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Sugarcane mills currently use sugarcane bagasse to cogenerate heat and electricity, supplying the process with mechanical, thermal and electrical energy. Some of these plants are able to produce surplus electricity to export to the national grid. With the improvement in collection techniques, sugarcane straw has also become available and has been used in some mills as fuel for steam boilers, mixed with sugarcane bagasse. However, due to different traits compared to bagasse, the use of sugarcane straw may pose additional problems of incrustation and corrosion on heat exchange surfaces. Several alternatives and technologies have been studied and tried out in order to increase the production of surplus electricity. Among others, biomass integrated gasifier–gas turbine combined cycle (BIGCC) is a promising technology. However, several attempts have resulted in failure, whether on a pilot or industrial scale. Biomass gasification integrated with internal combustion engines can become an opportunity for generation of small power capacity (<15 MW) and integrated to sugarcane mills. This paper analyzes the difficulties and barriers to increasing electricity generation in the sugarcane industry through studies, projects and experimental and industrial-scale installations that have already been carried out. • Bagasse and cane straw show great potential for electricity generation. • Sugarcane industry in Brazil accounts for 6.4% of the electricity generated. • Biomass integrated gasification and combined cycle can increase electricity generation. • Technological and economic challenges are major barriers to the development of BIGCC. • No BIGCC project already implemented is currently in commercial operation. [ABSTRACT FROM AUTHOR]

Abstract: While biofuels have currently been regarded as a good alternative for fossil fuels, there remain many debates on their impacts on human and environment. This paper tried to shed light on bio-ethanol in Brazil as one of the main producers and exporters in the world. The main question was to understand “how sustainable is bio-ethanol production in Brazil?” To answer, the political motives of producing bio-ethanol followed by its ecological and socio-economic impacts were discussed. The paper concluded that although bio-ethanol production in Brazil seems environmentally friendly, it might socio-economically be hazardous. [Copyright &y& Elsevier]

The biorefinery concept provides a wide perspective of products and uses from the biomass conversion. The drive for cost reductions and the threat of food competition have put residual biomass under the spotlight. Sugarcane is the most produced crop in the world, and its residual bagasse has got the additional feature of abundance. Going beyond its traditional use for electricity and thermal generation, this paper explores the potential alternative uses for the sugarcane bagasse in Brazil. Under an Input-Output perspective, Brazilian production recipes are obtained for six distinct biorefining technologies assuming the use of sugarcane bagasse as feedstock. Also, minimum selling prices are derived for the main products of each technological route assessed, comprising an initial estimative of their cost prices in Brazil. The biomass to ethanol and higher alcohol route presented the higher share (25%) of productive and service sectors into its production recipe. The bioplatform succinic acid route was the only one reaching competitive minimum selling prices (0.57 US$/kg) in comparison to current pricing of the fossil-derived succinic acid. [ABSTRACT FROM AUTHOR]

The replacement of fossil fuels by biofuels has been extremely important worldwide to stimulate the growth of economies based on the sustainability through the use of renewable resources. Anaerobic digestion for biogas production is recognized as a clean technology that allies the suitability of wastes with energy generation, fulfilling the requirements for a sustainable alternative to provide the optimization of the biofuels production. This alternative is especially interesting for the sugarcane ethanol production in Brazil, in which the generation of vinasse, the main liquid waste, is very expressive. Nevertheless, the use of vinasse for anaerobic digestion has been finding some challenges to its establishment in the Brazilian sugarcane biorefineries. This paper reviews the actual context of anaerobic digestion within the sugarcane ethanol production in Brazil, presenting the main obstacles for its full application and the directions to promote it as well. Alternatives for biogas use are also presented and compared, highlighting the environmental and energy advantages of applying anaerobic digestion in the sugarcane biorefineries. This scenario is envisaged as a suitable way to achieve the future biorefineries model, based on the use and recovery of renewable resources with economic, social, and environmental benefits. [ABSTRACT FROM AUTHOR]

Abstract: Bagasse from sugarcane is traditionally used in the Brazilian sugar and ethanol industry to meet the energy needs of its own production processes and, more recently, to generate surplus electricity for sale on the national grid. Currently, the industry faces a difficult choice between either enhancing electricity generation or increasing ethanol production through the biochemical processing of bagasse. The aim of this paper is to examine the most promising technical configurations for bioenergy production using sugarcane bagasse and to discuss which configuration would be the most attractive investment option for the industry. At present, electricity generation through Rankine cycle power plants is the only commercially available alternative. Nevertheless, the analysis cannot be restricted only to the short term. For this purpose, cost analysis for 2030 were developed, and even in scenarios where there is an effective cost reduction of untradeable routes, the alternative of burning bagasse to generate electricity provides the most benefits from an investor perspective. [Copyright &y& Elsevier]