Leveraging microalga feedstock for biofuel production and wasteland reclamation using remote sensing and ex situ experimentation Mayur Mausoom Phukan, Ph.D a, * , Nabajit Hazarika, Ph.D b , Plaban Bora, Ph.D c , Tapanjit Borah d , Bolin Kumar Konwar, Ph.D e a Department of Forest Science, School of Sciences, Nagaland University (Central), Lumami, 798627, Nagaland, India b Department of Environmental Science, School of Sciences, Nagaland University (Central), Lumami, 798627, Nagaland, India c Department of Energy Engineering, Assam Science and Technology University, Guwahati, 781013, Assam, India d Department of Energy, School of Engineering, Tezpur University (Central), Naapam, 784028, Assam, India e Department of Molecular Biology & Biotechnology, School of Sciences, Tezpur University (Central), Naapam, 784028, Assam, India article info Article history: Received 21 September 2019 Received in revised form 20 May 2020 Accepted 9 June 2020 Available online 14 June 2020 Keywords: Biofuel Microalgae Remote sensing (RS) Eutrophic PMCS Brahmaputra River Valley abstract Biofuel production becomes a sustainable developmental strategy, when wastelands are reprocessed as prospective mass culture sites (PMCS) for microalgae feedstock. Remote Sensing (RS) data and field visits were used to delineate eutrophic water bodies for PMCS. The floodplains of the Brahmaputra River Valley of Assam, India, were selected as PMCS and were defined using RS data. A green alga of the genus Parachlorella was isolated from an algal bloom present in the drainage system, of Tezpur University, Assam, India. The species was cultured in representative water samples from the PMCS and growth was monitored in open laboratory conditions against the control. The microalgal biomass was characterized and subjected to in situ transesterification. The fuel properties such as viscosity, density, calorific value and cetane number (CN) were determined to assess the fuel quality. The results showed the biodiesel fuel properties were within the American Society for Testing and Materials (ASTM) purview. Additionally, the thermo-chemical conversion and subsequent characterization underscored the feasibility of bio-oil production from open laboratory culture of microalgae. This study highlights the practicability of combining RS data and experimental appraisal for cost effective, environment friendly and sustainable biofuel production, from microalgae cultured in wasteland PMCS. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction The developed and emerging economies require prodigious quantities of petroleum and natural gas for their sustenance, management and development. Sourced from finite geological reservoirs, they are inherently unsustainable, environmentally detrimental and insufficient to preempt escalating energy de- mands. Hence, the immediate and compelling requirement for sustainable, alternative, efficient, cost effective and carbon neutral energy sources like biofuels [1 ,2]. The latter are increasingly attractive energy options based on their compatibility with existent technologies and infrastructure facilities [3,4]. Third generation biofuels from microalgae are recognized as the ultimate solution for sustainable fuels [5,6], with potential to mitigate energy crisis, environmental pollution and climate change [7 ,8]. Microalgae have the fastest and the highest biomass pro- ductivity among the autotrophic, photosynthetic organisms; be- sides being cardinal oxygen producers and carbon dioxide consumers [7 ,9]. They exceed yields achievable by terrestrial en- ergy crops by more than an order of magnitude [10], and conse- quently are prime stakeholders of photosynthetic biorefineries for sustainable production of biofuels and bio-products [11]. Micro- algae like any other biomass feedstock can be converted into renewable biofuels [12], which includes methane [13], bio-diesel [14], bio-oil [15,16], bio-ethanol [17] and photo biologically pro- duced bio-hydrogen [18]. The global interest in microalgal biofuels [19] and recent advancements in bioenergy research, could render microalgae as a potential global bioenergy feedstock. Microalgae biorefinery systems have been proposed in recent studies with the objective of improving microalgae biomass valorization [20,21]. * Corresponding author. E-mail addresses: mayur_101@yahoo.com (M.M. Phukan), nabajit4u@gmail.com (N. Hazarika), bncplaban@gmail.com (P. Bora), tapanji@tezu.ernet.in (T. Borah), bkkon@tezu.ernet.in (B.K. Konwar). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene https://doi.org/10.1016/j.renene.2020.06.047 0960-1481/© 2020 Elsevier Ltd. All rights reserved. Renewable Energy 159 (2020) 973e981