Low carbon biofuels and the New Brazilian National Biofuel Policy (RenovaBio): A case study for sugarcane mills and integrated sugarcane-microalgae biorefineries. (November 2019)

• Record Type: Journal Article
• Authors: Klein, Bruno Colling; Chagas, Mateus Ferreira; Watanabe, Marcos Djun Barbosa; Bonomi, Antonio; Maciel Filho, Rubens
• Is Part Of: Renewable & sustainable energy reviews. Volume 115(2019)
• Publication Date: 2019-11
• Subjects: Biofuel policy -- Sugarcane -- Microalgae -- Process integration -- Biofuels -- RenovaBio; AD anaerobic digestion -- AEZ agro-ecological zoning -- CAPEX capital expenditures -- CBio decarbonization credit -- CCS carbon capture and storage -- CHP Cogeneration of Heat and Power -- COD chemical oxygen demand -- COP21 21st Conference of Parties -- DAC direct air capture -- EISA Energy Independence and Security Act -- GHG greenhouse gases -- GREET Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation -- IPCA Í;ndice Nacional de Preços ao Consumidor (Brazilian inflation rate) -- IPCC Intergovernmental Panel on Climate Change -- IRR Internal Rate of Return -- LCA Life Cycle Assessment -- LCFS Low Carbon Fuel Standard -- LHV lower heating value -- LUC land use change -- MARR minimum acceptable rate of return -- MTC million tonnes of sugarcane -- NAS nitrifying-enriched activated sludge -- NDC Nationally Determined Contribution -- NOB nitrite-oxidizing bacteria -- NPV/I Net Present Value over investment ratio -- OPEX operational expenses -- PSA pressure swing adsorption -- RED Renewable Energy Directive -- UASB upflow anaerobic sludge blanket -- UNFCCC United Nations Framework Convention on Climate Change -- VSB Virtual Sugarcane Biorefinery; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.rser.2019.109365
• Languages: English
• ISSNs: 1364-0321

Abstract

Abstract: The newest endeavor by the Brazilian State for fostering bioenergy - the National Biofuel Policy, or simply RenovaBio - aims at establishing a mechanism for the commercialization of decarbonization credits linked to the carbon intensity of several biofuels. Under this horizon, this study evaluates the prospects for large-scale, integrated sugarcane-microalgae biorefineries in terms of their techno-economic and environmental feasibility, as well as the possible benefits brought by the RenovaBio program. Process integration was based on different energy and material vectors obtained from the sugarcane mill, especially the use of fermentation-derived CO2, CO2 in biogas, and vinasse as carbon sources for microalgae growth. Results show that the co-location of microalgae production with sugarcane mills leads to verticalized biorefineries currently behind in economic performance in comparison to conventional sugarcane mills due to an increase in both fixed and operational expenses. Anhydrous ethanol production costs remain in the range of US$ 0.36–0.42/L, below the market price of US$ 0.51/L. Integrating a microalgae facility with a sugarcane mill also helps to further improve the sustainability of anhydrous ethanol production: cradle-to-grave emissions of greenhouse gases fluctuate around 18 g CO2 eq/MJ, a reduction of 15% in comparison to conventional sugarcane-based ethanol. Depending on the scenario, a reasonably-sized integrated biorefinery would be able to mitigate around 500 thousand t CO2 eq/year when displacing gasoline with anhydrous ethanol. The analysis finally points out to integrated sugarcane-microalgae biorefineries becoming economically feasible at carbon prices as low as US$ 10/t CO2 eq under the RenovaBio scheme. Graphical abstract: Image 1 Highlights: RenovaBio Program is a promising policy for biofuels adoption in Brazil. Economic and environmental assessment of co-located sugarcane-microalgae plants. Microalgae biodiesel replaces fossil diesel in verticalized production of sugarcane. Low carbon intensity of ethanol from integrated biorefineries: around 18 g CO2 eq/MJ. Integrated biorefineries reach economic viability at CO2 prices of US$ 10/t.