Alternative fuel technologies emissions for road heavy-duty trucks: a review.

Many alternative fuel technologies have been studied for the transport sector to increase its sustainability while reducing costs, greenhouse gases (GHG), and air pollution emissions. Nevertheless, conventional diesel is still the predominant fuel for heavy-duty trucks. Road freight transport consumes 25% of the world's energy and is responsible for emissions with local health impacts and the global greenhouse effect. In this context, this paper reviewed items from 2015 to 2020 to analyze the technologies available for the road freight transport regarding pollutant and GHG emissions. Results are presented in two parts: first quantitatively, quantitative data was extracted from reviewed papers and statistically treated and, second, qualitatively through a comparative chart, which shows the impact on air pollutants from the use of a different type of fuels. In general, papers are mostly concerned with particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) emissions due to its impact on public health, with a low number of papers covering GHG emissions. The trade-off between different fuels and how this process can impact emissions, sometimes increasing or decreasing specific pollutants, is discussed. According to the analyzed papers, the main characteristics that affect the pollutant emissions are, in general, the fuel oxygen content and the combustion chamber temperature.

Energy Return on Investment (EROI) and Life Cycle Analysis (LCA) of biofuels in Ecuador.

In Ecuador, the net energy contribution of biofuels is unknown or unnoticed. To address this issue, we determined the Energy Return on Investment (EROI) for bioethanol and biodiesel. The selection of raw materials relied on their productive capacity, export and import records, and historical yields. Consequently, the scope included three raw materials for ethanol (sugar cane, corn, and forest residues) and four for biodiesel (African palm, pinion, bovine fat, and swine fat). Using a method based on the Life Cycle Analysis (LCA) of each biofuel, we assessed the entire production chain through statistical processing of primary and secondary information. Then we calculated the calorific values in the laboratory, compared energy inputs/outputs, and finally obtained the energetic returns. EROIs for bioethanol were: 1.797 for sugarcane, 1.040 for corn, and 0.739 for wood. The results for biodiesel were: 3.052 for African palm, 2.743 for pinion, 2.187 for bovine fat, and 2.891 for swine fat. These values suggest feasibility only for sugarcane in the case of ethanol. In contrast, biodiesel has better prospects because all the feedstocks analyzed had EROIs higher than two. Nevertheless, biodiesel is not available for trading in Ecuador because energy policy has overlooked systems based on higher energy return. Future studies should consider more comprehensive variables such as climate change, land use, and water management.

Avaliação ambiental estratégica e planejamento do setor de transportes paulista / Strategic environmental assessment and transportation sector planning in the state of São Paulo

RESUMO A Avaliação Ambiental Estratégica (AAE) é considerada o instrumento apropriado para integrar a sustentabilidade no planejamento. Foram aplicados os critérios de desempenho da Associação Internacional de Avaliação de Impacto a casos brasileiros de AAE de transporte, utilizando análise de conformidade e de conteúdo. Os resultados demonstraram um relativo ajuste dos estudos nacionais à expectativa de qualidade desejada para eficácia no uso da AAE, com algumas práticas satisfatórias e outras limitadas. Este artigo propõe orientações para o uso da AAE no planejamento de transportes do estado de São Paulo, a partir de contribuições identificadas nos estudos nacionais, complementadas por boas práticas internacionais.

ABSTRACT Strategic Environmental Assessment (SEA) is the appropriate tool for achieving sustainability in planning. Performance criteria of the International Association for Impact Assessment were applied to Brazilian transport cases of SEA by using compliance and content analysis. The results showed a relative alignment of the national studies to the expectation of quality for fostering SEA efficiency, with some satisfactory practices and limited other ones. This paper proposes guidelines for using SEA in transport planning in the state of São Paulo from contributions identified in the national studies, complemented by international good practice.