The global energy supply is based on petroleum derivate. Air pollution, acid precipitation, ozone depletion, deforestation and the gaseous emissions to the atmosphere are associated to the petroleum derivate use. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.info:eu-repo/semantics/publishedVersio

Kreutz, Cristiane

Martins, Ramiro

Zschach, Lis Geraldine

The Academic Society Journal

English

Biblioteca Digital do IPB

4° Congresso de Engenharia e Ciências Aplicadas nas Três Fronteiras 4° Congreso de Ingeniería y Ciencias Aplicadas em las Tres Fronteras Foz do Iguaçu, 02, 03 e 04 de outubro de 2019   ULTRASOUND AS PRETREATMENT IN BIOGAS PRODUCTION FROM CRUDE GLYCEROL Zschach Lis Geraldine1,2, Kreutz Cristiane3, Martins Ramiro José Espinheira2,4 1National University of Misiones, Misiones, Argentina  2Polytechnic Institute of Bragança, Bragança, Portugal. 3The Federal University of Technology, Paraná, Brazil. 4University of Porto, Porto, Portugal. E-mail: lisgeraldinezschach@gmail.com  Abstract. The global energy supply is based on petroleum derivate. Air pollution, acid precipitation, ozone depletion, deforestation and the gaseous emissions to the atmosphere are associated to the petroleum derivate use. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.  Palavras-chave: Ultrasound pretreatment, Anaerobic digestion, Crude glycerol.   

Ultrasound as pretreatment in biogas production from crude glycerol

Air pollution, acid precipitation, ozone depletion and the gaseous emissions to the atmosphere are associated to the petroleum derivate use, currently considered the main energy source used in the world. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.info:eu-repo/semantics/publishedVersio

      TAS Journal, vol. 2, n. 2, p. 02 ISSN 2595-1521 SETEMBRO 2019 lisgeraldinezschach@gmail.com Ultrasound as pretreatment in biogas production from crude glycerol Zschach L.G.*§, Kreutz C† and E Martins RJ§‡ *National University of Misiones, Misiones, Argentina. §Polytechnic Institute of Bragança, Bragança, Portugal. †Federal University of Technology, Paraná, Brazil. ‡University of Porto, Porto, Portugal. Abstract. Air pollution, acid precipitation, ozone depletion and the gaseous emissions to the atmosphere are associated to the petroleum derivate use, currently considered the main energy source used in the world. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.. Keywords. Ultrasound pretreatment, anaerobic digestion, crude glycerol. Introduction. Global energy supply is based on petroleum derivative. Studies made about this source suggest that it causes several environmental concerns as air pollution, acid precipitation and gas emissions to the atmosphere (1). In the interest of solving energy supply problems, the changes involved include to create energy savings on the demand side, improve the production process efficiency and replace petroleum derivate by renewable energy (2). Biofuels are considered a renewable energy source produced from natural matter. They can be solids as bio-char, liquid as ethanol or biodiesel or gaseous as biogas (3).  Crude glycerol is a residue of biodiesel production process. It can be used to produce biogas by an anaerobic digestion process (4, 5). In order to improve the anaerobic digestion process, pretreatments are being studied (6). The aim of this work was to investigate the effect of ultrasound (US) pretreatment in crude glycerol to produce biogas and with this to present an alternative of renewable energy production.   Materials and methods. To carry out the anaerobic digestion process, anaerobic sludge collected from septic tanks of rural area of Bragança, Portugal, was used as inoculum. The substrate       TAS Journal, vol. 2, n. 2, p. 02 ISSN 2595-1521 SETEMBRO 2019 lisgeraldinezschach@gmail.com evaluated was crude glycerol from the biodiesel production process obtained from the Laboratory of Biofuels, Management and Technology School, Polytechnic Institute of Bragança. Physicochemical characterization of the inoculum and the substrate were performed according to (7) procedures for total solids (TS), fixed solids (FS), volatile solids (VS) and chemical oxygen demand (COD).  The anaerobic digestion process was tested on batch reactors (250 ml) system for 23 days under mesophilic conditions (37°C). Reactors were filled with 200 ml of a mixture of inoculum and substrate. Different times of pretreatment were tested (15 and 30 minutes) of glycerol treatment and compared with glycerol untreated. Each reactor had a rubber in its stopper that allowed to measure biogas by moving with gas pressure the plunger of a syringe as shows the figure 1. The tests were performed in triplicate and the biogas volume produces were daily measured.   Figure 1. System of reactors to produce the biogas with the syringe and the thermometer. This test was carried out until the biogas volume produced dropped below the 1% of its accumulated production value. The biogas volume produced by the inoculum was discounted using a control system, so the results allowed us to evaluate the pretreatment effect in the crude glycerol.  Results. Values obtained for the physicochemical characterization of the content on the reactors are shown in the Table 1. By the increment of pretreatment time, total solids decreased. It could be associated to the solubilization of the glycerol produced by the pretreatment. COD values increased showing that the organic matter was disintegrated as was descripted by (8) in its studies made on activated sludge.        TAS Journal, vol. 2, n. 2, p. 02 ISSN 2595-1521 SETEMBRO 2019 lisgeraldinezschach@gmail.com Table 1. Average values of the physicochemical characterization to the content of reactors after anaerobic digestion process.  Without treatment 15 min of US 30 min of US TS [g/ml] 29.8 24.0 22.9 FS [g/ml] 8.1 1.9 3.1 VS [g/ml] COD [g/l] 21.7 22.4 22.1 25.64 19.8 39.0 Daily biogas production is graphically depicted in figure 2. Each curve represents the methane accumulated volume produced by treatment.  The results showed that the maximum production was reached by the reactors that who underwent 30-minute of pretreatment, with 2,021 ml of biogas, followed by 15-minute ultrasound treatment (1,356.6 ml of biogas) and lastly the reactors whose glycerol was not ultrasonically treated, with 1,010.5 ml of biogas produced.     Figure 2. Accumulated biogas production from crude glycerol.  Studies made by (8, 9) shows that the best results, in terms of biogas production, were reached by the substrate that had the longest ultrasound pretreatment time. The authors realized a co-digestion using maize straw and dairy manure and sewage sludge as substrates.  05001000150020001 6 11 16 21Volume of methane (ml)Days30 min of US15 min of USWithout treatment      TAS Journal, vol. 2, n. 2, p. 02 ISSN 2595-1521 SETEMBRO 2019 lisgeraldinezschach@gmail.com There are not studies made in crude glycerol and similar conditions as the perform on this work, however all published studies about ultrasound pretreatments made on substrates agree that with time increment, the biogas volume produced increases too.   Conclusion. Results showed that the ultrasound pretreatment improves the biogas production. The pretreatment with 30 minutes presented the best performance obtaining 2,021 ml of biogas against the 1,010.5 ml produced by the substrate that was not treated.  Acknowledgments. This work was financially supported by the Associate Laboratory LSRE-LCM – UID/EQU/50020/2019 – funded by national funds of Portugal through FCT/MCTES (PIDDAC). Disclosure. The authors report no conflicts of interest in this work. References.  (1) Dincer, I. (2000). Renewable energy and sustainable development: a crucial review. Renewable and Sustainable Energy Reviews, 4(2), 157-175.  (2) Lund, H. (2007). Renewable energy strategies for sustainable development. Energy, 32(6), 912-919.   (3) Demirbas A. (2009) Political, economic and environmental impacts of fuels: A review. Applied Energy 86 (2009) 108–117. 09 doi:10.1016/j.apenergy.2009.04.036 (4) Ormaechea, P., Castrillón, L., Marañón, E., Fernández-Nava, Y., Negral, L., & Megido, L. (2016). Influence of the ultrasound pretreatment on anaerobic digestion of cattle manure, food waste and crude glycerine. Environmental Technology, 38(6), 682-686. (5) Viana, M., Freitas, A., Leitão, R., Pinto, G., & Santaella, S. (2012). Anaerobic digestion of crude glycerol: a review. Environmental Technology Reviews, 1(1), 81-92 (6) Wu-Haan, W. (2008). Evaluation of ultrasonic pretreatment on anaerobic digestion of biomass for methane production (Master in Science). Iowa State University. (7) APHA (1998). Standard Methods fot the examination of water and wastewater. American Public Health Association, American Water Works Association, Water Enviromental Federation, 20th ed. Washington. (8) Grönroos, A., Kyllönen, H., Korpijärvi, K., Pirkonen, P., Paavola, T., Jokela, J., & Rintala, J. (2005). Ultrasound assisted method to increase soluble chemical oxygen demand (SCOD) of sewage sludge for digestion. Ultrasonics Sonochemistry, 12(1-2), 115-120.  (9) Zou, S., Wang, X., Chen, Y., Wan, H., & Feng, Y. (2015). Enhanvement of biogas production in anaerobic co-digestion by ultrasonic pretreatment. Energy Conversion and Management 112 (2016) 226–235. 

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Ultrasound as pretreatment in biogas production from crude glycerol

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