Effect of Biodiesel Blends on the Aging of EURO VI Aftertreatment System 2020-36-0263

In Brazil, the introduction of high biodiesel blends has been defined by standard CNPE n^o 16 of 2018, which stablished the latest chronogram for compulsory biodiesel incorporation to all diesel fuel commercialized nationally, from 11% v/v in 2019 to 15% v/v in 2023, and up to B20 in case of captive fleets. Nevertheless, with the adoption of more stringent emission standards in Brazil, concerns arise from the unrestricted use of higher biodiesel blends, especially regarding the assurance of Heavy-Duty Diesel (HDD) emissions aftertreatment systems correct operation and of fulfillment of national emissions requirements defined by PROCONVE. Considering the current emission standards (PROCONVE P7, equivalent to EURO V), such concerns already take place and become critical with the perspective of PROCONVE P8 (EURO VI) implementation, in 2022 for new models and 2023 for all commercialized vehicles, as defined by CONAMA Resolution n^o 490/2018. Therefore, in order to address the possible impacts of the use of biodiesel blends in CONAMA P8 HDD technology emissions aftertreatment systems, an evaluation of the emissions durability was conducted with B10 and B20. FPT Industrial 6 cylinders engine, with OEM calibration, was used in the emissions durability tests, simulating 300.000 km, as defined by PROCONVE P8 for trucks from 3,8 tons up to 16 tons and buses from 5 tons up to 7,5 tons. The engine was set up in the test bench with an EURO VI aftertreatment configuration, typical of future application in Brazil, consisting of a Diesel Oxidation Catalyst (DOC), a Diesel Particulate Filter (cDPF), a Selective Catalytic Reduction catalyst (SCR) and an Ammonia Slip Catalyst (ASC).

The tests conducted with B10 and B20 fuels and an EURO VI aftertreatment configuration (DOC+cDPF+SCR+ASC), typical of future application in Brazil, showed higher aging on DOC+cDPF catalysts, in comparison with SCR+ASC. Higher impact on NO2 formation after aging cycle, reducing passive regeneration capacity and NOx conversion, was verified for the aftertreatment system aged with B20. According to ARC test (Active Regeneration Check), the DOC conversion capacity of hydrocarbons (THC) decreased on both aged systems, with higher decreasing on B20, where slip occurred faster and NH3 levels increased after both aging cycles.