Dr. Richa Katiyar | Indian Institute of Technology Bombay (original) (raw)

Papers by Dr. Richa Katiyar

Journal of Water Process Engineering, 2021

Abstract The explosion in urban population are increasing burdens on water and energy systems, wh... more Abstract The explosion in urban population are increasing burdens on water and energy systems, which ultimately release harmful pollutants such as wastewater and toxic gases into the natural ecosystems. In order to eliminate these pollutants, the production of vehicular quality biodiesel along with the phycoremediation of wastewater using two different Chlorella species (Chlorella minutissima and Chlorella sorokiniana) was investigated. Both the Chlorella sp., due to their stress tolerance behavior showed higher growth rate, lipid content and biomass productivity, when cultivated in wastewater than in control. Chlorella sorokiniana exhibited 19.14% higher lipids than Chlorella minutissima, when cultivated in wastewater. The fatty acid methyl esters (FAMEs)/biodiesel profiling has shown the decrease in poly unsaturated fatty acids (PUFAs) with enhancement in saturated fatty acids (SFAs) and oleic acid content. The physical properties of biodiesel derived from Chlorella sorokiniana, exceeded the existing biodiesel standards for USA and Europe e.g. the biodiesel (89.23 ± 0.21%; w/w of lipids) obtained from Chlorella sorokiniana, grown in wastewater was having lower cold filter plugging point (−6.22 °C), higher cetane number (47) and average oxidative stability (3.43 h). During the process, these Chlorella species have also removed total phosphate (TP), total nitrogen (TN), chemical oxygen demand (COD) and total organic carbon (TOC) from wastewater. The removal efficiency of TOC was found to be 95% and 98% by Chlorella minutissima and Chlorella sorokiniana respectively. Overall, Chlorella sorokiniana grown in wastewater was found to be a better candidate for the biodiesel production together with phycoremediation of wastewater.

Biofuels, Bioproducts and Biorefining, 2021

Microalgae have garnered significant interest among researchers and industries as a potential sou... more Microalgae have garnered significant interest among researchers and industries as a potential source of valuable products that can find applications in the food, feed, biofuels, cosmetics, pharmaceuticals, and nutraceuticals industries. Microalgae can remediate various waste streams. This review discusses the current trends in the valorization of algal biomass and proposes integrated biorefinery approaches to produce high‐value products by sustainable routes. In such processes, the waste streams can be used as a source of nutrients for the production of microalgal biomass, rich in high‐quality lipids, digestible proteins and bioactive compounds. The integrated approaches presented in this study offer cost‐effective and environment‐friendly processing techniques while expanding the bioproducts portfolio in the food and therapeutics sector. The simultaneous or sequential extraction of valuable compounds from microalgae makes the biorefinery proposition appealing for waste minimization, revenue diversification, and complete feedstock utilization. The systematic exploration of microalgae on a large scale is required to evaluate its future as a favorable resource for biorefinery products. This would also necessitate detailed techno‐economic, environmental, and lifecycle assessment for the biorefinery processes. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Biofuels, 2019

Microalgae are considered potential feedstocks to generate biodiesel; however, the area requires ... more Microalgae are considered potential feedstocks to generate biodiesel; however, the area requires further refinement and metabolic engineering to enhance productivity along with cost reduction. Our study involved the production and quality evaluation of biodiesel from the lipids of Botryococcus sp. MCC31, after conventional and in situ transesterification. Lipids extracted fell within the range of 330 to 410 mg g À1 Dry Weight (DW) (33-41% w/w) and these were identified by 1 H Nuclear Magnetic Resonance (NMR) and 13 C NMR spectrum. After identification, the reaction conditions for indirect transesterification, in terms of catalyst type, were optimized for maximizing Fatty Acid Methyl Ester (FAME) yield. The total unsaturated and saturated fatty acids were 54% and 46%, respectively, and the results indicated higher amounts of methyl palmitate and methyl oleate, which comprised almost 65% of the total FAMEs. The biodiesel exhibited a density of 0.853 g/cc, viscosity of 3.512 mm 2 /s, Cetane Number (CN) of 57.57, Higher Heating Value (HHV) of 38.88, iodine value of 75.56 g I 2 /100 g, Degree of Unsaturation (DU) of 58% and a Cold Filter Plugging Point (CFPP) of 4.8 C. The results were in accordance with the details as specified by American Society for Testing and Materials (ASTM) and European Norms (EN) standards. The study illustrates that Botryococcus sp. MCC31 can be a valuable feedstock for generation of high-quality biodiesel.

Algal Research, 2020

Current market trend and consumer's growing demand for healthy natural products have strengthened... more Current market trend and consumer's growing demand for healthy natural products have strengthened microalgae as an emerging source of nutrient rich natural food supplement. The constituents of food play a critical role in evolution of non-communicable disease and malnutrition. In this regard, microalgae based food products own positive health impacts and combating effects on non-communicable disease and malnutrition. These products appear as favourable sources of vitamins, minerals, proteins, functional lipids/poly unsaturated fatty acids and carotenoids etc. Present study highlights microalgae based poly unsaturated fatty acids such as omega-3 i.e. alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid and omega-6 and its biosynthesis, production, applications in public health and economic analysis associated with its production. Poly unsaturated fatty acids are considered as one of the promising sources of human's diet and their optimal proportion (omega-3 to omega-6; 1:1 to 1:4) is essential for prevention of non-communicable disease and other chronic diseases. Microalgae based poly unsaturated fatty acids functions as an alternative to fish oil and possess number of benefits in terms of taste, no/reduced toxins accumulation and veganism nature over animal based oils. Moreover, microalgae produce higher amount of omega-3 in contrast to animal based oils, for instance; Isochrysis galbana and Phaeodactylum tricornutum produce closely ≥2 folds higher eicosapentaenoic acid and Crytthecodinium cohnii produce nearly ≥6 folds higher docosahexaenoic acid than cod liver oil. In contrast, terrestrial plant-based poly unsaturated fatty acids lack eicosapentaenoic acid/docosahexaenoic acid. Thus, microalgae based poly unsaturated fatty acids represent compatible market for production of food and feeds products over fish and plant based poly unsaturated fatty acids. Current review provides critical examination of the literature investigating application of microalgae based functional lipids as dietary and nutraceutical supplement to improve public health. In addition, process economics and challenges have also been discussed in this paper.

Environmental Science and Pollution Research, 2019

The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mi... more The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mixotrophically to augment production of biodiesel. The cultivation of Chlorella sp. using CL as media was carried out by employing a fed-batch technique in open tray (open tray+CL) and in software (BioXpert V2)-attached automated photobioreactor (PBR+CL) systems. Data showed the limit of nitrogen substituent and satisfactory organic source of carbon (OSC) in CL, causing > 2-fold higher lipid content in cells, cultivated in both the systems than in control. For the cells grown in both the systems, ≥ 3-fold enhancement in lipid productivity was observed than in control. The total fatty acid methyl ester (FAME) concentrations from lipids extracted from cells grew in PBR+CL and in open tray+CL techniques were calculated as 50.59% and 38.31%, respectively. The PBR+CL system showed improved outcomes for lipid content, lipid and biomass productivity, FAME characteristics and physical property parameters of biodiesel than those obtained from the open tray+CL system. The physical property parameters of biodiesel produced from algal cells grown in PBR+CL were comparable to existing fuel standards. The results have shown lower cold filter plugging point (− 6.57°C), higher cetane number (58.04) and average oxidative stability (3.60 h). Collectively, this investigation unveils the novel deployment of CL as a cost-effective feedstock for commercialisation of biodiesel production.

Renewable Energy, 2018

The investigation first time reports the efficacy of de-oiled algal biomass extract (DOABE) for m... more The investigation first time reports the efficacy of de-oiled algal biomass extract (DOABE) for mixotrophic cultivation of Chlorella sp. MCC27 to enhance biodiesel production in open tray systems and in BioXpert-V2 software connected photobioreactor (PBR). The cultivation systems with addition of DOABE (PBR systems þ DOABE and open tray system þ DOABE) as media were tested for quality and quantity of biodiesel. The presence of organic carbon and low nitrogen in DOABE caused >2 folds higher biomass productivity and >4 folds enhanced lipid productivity for the cells cultivated in PBR system þ DOABE and open tray system þ DOABE as compared to control (i.e. BBM). Biochemical analysis of cells from both the systems revealed the decrease in total carbohydrates and protein contents. The FAMEs analyses showed vehicular quality biodiesel. PBR system þ DOABE showed edge over open tray system þ DOABE in terms of biomass productivity and lipid content. The physical properties of biodiesel produced from Chlorella sp. MCC27 were more close to the fuel standards (ASTM D6751), when cells were cultivated in open tray system þ DOABE than in PBR system þ DOABE. Collectively, this study highlights the use of DOABE as a low cost feedstock for enhancing vehicular quality biodiesel production from microalgae.

International Journal of Chemical Reactor Engineering, 2017

Among the renewable fuels, butanol has become an attractive, economic and sustainable choice beca... more Among the renewable fuels, butanol has become an attractive, economic and sustainable choice because of cost elevation in petroleum fuel, diminishing the oil reserves and an increase of green house effect. Butanol can be derived from renewable sources by using the natural bio-resources and agro-wastes such as orchard wastes, peanut wastes, wheat straw, barley straw and grasses via Acetone Butanol Ethanol (ABE) process. On the other hand, butanol can be directly formed from chemical route involving catalysts also such as from ethanol through aldol condensation. This review presents extensive evaluation for the production of butanol deploying microbial and catalytic routes.

Green Energy and Technology, 2017

Renewable Energy, 2017

This integrated approach first time investigates the use of crude glycerol (CG), a primary by pro... more This integrated approach first time investigates the use of crude glycerol (CG), a primary by product of the biodiesel production, for heterotrophic cultivation of microalgae (namely, Chlorella sp.) in photobioreactor (PBR) to enhance biodiesel production. The glycerol was reported 28.5±0.70 % in CG, causing nearly two folds increase in biomass productivity (446.50±1.50 mg L-1 day-1) and nearly four folds enhanced lipid productivity (165.15±0.55 mg L-1 day-1) for the algal cells cultivated in PBR with addition of CG (PBR+CG) system as compared to Bold's Basal media (BBM) used as control. The total lipid content (34.36±0.51%) was also doubled for the cells grown in PBR+CG system than in BBM. The analysis of fatty acid methyl esters (FAMEs) profile by GC-MS showed reduction in total unsaturated fatty acids and poly unsaturated fatty acids, and increase in total saturated fatty acids (SFAs) for the biodiesel obtained from algal cells grown in PBR+CG system. Moreover, the physical properties estimation also specified higher cetane number (53.89) and average oxidative stability (3.41 h), which are comparable with ASTM D6751 and EN 14214 fuel standards. This study demonstrates the potential of the use of CG for enhancing the low cost biodiesel production for vehicular transportation.

Renewable and Sustainable Energy Reviews, 2017

The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mi... more The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mixotrophically to augment production of biodiesel. The cultivation of Chlorella sp. using CL as media was carried out by employing a fed-batch technique in open tray (open tray+CL) and in software (BioXpert V2)-attached automated photobioreactor (PBR+CL) systems. Data showed the limit of nitrogen substituent and satisfactory organic source of carbon (OSC) in CL, causing > 2-fold higher lipid content in cells, cultivated in both the systems than in control. For the cells grown in both the systems, ≥ 3-fold enhancement in lipid productivity was observed than in control. The total fatty acid methyl ester (FAME) concentrations from lipids extracted from cells grew in PBR+CL and in open tray+CL techniques were calculated as 50.59% and 38.31%, respectively. The PBR+CL system showed improved outcomes for lipid content, lipid and biomass productivity, FAME characteristics and physical property parameters of biodiesel than those obtained from the open tray+CL system. The physical property parameters of biodiesel produced from algal cells grown in PBR+CL were comparable to existing fuel standards. The results have shown lower cold filter plugging point (− 6.57 °C), higher cetane number (58.04) and average oxidative stability (3.60 h). Collectively, this investigation unveils the novel deployment of CL as a cost-effective feedstock for commercialisation of biodiesel production.

This integrated approach first time investigates the use of crude glycerol (CG), a primary by pro... more This integrated approach first time investigates the use of crude glycerol (CG), a primary by product of the biodiesel production, for heterotrophic cultivation of microalgae (namely, Chlorella sp.) in photo-bioreactor (PBR) to enhance biodiesel production. The glycerol was reported 28.5 ± 0.70% in CG, causing nearly two folds increase in biomass productivity (446.50 ± 1.50 mg L À1 day À1) and nearly four folds enhanced lipid productivity (165.15 ± 0.55 mg L À1 day À1) for the algal cells cultivated in PBR with addition of CG (PBRþCG) system as compared to Bold's Basal media (BBM) used as control. The total lipid content (34.36 ± 0.51%) was also doubled for the cells grown in PBRþCG system than in BBM. The analysis of fatty acid methyl esters (FAMEs) profile by GC-MS showed reduction in total unsaturated fatty acids and poly unsaturated fatty acids, and increase in total saturated fatty acids (SFAs) for the biodiesel obtained from algal cells grown in PBRþCG system. Moreover, the physical properties estimation also specified higher cetane number (53.89) and average oxidative stability (3.41 h), which are comparable with ASTM D6751 and EN 14214 fuel standards. This study demonstrates the potential of the use of CG for enhancing the low cost biodiesel production for vehicular transportation.

The microalgae biomass is emerging as a potential source of energy and bioproducts with several a... more The microalgae biomass is emerging as a potential source of energy and bioproducts with several advantages over conventional crops in terms of its ability to produce ~300-times more renewable oil. Microalgae also have a high photosynthetic response, product accumulation rate and biomass production rate compared with other energy crops. Microalgae have the ability to grow on nonagricultural soil using wastewater instead of drinking water. Furthermore, microalgae have high capability to fix carbon dioxide from the environment. Microalgae-based bioproducts have different applications in pharmaceuticals, food and feed industries, and agricultural and transportation sectors. The key objectives covered in this review pertain to the role of microalgae to (i) maintain food chain, (ii) conservation of land and water resources in the environment with sequestration of CO 2 , (iii) production of energy in the form of biodiesel with zero waste, and (iv) simultaneous release of higher oxygen to the environment compared with other energy crops.

Journal of Water Process Engineering, 2021

Biofuels, Bioproducts and Biorefining, 2021

Biofuels, 2019

Algal Research, 2020

Environmental Science and Pollution Research, 2019

Renewable Energy, 2018

International Journal of Chemical Reactor Engineering, 2017

Green Energy and Technology, 2017

Renewable Energy, 2017

Renewable and Sustainable Energy Reviews, 2017

The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mi... more The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mixotrophically to augment production of biodiesel. The cultivation of Chlorella sp. using CL as media was carried out by employing a fed-batch technique in open tray (open tray+CL) and in software (BioXpert V2)-attached automated photobioreactor (PBR+CL) systems. Data showed the limit of nitrogen substituent and satisfactory organic source of carbon (OSC) in CL, causing > 2-fold higher lipid content in cells, cultivated in both the systems than in control. For the cells grown in both the systems, ≥ 3-fold enhancement in lipid productivity was observed than in control. The total fatty acid methyl ester (FAME) concentrations from lipids extracted from cells grew in PBR+CL and in open tray+CL techniques were calculated as 50.59% and 38.31%, respectively. The PBR+CL system showed improved outcomes for lipid content, lipid and biomass productivity, FAME characteristics and physical property parameters of biodiesel than those obtained from the open tray+CL system. The physical property parameters of biodiesel produced from algal cells grown in PBR+CL were comparable to existing fuel standards. The results have shown lower cold filter plugging point (− 6.57 °C), higher cetane number (58.04) and average oxidative stability (3.60 h). Collectively, this investigation unveils the novel deployment of CL as a cost-effective feedstock for commercialisation of biodiesel production.

This integrated approach first time investigates the use of crude glycerol (CG), a primary by pro... more This integrated approach first time investigates the use of crude glycerol (CG), a primary by product of the biodiesel production, for heterotrophic cultivation of microalgae (namely, Chlorella sp.) in photo-bioreactor (PBR) to enhance biodiesel production. The glycerol was reported 28.5 ± 0.70% in CG, causing nearly two folds increase in biomass productivity (446.50 ± 1.50 mg L À1 day À1) and nearly four folds enhanced lipid productivity (165.15 ± 0.55 mg L À1 day À1) for the algal cells cultivated in PBR with addition of CG (PBRþCG) system as compared to Bold's Basal media (BBM) used as control. The total lipid content (34.36 ± 0.51%) was also doubled for the cells grown in PBRþCG system than in BBM. The analysis of fatty acid methyl esters (FAMEs) profile by GC-MS showed reduction in total unsaturated fatty acids and poly unsaturated fatty acids, and increase in total saturated fatty acids (SFAs) for the biodiesel obtained from algal cells grown in PBRþCG system. Moreover, the physical properties estimation also specified higher cetane number (53.89) and average oxidative stability (3.41 h), which are comparable with ASTM D6751 and EN 14214 fuel standards. This study demonstrates the potential of the use of CG for enhancing the low cost biodiesel production for vehicular transportation.