Thermoeconomic Analysis of Combined Production of Electricity and Second Generation Ethanol Based on the Dilute Acid Hydrolysis of Sugarcane Bagasse

D.N. Flório, S. Oliveira Junior
3.140 865

Abstract


In this study, a thermoeconomic assessment of an integrated ethanol production from sugarcane bagasse and traditional sugarcane juice is developed and discussed. An integrated distillery, which works with first and second generation ethanol production routes, is modeled and simulated. The thermoeconomic model assumes that the only agricultural input to the processes is the sugarcane itself (straw or other wastes recovered from the field were not considered in the analysis). The analyses are carried out for three operating scenarios: scenario I describes a traditional distillery or a first generation distillery; scenario II takes into account an integrated distillery operating with current acid hydrolysis technology; scenario III describes an improved distillery which operates with future technology for hydrolysis and pentose fermentation. Exergy analysis, production cost analysis and economic viability assessment are carried out for each scenario. As a result, it can be concluded that the global exergy efficiency decreases with the bagasse hydrolysis for scenario II. This situation is reversed when pentose fermentation is considered in scenario III. The economic viability assessment shows that hydrolysis is not viable in the present Brazilian economic scenario because it causes a drop of 4.0% in the internal rate of return (IRR) for scenario II and 2.3% for scenario III, when compared to scenario I.

Keywords


Exergy; acid hydrolys; biofuel; cogeneration; second generation ethanol.

Full Text:

PDF


DOI: http://dx.doi.org/10.5541/ijot.561

References


M. Sanchez, Latin America -- the 'Persian Gulf' of Biofuels? , The Washington Post. February 23, 2007. Accessed March 30, 20 Available at: http://www.washingtonpost.com/wpdyn/content/article/2007/02/22/AR2007022201361.html. RFA – Renewable Fuels Association, Ethanol industry outlook, World Fuel Ethanol Production, 2012.

J. Goldemberg, The Brazilian biofuels industry, Biotechnology for Biofuels, p.1-6, 2008.

M.O.S. Dias, T.L. Junqueira, O. Cavallet, M.P. Cunha, C.D.F. Jesus, C.E.V. Rossel, R.M. Filho, A. Bonomi, Integrated versus stand-alone second generation ethanol production from sugarcane bagasse and trash, Bioresource Technology, 103. 152-161, 2011

EES Engineering Equation Solver, 2012. Available at: www.fchart.com/ees/

L. F. Pellegrini, Thermo-Economic-Environmental analysis applied to the combined production of sugar, ethanol and electricity (in Portuguese), 346p., Doctoral Thesis, Mechanical Engineering Department, Polytechnic School of the University of São Paulo, São Paulo, 2009.

A. V. Ensinas, Thermal integration and termoeconomic optimization applied to the industrial process of sugar and ethanol from surgarcane (in Portuguese), 229 p., Doctoral Thesis, University of Campinas, Mechanical Engineering Department, Campinas, 2009.

H. I. Velásquez, Exergetic and exergo-enviromental evaluation of the biofuel production (in Portuguese), 235p., Doctoral Thesis, Mechanical Engineering Department, Polytechnic School of the University of São Paulo, São Paulo, 2009.

L. F. Pellegrini, S. Oliveira Junior, Combined production of sugar, ethanol and electricity: Thermoeconomic and environmental analysis and optimization, Energy 36, 3704-3715, 2011