Diversifying the technological strategies for recovering bioenergy from the two-phase anaerobic digestion of sugarcane vinasse: An integrated techno-economic and environmental approach

Author(s)

Fuess, Lucas Tadeu ^[1] ; Klein, Bruno Colling ^[2] ; Chagas, Mateus Ferreira ^[2] ; Alves Ferreira Rezende, Mylene Cristina ^[2] ; Garcia, Marcelo Loureiro ^[3] ; Bonomi, Antonio ^[2] ; Zaiat, Marcelo ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn EESC, Biol Proc Lab LPB, Av Joao Dagnone 1100, BR-13563120 Sao Carlos, SP - Brazil

^[2] CNPEM, Lab Nacl Ciencia & Tecnol Bioetanol CTBE, Rua Giuseppe Maximo Scolfaro 10000, BR-13083970 Campinas, SP - Brazil

^[3] Sao Paulo State Univ, UNESP, Inst Geosci & Exact Sci IGCE, Campus Rio Claro Av 24-A, 1515, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: RENEWABLE ENERGY; v. 122, p. 674-687, JUL 2018.
• Web of Science Citations: 13

Abstract

Technical, economic and environmental aspects of implementing two-phase anaerobic digestion (AD), i.e., acidogenic + methanogenic systems, in sugarcane biorefineries for the treatment of vinasse were assessed based on different strategies to using the hydrogen-rich biogas (biogas-H-2) generated via acidogenesis. Phase separation greatly enhanced the bioenergy recovered from vinasse AD compared with single-phase systems (methanogenic phase exclusively). The best results for generating electric energy were observed in combined cycle-based power plants that utilized biohythane (10.8 MW + 5.5 MW for the harvest and inter-harvest, respectively), which is the gaseous biofuel from blending biogas-H-2 with the methane-rich stream from the methanogenic phase (biogas-CH4). Moreover, the results of this study indicated that scaling up two-phase AD systems is economically feasible for the treatment of sugarcane vinasse (net present value = USD 208.58-219.86 million) because a better or equivalent economic performance was attained compared with single-phase processes. Optimizing the alkalinization of methanogenic reactors strongly affected both the economic and environmental performance of the process, with better results observed with the use of low sodium hydroxide dosages (4 g NaOH kg(-1)COD). In summary, our results highlighted that two-phase biodigestion may enhance energy production from vinasse by 20-30% without impairing the profitability of the biorefinery and could lead to slight improvements in the environmental performance of the ethanol production chain via the use of an optimized alkalinization strategy. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 09/15984-0 - Bioenergy production from wastewaters and environmental fitting of liquid and solid wastes generated
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/15606-9 - Thermophilic anaerobic biodigestion of vinasse in combined acidogenic-methanogenic systems to enhance bioenergy recovery in first generation sugarcane biorefineries
• Grantee: Lucas Tadeu Fuess
• Support Opportunities: Scholarships in Brazil - Doctorate