Érica Geraldes Castanheira

Using Life Cycle Assessment methodology to assess UHT milk production in Portugal.

Milk and dairy products constitute an important ingredient in the human diet. Ultra-high temperature (UHT) milk is the main dairy product consumed in Portugal and its production entails large inputs of resources which derive on negative environmental effects such as nutrient enrichment of the ecosystem and climate change. In this study, Life Cycle Assessment (LCA) methodology was considered for the environmental assessment of packaged UHT milk produced in Portugal, including simple (whole, semi-skimmed and skimmed) and cocoa milk from a cradle-to-gate perspective and to identify the environmental hot spots. Results showed that the production of the raw milk in the dairy farm is the main hot spot in almost all the categories under assessment mainly due to the emissions from enteric fermentation, manure management and fertilisers production and application. Furthermore, on-site emissions derived from dairy factory are remarkable together with the packages and energy requirements production. The values reported in this study are in the range of other related papers. However, differences were also identified due to several reasons such as allocation approach, data sources, characterisation factors, farm management regimes and assumptions considered. Therefore, these aspects should be carefully addressed and sensitivity to the assumptions and uncertainty of the results should be evaluated.

Life-cycle GHG assessment of soybean biodiesel

This paper presents a life-cycle (LC) greenhouse gas (GHG) emissions assessment of biodiesel produced in Portugal, based on soybean cultivated in Latin-America. The implications of different cultivation systems and land use change (LUC) scenarios are assessed. Multifunctionality in the soybean biodiesel chain is also addressed, based on a sensitivity analysis to allocation approaches. The results show the importance of LUC on biodiesel GHG emissions but significant differences in the GHG balance have been observed for the alternative LUC and cultivation systems assessed. Degraded grassland should be preferably used for soybean cultivation. No-(reduced-) tillage systems have lower GHG emissions than the corresponding tillage systems. Multifunctionality is also an important issue since results are very sensitive to the approach adopted to treat co-products.

Impact of policy on greenhouse gas emissions and economics of biodiesel production.

As an alternative transportation fuel to petrodiesel, biodiesel has been promoted within national energy portfolio targets across the world. Early estimations of low lifecycle greenhouse gas (GHG) emissions of biodiesel were a driver behind extensive government support in the form of financial incentives for the industry. However, studies consistently report a high degree of uncertainty in these emissions estimates, raising questions concerning the carbon benefits of biodiesel. Furthermore, the implications of feedstock blending on GHG emissions uncertainty have not been explicitly addressed despite broad practice by the industry to meet fuel quality standards and to control costs. This work investigated the impact of feedstock blending on the characteristics of biodiesel by using a chance-constrained (CC) blend optimization method. The objective of the optimization is minimization of feedstock costs subject to fuel standards and emissions constraints. Results indicate that blending can be used to manage GHG emissions uncertainty characteristics of biodiesel, and to achieve cost reductions through feedstock diversification. Simulations suggest that emissions control policies that restrict the use of certain feedstocks based on their GHG estimates overlook blending practices and benefits, increasing the cost of biodiesel. In contrast, emissions control policies which recognize the multifeedstock nature of biodiesel provide producers with feedstock selection flexibility, enabling them to manage their blend portfolios cost effectively, potentially without compromising fuel quality or emissions reductions.

Environmental performance of palm oil biodiesel — A life-cycle perspective

The increased use of palm oil as feedstock for biodiesel production has been a focus of discussion due to several environmental problems. This paper presents a Life Cycle Assessment (LCA) of biodiesel from palm oil (PME). Alternative land use change (LUC) scenarios and fertilization types have been evaluated. A life-cycle inventory and modeling of palm plantation and oil extraction in Colombia, transportation and biodiesel production in Europe has been implemented. Life-cycle impact assessment (LCIA) results in terms of global warming potential. acidification, eutrophication, ozone layer depletion and photochemical oxidation are presented for the various LUC scenarios and types of fertilization.

Governance of the emerging biofuel markets in European Union: the Portuguese context

European Union supports alternative fuels, in particular, biofuels to comply with the triple objective of reducing greenhouse gases emissions, diversifying fuel supply and developing long-term replacements for fossil fuels. The European Community set the goal to substitute 20% of the fossil fuels for road transport with alternative fuels by 2020 but the present market penetration of the biofuels is still very low. To support the market transition from conventional to alternative fuels, policies have been taken in the past and are defined at present, but many uncertainties remaining. It is crucial to provide an assessment of the effectiveness of policy measures and to investigate the appropriate policy recommendations to support market transition to alternative fuels. This paper surveys and discusses European Union energy markets and the instruments to promote biofuels, including policies, legislation and provision for possible tax exemptions or reductions for renewable energy sources. The circumstances of biofuels in Portugal are also analysed.