Large-scale Photobioreactors Research Articles

The Use of the Autotrophic Culture of Arthrospira platensis for CO2 Fixation from Biogas Combustion

The increased concentration of CO2 in the atmosphere has a strong impact on global warming. Therefore, efficient technologies must be used to reduce CO2 emissions. One of the methods is the biofixation of CO2 by microalgae and cyanobacteria. This is now a widely described technology that can improve the economics of biomass production and reduce CO2 emissions. There are no reports on the possibility of using it to clean exhaust gases from biogas combustion. The aim of the research was to determine the possibility of using Arthrospira platensis cultures to remove CO2 from biogas combustion. The efficiency of biomass production and the effectiveness of biological CO2 fixation were evaluated. The use of exhaust gases led to a more efficient increase in cyanobacterial biomass. The growth rate in the exponential phase was 209 ± 17 mgVS/L·day, allowing a biomass concentration of 2040 ± 49 mgVS/L. However, the use of exhaust gases led to a decrease in the pH of the culture medium and a rapid decline in the Arthrospira platensis population. The cyanobacteria effectively fixed CO2, and its concentration was limited from 13 ± 1% to 1.3 ± 0.7%. There was no influence of the exhaust gases on changes in the qualitative composition of the cyanobacterial biomass. In the culture fed with exhaust gas, the A. platensis population quickly entered the death phase, which requires close monitoring. This is an important indication for potential operators of large-scale photobioreactors.

Exploring advanced phycoremediation strategies for resource recovery from secondary wastewater using a large scale photobioreactor

This study aimed to investigate the operation of a 1000L microalgae-based membrane photobioreactor system in a greenhouse for continuous secondary wastewater treatment using Desmodesmus sp., a green microalgae strain originally isolated from a German sewage plant. The research spanned both summer and winter seasons, seeking to comprehend key trends and optimization strategies. Maintaining low cell concentrations in the photobioreactor during periods of light inhibition proved advantageous for nutrient uptake rates. Effective strategies for enhancing algae-based wastewater treatment included cell mass recycling, particularly during periods of high light availability. In comparison to conventional continuous cultivation methods, employing cell recycling and high dilution rates during times of abundant light, alongside using low cell concentrations and dilution rates during light inhibition, resulted in an 80 % and 10 % increase in overall biomass productivity during summer and winter, respectively. Furthermore, nitrogen/phosphorus (N/P) removal rates exhibited a 23 % improvement during winter, while remaining unchanged in summer.

Production of the dinoflagellate Amphidoma languida in a large scale photobioreactor and structure elucidation of its main metabolite AZA-39

Shellfish contamination with azaspiracids (AZA) is a major and recurrent problem for the Irish shellfish industry. Amphidoma languida, a small thecate dinoflagellate of the family Amphidomataceae, is widely distributed in Irish coastal waters and is one of the identified source species of azaspiracids. Irish and North Sea strains of Am. languida have been found to produce as major metabolites AZA-38 and -39 whose structures have only been provisionally elucidated by mass spectrometry and their toxic potential is currently unknown. In order to provide pure AZA-38 and -39 for subsequent structural and toxicological analyses, we present the first successful large-scale culture of Am. languida. A 180 L in house prototype bioreactor was used for culture growth and harvesting in semi-continuous mode for two months. Two different runs of the photobiorector with different light and pH setting showed the highest toxin yield at higher light intensity and slightly higher pH. AZA-38 and -39 cell quota were measured throughout the complete growth cycle with AZA-39 cell quota increasing in proportion to AZA-38 at late stationary to senescence phase. Over two experiments a total of 700 L of culture was harvested yielding 0.45 mg of pure AZA-39. The structure of AZA-39 was elucidated through NMR data analyses, which led to a revision of the structure proposed previously by mass spectrometry. While the spirotetrahydrofuran/tetrahydrofuran of rings A and B has been confirmed by NMR for AZA-39, a methyl is still present in position C-14 and the carboxylic acid chain is different from the structure proposed initially.

Chlorella vulgaris acclimated cultivation under flashing light: An in-depth investigation under iso-actinic conditions

Chlorella vulgaris was cultivated under continuous and flashing light. Special care was taken in designing a culture device ensuring iso-actinic conditions, and a protocol ensuring acclimation. Continuous light cultures were carried out from 25 to 800 μmolPhotonPAR/m2/s. They served as control. Flashing light (square shape, duty cycle of 0.5) was applied with four frequencies: 0.1, 1, 10, and 100 Hz. The monitored outcomes were the culture growth rate, cell pigment content (chlorophylls, lutein, violaxanthin, and zeaxanthin), and photosynthetic apparatus (Fv/Fm and light curve). Acclimated cultures under continuous light showed photolimitation and photosaturation phases, without sign of photoinhibition, even under 800 μmolPhotonPAR/m2/s. Frequencies of 1 Hz and above induced little to no difference between cells acclimated under flashing light and their control (same amount of continuous light). Indeed, cells exhibited the same growth rate, similar absolute pigment composition, and light curve characteristics. They only differ by a lower chlorophyll b to chlorophyll a ratio at high intensity, suggesting an acclimation strategy favoring an increased number of photosystems instead of an increased light-harvesting capability. Conversely, cells cultivated at 0.1 Hz showed a lower growth rate and an incapacity to adapt efficiently to high incident illumination. From a biotechnological perspective, these results support the idea that high frequency flashing light, in the tested conditions, does not bring benefits with respect to the same average amount of continuous light. Consequently, it may ease the design of large scale photobioreactors, where light/dark cycles are inevitable.

Development of a limitless scale-up photobioreactor for highly efficient photosynthesis-based polyhydroxybutyrate (PHB)-producing cyanobacteria

Photosynthetic polyhydroxybutyrate (PHB) production is an attractive technology for realizing a sustainable society by simultaneously producing useful biodegradable plastics and mitigating CO2. It is necessary to establish an economical large-scale photobioreactor (PBR) capable of effectively cultivating photosynthetic microorganisms such as cyanobacteria. A roll-to-roll winding machine/heat-sealer hybrid system for fabricating an easy-to-scale-up PBR was developed in the present study. The baffle design was optimized to facilitate mass transfer within the PBR, and the operating conditions of the gas sparger were investigated to maximize the CO2 transfer efficiency. The newly developed PBR was able to produce biomass of PHB content 10.7 w/w% at a rate of 6.861 g m−2 d−1, 21 % improved biomass productivity compared with the existing PBR. It was confirmed that biomass productivity was maintained even when PBR was scaled up to 2 tons. Consequently, the newly developed PBR is expected to improve the feasibility of photosynthetic PHB production.

Statistical optimization and formulation of microalga cultivation medium for improved omega 3 fatty acid production.

Microalgae are considered a rich source of high-value metabolites with an array of nutraceutical and pharmaceutical applications. Different strategies have been developed for cultivating microalgae at large-scale photobioreactors but high cost and low productivity are the major hurdles. Optimizing the composition of media for the cultivation of microalgae to induce biomass production and high-value metabolite accumulation has been considered as an important factor for sustainable product development. In this study, the effect of plant growth regulators together with basal microalgal cultivation medium on biomass, total lipid, and EPA production was studied using the Plackett–Burman model and Response surface methodology. The traditional one-factor-at-a-time optimization approach is laborious, time-consuming, and requires more experiments which makes the process and analysis more difficult. The Designed PB model was found to be significant for biomass (396 mg/L), lipid (254 mg/L), and EPA (5.6%) production with a P value < 0.05. The major objective of this study is to formulate a medium for EPA production without compromising the growth properties. Further, we had formulated a new media using RSM to achieve the goal and the significant variables selected were NaNO3, NaH2PO4, and IAA and was found to be significant with 16.72% EPA production with a biomass production of 893 mg/L with a P value < 0.05. The formulated medium can be used in large-scale cultivation systems which can enhance biomass production as well as the omega 3 fatty acid production in marine microalgae Nannochloropsis oceanica.Supplementary InformationThe online version contains supplementary material available at 10.1007/s43393-021-00069-1.

Potential of Producing Flavonoids Using Cyanobacteria As a Sustainable Chassis.

Numerous plant secondary metabolites have remarkable impacts on both food supplements and pharmaceuticals for human health improvement. However, higher plants can only generate small amounts of these chemicals with specific temporal and spatial arrangements, which are unable to satisfy the expanding market demands. Cyanobacteria can directly utilize CO2, light energy, and inorganic nutrients to synthesize versatile plant-specific photosynthetic intermediates and organic compounds in large-scale photobioreactors with outstanding economic merit. Thus, they have been rapidly developed as a "green" chassis for the synthesis of bioproducts. Flavonoids, chemical compounds based on aromatic amino acids, are considered to be indispensable components in a variety of nutraceutical, pharmaceutical, and cosmetic applications. In contrast to heterotrophic metabolic engineering pioneers, such as yeast and Escherichia coli, information about the biosynthesis flavonoids and their derivatives is less comprehensive than that of their photosynthetic counterparts. Here, we review both benefits and challenges to promote cyanobacterial cell factories for flavonoid biosynthesis. With increasing concerns about global environmental issues and food security, we are confident that energy self-supporting cyanobacteria will attract increasing attention for the generation of different kinds of bioproducts. We hope that the work presented here will serve as an index and encourage more scientists to join in the relevant research area.

Optimization of biomass production from Stichococcous sp. biofilms coupled to wastewater treatment

Microalgae have been extensively used as animal feedstock and for the production of high-added value bioproducts, such as pigments and biodiesel. A promising strategy to simplify biomass recovery is by growing microalgae on flat biofilms, from where biomass may be easily harvested. Initially, the microalgae Stichococcus sp. was grown in photo-bioreactors, on seawater enriched with inorganic salts, on three different materials: ceramic tile, HD-polyethylene and sandblasted-glass, the latter of which exhibited the highest yield (up to 0.86 ± 0.02 mg cm−2 after 18 days cultivation period). Thereafter, the microalgae were grown on seawater enriched with winery-wastewater, applying nitrogen starvation during the last 2 days of cultivation, indicating biomass production of 1.00 ± 0.01 mg cm−2 (seawater plus organic carbon) to 1.30 ± 0.03 mg cm−2 (seawater plus organic carbon plus 2 days nitrogen starvation) to 1.43 ± 0.03 mg cm−2 (seawater plus inorganic carbon plus organic carbon plus 2 days nitrogen starvation). Trials on large scale photo-bioreactors confirmed the remediation potential of Stichococcus sp. for the treatment of winery-wastewater, while the organic carbon in wastewater boosted the yield of biomass production. Finally, the potential biomass yield of an industrial scale plant, treating winery-wastewater, was calculated to yield between 25−32 kg biomass (dry-basis) per 1000 m2 of shallow pond type reactor, per 18 days cultivation.

Innovative large-scale photobioreactor for coal propelled power plant effluents treatment

This paper presents a phycoremediation technology application for effective wastewater treatment of two Israeli coal propelled power plants, one in Ashkelon (Rothenberg) and the second in Hadera (Orot Rabin). The technology is based on a new photobioreactor (PBR) at the heart of a biological integrative pollution prevention and control (Bio-IPPC) system. Unlike other known tubular and flat plate PBRs that are applicable in small Wastewater Treatment Plants (WWTP), this special PBR can be applied in large-scale domestic and industrial WWTPs. The unique PBR interior configuration, which includes multiple high porous polypropylene beds, enables the system to handle pollutants from both gaseous and aquatic effluents. Furthermore, while most existing algal-based technologies preserve cultured strains, this setup relies on WWTP habitat endemic flora. In the pilots of both power plants, the native biomass was single cyanobacteria Synechocystis salina, although the PBR photosynthetic composition can include multiple species of mixotrophic and/or autotrophic microorganisms. The results show that the photosynthetic biomass that grew on the PBR PP beds effectively assimilated the biomass nutrients such as nitrogen, phosphorous, magnesium, boron and calcium, and the toxic elements strontium and fluoride. Moreover, the system also mitigated greenhouse gas emission by the assimilation of bicarbonate (HCO3−) from the aquatic phase and CO2 from the gas phase.

Production optimisation of Tisochrysis lutea as a live feed for juvenile Sydney rock oysters, Saccostrea glomerata, using large-scale photobioreactors

The aquaculture industry uses microalgae as a live feed for juvenile oysters in hatcheries to meet their nutritional requirements, including their need for several essential Poly Unsaturated Fatty Acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The mass culture of microalgae is not only a major bottleneck for the production of juvenile oysters, but also a significant cost, accounting for 20–50% of hatchery operating costs. Currently, low biomass concentrations, high production costs and poor cultivation systems limit the quantity and quality of microalgae feed. This study focused on Tisochrysis lutea, a microalgae species commonly used in aquaculture, and we assessed the potential of photobioreactors with an improved light source and CO2 input to increase biomass production and improve biochemical composition of algal feed. Two photobioreactor systems were compared: the current industry set up (DPI) comprising fluorescent lighting and minimal CO2 input versus an optimized system utilising LEDs and increased CO2. Cultures of T. lutea were monitored over a 12-day growth period and harvested on day 14 for biochemical analysis. Final cell density was significantly higher in the optimized system relative to the conventional culture systems (6.2 × 106 cells / mL versus 3.7 × 106 cells / mL, respectively). The biochemical profile of T. lutea was not significantly different between the two photobioreactors systems. The algal biomass produced during this comparative experiment was used in a feeding trial on oyster spat, Saccostrea glomerata. Spat fed with algae produced in optimized vs conventional photobioreactors showed no significant difference in growth, but oyster spat fed with T. lutea grown in optimized photobioreactors did show a significant increase in their EPA content. Overall, our results contribute to our understanding of how altered culture conditions affect microalgal production and biochemical composition, and subsequently of oyster spat. This study further supports the potential of LEDs to reduce operating costs for oyster hatcheries but also to significantly improve microalgae yield with no negative effect on the condition of oyster spats production.

Design and performance of a low-cost, automated, large-scale photobioreactor for microalgae production

Microalgae feed production is a major cost in bivalve aquaculture. Its efficiency is increased by scaling it up under automated control of environmental conditions. The initial cost of commercially available systems can be prohibitive. Therefore, a large volume full-scale photobioreactor built of low-cost, readily available materials was developed and tested. A cone-bottom, polyethylene tank was internally illuminated with submersible fluorescent lamps and equipped with a monitoring and control system that measured temperature, pH and optical density of the microalgal culture. Injection of CO2 was automated to maintain pH within a target range. System performance was evaluated by growing four batch cultures of Tetraselmis chuii. Temperature inside the photobioreactor was 29.5 ± 2.38 °C (mean ± SD, range 21−35 °C) and pH was 7.56 ± 0.87 (mean ± SD, range 5.29–8.97). Optimal harvest time was after 300 h (12.5 days) of growth, yielding 1700 L of microalgae at a density of 2500 cells/ μl (1200 cells/ μl/ m2 illuminated surface area). With 24 h illumination, the fluorescent lights, air pump and monitoring/ control device consumed 14.9, 1.9 and 0.1kwh/ day, respectively. Assuming the microalgae are harvested at their optimal density after 12.5 days, each batch would consume 211kwh or 0.124kwh/ liter. The photobioreactor described provides an economical option for growing large amounts of microalgae for aquaculture feed and other purposes.

Transcriptomic and metabolomic adaptation of Nannochloropsis gaditana grown under different light regimes

Omic technologies are a major source of information in understanding the cellular processes while their employment for studying microalgal biomass and productivity is rapidly expanding. Microalgae are known for their complex cellular metabolism. Environmental conditions affect intensely both their metabolic and transcriptomic profiles, resulting in production of numerous compounds with applications in pharmaceuticals, cosmetics, nutrition and biofuel. In an attempt to detect global changes occurring during environmental light alteration, an integrated omics approach was employed while the results were evaluated using different statistical approaches. An RT-qPCR based platform was utilized for the targeted transcript profiling of Nannochloropsis gaditana genes involved in primary and secondary metabolism, while the metabolite profiles were analyzed by GC–MS and GC-FID analytical methods. The combined transcriptomic and metabolomic results revealed extensive metabolic adaptations triggered by different chromatic qualities of light. In summary, an overall induction in both transcripts and metabolites, involved mainly in amino acid metabolism, was observed under red filtered light. Blue filtered light provoked decreased carbohydrate concentration but elevated polyunsaturated fatty acids content. Moreover, green filtered light induced the lowest responses in metabolite and gene transcript levels, indicating that its photons are poorly absorbed by N. gaditana. The current work suggests that spectral light changes leading to biochemical and metabolic manipulation of microalga N. gaditana can be accomplished by light filtering of solar irradiance, a cost-effective method which could be routinely applied in large scale photobioreactor cultivating systems.

Modeling and Experimental Investigation of the Effect of Nitrogen Starvation and Ph Variation on the Cultivation of the Extremophile Microalga Coccomyxa Melkonianii Scca048.

The effects of nitrogen concentration and pH on the growth kinetics of the extremophile microalgal strain Coccomyxa melkonianii SCCA 048 in multiwell and batch photobioreactors are investigated in this work. Moreover, the experimental results were successfully interpreted by a simple, mathematical model which represents a starting point towards the development of a suitable tool for the design, control, and optimization of large scale photobioreactors where C. melkonianii would be cultivated. On the basis of fatty acids methyl esters (FAMEs) profile, potential properties of biodiesel have been predicted through suitable software.

Identification of the key structural parameters for the design of a large-scale PBR

Although Photobioreactors (PBRs) are designed for industrial or experimental purposes, there are no standards for their design. PBRs are usually designed on the basis of the subjective decisions of researchers or producers, and most studies have examined small-scale PBRs. Furthermore, although it is important to enlarge the PBRs to obtain economic feasibility for microalgae production, the influence of each structural parameter on productivity in a large-scale PBR has not, to date, been fundamentally analysed. In this study, microalgae productivity according to the structural parameters (baffle and nozzles) was calculated and analysed using computational fluid dynamics (CFD) and the biomass production prediction grafting mixing and growth (BPMG) model. The influence of the structural parameters was then observed using statistical analysis. From simulation results, the microalgae productivity increased up to 90% depending on the installation condition of the baffle, although all the installation conditions of the baffle did not have a positive effect on the microalgae productivity. The installation depth (Bid) and the bottom clearance (Bc) values of the baffle as the main effects on the microalgae productivity were significant at the 99.9% confidence level. In addition, the influence of each structural parameter on the improvement of the microalgae productivity was evaluated, such that the t-values of the Bid, the Bc, and the number of nozzles (Nn) were found to be −8.437∗∗∗, −5.346∗∗∗, and 1.975, respectively. The interaction effect between the Bid and the Bc of the baffle showed a significant difference at the 95% confidence interval.

Produktivitas Minyak dan Kandungan Asam Lemak Thalassiosira Sp. yang Dikultivasi dengan Makronutrien Pupuk

: Previous study showed that the diatom Thalassiosira sp. was potential as a source of biodiesel fuel from lipids (oils). To determine biomass productivity as well as oil productivity in large-scale outdoor photobioreactors, the present study investigated the biomass production and optimization of growth macronutriens medium composition from fertilizers. The oils were extracted in chloroform: methanol (1:1) and analyzed by the GC-FID method. The results showed that the best medium composition to grow algal cells contained fertilizers of TSP-36 and Si-P-(PG) with a final concentration of each 10 mg/L with the highest cell density was 3.00 × 10 6 cells/mL and 4.90 × 10 6 cells/mL, respectively. The average of biomass productivity as wel as and oil productivity of Thalassiosira sp. cultivated in the outdoor photobioreaktors was 0.08 g/L culture/d and 22.50 µL/L culture/d, respectively . Thalassiosira sp. oil contained fatty acids of 0.30 mg/g capric acid (C10:0), 0.18 mg/g lauric acid (C12:0), 0.23 mg/g palmitic acid (C16:0), 0.50 mg/g stearic acid (C18:0), and 0.52 mg/g oleic acid (C18:1).

Growth of algal biomass in laboratory and in large-scale algal photobioreactors in the temperate climate of western Germany

Growth of Chlorella vulgaris was characterized as a function of irradiance in a laboratory turbidostat (1L) and compared to batch growth in sunlit modules (5–25L) of the commercial NOVAgreen photobioreactor. The effects of variable sunlight and culture density were deconvoluted by a mathematical model. The analysis showed that algal growth was light-limited due to shading by external construction elements and due to light attenuation within the algal bags. The model was also used to predict maximum biomass productivity. The manipulative experiments and the model predictions were confronted with data from a production season of three large-scale photobioreactors: NOVAgreen (<36,000L), IGV (2,500–3,500L), and Phytolutions (28,000L). The analysis confirmed light-limitation in all three photobioreactors. An additional limitation of the biomass productivity was caused by the nitrogen starvation that was used to induce lipid accumulation. Reduction of shading and separation of biomass and lipid production are proposed for future optimization.

PhotoBioLib: A Modelica library for modeling and simulation of large-scale photobioreactors

Abstract This paper presents PhotoBioLib , a library developed in Modelica language for modeling and simulation of industrial tubular photobioreactors without necessity of a previous knowledge of programming neither the involved dynamics. Therefore, it provides models very similar to the real ones, with a high configuration potential, interconnection possibilities with other libraries and a high simulation speed. The library has been validated with real data.

Photonic Application of Diatom Frustules

Diatoms are unicellular aquatic microalgae possessing amazing self-assembled ordered micro-and nanoporous hierarchical silica cell walls called frustules. The quasi-periodic and highly regular pore patterns on the diatom surface are very attractive for applications based on optical and photonic properties of materials. The present contribution reports on pioneering research aimed at explore the multiple scattering and localization of light shown by diatom frustules in order to amplify their photoluminescence in a random laser (RL), as this technology is highly attractive for medical diagnostics and other advanced applications. RL is a special type of laser in which the optical feedback is due to light scattering in an amplifying medium instead of a conventional optical cavity. We have studied a set of selected frustules with different shapes and pore patterns, obtained from diatom cultivation in large scale photobioreactors, for comparative analysis of their random lasing effect in the bioscaffold soaked with organic dyes having luminescence in the visible range. Taking advantage from a multidisciplinary approach combining expertise from biology, physics and materials sciences, relying on high-resolution instrumentation and advanced algal cultivation equipment the results about random laser emission in the composite material were obtained. This will allow going ahead in the research aimed to the application to photonic devices in the field of medicine and medical diagnostic.

Multi-objective exergetic optimization of continuous photo-biohydrogen production process using a novel hybrid fuzzy clustering-ranking approach coupled with Radial Basis Function (RBF) neural network

This work was focused on the development of a novel hybrid fuzzy clustering-ranking approach coupled with radial basis function (RBF) neural network for the optimization of the key operational parameters for hydrogen production from photo-fermentation. The bioconversion of syngas to hydrogen via water-gas shift (WGS) reaction was carried out using the light-dependent microorganism Rhodospirillum rubrum and acetate as the sole carbon source. The RBF neural network was used to correlate exergetic outputs (normalized exergy destruction as well as rational and process exergetic efficiencies) to two exogenous input variables (culture agitation speed and syngas flow rate). The developed RBF model was interfaced with the proposed hybrid fuzzy clustering-ranking algorithm to simultaneously maximize the rational and process exergetic efficiencies and minimize the normalized exergy destruction. Moreover, the conventional fuzzy optimization algorithm was applied in order to assess the capability of the proposed approach over the existing methods for multi-objective optimization of complex biofuel production systems such as a continuous photobioreactor with respect to the sustainability and productivity issues. Once the development of the objective functions were carried out using RBF Neural Networks, the proposed algorithm was able to identify the optimum exergetically-sustainable operational parameters of carbon monoxide fermentation to biohydrogen with 20 clusters. This corresponded to the syngas flow rate of 13.68 mL/min and culture agitation speed of 348.62 rpm yielding the process exergetic efficiency of 16.46%, rational exergetic efficiency of 91.59%, and normalized exergy destruction of 2.14. The predicted optimum values by the proposed algorithm in this study were more suitable compared with the conventional fuzzy method. Therefore, the novel algorithm developed in this study may be a promising approach for navigation of the most cost-effective and environmental friendly operational parameters for fermentative hydrogen production from pilot and large scale photobioreactors.

Exergy-based sustainability assessment of continuous photobiological hydrogen production using anaerobic bacterium Rhodospirillum rubrum

The present research work was aimed at analyzing a continuous photobioreactor for hydrogen production from syngas via Rhodospirillum rubrum from exergetic point of view. Exergy balance equation was developed for the investigated photobioreactor based on both conventional exergy and eco-exergy concepts in order to determine its exergetic performance parameters. Two new exergetic criteria called the process exergetic efficiency and normalized exergy destruction were also introduced in order to maximize biohydrogen production and minimize resources destruction. The results obtained showed that the process exergy efficiency, a decision making parameter, varied between 14.71–22.90% and 14.71–22.84% using the conventional exergy and eco-exergy approaches, respectively. The minimum normalized exergy destruction was found to be 0.97 using both approaches. In general, no noticeable changes were observed in the conventional exergetic and eco-exergetic performance parameters of the bioreactor over 540 h of continuous operation. Nevertheless, eco-exergetic analysis owing to the inclusion of the work of information embedded in the genomes of living organisms is still recommended for improving the design features of photobioreactors for hydrogen production. The outcomes of the present study could provide practical insights to engineers and researchers dealing with analysis, design, development, optimization, and improvement of large-scale photobioreactors for hydrogen production.