜₕₐₙₒₗBR). One reason is that Indian ethanol is exclusively produced from molasses, a co-product of sugar production, resulting in allocation of the environmental burden. Additionally, Indian sugar mills and distilleries produce surplus electricity for which they receive credits for displacing grid electricity of relatively high CO₂ emission intensity. When economic allocation is applied, the greenhouse gas emissions for Indian and Brazilian ethanol are comparable. Non-renewable energy use is higher for Indian ethanol, primarily due to energy requirements for irrigation. For water use and related impacts, Indian ethanol scores worse due groundwater irrigation, despite the dampening effect of allocation. The variation on greenhouse gas emissions and non-renewable energy use of Indian mills is much larger for high and low performance than the respective systems in Brazil. CONCLUSIONS: Important measures can be