Open Raceway Research Articles

Extraction of microalgal oil from Nannochloropsis oceanica by potassium hydroxide-assisted solvent extraction for heterogeneous transesterification

The feasibility of potassium hydroxide for simultaneous removal of chlorophyll during solvent extraction from wet microalgae (200 g/L) was evaluated. Extracted oil was converted to biodiesel by ZSM-5-based heterogeneous catalysts. The total oil (fatty acid-based) content of Nannochlorposis oceanica cultivated in open raceway ponds was 19.5%. The oil recovery yields from dry and wet microalgae using hexane were 44.4 and 11.8%, respectively, whereas using a hexane-methanol mixture were increased to 79.3 and 74.8%, respectively. For the heterogeneous transesterification of microalgal oil extracted by the hexane-methanol mixture from wet microalgae, the fatty acid methyl ester (FAME) contents were 2.3, 48.3, and 4.7% of product recovered after reaction for ZSM-5, Na/ZSM-5, and SO42−/ZSM-5, respectively; by the potassium hydroxide-assisted process, the corresponding FAME contents were increased to 21.9, 86.2, and 86.0%, respectively, due to improvement of the oil properties by the decrease of the chlorophyll content. Through the addition of potassium hydroxide, chlorophyll was effectively removed from oil, and eventually, the biodiesel conversion was sharply increased with heterogeneous Na/ZSM-5 and SO42−/ZSM-5 catalysts.

Orange light spectra filtered through transparent colored polyvinyl chloride sheet enhanced pigment content and growth of Arthrospira cells

Microalgae are significantly affected by the spectra composition with various wavelengths. The development of light harvesting pigments can be controlled with specific wavelength of filtered light received by microalgae. Coverage of open raceway pond using transparent colored polyvinyl chloride sheets (PVCS) to filter light spectra, was assessed for the capacity to enhance biomass growth rate. Results showed that orange PVCS filtered light spectra at wavelengths from 480 to 665 nm, increased biomass dry weight (3.3 g/L) by 61% compared with control condition (white PVCS = 350–750 nm). Light spectra filtered through orange PVCS were more easily absorbed by the light harvesting pigment protein complex (phycobilisome) of Arthrospira platensis cells and subsequently transferred to intracellular photosynthesis reaction centers. Therefore, A. platensis cells cultivated with light spectra filtered through orange PVCS contained 62.7 mg/L chlorophyll-a and 23.5 mg/L carotenoid, which were 40% and 29% higher than control condition (with white PVCS).

Techno-economic analysis of co-processing of vacuum gas oil and algae hydrothermal liquefaction oil in an existing refinery

Co-processing of ligno-cellulosic bio-oil and vacuum gas oil (VGO) in an existing refinery for the production of gasoline with renewable carbon has demonstrated a good technical and economic feasibility and the potential to partial replace the petroleum-derived gasoline. The co-processing of VGO and algae hydrothermal liquefaction oil (AHTLO) has drawn attention and showed the highly technical feasibility. However, the economic performance for the co-processing of VGO and AHTLO remains unclear. In this work, techno-economic analysis for VGO and AHTLO co-processing is conducted to evaluate its overall economics and also obtain the optimal algal production technology from algal turf scrubbers (ATS) and open raceway ponds (ORP). Two co-processing scenarios integrated the two algal production technologies, ATS scenario and ORP scenario, are proposed to illustrate their differences. The results show that minimum gasoline selling price of ATS scenario is only $3.11 per gallon while the one of the ORP scenario reaches $3.24 per gallon. The VGO cost still takes near 60% of the gasoline price. The comparisons between the co-processing gasoline and petroleum-derived gasoline show that the saved capital investment is the main reason why the production cost of the co-processing gasoline can be reduced. The sensitivity analysis demonstrates that the fuel yield, VGO and diesel prices and the capacity of the co-processing FCC to be the important factors in the economic viability. Gasoline from the co-processing of VGO and AHTLO may be a potential way to partial replace petroleum-derived gasoline in certain circumstances.

Novel Stacked Modular Open Raceway Ponds for Microalgae Biomass Cultivation in Biogas Plants: Preliminary Design and Modelling

Abstract Microalgae hold great potential as a source for renewable energy due to their high photosynthetic efficiency, high growth rates and independence from fertile agricultural lands. However, large-scale cultivation systems of microalgae biomass are still not economically viable mainly due to the difficulties with maintaining optimum growth conditions of microalgae in open pond systems and high costs of biomass cultivation and harvesting. Here we propose the Novel Stacked Modular Open Raceway Ponds (SMORPs) system for microalgae biomass cultivation to be integrated in biogas production plant. The proposed technological solution will eliminate the drawbacks of current microalgae cultivation technologies, mainly, will reduce the land use, improve lighting conditions and reduce the cost of cultivation as a result of the application of waste products from biogas production, i.e. anaerobic digestion effluent and flue gas. In this study we propose the initial design of the SMORP concept and a microalgae biomass kinetic model as a simple approach to screen microalgae strains potentially applicable for large-scale ponds. The developed tool is also useful to evaluate the potential benefit of additional artificial LED light sources and to assess the maximum biomass growth rate with minimal light intensity.

Does growing Nannochloropsis sp. in innovative flat plate photobioreactors result in changes to fatty acid and protein composition?

Solar cultivation of microalgae in photobioreactors is a valuable bioprocess for the sustainable production of commercially useful metabolites. However, the conventional culture temperature control method in solar closed photobioreactors of evaporative cooling is neither economical nor sustainable. In this study, a novel spectrally selective, insulated glazed flat plate (IGP) photobioreactor employing an infrared reflecting system embedded in the illumination surface was used for cultivation of Nannochloropsis sp. The impact of the temperature control technology on protein, lipid, carbohydrate content and fatty acid profile of Nannochloropsis sp. was investigated and compared to closed photobioreactors using passive evaporative cooling (PEC) and an infrared reflecting film (IRF) on the surface as well as an open raceway pond (ORP). Among all cultivation systems tested, the biochemical composition of biomass (mg g−1 organic biomass) showed a general trend of lipid > protein > carbohydrate, with no large variation of each across treatments. However, the areal and volumetric productivities of these constituents were significantly higher in the photobioreactors than in the ORP; results consistent with biomass productivity data. Of the major saturated and monounsaturated fatty acids present, only the proportion of C16:0, which is 24% higher in the photobioreactors than in the ORP, changed significantly among cultivation systems. The highest content of high-value dietary fatty acids, eicosapentaenoic acid (EPA, C20:5n-3; 15.5%) and ϒ-linolenic acid (C18:3n-6; 8%) were found in the ORP but were similar to that produced in the IGP (15.9 and 3.4%, respectively). Among all photobioreactors, the IGP had the least diel temperature changes and an EPA content that was 21% higher than PEC. Photobioreactors constructed with spectrally selective materials effectively allow management of internal reactor temperature with no significant negative impact on biochemical and fatty acid profiles of microalgae.

Application of surfactants for controlling destructive fungus contamination in mass cultivation of Haematococcus pluvialis

Large-scale cultivation of Haematococcus pluvialis is frequently contaminated by the destructive fungus Paraphysoderma sedebokerense, which can cause huge losses in astaxanthin production. Here, we propose the use of four commercial surfactants to control P. sedebokerense contamination in H. pluvialis cultures. In laboratory experiments, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and primary alcohol ethoxylate treatments showed inhibitory effects on fungal contamination. Moreover, sodium dodecylbenzene sulfonate was the most promising because treatment at 7 mg L−1 was effective against fungal infection without negatively affecting the growth or astaxanthin contents of H. pluvialis. This could be ascribed to their different cell coverings and structures. Additionally, applying sodium dodecylbenzene sulfonate to open raceway ponds prevented fungal contamination, and astaxanthin production reached 1.82 g m−2. Therefore, sodium dodecylbenzene sulfonate can be used as an effective and economical control agent for commercial production of astaxanthin fromH. pluvialis.

Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation

Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation

Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation.

In the United States, 35% of the total carbon dioxide (CO2) emissions come from the electrical power industry, of which 30% represent natural gas electricity generation. Microalgae can biofix CO2 10 to 15 times faster than plants and convert algal biomass to products of interest, such as biofuels. Thus, this study presents a protocol that demonstrates the potential synergies of microalgae cultivation with a natural gas power plant situated in the southwestern United States in a hot semi-arid climate. State-of-the-art technologies are used to enhance carbon capture and utilization via the green algal species Chlorella sorokiniana, which can be further processed into biofuel. We describe a protocol involving a semi-automated open raceway pond and discuss the results of its performance when it was tested at the Tucson Electric Power plant, in Tucson, Arizona. Flue gas was used as the main carbon source to control pH, and Chlorella sorokiniana was cultivated. An optimized medium was used to grow the algae. The amount of CO2 added to the system as a function of time was closely monitored. Additionally, other physicochemical factors affecting algal growth rate, biomass productivity, and carbon fixation were monitored, including optical density, dissolved oxygen (DO), electroconductivity (EC), and air and pond temperatures. The results indicate that a microalgae yield of up to 0.385 g/L ash-free dry weight is attainable, with a lipid content of 24%. Leveraging synergistic opportunities between CO2 emitters and algal farmers can provide the resources required to increase carbon capture while supporting the sustainable production of algal biofuels and bioproducts.

Assessment of biomass potentials of microalgal communities in open pond raceways using mass cultivation.

Metagenome studies have provided us with insights into the complex interactions of microorganisms with their environments and hosts. Few studies have focused on microalgae-associated metagenomes, and no study has addressed aquatic microalgae and their bacterial communities in open pond raceways (OPRs). This study explored the possibility of using microalgal biomasses from OPRs for biodiesel and biofertilizer production. The fatty acid profiles of the biomasses and the physical and chemical properties of derived fuels were evaluated. In addition, the phenotype-based environmental adaptation ability of soybean plants was assessed. The growth rate, biomass, and lipid productivity of microalgae were also examined during mass cultivation from April to November 2017. Metagenomics analysis using MiSeq identified ∼127 eukaryotic phylotypes following mass cultivation with (OPR 1) or without (OPR 3) a semitransparent film. Of these, ∼80 phylotypes were found in both OPRs, while 23 and 24 phylotypes were identified in OPRs 1 and 3, respectively. The phylotypes belonged to various genera, such as Desmodesmus, Pseudopediastrum, Tetradesmus, and Chlorella, of which, the dominant microalgal species was Desmodesmus sp. On average, OPRs 1 and 3 produced ∼8.6 and 9.9 g m−2 d−1 (0.307 and 0.309 DW L−1) of total biomass, respectively, of which 14.0 and 13.3 wt% respectively, was lipid content. Fatty acid profiling revealed that total saturated fatty acids (mainly C16:0) of biodiesel obtained from the microalgal biomasses in OPRs 1 and 3 were 34.93% and 32.85%, respectively; total monounsaturated fatty acids (C16:1 and C18:1) were 32.40% and 31.64%, respectively; and polyunsaturated fatty acids (including C18:3) were 32.68% and 35.50%, respectively. Fuel properties determined by empirical equations were within the limits of biodiesel standards ASTM D6751 and EN 14214. Culture solutions with or without microalgal biomasses enhanced the environmental adaptation ability of soybean plants, increasing their seed production. Therefore, microalgal biomass produced through mass cultivation is excellent feedstock for producing high-quality biodiesel and biofertilizer.

Strategic implementation of phosphorus repletion strategy in continuous two-stage cultivation of Chlorella sp. HS2: Evaluation for biofuel applications

Lipid production in microalgae under nitrogen (N) starved condition can be enhanced by excess phosphorus (P) supply in the second stage of two-stage cultivation strategy. However, implementing two-stage cultivation is difficult in large-scale cultivation system as it requires high energy of transferring large algal biomass from first stage to second stage. To address this problem, we have optimized a continuous two-stage (CTS) cultivation strategy using Chlorella sp. HS2, where nitrogen in the growth environment is depleted naturally via consumption. To enhance both biomass and lipid productivity this strategy explored supplementation of additional P from 50% to 2500% of the initial concentration at the start of N-limited second stage of growth. The results of the optimization study in photobioreactor (PBR) showed that supplementing 500% of initial P and 100% of initial other nutrients (O) (N0–P500–O100) on 5th day showed the maximum biomass productivity of 774.4 mg L−1 d−1. It was observed that Chlorella sp. HS2 grown in PBR yielded higher biomass (3.8 times), lipid (6.1 times) and carbohydrate (5.5 times) productivity in comparison to the open raceway ponds (ORP) study, under optimum nutrient and carbon supply condition. The maximum lipid (289.6 mg L−1 d−1) and carbohydrate (219.2 mg L−1 d−1) productivities were obtained in TPBR-3, which were 1.9 and 1.3 times higher than that of TPBR-2 (+ve control) and 9.6 and 3.7 times higher than that of TPBR-1 (-ve control), respectively. Fatty acid mainly composed of C16/C18 (84.5%–85.7%), which makes the microalgal oil suitable for biofuel production. This study concluded that feeding excess amount of P is an effective and scalable strategy to improve the biomass and lipid productivity of CTS cultivation.

Analysis and design of expert system for microalgae production to produce biofuel

Microalgae are third-generation (3G) biomass sources to produce biofuel. The microalgae process to produce bio-oil consist of several activities such as cultivation, dewatering, and extraction. The cultivation of microalgae mainly using the Open Raceway Pond (ORP) with paddlewheel operation. The dewatering process using the centrifugation and drum filtration reduced the concentration of microalgae slurry to 20%. Furthermore, hydrothermal liquefaction (HTL) was used to extract to the bio-crude. Dissemination tools are needed to deliver knowledge of the microalgae production from cultivation to bioenergy In this research, the expert system was proposed to help the practitioner to apply the microalgae production. The methods used in this research consist of knowledge acquisition, knowledge representation, and development of the inference engine. The result of this study was the knowledge-based expert system for microalgae production. The expert system could help the practitioner in the preparation process of the microalgae cultivation.

Evaluation of bio-crude oil through hydrothermal liquefaction of microalgae-bacteria consortium grown in open pond using wastewater

The present study demonstrates a promising approach for production of bio-crude oil via hydrothermal liquefaction of microbial biomass grown in large-scale open raceway pond. Three key attributes to achieve process feasibility are co-cultivation of microalgae and bacteria resulting in high biomass titre, utilization of paper industry wastewater as cheap source of nutrients and water, and one-step direct conversion of biomass into bio-crude oil. High biomass titre of 4 g L−1 with 90% of COD removal efficiency was achieved, depicting robust performance of the microalgae-bacteria consortium in industrial wastewater and under fluctuating environmental condition. Statistical optimization resulted in highest bio-crude oil yield of 21.7 (%, w/w) under optimal temperature, biomass loading and reaction time of 299.7 °C, 16.1 (%, w/v) and 65 min, respectively. Bio-crude oil with energy recovery of 43% and heating value of 33.1 MJ kg−1 reflects 81.7% and 73.4% heating value of biodiesel and diesel, respectively. While high percentage of hydrocarbon content in bio-crude oil indicates good oil quality, the presence of significant esters fraction might offer resemblance to biodiesel. Lower H/C ratio and higher O/C ratio in comparison to diesel indicate requirement of upgradation of bio-crude oil before it can be realized at commercial scale.

Design, Fabrication, and Performance Evaluation of Open Raceway Ponds for the Cultivation of Chlorella vulgaris Beijerinck in the Philippines

Two pilot-scale open raceway pond systems were designed and fabricated in the University of the Philippines Los Baños (UPLB) for the cultivation of Chlorella vulgaris Beijerinck to observe the biomass productivity of the alga in an open condition in the Philippines. One design was an oval track with a middle island, while the other was a multi-stage raceway pond (MSRP) consisted of several sections separated by baffles. The pond designs aimed to accommodate 1,000 L of culture. The nutrient media used was composed of urea, NPK (16-20-0), FeCl3, and Na2EDTA – a locally formulated medium that sustains the growth of the species. Paddlewheel was installed to provide mixing, which was turned on during the daytime, while aeration was continuously supplied through perforated air-distributor PVC pipes installed on the pond floor. Only natural light was utilized, and no lighting was provided during the night. The growth rate was generated by monitoring the biomass concentration in the pond through spectrophotometry at 425 nm, where optical density and biomass concentration relationship was initially established. Using the equation for first-order kinetics and taking the points from the exponential phase, the specific growth rate of Chlorella obtained from the oval raceway pond was computed to be 0.007308 h–1 with doubling time of 94.84 h. The biomass productivity rate was computed to be 308.49 g/m3-d or equivalent to 63.24 g/m2-d. On the other hand, the MSRP obtained a specific growth rate of 0.003389 h–1 with a doubling time of 204.55 h and equivalent biomass productivity of 302.19 g/m3-d or 60.44 g/m2-d. The biomass productivity obtained is comparable, even superior to other commercial open pond cultivation using C. vulgaris.

Bioethanol from hydrolyzed Spirulina (Arthrospira platensis) biomass using ethanologenic bacteria

Photosynthetic microorganisms are considered excellent feedstock for biofuel production in developing biomass production technologies. A study was conducted to evaluate ethanol production with the sequential enzymatic saccharification and fermentation of Arthrospira platensis (Spirulina) biomass with the metabolically engineered Escherichia coli strain MS04. A. platensis was cultivated semicontinuously in an open raceway pond, and the carbohydrate content was determined to be as high as 40%. The enzymatic saccharification was designed to release the maximum amount of glucose. After 40 h of enzymatic saccharification, 27 g L−1 of monosaccharides was obtained. These slurries were fermented with ethanologenic bacteria, achieving 12.7 g L−1 ethanol after 9 h of fermentation, which corresponds to 92% conversion yield of the glucose content in the hydrolysate, 0.13 g of ethanol per 1 g of Spirulina biomass and a volumetric productivity of 1.4 g of ethanol L−1 h−1. Therefore, we conclude that it is possible, in a short time, to obtain a high ethanol yield corresponding to 160 L per ton of dry biomass with a high productivity.

Synergistic Long-Term Temperate Climate Nitrogen Removal Performance in Open Raceway Pond and Horizontal Subsurface Flow Constructed Wetland Operated Under Different Regimes

This study investigated the potential of horizontal subsurface flow constructed wetlands (HSSF-CWs) and open raceway ponds (RWPs) operated under different regimes (plants, impregnated activated charcoal (IAC), and algae) for long-term nitrogen removal to control eutrophication problems. For experimental purposes, five mesocosms HSSF-CWs and two RWPs were set up in Wuxi, China, a temperate climate zone. Three HSSF-CW units were cultivated with different regions’ plant species including Nasturtium officinale, Juncus effusus, and Brassica juncea, whereas the one unit packed with IAC and the fifth was left as a control, while two species of algae (Spirogyra and C. pyrenoidosa) were cultured in RWPs. All the amendments tested in this study were almost equally effective for long-term nitrogen removal. The results demonstrated that more than 75.7, 88, and 66%, removal of TN, $$ {\mathrm{NH}}_4^{+} $$–N, and $$ {\mathrm{NO}}_3^{-} $$–N was achieved by the HSSF-CWs, packed with IAC and N. officinale. Concerning RWPs, both algal species showed almost similar results but slightly lower than others, which may be attributed to the less compatibility with the environment. It was observed that nitrogen removal performance was higher in the winter-spring (March–April) season as compared with winter (January–February). Moreover, all plants, particularly N. officinale growth, were quite steadier than others. The present study validates the impression that both treatment systems were potentially effective in long-term nitrogen removal from sewage and could be considered beneficial to control the eutrophication.

Simulation and analysis of open raceway pond system at Manit, Bhopal

Microalgae can become completely faster than terrestrial plants and are a successful feedstock for viable appreciation including items that envelop pharmaceuticals, neutraceuticals, proteins and most significantly biofuels. Since the biomass productivity of microalgae absolutely depends emphatically on the temperature of development, point-by-point data on the temperature of the reactor as a component of time and topographic area is essential to assess the sincere capability of microalgae as a traditional feedstock. Microalgae is indeed a promising source of renewable biofuels, and techno-financial upgrades can be made by improving and controlling the stage of biomass development. This research explores the improved performance of a first-standard green growth development display that encompasses the effect of regular (and such) notions of climate in an open system related to creation. Thus, the simulation of the procedure is stochastic just as basic; it helps restore the dissemination of outcomes from normal changeability that speak to the daily acknowledgement. It also communicates variety day-to-night in the vitality based on cycling sunlight. The simulation is then used to optimize the design of the pond and the manages (growth time, depth of the raceway, pH control, etc.) to enhance protability. Because the simulation is stochastic, nonlinear, and with different optima, an optimization method for multiplayer direct inquiry is used with relentless state assembly criteria. Conclusions are that (1) representing common variety in optimization prompts detectable protability improvement, (2) model impact investigation uncovers where key science exploration is expected to support basic techno-monetary wonders, and (3) the stochastic optimization approach is broadly relevant.

Development of a single helical baffle to increase CO2 gas and microalgal solution mixing and Chlorella PY-ZU1 biomass yield

A single helical baffle (SHB), consisting of twisted turns, was developed to convert straight flow into spiral flow in a Chlorella PY-ZU1 open raceway pond (ORWP) bubbled with 15% CO2. Microalgal solution flowing through the SHB alternative helical interspaces generated whirling flow both vertically and horizontally, which decreased mixing and increased mass transfer rates. The optimized SHB had a pitch length to total SHB length ratio of 0.13 and SHB diameter to ORWP single channel width ratio of 0.30, which decreased mixing times and increased mass transfer coefficients by 41.1% and 38.4% respectively. SHB moved Chlorella PY-ZU1 from the ORWP bottom to the top, increasing light exposure for photosynthesis. Cellular electron transfer rates and photochemical efficiency (φPSII) increased by 18%, chlorophyll a content increased by 16% and variable to maximum fluorescence ratio increased by 13%. The microalgal biomass of SHB ORWP was 23% higher than that of conventional ORWP.

Non-photochemical quenching, a non-invasive probe for monitoring microalgal grazing: influence of grazing-mediated total ammonia-nitrogen

ABSTRACT Contaminant invasion is one of the risks associated with microalgal cultivation in open raceway ponds, and the presence of zooplankton predators often results in a pond culture crash. For effective pond management, an early grazer-detection tool is needed to implement timely interventions. Microalgae and their predators co-exist in the pelagic food web and microalgal prey species have evolved to detect and mount physiological responses against the predator. However, algal prey-predator interactions in mass cultivation are poorly understood. This study aimed to understand the causal relationship between prey photosynthetic physiology, particularly non-photochemical quenching (NPQ), and predator infestation. We used the high biomass and glycerol-accumulating green algal species Dunaliella tertiolecta and the dinoflagellate Oxyrrhis marina as the prey and predator, respectively. Measurement of photosynthetic parameters suggests that NPQ levels significantly drop in the grazing culture, which may be related to increased total ammonia-nitrogen (TAN) accumulation by prey cells. This study suggests using an integrated approach by using NPQ and TAN measurements for early detection of predator infestation.

Non-destructive extraction of lipids from Botryococcus braunii and its potential to reduce pond area and nutrient costs

The production of oil from microalgae is a process with a long way to go before reaching commercial viability. High costs associated with harvesting and solvent extraction make it difficult to compete with fossil fuel. The in-situ, non-destructive, repetitive extraction of lipids from Botryococcus braunii (milking) offers an alternative to the conventional microalgal-oil production process, with significantly reduced nutrient, dewatering and cultivation costs. Here, we compare low shear column solvent extraction with high shear stirred tank solvent extraction to ascertain which is better suited to a repetitive extraction process using B. braunii and carry out a preliminary economic analysis on the nutrient costs and raceway pond area requirements once scaled to industrial production. Stirred tank extraction with heptane resulted in five times higher productivities than that of column solvent extraction. Using this to generate an extraction model we found a lipid productivity of 104 mg L-1 day-1 was possible, six times greater than that of previous repetitive extraction studies. Thanks to the high lipid content of the B. braunii biomass generated in the recovery phase, when scaled to open raceway ponds, a lipid productivity of 13.4 g m-2 day-1 can be predicted. With this productivity, an estimated combined carbon, nitrogen and phosphorus cost of $2.52 L-1 of oil produced and a cultivation pond area of 3.53 km2 (assuming an annual oil production of 15,900 m3 year-1) is predicted, corresponding to reductions when compared to conventional extraction of 40% and 50% respectively. This repetitive extraction process provides an alternative method for the production of 3rd generation biofuels without the need to harvest and dewater algal biomass with significant reductions in nutrient and pond area requirements.

Microalgae‐based biodiesel production in open raceway ponds using coal thermal flue gas: A case of West Bengal, India

AbstractIndia is one of the most populous countries and is the third largest greenhouse gas–emitting nation. Energy security is a serious issue for India as it relies heavily on fossil fuel imports. Biodiesel production using microalgae as feedstock can address both of these issues. In this study, the technical feasibility of microalgae‐based biodiesel production is carried out for a coal thermal power plant (i.e., Budge Budge Thermal Station) in the state of West Bengal, India, using a generic methodology. An oleaginous microalgae species that is tolerant toward flue gas was identified (i.e., Nannochloropsis sp). A 75‐acre open raceway microalgae production plant was designed keeping the costs, energy demand, and CO2 emissions low. The open raceway pond can use 38 tons of CO2, produce 19 tons of algal biomass, and treat 9320 m3 of wastewater per acre annually.