**Sara Restrepo-Valencia \* and Arnaldo Walter**

Department of Energy, School of Mechanical Engineering, University of Campinas—UNICAMP, Campinas 13083860, Brazil; awalter@fem.unicamp.br

**\*** Correspondence: sara.valencia@fem.unicamp.br; Tel.: +55-19-352-13283

† The present work is an extension of the paper "A. Techno-Economic Assessment of BECCS Systems in the Brazilian Sugarcane Sector" presented at the 13th Conference on Sustainable Development of Energy, Water and Environment Systems—SDEWES Conference, 30 September–4 October, Palermo, Italy.

Received: 28 December 2018; Accepted: 4 March 2019; Published: 22 March 2019

**Abstract:** For significantly reducing greenhouse gas emissions, those from electricity generation should be negative by the end of the century. In this sense, bio-energy with carbon capture and storage (BECCS) technology in sugarcane mills could be crucial. This paper presents a technical and economic assessment of BECCS systems in a typical Brazilian sugarcane mill, considering the adoption of advanced—although commercial—steam cogeneration systems. The technical results are based on computational simulations, considering CO2 capture both from fermentation (released during ethanol production) and due to biomass combustion. The post combustion capture technology based on amine was considered integrated to the mill and to the cogeneration system. A range of energy requirements and costs were taken from the literature, and different milling capacities and capturing rates were considered. Results show that CO2 capture from both flows is technically feasible. Capturing CO2 from fermentation is the alternative that should be prioritized as energy requirements for capturing from combustion are meaningful, with high impacts on surplus electricity. In the reference case, the cost of avoided CO2 emissions was estimated at 62 €/t CO2, and this can be reduced to 59 €/t CO2 in case of more efficient technologies, or even to 48 €/t CO2 in case of larger plants.

**Keywords:** bioelectricity; carbon capture; negative emissions; sugarcane; biomass; climate change
