Faculty Publications
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Item Application of ultrasound in microbial and algal biofuel production(Bentham Science Publishers, 2023) Poddar, M.K.; Pattanaik, L.; Dikshit, P.K.The application of ultrasound has received immense research attentions in the past few years due to its application in various sectors including dye degradation, pretreatment process, fuel production, bioprocessing, etc. Recently, ultrasonication has been used as a novel bioprocessing tool for enhancing biofuel production from microbial and algal biomass during the fermentation process. Additionally, this technique is also used in many areas of downstream processing such as extraction of lipids from biomass, filtration, and crystallization. The usage of ultrasonication during the fermentation process can result in the enhancement of the transfer of oxygen for aerobic culture, homogenization of biomass for the reduction in clump formation, and faster substrate transfer to biomass which further results in enhanced microbial growth. In view of this, the present chapter mainly focuses on the role of ultrasonication in microbial and algal lipid production and its extraction process with an aim for liquid biofuel production. Additionally, the influence of various operating parameters (power intensity, frequency, duration, reactor design, and kinetics) over the growth, lipid production, and extraction process are also described in detail. © 2023 Bentham Science Publishers. All rights reserved.Item Use of Microalgae for the Development of Carbon Neutral Bio-CNG Process(Springer Science and Business Media Deutschland GmbH, 2024) Datta, P.; Bej, S.; Madav, M.; Raval, K.The comprehensive chapter focuses on the upgradation techniques and conversion of the biogas generated from the huge amount of biowaste, to methane-enriched bio-compressed natural gas (bio-CNG). The sustainable bio-fixation of the extracted CO2 by employing various algal strains for carbon capture and utilization (CCU) along with the culture conditions has been discussed. The comparative analyses highlight that the integrated biorefinery approach does not involve harmful chemicals, high energy utilization and high operating expenses. The post-treatment and consumption of biogas-separated CO2 by algae make the process carbon neutral. The potential algal strains, their CO2 utilization capacity, and subsequent formation of high algal biomass along with several significant value-added products such as biofuels, biochemicals and biofertilizers in different types of photobioreactors and other process parameters, are also elaborated. The emerging role of efficient algal species in reducing greenhouse gas emissions and addressing the climate change issue has been illustrated for making it an eco-friendly strategy. The systematic valorization of algal biomass contributes to promising resource regeneration and promotes a circular economy in the sector of bioenergy industries to sustainably fulfill the global energy demand. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Item Plasma-Activated Water as Nitrogen Source for Algal Growth: A Microcosm Study(Institute of Electrical and Electronics Engineers Inc., 2021) Sukhani, S.; Punith, N.; Ekatpure, A.; Salunke, G.; Manjari, M.; Harsha, R.; Chanakya, H.N.; Lakshminarayana, R.Nitrogen is one of the most critical nutrients affecting algal cell biomass growth and thereby plays a crucial role in algal growth economics. Conventionally, all man-made nitrogen (N) sources are based on hydrogen derived from fossil fuels. This investigation examines the effect of a new N source, i.e., plasma-activated water (PAW), on yields of algal biomass. The N uptake rates of the algae for PAW were determined and it was compared with the conventional N sources. Four treatments of N source in duplicates were run to evaluate the potential of algae cultivation in batch microcosms (5 L). Mixotrophic algal cultures from a nearby eutrophied lake were incubated for 1 week with nitrate-N (NaNO3), nitrite-N (NaNO2), nitrate+nitrite (NaNO3+NaNO2), and PAW as sole N source in basal Bold's media. Even though the cultures were not axenic, steady increase in chlorophyll and biomass was observed for all the cases studied. The highest biomass yield was observed in nitrate-N fed cultures, at an average of 32.5 mg/( \text{L}\cdot day), followed by a combination of nitrate+nitrite [27.1 mg/( \text{L}\cdot day)], PAW-N [26.6 mg/( \text{L}\cdot day)], and nitrite-N [22.5 mg/( \text{L}\cdot day)] fed cultures. Nitrogen uptake rates were similar in all cultures studied. The highest rates observed were in nitrite-N [4.05 mg/( \text{L}\cdot day)], closely followed by PAW [3.56 mg/( \text{L}\cdot day)]. The results suggest that PAW can be utilized as a N source with pre-exposed cultures. The algal biomass yields of PAW were comparable to conventional sources although cultures with PAW showed signs of better uptake of N. © 1973-2012 IEEE.Item Performance, combustion and emission characteristics of a diesel engine fuelled with Schizochytrium micro-algae biodiesel and its blends(Taylor and Francis Ltd., 2022) Rajendra Prasad Reddy, B.; Rana Prathap Reddy, N.; Manne, B.; Srikanth, H.V.The use of the third-generation feedstock for biodiesel production has become increasingly popular over the past decade. Among the various third-generation feedstock identified, biodiesel synthesised from the microalgae attracted the attention of researchers throughout the world. The present research includes a study on the suitability of Schizochytrium microalgae biodiesel as an alternative fuel for the diesel engine. The investigation was carried out on the production, characterisation of Schizochytrium microalgae biodiesel through the transesterification process followed by performance, combustion and emission characteristics of a diesel engine fuelled with Schizochytrium microalgae biodiesel and its blends. The study revealed that the properties of biodiesel were obtained to meet the specified ASTM D6751 standards. The engine performance, combustion and emission characteristics were found to be satisfactory than those of fossil diesel. © 2020 Informa UK Limited, trading as Taylor & Francis Group.Item Role of ZSM5 catalyst and char susceptor on the synthesis of chemicals and hydrocarbons from microwave-assisted in-situ catalytic co-pyrolysis of algae and plastic wastes(Elsevier Ltd, 2022) Suriapparao, D.V.; Tanneru, T.; Rajasekhar Reddy, B.R.; Yerrayya, A.; Bhasuru, B.A.; Pandian, P.; Prakash, S.R.; Sankar Rao, C.; Sridevi, V.; Desinghu, J.The synergetic effect between algae biomass in co-pyrolysis with synthetic plastics (polypropylene (PP), polyethylene (PE), and expanded polystyrene (EPS)) was investigated in this work. Individual feedstock pyrolysis and co-pyrolysis of algae with PP, PE, and EPS were conducted at a constant supply of microwave energy (420 J/s). Pyrolysis char was used as a susceptor in all the experiments. The average heating rate was varied in the range of ∼50–60 °C/min for achieving the final pyrolysis temperature of 600 °C. In catalytic co-pyrolysis, the ZSM-5 catalyst was used for upgrading the physicochemical properties of pyrolysis oil. The use of catalyst promoted the excessive cracking of biomass in co-pyrolysis, leading to higher gas and coke residue comparatively. The viscosity, density, and flash point of oil obtained in catalytic co-pyrolysis were significantly reduced. While the oil obtained from individual pyrolysis of algae is rich in phenolic derivatives, and that of PP, PE has aliphatic hydrocarbons, and EPS has monoaromatic hydrocarbons as major compounds. The synergistic role of plastic and biomass in co-pyrolysis was observed in the formation of products and oil composition. The bio-oil from catalytic co-pyrolysis is composed of aliphatic oxygenates, aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and phenolics. The chemicals and hydrocarbons present in the oil have a carbon number in the range of C6 to C30. An increase in carbon and hydrogen elemental composition was observed in bio-oil obtained from co-pyrolysis. © 2021 Elsevier LtdItem Anti-biofouling evaluation of vacuum-assisted hydrophobic ytterbium oxide (Yb2O3) coating on stainless steel by facile spray combustion(Springer, 2024) Karle, S.S.; Kailasam, K.; Vardhan, R.V.; Praveen, L.L.; Gautam, V.; Mandal, S.Despite the development of numerous coating techniques and materials, today’s anti-biofouling applications require coatings that are facile and mechanically robust in nature. Studies on the hydrophobicity of rare-earth oxides have risen due to their unusual chemical properties; ytterbium oxide is one such oxide substance. In this study, spray combustion was used to create a hydrophobic coating of ytterbium oxide (Yb2O3) on a stainless steel (SS) substrate, which was then vacuum-treated. GI-XRD analysis confirmed the sesquioxide cubic crystalline structure of Yb2O3. FESEM images displayed an underneath wavy morphological coating with discrete particles on the surface. The thickness and roughness were ~12 and ~0.17 µm, respectively. When 5 and 10 N loads were applied, the coating showed better scratch hardness than uncoated SS. Water contact angle (WCA) <10° indicated superhydrophilicity in the fabricated coating. After vacuum treatment, it became hydrophobic, and the WCA was 128°; because of the increment in the relative area fraction of the C–H bond. The proportion of area covered by blue–green algae (Phormidium sp.) on vacuum-treated Yb2O3 coating was only 3% compared to uncoated SS samples, 80%. © Indian Academy of Sciences 2024.