Specific microalgae species are an adequate source of EPA and DHA and are able to provide a complete protein, which makes them highly interesting for human nutrition. However, microalgae cultivation has also been described to be energy intensive and environmentally unfavorable in pilot-scale reactors. Moreover, production in cold temperature zones has not been sufficiently investigated. In particular, the effects of tube materials and cultivation season length have rarely been previously investigated in the context of a comparative LCA of microalgae cultivation. A computational “top-down” model was conducted to calculate input flows for Nannochloropsis sp. and Phaeodactylum tricornutum cultivation in a hypothetical tubular photobioreactor. Cultivation processes were calculated according to detailed satellite climatic data for the chosen location in Central Germany. This model was applied to a set of different scenarios, including variations in photobioreactor material, tube diameter, microalgae species, and cultivation season length. Based on these data, a life cycle assessment (LCA) was performed following ISO standard 14040/44. The impact assessment comprised the global warming potential, acidification, eutrophication, cumulative energy demand, and water scarcity. The results showed that a long cultivation season in spring and fall was always preferable in terms of environmental impacts, although productivity decreased significantly due to the climatic preconditions. Acrylic glass as a tube material had higher environmental impacts than all other scenarios. The cultivation of an alternative microalgae species showed only marginal differences in the environmental impacts compared with the baseline scenario. Critical processes in all scenarios included the usage of hydrogen peroxide for the cleaning of the tubes, nitrogen fertilizer, and electricity for mixing, centrifugation, and drying. Microalgae cultivation in a tubular photobioreactor in a “cold-weather” climate for food is sustainable and could possibly be a complement to nutrients from other food groups. The added value of this study lies in the detailed description of a complex and flexible microalgae cultivation model. The new model introduced in this study can be applied to numerous other scenarios to evaluate photoautotrophic microalgae cultivation in tubular photobioreactors. Thus, it is possible to vary the facility location, seasons, scale, tube dimensions and material, microalgae species, nutrient inputs, and flow velocity. Moreover, single processes can easily be complemented or exchanged to further adjust the model individually, if, for instance, another downstream pathway is required.

特定的微藻物种是EPA和DHA的充足来源，并且能够提供完整的蛋白质，这使它们对于人类营养非常感兴趣。然而，在中试规模的反应堆中，微藻的培养也被认为是能源密集型的并且对环境不利。此外，尚未对低温区的生产进行充分研究。特别是，在比较性微藻培养的LCA的背景下，以前很少研究管材和培养季节长度的影响。进行了一个“自上而下”的计算模型，以计算Nannochloropsis sp的输入流量。和三角果蝇在假定的管状光生物反应器中进行培养。根据详细的卫星气候数据计算了德国中部所选地点的耕作过程。该模型应用于一组不同的场景，包括光生物反应器材料，管直径，微藻物种和栽培季节长度的变化。基于这些数据，遵循ISO标准14040/44进行了生命周期评估（LCA）。影响评估包括全球变暖潜力，酸化，富营养化，累积能量需求和水资源短缺。结果表明，尽管由于气候先决条件导致生产力显着下降，但从环境影响的角度来看，春季和秋季的栽培季节始终是首选。与其他所有方案相比，作为管材的丙烯酸玻璃对环境的影响更大。与基准情景相比，替代性微藻物种的种植仅显示出对环境影响的边际差异。在所有情况下，关键的过程都包括使用过氧化氢清洁管道，使用氮肥以及用电进行混合，离心和干燥。在“寒冷天气”的气候中，在管状光生物反应器中微藻的种植是可持续的，并且可能是其他食物营养的补充。这项研究的附加价值在于对复杂而灵活的微藻培养模型的详细描述。在这项研究中引入的新模型可以应用于许多其他方案，以评估管状光生物反应器中的光养自养微藻培养。因此，可以改变设施的位置，季节，规模，管子的尺寸和材料，微藻种类，营养输入和流速。此外，例如，如果需要其他下游途径，可以轻松地补充或交换单个过程以进一步单独调整模型。