• Energy Research

International civil aviation strives to significantly reduce its greenhouse gas (GHG) emissions, and the use of Sustainable Aviation Fuels (SAF) is an alternative for such purpose. However, for an alternative fuel to be considered SAF, some conditions must be met, and production must be certified for sustainability. This paper presents an assessment of the necessary conditions for the sustainable production of these biofuels in Brazil. It is based on a geospatial publicly available database (SAFmaps) that was built with the aim of providing information to stakeholders who would be interested in the production of SAF. The geographic scope corresponds to an area that is about half of the country. The case studies reported in this paper are related to four crop-based feedstocks (eucalyptus, soybean, sugarcane, and corn), which could be used for SAF production, according to three certified routes (FT, HEFA, and ATJ) (Fischer–Tropsch, Hydroprocessed Esters and Fatty Acids and Alcohol to Jet); in total, six potential production sites were assessed. For each crop, the detailed assessment is based on estimates of suitability for biomass production, yields, and costs. The assumptions made allowed us to explicitly analyse the risk of deforestation (production could only occur with displacement of pastures) and the necessary preservation of sensitive biomes and of legally protected areas, in addition to observing the restrictive conditions imposed by CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). To reduce GHG emissions, transporting biomass over long distances was assumed to be only by rail or pipeline. In addition, we address alternatives to minimise the risks associated with induced land-use change (iLUC) and to reduce impacts on the landscape. The results show that the production of SAF through the ATJ route, using ethanol produced from sugarcane and corn, requires less land. Economic assessment was outside the scope of this paper.

Production costs of bio-ethanol from sugarcane in Brazil have declined continuously over the last three decades. The aims of this study are to determine underlying reasons behind these cost reductions, and to assess whether the experience curve concept can be used to describe the development of feedstock costs and industrial production costs. The analysis was performed using average national costs data, a number of prices (as a proxy for production costs) and data on annual Brazilian production volumes. Results show that the progress ratio (PR) for feedstock costs is 0.68 and 0.81 for industrial costs (excluding feedstock costs). The experience curve of total production costs results in a PR of 0.80. Cost breakdowns of sugarcane production show that all sub-processes contributed to the total, but that increasing yields have been the main driving force. Industrial costs mainly decreased because of increasing scales of the ethanol plants. Total production costs at present are approximately 340 US$/methanol3 (16 US$/GJ). Based on the experience curves for feedstock and industrial costs, total ethanol production costs in 2020 are estimated between US$ 200 and 260/m3 (9.4–12.2 US$/GJ). We conclude that using disaggregated experience curves for feedstock and industrial processing costs provide more insights into the factors that lowered costs in the past, and allow more accurate estimations for future cost developments.

AbstractThis paper presents a techno‐economic evaluation of potential Greenfield projects of integrated first‐ and second‐generation sugarcane biorefineries, in which ethanol is converted to bio‐based propylene through metathesis of ethylene with 2‐butene. Two scenarios were tested, considering improvements both in first‐ 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. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Resumo: Este artigo analisa as transformações nas condições de trabalho na atividade canavieira à luz da legislação brasileira nas últimas duas décadas, período em que o setor se expandiu e adotou novas soluções tecnológicas e caminhos gerenciais. Um tema central é compreender os efeitos da mecanização do corte da cana, que chegou a 90% da safra nacional, em média. Foram catalogados 15.488 autos de infração trabalhistas, emitidos pelos fiscais do governo federal entre 2000 e 2019, contra os 280 grupos empresariais autorizados pela ANP, tanto em suas operações agrícolas quanto industriais. Para permitir comparações, dividiu-se o país em três regiões – São Paulo, Nordeste e Demais UFs. O artigo demonstra que as irregularidades mais comuns se referem a saúde e segurança do trabalhador, descanso obrigatório, jornada e remuneração. A emissão de autos registrou tendência de alta até 2013, diante da expansão canavieira e da estratégia das autoridades em pressionar o setor e melhorar a imagem do etanol brasileiro. A aplicação de multas passou a cair em 2014. Entre as principais causas, intensificação da colheita mecanizada, que reduziu a quantidade de trabalhadores no corte manual, etapa na qual se concentravam irregularidades, e redução do ímpeto da fiscalização, diante da crise fiscal do país.

Abstract This study discusses four European and American regulatory schemes designed for accounting lifecycle GHG emissions in relation to the Brazilian sugarcane ethanol. The objective is to critically examine the methodologies and associated parameters used in existing regulatory schemes for calculating GHG emissions, and to explore methodological convergences. The issues related to direct lifecycle and indirect land use change emissions have been addressed. It is found that there are commonalities between the European Renewable Energy Directive (EU-RED) and the UK's Renewable Transport Fuels Obligation (UK-RTFO), but the US-EPA's Renewable Fuel Standard (US-EPA) and the Low Carbon Fuel Standard of the California Air Resources Board (CA-CARB) vary greatly not only among themselves, but also in relation to the European regulations. Agricultural practices (especially soil carbon and nitrogen dynamics), co-product credits from surplus electricity and uncertainties around economic modeling approaches for indirect land use change are the major areas where methodological divergences exist. Incorporation of domestic agricultural practices, sugarcane mills operations, and realistic modeling of indirect impacts of land use change using regional models could provide more coherence in estimations of GHG emissions. Furthermore, the Brazilian trend of novelty in all phases of sugarcane bioenergy systems should be considered when projecting GHG emissions.

For significantly reducing greenhouse gas emissions, those from electricity generation should be negative by the end of the century. In this sense, bio-energy with carbon capture and storage (BECCS) technology in sugarcane mills could be crucial. This paper presents a technical and economic assessment of BECCS systems in a typical Brazilian sugarcane mill, considering the adoption of advanced—although commercial—steam cogeneration systems. The technical results are based on computational simulations, considering CO2 capture both from fermentation (released during ethanol production) and due to biomass combustion. The post combustion capture technology based on amine was considered integrated to the mill and to the cogeneration system. A range of energy requirements and costs were taken from the literature, and different milling capacities and capturing rates were considered. Results show that CO2 capture from both flows is technically feasible. Capturing CO2 from fermentation is the alternative that should be prioritized as energy requirements for capturing from combustion are meaningful, with high impacts on surplus electricity. In the reference case, the cost of avoided CO2 emissions was estimated at 62 €/t CO2, and this can be reduced to 59 €/t CO2 in case of more efficient technologies, or even to 48 €/t CO2 in case of larger plants.

AbstractThe ongoing debate about costs and benefits of wood‐pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention asUSexports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, ‘How is the production of wood pellets in theSE USAaffecting forest systems and the ecosystem services they provide?’ To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in theSE USAare a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long‐term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management.

This paper discusses the complementarity between hydroelectricity and surplus electricity from sugarcane biomass based cogeneration plants in sugarcane mills. The paper investigates opportunities a ...