Conversion of residues from agro-food industry into bioethanol in Iran: An under-valued biofuel additive to phase out MTBE in gasoline Hamed Kazemi Shariat Panahi a , Mona Dehhaghi a, b , Mortaza Aghbashlo c, * , Keikhosro Karimi d, e, ** , Meisam Tabatabaei f, g, h, *** a Department of Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran b Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia c Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran d Department of Chemical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran e Industrial Biotechnology Group, Research Institute for Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran f Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran g Biofuel Research Team (BRTeam), Karaj, Iran h Faculty of Plantation and Agrotechnology, University Technology MARA (UiTM), 40450, Shah Alam, Selangor, Malaysia article info Article history: Received 2 November 2018 Received in revised form 26 March 2019 Accepted 15 June 2019 Available online 18 June 2019 Keywords: Fermentation Greenhouse gas Hydrolysis Lignocellulose Liquid biofuel Pretreatment abstract It is obvious that Iran agricultural industry, unlike Brazil and USA, cannot afford to provide conventional biomass, i.e. sugary or starchy biomass for bioethanol production, mainly due to climatic and geographic conditions. With some exception of date (fruit), first-generation ethanol production triggers food vs. fuel debates in Iran and put nation to hunger. Agricultural products including apple, barley, carrot, corn, grape, orange, potato, rice, sugar beet, sugarcane, and wheat are consumed domestically, exported, or even lost because of poor harvesting and processing conditions such as transportation or packaging. These products may alone generate 21.56 million ton per annum green wastes upon processing in the food industry. Every year about 5.4 billion liters of bioethanol can be produced by establishing second- generation ethanol plants next to the food processing sectors. Seventy-seven-percent of this amount of bioethanol can easily support 5% ethanol (E5) policy to phase out the consumption of 4.2 billion liters methyl tert-butyl ether (MTBE) for raising the octane number of gasoline in the country. If more comprehensive policy is adopted, larger quantities of lignocellulosic feedstocks can be gathered from agro as well as forestry practices. Second-generation bioethanol technology can help Iran to tackle air pollution in its big cities and to address the adverse effects of MTBE on its populations and ecosystem. The other advantages are improvement of fuel security, mitigation of climate change, and development of economy. The motivation can be created through passing a framework policy to cut fossil fuel sub- sidies, to mandate bioethanol blends in gasoline, and to impose carbon taxes. Development of coherent socially and environmentally relevant strategies and facilitation of investment in bioethanol industry are also necessary. © 2019 Elsevier Ltd. All rights reserved. 1. Introduction Air pollution is considered as a cause of death, and while indoor air pollution can be reduced in some extent using a number of technologies, the control of outdoor pollution is difficult. It is pre- dicted that the annual deaths associated with outdoor pollution will rise from 3 million to 4.5 million by 2020 [1]. This number of premature deaths is accounted for US$225 billion and US$5.11 * Corresponding author. ** Corresponding author. Department of Chemical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran. *** Corresponding author. Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran. E-mail addresses: maghbashlo@ut.ac.ir (M. Aghbashlo), karimi@cc.iut.ac.ir (K. Karimi), meisam_tabatabaei@abrii.ac.ir, meisam_tabatabaei@uitm.edu.my (M. Tabatabaei). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene https://doi.org/10.1016/j.renene.2019.06.081 0960-1481/© 2019 Elsevier Ltd. All rights reserved. Renewable Energy 145 (2020) 699e710