Exergetic Analysis of the Biodiesel Production Process in a Biofuel Plant
Keywords:Exergy, biofuel, biodiesel, transesterification.
This paper deals with the exergy analysis of the biodiesel production process from the binary mixture of soybean oil and beef tallow. The biodiesel is produced by transesterification of the methyl group and through basic catalysis. Thus, it was investigated the biofuel production process of a specific plant in the State of Minas Gerais, Brazil, characterizing the parameters of the main equipment and analyzing the raw material and by-products of the process and quantifying the mass and energy. The exergy analysis methodology followed the mass balance of each step, calculating irreversibility and exergetic balance and efficiency of the plant. The calculation of chemical exergy of the compounds of biomass from soybean oil and beef tallow, biodiesel, glycerol and free fatty acids was accomplished by raising the calorific value of the compounds by their chemical composition and mass percentage. Moreover, they were also calculated the specific irreversibility of methanol and process inputs, the irreversibility concerning electricity, mechanical work and steam. It was found that the useful exergy was 63.4%, however, considering that the glycerin can be sold as a final product and that some raw materials can be reused, the useful exergy of the system could be equal to 94.2%. The exergy efficiency of the plant is 71.7%, due to the irreversibility of the system. The exergy destroyed was 5.8% and could be minimized by changing variables such as temperature, reaction time and type of catalyst.
ANP 2016. Agência Nacional de Petróleo, Gás Natural e Biocombustíveis. http://www.anp.gov.br/.
Arredondo HIV. Avaliação exergética e exergo-ambiental da produção de biocombustíveis. Thesis, Universidade de São Paulo, São Paulo, Brazil 2009.
Arredondo HIV, Oliveira Junior S and Bejumea P. Exergy efficiency analysis of chemical and biochemical stages involved in liquid biofuels production process. Energy 2012; 41: 138-145. https://doi.org/10.1016/j.energy.2011.06.025
Badday AS, Abdullah AZ, Lee KT and Khayoon MS. Intensification of biodiesel production Via ultrasonic-assisted process: A critical review on fundamentals and recent development. Renewable and Sustainable Energy Reviews 2012; 16: 4574-4587. https://doi.org/10.1016/j.rser.2012.04.057
Borugadda VB and Goud VV. Biodiesel production from renewable feedstocks: Status and opportunities. Renewable and Sustainable Energy Reviews 2012; 16: 4763-4784. https://doi.org/10.1016/j.rser.2012.04.010
Figueroa-Jimenez S, Gamarra-Torres J, Bonilla-Correa D and Peralta-Ruiz Y. Evaluation of Biodiesel Production Process from Palm Oil (Eleais Guineensis) using Exergy Analysis Methodology. Chemical Engineering Transactions 2015; 43: 529-534.
Mendeleev DI. Sochineniya (Collection of Works), Moscow: Akad. Nauk SSSR 1949; 15.
Moran MJ, Shapiro HN, Boettner DD and Baley MB. Fundamentals of Engineering Thermodynamics. 7th Edition, John Wiley & Sons, Inc., USA 2011.
Madheshiya AK and Vedrtnam A. Energy-exergy analysis of biodiesel fuels produced from waste cooking oil and mustard oil. Fuel 2018; 214: 386-408. https://doi.org/10.1016/j.fuel.2017.11.060
Silva MM. Análise Exergética da Produção do Biodiesel por Mistura Binária de Sebo Bovino e Óleo de Soja. Master Dissertation, Departamento de Engenharia Nuclear. Universidade Federal de Minas Gerais, Brazil 2017.
Szargut J, Morris DR and Steward FR. Exergy Analysis of Thermal, Chemical and Metallurgical Processes. ed. New York 1988.
Talens L, Villalba G and Gabarrell X. Exergy analysis applied to biodiesel production. Resources Conservation and Recycling 2007; 51: 397-407. https://doi.org/10.1016/j.resconrec.2006.10.008