Hydrothermal liquefaction of freshwater microalgae biomass using Fe₃O₄ nanoparticle as a catalyst

ABSTRACT

Harvesting microalgal biomass using economic and ecological magnetic nanoparticles has been a promising approach due to its superior efficiency, low operating costs, scalable performance, and environmental safety. In this study, we have investigated the efficient harvesting of freshwater microalgae Chlorella sorokiniana (UUIND6) by using synthesized magnetic nanoparticles (Fe₃O₄). Simultaneously, the harvested microalgae biomass has been applied for hydrothermal liquefaction. Fe₃O₄ nanoparticles accrued in the magnetically harvested microalgae biomass have played a catalytic role in the hydrothermal liquefaction process under the varied parameters of temperature (250‒350°C), concentration (0.5‒1.5%), and retention times (30‒60 min). The results have revealed an efficient harvesting of microalgae biomass of ~ 83% in 60 min to be used for hydrothermal liquefaction. The response surface methodology was applied to maximize the yield of biochar and bio-oil. It was observed that the maximum biochar of 71.2% was obtained at 250°C using 0.5% Fe₃O₄ catalysts (Fe₃O₄) in 45 min. However, the maximum amount of bio-oil of 28% was obtained at 350°C using 1.5% Fe₃O₄ catalysts in 45 min. This study presents an economical pioneering approach to produce biochar and bio-oil from microalgae biomass for biofuel as well as ecologically safe applications.

Graphical Abstract

KEYWORDS:

• Microalgae
• Fe₃O₄ nanoparticle
• magnetic harvesting
• thermochemical process
• catalytic hydrothermal liquefaction
• biochar and bio-oil

Abbreviations and nomenclature

EDS/EDX	=	Energy dispersive X-ray analysis
FE-SEM	=	Field-emission scanning electron microscopy
FTIR	=	Fourier transform infrared spectroscopy
HTL	=	Hydrothermal liquefaction
OD	=	Optical density
XRD	=	X-ray diffraction

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data will be available based on the request.

Declaration

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15567036.2023.2277892.

Additional information

Funding

This paper was supported by the grant provided by DST, Goverment of India under the project (DST/INT/RUS/RSF/P-60/2021). This work was funded by the Russian Science Foundation (RSF), Grant No. 22-49-02003. This publication was supported by the RUDN University scientific project grant system, project№ 2027042000.

Notes on contributors

Jyoti Rawat

Jyoti Rawat is currently working as a Senior Research fellow in the Department of Food Science & Technology at Graphic Era (Deemed to be University) in Dehradun, India. She has obtained her PhD in Biotechnology from the Department of Biotechnology, Kumaun University Nainital (2023). She has published more than 10 research and review papers in esteemed journals and has more than 10 book chapters with reputed publishers. Her area of research is focused on biofuel production from microalgae.

Krishna Kumar Jaiswal

Krishna Kumar Jaiswal is an Assistant Professor in Department of Green Energy Technology at Pondicherry University (A Central University), India. He has obtained his Ph.D. in Green Energy Technology and postdoctoral experiences with a broad area of research in bioenergy and biofuels. His research and teaching (M.Tech. and Ph.D. courses) focus on bioprocess engineering, nanotechnology, and biofuel technologies in the Department of Green Energy Technology. He is actively researching and developing new technologies for bioprocessing and biofuels.

Nisha Das

Nisha Das completed her master’s in chemistry from Odisha University of Agriculture and Technology (OUAT) in 2018. Thereafter, she worked as a Senior Research Fellow from 2019-2022 in the Bharat Petroleum Pvt. Ltd. biofuel-funded project at OUAT. Her research interests mainly focus on various biofuel production from waste biomass via chemical and thermochemical-based technologies.

Sanjay Kumar

Sanjay Kumar is an Assistant Professor in the Department of Food Science & Technology at Graphic Era (Deemed to be University) in Dehradun, India. He has completed his PhD in Biotechnology from Graphic Era Deemed to be University, India (2022). His research interests primarily focus on new product development, machine design, and food processing. His research findings have been published in reputable journals with high-impact factors.

Prateek Gururani

Prateek Gururani is an Assistant Professor in Department of Biotechnology at Graphic Era (Deemed to be) University, Dehradun (India). He obtained M.Tech specialization in Food and Bioprocess Engineering from G.B. Pant University of Agriculture and Technology, Pantnagar (India). His research area involves biofuel production (Clean energy) and wastewater treatment.

Bhawna Bisht

Bhawana Bisht is an Assistant Professor in Department of Food Science and Technology at Graphic Era (Deemed to be) University, Dehradun (India). She is also pursuing Ph.D. in Food Technology from Graphic Era (Deemed to be University), Dehradun, India. She has completed her M.Tech in Food and Bioprocess Engineering from G.B. Pant University of Agriculture & Technology, Pantnagar, India. Bhawna’s research focuses on harnessing the potential of algae with cutting-edge 3D food printing technology to revolutionize the way food consumption is not only visually appealing but also nutritionally dense and environmentally friendly. Her research findings have been published in reputable scientific journals and presented at national and international conferences.

Mikhail S. Vlaskin

Mikhail S. Vlaskin is Head and Scientist of laboratory in Joint institute for high temperatures of Russian academy of sciences (JIHT RAS). He obtained Ph.D. in ‘Energy Systems and Complexes’ from Joint Institute for High Temperatures of Russian Academy of Sciences. Dr. Vlaskin is specialized in the field of microalgae for food & feed, CO2 sequestration, waste water treatment and biofuel production. His research area focuses on Bioenergy, waste-to-energy. Hydrothermal technologies: hydrothermal carbonization, hydrothermal liquefaction of biomass and organic waste including municipal solid

Manoranjan Nayak

Manoranjan Nayak has been working at the intersection of R&D, Industry, and Policy in the Biotechnology Sector. He received his Ph.D. degree in Biotechnology from Utkal University, India, in 2014. Currently, he is continuing as an Associate Professor at Amity Institute of Biotechnology, Amity University, Noida, India, from February 2021. He is pursuing R&D activities in the areas of energy & environment. He has been working on various aspects of the algae biofuel challenge aiming at green process-&-product development, value-added products with concomitant flue-gas carbon-dioxide sequestration and wastewater/ solid waste utilization, bioremediation and valorization in Green-Biorefinery models.

Vinod Kumar

Vinod Kumar is an Associate Professor in the Department of Life Sciences at Graphic Era (Deemed to be) University, Dehradun (India). He obtained his Ph.D. in Chemistry (Biochemistry) from H.N.B. Garhwal University, Srinagar, Uttarakhand, India. He is also a Research Scientist (Visiting) in Department of Environmental Monitoring and Forecasting, Ecological Faculty, RUDN University, Moscow, 117198, Russia. Dr. Kumar’s research area focuses on Algal biofuel, Bioenergy, Biochemistry, and wastewater treatment.