Ecological analysis of hydrogen production via biogas steam reforming from cassava flour processing wastewater Jonni Guiller Ferreira Madeira a, * , Ronney Arismel Mancebo Boloy a , Angel Ramon Sanchez Delgado b , Fl  avia Renata Lima c , Elu ~ a Ramos Coutinho b , Ricardo de Castro Pereira Filho d a Group of Entrepreneurship, Energy, Environment and Technology-GEEMAT, Mechanical Engineering Department, Federal Center of Technological Education of Rio de Janeiro-CEFET/RJ, R. do Areal, 522 - Parque Mambucaba, Angra dos Reis, RJ, 23953-030, Brazil b Federal Rural University of Rio de Janeiro-UFRRJ, Rodovia BR 465 - Km 7, Campus Universit ario - Zona Rural, Serop edica, RJ, 23851-970, Brazil c Barra Mansa University-UBM, R. Ver. Pinho de Carvalho, 267 - Centro, Barra Mansa, RJ, 27330-550, Brazil d Universitary Center of Volta Redonda, Volta Redonda, RJ, Brazil article info Article history: Received 8 November 2016 Received in revised form 7 June 2017 Accepted 9 June 2017 Available online 9 June 2017 Handling Editor: Yutao Wang Keywords: Biohydrogen Ecological efficiency Wastewater Cassava Pollution indicator abstract The use of bioenergy has turned into a good alternative for reducing the emission of pollutant gases. In Brazil, this sort of energy has increased in usage during the last years. Biohydrogen, produced from cassava, appears as an alternative fuel to fossil fuels and, also, becomes economically competitive, since this is a low cost carbon source. The repertoire of results about the ecological impact from the production of bioenergy from cassava wastewater is very limited because, in general, this commodity is more common in underdeveloped countries. This paper evaluates and quantifies the environmental impact of electricity production in a cassava wastewater treatment plant. The ecological efficiency methodology developed by Cardu and Baica [Regarding a new variant methodology to estimate globally the ecologic impact of thermopower plants. Energy conversion and management 40, no. 14 (1999): 1569e1575] is used as a benchmark in this study. The methodology mainly assesses the emissions of equivalent carbon dioxide (CO 2 , SOx, CH 4 and particulate matter), pollutant indicators and ecological effects of a cassava wastewater plant utilizing biohydrogen as energetic carrier. As a result some environmental parameters, such as equivalent carbon dioxide emissions, pollutant indicator and ecological efficiency are evaluated due to the fact that they are important to electricity production. In this way, the environmental pa- rameters was calculated to evaluate how interesting is the process from the environmental feasibility point of view. The average values of the environmental parameters among different biogas compositions was calculated, the average pollution indicator was 10.11 kgCO 2 e/kgH 2 with an average ecological effi- ciency of 93.37%. As a conclusion, bioenergy production using biohydrogen from cassava wastewater treatment plant can be justified by the determination of environmental parameters, allowing innovation for producing energy from a cassava wastewater treatment plant, and adding important findings to the energy industry. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction The development of sustainable technologies for the production of bioenergy has become an attractive alternative for the energy sector regarding reduction of pollutant emissions. The need to change the energy matrix, due to several factors, has provided great incentive for the insertion of this form of energy generation in Brazil and many countries around the world. Recently, there have been several significant advances in the research related to the treatment of effluents (He et al., 2013; Kothari et al., 2013; Wang et al., 2012). This treatment offers several advantages considering environmental and social aspects. Studies that demonstrate a procedure which allows the design of new configurations to maximize energy production and recover as many nutrients as possible in a wastewater treatment plant were undertaken by Khiewwijit et al. (2015). * Corresponding author. E-mail address: gaiada123@hotmail.com (J.G.F. Madeira). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2017.06.076 0959-6526/© 2017 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 162 (2017) 709e716