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Maroušek J, Maroušková A, Gavurová B, Tuček D, Strunecký O. Competitive algae biodiesel depends on advances in mass algae cultivation. BIORESOURCE TECHNOLOGY 2023; 374:128802. [PMID: 36858122 DOI: 10.1016/j.biortech.2023.128802] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
The aim of this review was to study why, despite large investments in research and development, algae biodiesel is still not price competitive with fossil fuels. Microalgal production was confirmed to be a critical cost item (84 up to 93 %) for biodiesel regardless of the production technology. Techno-economic assessment revealed the main cost drivers during mass cultivation. It is argued that a breakthrough in the cultivation efficiency of microalgae is identified as a necessary condition for achieving price-competitive microalgal biodiesel. The key bottlenecks were identified as follows: (1) light and O2 concentration management; (2) overnight respiratory loss of oil. It is concluded that most of the research on microalgae biodiesel yields economically over-optimistic presumptions because it has been based on laboratory scale experiments with a low level of interdisciplinary overlap.
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Affiliation(s)
- Josef Maroušek
- Institute of Technology and Business in České Budějovice, Faculty of Technology, Okružní 517/10, České Budějovice 370 01, Czech Republic; University of South Bohemia in České Budějovice, Faculty of Agriculture, Studentská 1668, České Budějovice 370 05, Czech Republic.
| | - Anna Maroušková
- Institute of Technology and Business in České Budějovice, Faculty of Technology, Okružní 517/10, České Budějovice 370 01, Czech Republic
| | - Beata Gavurová
- Technical University of Kosice, Faculty of Mining, Ecology, Process Control and Geotechnologies, Letna 9, Košice 042 00, Slovakia
| | - David Tuček
- Tomas Bata University in Zlín, Faculty of Management and Economics, Mostní 5139, Zlín 760 01, Czech Republic
| | - Otakar Strunecký
- Institute of Technology and Business in České Budějovice, Faculty of Technology, Okružní 517/10, České Budějovice 370 01, Czech Republic; University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Institute of Aquaculture and Protection of Waters, Na Sádkách 1780, 370 05 České Budějovice, Czech Republic
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Jouannais P, Hindersin S, Löhn S, Pizzol M. Stochastic LCA Model of Upscaling the Production of Microalgal Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10454-10464. [PMID: 35763500 DOI: 10.1021/acs.est.2c00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microalgae are currently being investigated for their promising metabolites but assessing the environmental impact of producing these compounds remains a challenge. Microalgae cultivation performance results from the complex interaction of biological, technological, geographical, and physical factors, which bioengineers try to optimize during the upscaling process. The path from the discovery of a microalgal compound to its industrial production is therefore highly uncertain. Nonetheless, it is key to anticipate the potential environmental impacts associated with the future production of a microalgal target compound. This is achieved in this study by developing an ex-ante, parameterized, and consequential LCA model that performs dynamic simulations of microalgae cultivation. The model is applied to calculate the environmental impacts of 9000 stochastically generated combinations of photobioreactor geometries and operational setups. The demonstration of the model is done for a fictive microalgal strain, parameterized to resemble Chlorella vulgaris, and a fictive target compound assumed to be a carbohydrate. The simulations are performed in Aalborg, Denmark, and Granada, Spain to appreciate geographical variability, which highly affects the requirements for thermoregulation. Open-source documentation allows full reproducibility and further use of the model for the ex-ante assessment of microalgal products.
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Affiliation(s)
- Pierre Jouannais
- Department of Planning, Aalborg University, Rendsburggade 14, 9000 Aalborg, Denmark
| | - Stefan Hindersin
- Sea & Sun Technology LTD, Arndtstraße 9 -13, 24610 Trappenkamp, Germany
| | - Sarah Löhn
- Institute of Environmental Technology and Energy Economics, Waste Resource Management, Hamburg University of Technology, Blohmstraße 15, 21079 Hamburg, Germany
| | - Massimo Pizzol
- Department of Planning, Aalborg University, Rendsburggade 14, 9000 Aalborg, Denmark
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Modeling and Simulation of Photobioreactors with Computational Fluid Dynamics—A Comprehensive Review. ENERGIES 2022. [DOI: 10.3390/en15113966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Computational Fluid Dynamics (CFD) have been frequently applied to model the growth conditions in photobioreactors, which are affected in a complex way by multiple, interacting physical processes. We review common photobioreactor types and discuss the processes occurring therein as well as how these processes have been considered in previous CFD models. The analysis reveals that CFD models of photobioreactors do often not consider state-of-the-art modeling approaches. As a comprehensive photobioreactor model consists of several sub-models, we review the most relevant models for the simulation of fluid flows, light propagation, heat and mass transfer and growth kinetics as well as state-of-the-art models for turbulence and interphase forces, revealing their strength and deficiencies. In addition, we review the population balance equation, breakage and coalescence models and discretization methods since the predicted bubble size distribution critically depends on them. This comprehensive overview of the available models provides a unique toolbox for generating CFD models of photobioreactors. Directions future research should take are also discussed, mainly consisting of an extensive experimental validation of the single models for specific photobioreactor geometries, as well as more complete and sophisticated integrated models by virtue of the constant increase of the computational capacity.
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Lab-scale photobioreactor systems: principles, applications, and scalability. Bioprocess Biosyst Eng 2022; 45:791-813. [PMID: 35303143 PMCID: PMC9033726 DOI: 10.1007/s00449-022-02711-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/14/2022] [Indexed: 12/20/2022]
Abstract
Phototrophic microorganisms that convert carbon dioxide are being explored for their capacity to solve different environmental issues and produce bioactive compounds for human therapeutics and as food additives. Full-scale phototrophic cultivation of microalgae and cyanobacteria can be done in open ponds or closed photobioreactor systems, which have a broad range of volumes. This review focuses on laboratory-scale photobioreactors and their different designs. Illuminated microtiter plates and microfluidic devices offer an option for automated high-throughput studies with microalgae. Illuminated shake flasks are used for simple uncontrolled batch studies. The application of illuminated bubble column reactors strongly emphasizes homogenous gas distribution, while illuminated flat plate bioreactors offer high and uniform light input. Illuminated stirred-tank bioreactors facilitate the application of very well-defined reaction conditions. Closed tubular photobioreactors as well as open photobioreactors like small-scale raceway ponds and thin-layer cascades are applied as scale-down models of the respective large-scale bioreactors. A few other less common designs such as illuminated plastic bags or aquarium tanks are also used mainly because of their relatively low cost, but up-scaling of these designs is challenging with additional light-driven issues. Finally, this review covers recommendations on the criteria for photobioreactor selection and operation while up-scaling of phototrophic bioprocesses with microalgae or cyanobacteria.
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Bright as day and dark as night: light-dependant energy for lipid biosynthesis and production in microalgae. World J Microbiol Biotechnol 2022; 38:70. [PMID: 35257233 DOI: 10.1007/s11274-022-03245-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/08/2022] [Indexed: 10/18/2022]
Abstract
Microalgae are photosynthetic organisms functioning as the green bio-factories for various pharmaceutical and biofuel products. To date, numerous attempts have been carried out to manipulate culture conditions to maximize the production of the desired metabolites. Because light is the energy source of microalgae for their growth and metabolites biosynthesis, it has been one of the most investigated variables emphasized on the deep understanding of how microalgae respond towards light changes as an external stimulus. This review discusses the effects of different light sources, light intensities, light wavelengths and length of photoperiod on various microalgae species, especially in terms of biomass and lipid productivity. Additionally, the relationship between photoregulation processes and lipid productivity of microalgae are also deliberated. The current available approaches of microalgae mass cultivation, including different types of open and closed systems are recapitulated with the intention to highlight the significant insights for the design of future photoreactors.
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Todisco E, Louveau J, Thobie C, Dechandol E, Hervé L, Titica M, Pruvost J. A dynamic model for temperature prediction in a façade-integrated photobioreactor. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.03.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
There are two main approaches for cultivating microalgae on a large scale: open or closed cultivation. The main difference between open and closed systems is related to how they operate (e.g., cooling and gas exchange), vulnerability for outside influence (e.g., rainwater and introduction of unwanted species), and costs for building and operating the system. In this chapter we introduce the main cultivation technologies and discuss their main advantages and disadvantages when cultivating microalgae.
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Benvenuti G, Ruiz J, Lamers PP, Bosma R, Wijffels RH, Barbosa MJ. Towards microalgal triglycerides in the commodity markets. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:188. [PMID: 28725268 PMCID: PMC5514516 DOI: 10.1186/s13068-017-0873-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/11/2017] [Indexed: 05/04/2023]
Abstract
BACKGROUND Microalgal triglycerides (TAGs) hold great promise as sustainable feedstock for commodity industries. However, to determine research priorities and support business decisions, solid techno-economic studies are essential. Here, we present a techno-economic analysis of two-step TAG production (growth reactors are operated in continuous mode such that multiple batch-operated stress reactors are inoculated and harvested sequentially) for a 100-ha plant in southern Spain using vertically stacked tubular photobioreactors. The base case is established with outdoor pilot-scale data and based on current process technology. RESULTS For the base case, production costs of 6.7 € per kg of biomass containing 24% TAG (w/w) were found. Several scenarios with reduced production costs were then presented based on the latest biological and technological advances. For instance, much effort should focus on increasing the photosynthetic efficiency during the stress and growth phases, as this is the most influential parameter on production costs (30 and 14% cost reduction from base case). Next, biological and technological solutions should be implemented for a reduction in cooling requirements (10 and 4.5% cost reduction from base case when active cooling is avoided and cooling setpoint is increased, respectively). When implementing all the suggested improvements, production costs can be decreased to 3.3 € per kg of biomass containing 60% TAG (w/w) within the next 8 years. CONCLUSIONS With our techno-economic analysis, we indicated a roadmap for a substantial cost reduction. However, microalgal TAGs are not yet cost efficient when compared to their present market value. Cost-competiveness strictly relies on the valorization of the whole biomass components and on cheaper PBR designs (e.g. plastic film flat panels). In particular, further research should focus on the development and commercialization of PBRs where active cooling is avoided and stable operating temperatures are maintained by the water basin in which the reactor is placed.
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Affiliation(s)
- Giulia Benvenuti
- Bioprocess Engineering, AlgaePARC, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Jesús Ruiz
- Algades–Alga, Development, Engineering and Services, S.L., c. Margaritas, Costa Oeste, El Puerto de Santa María, 11500 Cádiz, Spain
| | - Packo P. Lamers
- Bioprocess Engineering, AlgaePARC, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Rouke Bosma
- Bioprocess Engineering, AlgaePARC, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - René H. Wijffels
- Bioprocess Engineering, AlgaePARC, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
- Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway
| | - Maria J. Barbosa
- Bioprocess Engineering, AlgaePARC, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands
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