BECCS opportunities in Brazil: Comparison of pre and post-combustion capture in a typical sugarcane mill

Abstract

In order to make feasible the efforts that would limit the rise of Earth's temperature to no more than 2 °C, profound changes are required in the energy systems. In this sense, BECCS are considered instrumental to attain possible negative emissions. This draws attention to the sugarcane industry in Brazil, where it is possible to produce fuel ethanol at a relative low cost and a large amount of relatively cheap biomass is available. This paper is part of a research that aims to study the combined production of liquid fuels and electricity, using sustainable sources of biomass and maximizing carbon capture. Two cases related to an innovative technology were evaluated and in both the capture is based on amine technology: pre-combustion capture of CO2 from the fuel gas derived from biomass gasification, and post-combustion capture from gas turbine exhaust gases. Information from the scientific literature was used in modelling the systems, as well as estimating energy penalties and costs associated with capturing, transporting and storing CO2. The results indicate technical feasibility of both capture options, but difficulties in setting the full integration of the power unit (BIG-CC) with the sugarcane mill and the CCS system, due to the high demand for thermal energy as low-pressure steam. The estimated CO2 abatement cost is in the range 60–71 €/tCO2 for pre-combustion capture, and 52–63 €/tCO2 in the case of post-combustion. Feasibility results are impacted by the scale of CO2 capture (0.82–1.44 MtCO2/year), particularly in the pre-combustion case, and the relatively high cost of electricity generation.