Sugarcane Ethanol Production In Brazil Research Articles

Identifying suitable areas for expanding sugarcane ethanol production in Brazil under conservation of environmentally relevant habitats

Biofuels are predicted to constitute a large proportion of fuel consumption in the global transport sector under stringent climate mitigation polices in future. In Brazil, sugarcane ethanol has been widely deployed at large scale and an oriented expansion of sugarcane is considered to be a key measure to ensure the expected positive outcomes from biofuels. In this study, more recent and accurate georeferenced information were combined with an enhanced land use classification system to update the original Sugarcane Agroecological Zoning (SAEZ). We also excluded environmentally relevant areas ( ERA ) in our updated SAEZ to create a new set of reference maps for supporting future prioritization of areas for sugarcane ethanol expansion. We mapped 41.7 Mha as suitable land for sugarcane expansion in center-south region of Brazil, differently from the 50 Mha indicated in the original SAEZ. After excluding the ERA, 33.7 Mha was found to be suitable for sugarcane expansion, of which 20 Mha is currently occupied with pasture lands. About half of these areas were located in Mato Grosso do Sul and Minas Gerais states and an exploratory assessment of two microregions from these states demonstrated the importance of conducting regional assessments to prioritize the areas for a more sustainable sugarcane expansion to meet future bioenergy demands. • Our analysis identified an area 17% smaller than original agro-ecological zoning suitable for sugarcane expansion. • By excluding environmentally relevant areas, the total suitable area for sugarcane expansion is reduced to 33.7 Mha. • About two thirds of that area is currently occupied with pasture lands. • About half of suitable areas occupied with pasture lands are in two Brazilian states. • Local conditions are fundamental for oriented expansion of bioenergy production.

Land use change and the carbon debt for sugarcane ethanol production in Brazil

Farming sugarcane, as a renewable source of ethanol for use as a fuel, is a common practice in Brazilian agriculture. Despite being renewable, whether ethanol use actually reduces greenhouse gas (GHG) emissions depends on how the sugarcane is produced. Studies have shown that land use changes due to sugarcane farming are responsible for a substantial amount of the carbon emitted into the atmosphere, and may be equivalent to, or even greater than, the great “villains” of global warming–the fossil fuels. In the context of climate change, are there alternative land use changes that could create a lower overall carbon debt for ethanol and sugarcane production? In attempting to answer this question, this study aimed to: (i) map carbon stocks in the Brazilian biomes; (ii) quantify the carbon loss under different scenarios of land use changes for sugarcane-ethanol production; (iii) calculate the payback time for land conversion to sugarcane; and (iv) quantify the current areas of cultivated and degraded pasture by biome. The results show that the carbon debt from the deforestation of Brazilian biomes for ethanol production is equivalent to 608 Mg CO2 ha−1 for the Amazon, 142 Mg CO2 ha−1 for the Cerrado and 212 Mg CO2 ha−1 for the Atlantic Forest with respective payback times of 62, 15 and 22 years. However, carbon emitted from the conversion of existing pasture land to sugarcane production rather than forest would be much smaller, with a shorter payback time. We conclude that pasturelands, especially those already degraded, would be the most suitable areas for land conversion to sugarcane production for ethanol. Pasture recovery would increase carbon stocks, reduce GHG emissions and reduce the negative direct and indirect land use changes associated with sugarcane expansion in Brazil.

Modeling approaches for agricultural N2O fluxes from large scale areas: A case for sugarcane crops in the state of São Paulo - Brazil

Anthropogenic greenhouse gas (GHG) emissions and climate change are issues that currently receive a great deal of attention, both from society and the scientific community. Combustion of fossil fuels is considered the main reason for the increasing concentrations of GHG in the atmosphere and therefore, the main cause of climate change. In such context, biofuels are usually presented as an energy source that considerably reduces GHG emissions when compared to the use of fossil fuels. However, some issues of biofuel production such as the emissions associated with both change in land use and the use of nitrogen fertilizers are still under scrutiny. The focus of this study is related to N2O soil emissions associated with sugarcane ethanol production in Brazil. Signatory countries of the United Nation's Framework Convention on Climate Change (UNFCCC) are required to prepare and periodically update an inventory of GHG emissions and sinks. The International Panel of Climate Change (IPCC), through the Agriculture, Forest and Other Land Use (AFOLU), establishes guidelines to calculate N2O soil emissions on three different levels, or tiers. The simplest Tier 1 uses few equations and default emissions factors. The most elaborated, Tier 3, uses computation modeling, field measurements and Geographic Information Systems (GIS). This study proposes using the limited data available, procedures for Tier 3 estimates of N2O soil emissions in sugarcane crops in the state of São Paulo - Brazil. It also compares N2O sugarcane emissions calculated by Tier 1 and Tier 3 methods. Results show that in most cases the difference in results from Tier 1 and Tier 3 methods are beyond the error margin of the Brazilian Inventory.

Sustainability assessment of sugarcane-ethanol production in Brazil: A case study of a sugarcane mill in São Paulo state

To improve decision-making, sustainability-based approaches to impact assessment demand that we move beyond narrowly defined considerations to address the full suite of requirements for sustainability, as well as the interconnections, feedbacks and uncertainties that typify complex socio-ecological systems at all scales. This paper applies a sustainability assessment framework to assess a sugarcane-ethanol mill in São Paulo state, Brazil, seeking to identify opportunities for improvements towards sustainability. The analysis highlights the importance of broader strategic planning for providing an appropriate context for more sustainable sugarcane-ethanol production at the watershed, municipal, and mill level. Five particularly important multi-scalar issues that were identified are (1) the maintenance of long-term water availability and quality; (2) the enhancement of biodiversity and reversal of ecological fragmentation; (3) the planned elimination of sugarcane straw burning and subsequence increase in mechanized harvesting; (4) the impacts of indirect and direct land-use change; and (5) the quality, availability and durability of livelihood opportunities. To address these issues requires long term integrated planning and monitoring, better understanding of cumulative impacts and thresholds, recognition of important tradeoffs, and a credible and collaborative decision-making process that involves and empowers stakeholders to set the agendas and seek common goals.

Trends in global warming and human health impacts related to Brazilian sugarcane ethanol production considering black carbon emissions

Sugarcane produced in Brazil has several environmental advantages. However, burning residues, which leads to GHG and black carbon (BC) emissions, has been used to facilitate manual harvest. BC emissions have a net warming effect and cause health problems. Mechanized harvest without burning is gradually replacing manually harvested burned sugarcane. Global warming potential (GWP) and human health indicators of sugarcane ethanol production in Brazil, in the pre-mechanization (100% burned), current (∼50% burned) and future (100% without burning) scenarios, were calculated. In the past, the GWP of ethanol production was 1.1kgCO2eqL−1 and BC emissions were 32.6kgCO2eqL−1. The human health impact in disability adjusted life years (DALY) was 3.16E−05DALYL−1 ethanol. The current ethanol production process has a GWP 46% smaller, while BC emissions are seven times smaller than before mechanization started. The human health impact is currently 7.72E−06DALYL−1. In the future, with complete mechanization and the integration of first and second generation ethanol, the expected GWP emissions will be 70% smaller, and BC emissions will be 216 times smaller than when all sugarcane was harvested with burning. These results show that ethanol production in Brazil is improving in terms of global warming and human health aspects. Other upstream aspects of ethanol production such as direct and indirect land use change, and downstream impacts such as the emissions of acetaldehydes were not considered in this study, which focused on a major technological shift in residue management in the agricultural phase of sugarcane ethanol production. A broader assessment of the sustainability of ethanol must account for those issues, as well as economic and social aspects. Sugarcane-derived ethanol produced in Brazil has been considered one of the most sustainable biofuels options, but it is essential to identify and promote practices and policies that further improve its production, such as the phase out of pre-harvest sugarcane burning and the increase in ethanol yield per unit of area.

Competitiveness of Brazilian sugarcane ethanol compared to US corn ethanol

Corn ethanol produced in the US and sugarcane ethanol produced in Brazil are the world’s leading sources of biofuel. Current US biofuel policies create both incentives and constraints for the import of ethanol from Brazil and together with the cost competitiveness and greenhouse gas intensity of sugarcane ethanol compared to corn ethanol will determine the extent of these imports. This study analyzes the supply-side determinants of cost competitiveness and compares the greenhouse gas intensity of corn ethanol and sugarcane ethanol delivered to US ports. We find that while the cost of sugarcane ethanol production in Brazil is lower than that of corn ethanol in the US, the inclusion of transportation costs for the former and co-product credits for the latter changes their relative competitiveness. We also find that the relative cost of ethanol in the US and Brazil is highly sensitive to the prevailing exchange rate and prices of feedstocks. At an exchange rate of US$1=R$2.15 the cost of corn ethanol is 15% lower than the delivered cost of sugarcane ethanol at a US port. Sugarcane ethanol has lower GHG emissions than corn ethanol but a price of over $113 per ton of CO 2 is needed to affect competitiveness.

Competitiveness of Brazilian Sugarcane Ethanol Compared to US Corn Ethanol

Corn ethanol produced in the US and sugarcane ethanol produced in Brazil are the world’s leading sources of biofuel. Current US biofuel policies create both incentives and constraints for the import of ethanol from Brazil and together with the competitiveness and greenhouse gas intensity of sugarcane ethanol compared to corn ethanol will determine the extent of these imports. This study analyzes the supply-side determinants of this competitiveness and compares the greenhouse gas intensity of corn ethanol and sugarcane ethanol delivered to US ports. We find that while the cost of sugarcane ethanol production in Brazil is lower than that of corn ethanol in the US, the inclusion of transportation costs for the former and co-product credits for the latter changes their relative competitiveness. We also find that the relative cost of ethanol in the US and Brazil is highly sensitive to the prevailing exchange rate and prices of feedstocks. At an exchange rate of US$1 = R$2.15 the cost of corn ethanol is 15% lower than the delivered cost of sugarcane ethanol at a US port. Sugarcane ethanol has lower GHG emissions than corn ethanol but a price of over $113 per ton of CO2 is needed to affect competitiveness.

Sugarcane ethanol production in Brazil: an expansion model sensitive to socioeconomic and environmental concerns

AbstractBrazilian agriculture is characteristically dynamic; land and production resources have a skewed ownership distribution; and agricultural production is essential for small holders of rural poor regions. Also, the main agricultural land use is composed of pastures where extensive livestock production prevails. Because of increasing demand Brazil is expected to expand its sugarcane‐based ethanol production. Addressing concerns about social and environmental impacts of such an expansion requires careful consideration of the complexity of Brazilian agriculture in general and specific local conditions in particular. This perspective outlines an expansion model for sugarcane ethanol production that is sensitive to socioeconomic and environmental concerns. Through integration with the prevailing land use, the model avoids the usual displacement of extensive livestock production to remote regions, causing leakage effects with deforestation and promotes milk and beef cattle intensification and investment opportunities for local society. The expansion model is feasible at current market conditions and should have good prospects for complying with sustainability criteria within various certification schemes presently under development. A case study, developed in the Pontal do Paranapanema region (state of São Paulo, Brazil) illustrates the model in agrarian reform settlements. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd