Environmental and financial implications of ethanol as a bioethylene feedstock versus as a transportation fuel

Bulk chemicals production from biomass may compete with biofuels for low-cost and sustainable biomass sources. Understanding how alternative uses of biomass compare in terms of financial and environmental parameters is therefore necessary to help ensure that efficient uses of resources are encouraged by policy and undertaken by industry. In this paper, we compare the environmental and financial performance of using ethanol as a feedstock for bioethylene production or as a transport fuel in the US life cycle-based models are developed to isolate the relative impacts of these two ethanol uses and generate results that are applicable irrespective of ethanol production pathway. Ethanol use as a feedstock for bioethylene production or as a transport fuel leads to comparable greenhouse gas (GHG) emissions and fossil energy consumption reductions relative to their counterparts produced from fossil sources. By displacing gasoline use in vehicles, use of ethanol as a transport fuel is six times more effective in reducing petroleum energy use on a life cycle basis. In contrast, bioethylene predominately avoids consumption of natural gas. Considering 2013 US ethanol and ethylene market prices, our analysis shows that bioethylene is financially viable only if significant price premiums are realized over conventional ethylene, from 35% to 65% depending on the scale of bioethylene production considered (80 000 t yr−1 to 240 000 t yr−1). Ethanol use as a transportation fuel is therefore the preferred pathway considering financial,GHGemissions, and petroleum energy use metrics, although bioethylene production could have strategic value if demand-side limitations of ethanol transport fuel markets are reached

The potential of a bioeconomy to reduce Brazilian GHG emissions towards 2030:a CGE-based life cycle analysis

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 reduction142265285FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/50347–