• Energy Research

Sugarcane ethanol has been produced in Brazil since the early 20th century, but production increased in the mid‐1970s aiming at substituting 20% of the gasoline. Despite an increase in the 2000s production has been stable since 2008. This paper presents a review of the main developments achieved and future challenges. The sector has had positive economic and environmental results through technological development, as a result of research and development by private companies and strong public support. Sugarcane yield has steadily increased and positively impacted production costs, primarily due to better agronomic practices and breeding programs. Owing to environmental and economic reasons, there are on‐going programs to phase out burning, with the gradual replacement of manual harvest with burning by unburnt mechanised harvest. Important agronomic impacts are expected, caused by the large amount of straw left on the soil surface, which also represents a significant bioenergy potential. The sugarcane industry in Brazil has taken advantage of the combined production of sugar and ethanol, and, recently, many mills have enlarged their revenues with surplus electricity. The current efforts for diversification aim at ethanol production through hydrolysis of sugarcane residues and the development of chemical routes. From an environmental point of view, impacts related to land use change are expected on greenhouse emissions, water resources, and biodiversity. Ethanol production is likely to expand in Brazil due to the potential size of the domestic market and to the opportunities for exporting, but this will occur in a context of different and new challenges.WIREs Energy Environ2014, 3:70–92. doi: 10.1002/wene.87This article is categorized under:Bioenergy > Economics and PolicyBioenergy > Systems and InfrastructureBioenergy > Climate and Environment

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Abstract The Brazilian experience of more than three decades in the development and production of fuel ethanol from sugarcane has been an example of the technical and institutional requirements for the sustainable development of second generation ethanol (lignocellulosic ethanol) production. The main goal of this paper is to demonstrate the positive sugarcane conditions for the development of second generation ethanol. In order to do that, different industrial scenarios are considered to discuss technical and economic aspects of present and future sugarcane biorefineries. Furthermore, a carbon balance is performed to assess the added value to the carbon present in different sugarcane biorefinery products. The current Brazilian sugarcane production, which is processed in more than 400 mills, is around 600 Tg y −1 , occupying an area of 78,000 km 2 . It can supply 84 Tg of bagasse at no cost and about 42 Tg of trash, which can be processed as a lignocellulosic material for ethanol production or other higher added value products in a biorefinery – as carbon balance results showed that a biorefinery is able to add value to the carbon presented in the sugarcane – using second generation technologies.

Abstract Mechanized sugarcane green harvesting has been increasingly adopted in Brazil, rising straw availability at the field. Computer-aided tools are used to predict the optimum conditions for straw recovery systems. This study aims at developing a model-based method for optimization of sugarcane straw recovery costs and internal rate of return (IRR), as a function of sugarcane productivity, straw recovery fractions and transport distances considering two recovery systems: integral harvesting (IS) and baling system (BS). A simulation procedure using the Virtual Sugarcane Biorefinery (VSB), according to a Central Composite Design (CCD) is used in this study. The scenarios were based on an autonomous ethanol plant, with milling capacity of four million tons per year. The influence of these agricultural parameters on the sugarcane straw recovery costs and internal rate of return was evaluated through this approach, where the CCD was used for the development of an empirical model for optimization as well as a statistical evaluation of results. An optimized IRR (26.3%) was obtained for integral system, with low transport distance (20 km), maximum sugarcane stalk productivity (100 t ha−1) and maximum recovery fraction (70%). The same conditions lead to higher IRR (26.2%) for baling system. Results showed that the IS promotes the highest reduction of the agricultural components of straw recovery cost and the optimum IRR considering the vertical integration of sugarcane biorefineries was observed by adopting this system.

Agricultural intensification, and particularly double cropping, has been suggested as a practical strategy to reconcile biofuel feedstock production with other land-use priorities. Here we assess ethanol production under conditions representative of current practice in the west central region of Brazil: maize grown as a second crop with soybean on land that formerly grew a single soybean crop, and energy processed from a combined heat and power plant using plantation-grown eucalyptus chips. For maize ethanol thus produced we find large reductions in greenhouse gas emissions compared to gasoline, and considerable economic and employment benefits at both local and national levels. We also calculate reduced land-use emissions with maize ethanol production compared to the situation without it. Our study thus documents an example of how the complex linkages of bioenergy to food production and security, environment and economic development can be—and indeed appear to be—managed for positive outcomes using current technology. Double cropping can increase production from a given area of land. This study finds that maize ethanol produced from a second crop with soybeans in west central Brazil can reduce greenhouse gas emissions compared with gasoline and also have economic and employment benefits.

AbstractThis work presents an assessment of sugar‐energy sector expansion in Brazil, focusing on the growth of the bioelectricity supply and considering two scenarios. The first scenario, called the BASE scenario, was based on the projection made by the Brazilian Energy Research Company (EPE) for the Brazilian commitments at the Paris agreement, presented during the COP 21 (Conference of the parties) conference and ratified in the Nationally Determined Contributions (NDC), assuming that all the electricity from biomass could be produced by the sugarcane sector. The second is a scenario considering a higher share of the sugar‐energy sector in the Brazilian electricity matrix, called the BIO scenario. The investment needed for each scenario was evaluated, using a bottom‐up approach and assuming currently available technologies. The results showed that the BIO scenario could produce 55 TWh of surplus electricity more than the BASE scenario, boosting the share of the sugar‐energy sector in the electricity matrix, reaching a total of almost 130 TWh per year and requiring an additional investment that was 39% higher than in the BASE scenario. As the sugarcane surplus electricity could replace electricity from natural gas power plants, the BIO scenario could reduce emissions by 18.4 MtCO2eq in comparison with the BASE scenario. Through the input–output model used to evaluate the socioeconomic impacts, it was observed that the BIO scenario could add 919 000 job positions and cause a positive impact to the gross domestic product (GDP) of US$ 28.8 billion, which corresponds, in comparison with the BASE scenario, to adding 83 000 more job positions, and provides a 12.5% higher contribution to GDP. The total output was 8.6% higher in the BIO scenario in comparison with the BASE scenario. All of these analyses were carried out for three selected regions in the country: the traditional region, comprising São Paulo and Paraná states; the expansion region, including Goiás, Minas Gerais, Mato Grosso and Mato Grosso do Sul states; and the rest of Brazil region. A spillover effect was observed over the total output in the Rest of Brazil region, showing that the impact of the investment over this region was proportionally higher in comparison to the investment done in other in other regions. The Rest of Brazil Region also presents a higher share of the indireect effects over the GDP, jobs created and total output. The final results of this research show the potential of the sugar‐energy sector to boost electricity generation, which can contribute to the reduction of greenhouse gas (GHG) emissions, and to preserving the share of renewable sources in the Brazilian electricity matrix and increasing energy security and generation closer to the biggest centers of consumption, mitigating challenges for electricity transmission between subsystems in the National Interconnected System (SIN). © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.

The carbon tax is a cornerstone of the climate policy in Sweden. Historically, it has played a central role in the replacement of fossil fuels in the heating sector. The purpose of this paper was to analyze the policy-making process that led to the formulation and adoption of the carbon tax in the Swedish heating sector, from 1980 to 1991. We used the Advocacy Coalition Framework (ACF), according to which policy actors form coalitions based on shared beliefs. Drawing from both literature and empirical experiences gathered through in-depth interviews, we identified supporting and opposing coalitions that diverged in their views concerning bioenergy development and the potential impact of the carbon tax. This study illustrates the complex conditions for introduction of environmental taxes and expansion of new industries, particularly when established businesses perceive the new activities as a threat. The Swedish experience shows that countries can progress by exploring internal synergies and innovative policy designs, despite potential resistance of established constituencies. The successful adoption of the carbon tax in the Swedish heating sector serves as inspiration for policymakers in other sectors and countries, as they contemplate policies to promote the decarbonization of the energy system.

Allocation of Water Resources at the basin level is a critical issue for economic growth as well as for environmental sustainability. This study integrates network-based optimization with an Input-Output model, made available through a Spatial Decision Support System (HEAL), to support design and evaluation of water allocation policies. The innovative platform was applied to a case study using four-interlinked hydrographic basins in Northeastern of Brazil. The integrated modeling was able to measure broader socioeconomic impacts of decisions on reservoir volumes and water allocations at basin level, through indicators in a sectoral and regional scale, including ones associated with Sustainable Development Goals, such as the Water Use Efficiency (WUE) indicator. Results of the trade-offs between two scenarios, representative of the limits of performance of regulatory water instruments, were generated using the integrated modeling. They were compared with the Reference scenario for the base year (2011) and show that the economic sector most negatively affected by the regulatory instrument use is the industrial sector. Furthermore, the sugar and ethanol industry, main water users in the industrial sector (93.1% of the sector's water use) and less efficient (WUE 1.47 US$/m3 vs. 30.70 US$/m3 average of the sector) in the base year, maintain their percentage share of water use in the sector and even slightly expand it (93.2%), with slight efficiency gains (+2.3%). On the other hand, non-water-intensive industries, have their shares reduced (from 6.9 to 6.8%) and lose efficiency (−9.5%). Results of the same trade-offs by region showed that the largest proportional economic losses occur in the drier areas, damaging the economy, especially in the most industrialized municipalities with the highest GDPs. Integrated economic modeling can expand aspects involved in water security issues, assisting management by introducing socioeconomic impact measures, in a broader scale, associated with allocation decisions. Hydrological allocation criteria cannot distinguish between user efficiency and which economic sectors are using how much water. This results in economic and social losses. In water-scarce regions and with growing transfer needs, such as in the basins studied, adequate incentives, through management instruments designed based on economic theory, are essential to promote sustainable development.