Implications of regional N2O-N emission factors on sugarcane ethanol emissions and granted decarbonization certificates

Author(s)

Carvalho, Joao Luis Nunes ^[1] ; Oliveira, Bruna Goncalves ^[2] ; Cantarella, Heitor ^[2] ; Chagas, Matheus Ferreira ^[1] ; Gonzaga, Leandro Carolino ^{[1, 3]} ; Lourenco, Kesia Silva ^[2] ; Bordonal, Ricardo Oliveira ^[1] ; Bonomi, Antonio ^[1]

Affiliation

^[1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biorenewables Natl Lab LNBR, Rua Giuseppe Maximo Scolfaro 10000, BR-13083100 Campinas, SP - Brazil

^[2] Agron Inst Campinas IAC, Soils & Environm Resources Ctr, Barao Itapura 1481, BR-13001970 Campinas, SP - Brazil

^[3] Univ Campinas UNICAMP, Interdisciplinary PhD Program Bioenergy, Rua Monteiro Lobato 80, Cidade Univ, BR-13083862 Campinas, SP - Brazil

• Document type: Journal article
• Source: RENEWABLE & SUSTAINABLE ENERGY REVIEWS; v. 149, OCT 2021.
• Web of Science Citations: 0

Abstract

Reducing greenhouse gas (GHG) emissions by substituting fossil fuels depends on how biofuels are produced and how emissions are calculated. Nitrous oxide (N2O) emissions from synthetic and organic N fertilizers are important sources of GHG from sugarcane ethanol. This study aimed to synthesize the literature information and derive regional N2O emissions factors (EFs) for N fertilizers according to Tier 2 approach. This study also evaluated how the use of Tier 2 affects emissions compared with those obtained by the IPCC Tier 1. Moreover, this study examined how N fertilizers can affect GHG emissions and the earning of decarbonization certificates (CBIOs) by ethanol producers. For an ethanol distillery producing 339 million liters annually, the use of Tier 1 and Tier 2 resulted in emissions of 176.5 and 145.2 Gg CO2eq, whereas for the same amount of energy, gasoline would emit 661.8 Gg CO2eq. The addition of nitrification inhibitors (NIs) to N fertilizers and improvements in vinasse/fertilizer management further reduced emissions compared with Tier 2. In Tier 1, the GHG emission savings would result 485,270 CBIOs, worth 4.85 million US\$ at US\$10 per CBIO. But if the IPCC Tier 2 is considered, the annual CBIOs would be worth 5.17 million US\$. Using NIs and improving vinasse/fertilizer management may bring an additional US\$ 31,700 and US\$ 48,000 revenue above that of Tier 2. Public and sectorial policies behind decarbonization certificates can encourage farmers and decision-makers to pursue more efficient and economical solutions to further decrease GHG emissions and improve the sustainability of ethanol. (AU)

• FAPESP's process: 18/20698-6 - Nitrification inhibitor as strategy to mitigate N2O emissions and its impacts on the active nitrifying and denitrifying soil microbial communities after concentrated vinasse and mineral N application
• Grantee: Késia Silva Lourenço
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 18/20793-9 - Nitrification and urease inhibitors as strategies to mitigate N2O emissions and NH3 volatilization in sugarcane production with addition of organic residues
• Grantee: Heitor Cantarella
• Support type: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 19/12557-6 - Distinguishing microbial pathways to nitrous oxide emissions following addition of concentrated vinasse and the nitrification inhibitor DMPP to sugarcane soil
• Grantee: Bruna Gonçalves de Oliveira Carvalho
• Support type: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/02299-4 - Nitrification inhibitor as strategy to mitigate N2O emissions in sugarcane production
• Grantee: Bruna Gonçalves de Oliveira Carvalho
• Support type: Scholarships in Brazil - Post-Doctorate