This paper presents a techno-economic evaluation of potential Greenfi eld projects of integrated fi rst-and second-generation sugarcane biorefi neries, in which ethanol is converted to bio-based propylene through metathesis of ethylene with 2-butene. Two scenarios were tested, considering improvements both in fi rst-and second-generation ethanol production: with and without pentoses fermentation, which increases the amount of ethanol produced. The viability of the proposed propylene production facility was studied through Minimum Bio-Propylene Selling Price (MBSP), and sensitivity and risk analysis were performed. Results show that, compared to the average propylene prices in recent years, the MBSP (based on the average estimates) would be no more than 85-90% higher than the price of the conventional fossil-fuel based product. In addition, three aspects were further assessed: (i) scaling of production plants, (ii) learning effects, and (iii) policies that would result lower capital costs. The results show that the cumulative effect would lead a substantial reduction of the MBSP, leading to a competitive price of 1347 US$/t.

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The desired energy transition to guarantee net-zero greenhouse gases (GHGs) emissions needs to take place in every sector of the global economy. The transport sector is responsible for a large share of energy consumption and GHGs emissions while contributing to the increase in air pollution. Although new technologies are available, the use of diesel in road transport is still predominant. These new technologies, nonetheless, still present inconsistencies in their environment, economic performances and do not necessarily provide improvements when considering the entire fuel life cycle used in medium and heavy-duty trucks. This systematic review addresses the uncertainties in life cycle studies regarding the road transport sector fuel consumption, GHGs, and air pollutant emissions economic analyses. Results show that there are higher chances of reducing GHGs emissions through biogas or fuel-cell hydrogen trucks, while PM 2.5 and NOx emissions have higher chances of being reduced with fuel-cell hydrogen or natural gas trucks. There is, however, a reduced interest by the scientific community in the transport literature in dealing with air pollutants, and the focus is mainly on GHGs emissions. When it comes to economic viability, natural gas and hybrid trucks are the best substitutes.

Brazil is one of the largest emitters of greenhouse gases in the world with most of its emissions coming from the land use, land use change, and forestry (LULUCF) sector. New commitments have been set by the Paris Agreement and are reflected in the country's Nationally Determined Contribution (NDC). The Brazilian NDC has three main pillars to reduce emissions: increasing the share of biomass in the total primary energy supply to 18%, reducing deforestation, and achieving 45% of renewable energy in the energy mix. It is important to enlarge the share of biomass in the Brazilian economy, but it is also important to assess the potential impacts on deforestation in order to set the right strategy eventually. This study is thus an effort to investigate the contributions of a biobased economy to reduce Brazilian emissions, considering the broader concept of the bioeconomy, using biomass for energy, chemicals, and materials. To satisfy the objectives of the project, especially those related to its interest in economy‐wide changes in feedstock (from fossil to biobased), computable general equilibrium modeling (CGE) was chosen as the basic methodology integrated with an economic input–output life cycle analysis (EIO‐LCA). Results show that the impacts of the bioeconomy scenarios are positive but not sufficiently high to reduce the estimated emissions drastically. Emissions by the energy sector produce the highest reductions (7.5%) but the 12% increase in the LULUCF sector offsets those reduction. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd