Technical, Economic And Environmental Assessment Of Ethanol Production Using A Biochemical-thermochemical Hybrid Route

The present work proposes, in the context of a Biorefinery, to assess the biochemical-thermochemical hybrid route through the recovery of the residual cellulignin from pre-treatment and hydrolysis of sugarcane bagasse and straw in an integrated first- and second-generation ethanol plant (1G2G plant), by means of residual cellulignin gasification in a thermochemical ethanol plant. In this assessment, a decentralized plant concept is considered, in which four first-and second-generation ethanol biochemical plants (1G2G biochemical plants) processing 4 million tonnes of sugarcane per year (4 MTC/y) each and producing first-and second-generation ethanol supply residual cellulignin for a central standalone feedstock flexible thermochemical plant, configuring an 1G2G biochemical-thermochemical ethanol hybrid scenario. As base scenario, four 1G2G autonomous plants with residual cellulignin burned in the boilers is selected. For the routes comparison, main technical, economic and environmental aspects of each scenario are assessed. Results showed an increase in total anhydrous ethanol production for 1G2G biochemical-thermochemical ethanol hybrid scenario, besides higher alcohols that are also produced in this scenario. An increase of capital investment is observed for the 1G2G biochemical-thermochemical ethanol hybrid scenario justifying the Internal Rate of Return (IRR) lower than the base scenario, yet with a positive net present value (NPV). Environmental results showed similar impacts for both scenarios.501451502nd International Conference on Biomass (IConBM)Jun 19-22, 2016Taormina, Ital

Techno-economic analysis and climate change impacts of sugarcane biorefineries considering different time horizons

Background: Ethanol production from lignocellulosic feedstocks (also known as 2nd generation or 2G ethanol process) presents a great potential for reducing both ethanol production costs and climate change impacts since agricultural residues and dedicated energy crops are used as feedstock. This study aimed at the quantification of the economic and environmental impacts considering the current and future scenarios of sugarcane biorefineries taking into account not only the improvements of the industrial process but also of biomass production systems. Technology assumptions and scenarios setup were supported by main companies and stakeholders, involved in the lignocellulosic ethanol production chain from Brazil and abroad. For instance, scenarios considered higher efficiencies and lower residence times for pretreatment, enzymatic hydrolysis, and fermentation (including pentoses fermentation); higher sugarcane yields; and introduction of energy cane (a high fiber variety of cane). Results: Ethanol production costs were estimated for different time horizons. In the short term, 2G ethanol presents higher costs compared to 1st generation (1G) ethanol. However, in the long term, 2G ethanol is more competitive, presenting remarkable lower production cost than 1G ethanol, even considering some uncertainties regarding technology and market aspects. In addition, environmental assessment showed that both 1G (in the medium and long term) and 2G ethanol can reduce climate change impacts by more than 80% when compared to gasoline. Conclusions: This work showed the great potential of 2G ethanol production in terms of economic and environmental aspects. These results can support new research programs and public policies designed to stimulate both production and consumption of 2G ethanol in Brazil, accelerating the path along the learning curve. Some examples of mechanisms include: incentives to the establishment of local equipment and enzyme suppliers; and specific funding programs for the development and use of energy cane10FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçã