Techno-economic assessment of microalgae cultivation in a tubular photobioreactor for food in a humid continental climate

Abstract

Fish as the primary source for the essential n − 3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) cannot cover the global demand for these important nutrients resulting in a supply gap of currently 1.1 million tons of EPA + DHA annually. A further exploitation of natural fish stocks is linked to great damage to ecosystems. Oleaginous microalgae are a natural source for EPA and DHA and could possibly contribute to closing this gap. The cultivation in photobioreactors (PBR) in a ‘cold-weather’ climate showed that microalgae compare favorably to aquaculture fish. The present study assesses the economic potential of microalgae for food in such system model. Techno-economic assessment was conducted on the basis of a dynamic system model for the cultivation of Nannochloropsis sp. in industrial scale in Central Germany over a time span of 30 years. The net present value (NPV) and return-on-investment (ROI) were obtained for a number of scenarios in which technic and economic parameters were altered. Taking the size of the PBR considered into account, the cultivation of Nannochloropsis sp. yielded a positive NPV of EUR 4.5 million after 30 years which translates to an annualized ROI of 1.87%. The sensitivity analysis overall resulted in annualized ROIs between 1.12 and 2.47%. Major expenditures comprised the PBR infrastructure, maintenance and labor cost. An extended cultivation season by four weeks was responsible for an NPV surplus of almost one third (32%). An increase in the selling price by 15% was responsible for a 47% higher NPV. In comparison with Atlantic salmon (Salmo salar) raised in aquaculture, EPA from Nannochloropsis sp. resulted in about halved cultivation costs (− 44 to − 60%). In this study we could show that microalgae from photoautotrophic cultivation not only have the potential to supply humans with essential nutrients, but they are also a lucrative investment, even in a ‘cold-weather’ climate where cultivation cannot take place year round. Graphic abstract

Total Phenolic Content, Biomass Composition, and Antioxidant Activity of Selected Marine Microalgal Species with Potential as Aquaculture Feed

“…Since phenolic compounds can be obtained in similar or higher amounts from readily available and inexpensive waste, developing a microalgal process for phenolics production should also target to other products in the context of a biorefinery. Under this scope, phenolics and other bioactive compounds from microalgae can be an excellent co-product of aquaculture feed, as has been recently suggested by techno-economic analysis [ 61 ].…”

Health Benefits, Food Applications, and Sustainability of Microalgae-Derived N-3 PUFA

“…WHO and other health organizations in various countries/regions recommend a dietary intake of EPA and DHA at a range of 250 to 1000 mg/day [113] and the most commonly recommended dose is 500 mg/day [9]. Fish, as the primary source of EPA and DHA, cannot meet the global demand, resulting in a gap of nearly 1.1 million tons annually [152]. A further exploitation of natural fish and other marine sources for EPA and DHA is linked to the damage of ecosystems.…”

“…A recent study assessed the economic potential of microalgae as food ingredients, based on a photobiorector system for the cultivation of Nannochloropsis sp. at the industrial scale in Central Germany over a time span of 30 years [152]. The cultivation in photobioreactors in a cold-weather climate showed that microalgae compared favorably to fish aquiculture.…”

“…Major expenditures comprised photobioreactor infrastructure, maintenance, and labor cost. Higher net present value and return-oninvestment are expected to increase substantially when the cultivation occurs in a region with warm climates and extended cultivation seasons [152].…”

Cell‐cultivated food production and processing: A review

“…A study on the economics of autotrophic cultivation of microalgae (Nannochloropsis sp.) in a photobioreactor (PBR) for food production was reported by Schade et al (2021). The production of microalgae in PBRs was chosen over open raceway ponds due to the decreased risks of contamination and higher environmental control in suboptimal climates.…”