A comparative assessment of anaerobic digestion power plants as alternative to lagoons for vinasse treatment: life cycle assessment and exergy analysis

Abstract The treatment of vinasse in lagoons causes methane emissions during the anaerobic decomposition of the organic matter. The recovery of this methane, to produce renewable energy in anaerobic digestion power plants (ADPPs) replacing fossil fuels and reducing greenhouse gas emission, could bring environmental benefits. The aims of this work were: (1) to compare alternatives of ADPPs available for the treatment of vinasse; and (2) to evaluate the impacts of ADPPs as alternative for lagooning Cuban vinasse; both by means of Life Cycle Assessment (LCA) and exergy analysis (EA). The LCA and EA showed that the ADPPs improve the environmental profile with respect to the lagooning of vinasse, reducing up to 77% the total score and recovering up to 46% of the exergy extracted from the natural environment during the process, respectively. The highest environmental benefits for the ADPPs were observed when the subprocesses biogas production from raw vinasse, sulfide removal by biooxidation with air oxygen addition and energy generation in spark ignition engines were used. In that case, the treatment of 1072 ton of vinasse (exergy content of 740.6 GJ ex ) can produce 175 GJ ex as “electricity and heat”, 191 GJ ex as “wastewater for fertirrigation”, 21.7 GJ ex as “digestate”, and 0.41 GJ ex as “sulfur in the filter cake”. This way, the produced 1.3 million cubic meters of vinasse (1.34·10 6 ton/year) reported by the Cuban Ministry of the Cane Sugar Industry can replace 485263 GJ ex per year as energy and bio-fertilizers, reducing the negative environmental impacts for the studied categories.

[1]  Masson-Delmotte,et al.  The Physical Science Basis , 2007 .

[2]  Jo Dewulf,et al.  Comparative Life Cycle Assessment of four alternatives for using by-products of cane sugar production. , 2009 .

[3]  J. Dewulf,et al.  The sulfur chain in biogas production from sulfate-rich liquid substrates: a review on dynamic modeling with vinasse as model substrate , 2013 .

[4]  A. Martell,et al.  Studies on the mechanism of chelate degradation in iron-based, liquid redox H2S removal processes , 1995 .

[5]  Jie Chang,et al.  Methane emissions from rice paddies natural wetlands, lakes in China: synthesis new estimate , 2013, Global change biology.

[6]  T. Nandy,et al.  Wastewater management in a cane molasses distillery involving bioresource recovery. , 2002, Journal of environmental management.

[7]  Jan Szargut,et al.  Exergy Analysis of Thermal, Chemical, and Metallurgical Processes , 1988 .

[8]  Jo Dewulf,et al.  Exergy-based accounting for land as a natural resource in life cycle assessment , 2013, The International Journal of Life Cycle Assessment.

[9]  Göran Wall,et al.  On exergy and sustainable development in environmental engineering , 2010 .

[10]  J. H. Shieh,et al.  Energy and exergy estimation using the group contribution model , 1983 .

[11]  Lu Aye,et al.  Environmental and economic analyses of waste disposal options for traditional markets in Indonesia. , 2006, Waste management.

[12]  Jo Dewulf,et al.  Integration of Solid Oxide Fuel Cell in a sugar–ethanol factory: analysis of the efficiency and the environmental profile of the products , 2011 .

[13]  Kazuo Matsushige,et al.  Chemical exergy of organic matter in wastewater , 1986 .

[14]  J Dewulf,et al.  Cumulative exergy extraction from the natural environment (CEENE): a comprehensive life cycle impact assessment method for resource accounting. , 2007, Environmental science & technology.

[15]  Hikmet Toprak,et al.  Temperature and organic loading dependency of methane and carbon dioxide emission rates of a full-scale anaerobic waste stabilization pond. , 1995 .

[16]  Augustine Ntiamoah,et al.  Comparative Life Cycle Assessment of Charcoal, Biogas, and Liquefied Petroleum Gas as Cooking Fuels in Ghana , 2011 .

[17]  W. Wiegant,et al.  Granulation of biomass in thermophilic upflow anaerobic sludge blanket reactors treating acidified wastewaters , 1986, Biotechnology and bioengineering.

[18]  Electo Eduardo Silva Lora,et al.  Cost calculations for biogas from vinasse biodigestion and its energy utilization. , 2011 .

[19]  Elena Rosa Domínguez,et al.  Life cycle assessment of the cogeneration processes in the Cuban sugar industry , 2013 .

[20]  J. Dewulf,et al.  Characterization of the sulfate reduction process in the anaerobic digestion of a very high strength and sulfate rich vinasse , 2014 .

[21]  Sergey Kalyuzhnyi,et al.  Mathematical modelling of competition between sulphate reduction and methanogenesis in anaerobic reactors , 1998 .

[22]  P. Weiland.  Biogas production: current state and perspectives , 2009, Applied Microbiology and Biotechnology.

[23]  T. Rehl,et al.  Life cycle assessment of biogas digestate processing technologies , 2011 .

[24]  Stijn Bruers,et al.  Exergy: its potential and limitations in environmental science and technology. , 2008, Environmental science & technology.

[25]  Electo Eduardo Silva Lora,et al.  Use of the life cycle assessment (LCA) for comparison of the environmental performance of four alternatives for the treatment and disposal of bioethanol stillage. , 2010 .

[26]  Jo Dewulf,et al.  The environmental sustainability of anaerobic digestion as a biomass valorization technology. , 2012, Bioresource technology.

[27]  Wojciech M. Budzianowski.  Can ‘negative net CO2 emissions’ from decarbonised biogas-to-electricity contribute to solving Poland’s carbon capture and sequestration dilemmas? , 2011 .

[28]  Binxin Wu,et al.  An integrated physical and biological model for anaerobic lagoons. , 2011, Bioresource technology.

[29]  O. Ince,et al.  Comparative evaluation of full‐scale UASB reactors treating alcohol distillery wastewaters in terms of performance and methanogenic activity , 2005 .

[30]  J. Szargut.  Exergy Method: Technical and Ecological Applications , 2005 .

[31]  R. Braun.  Anaerobic digestion: a multi-faceted process for energy, environmental management and rural development , 2007 .

[32]  L. M. Safley,et al.  Biogas production from anaerobic lagoons , 1988 .