BIOENERGY 2020+ GmbH, Inffeldgasse 21b, A-8010 Graz, Austria; University of Natural Resources and Life Sciences, Department for Agrobiotechnology, Institute of Environmental Biotechnology, Konrad Lorenz Str. 20, A-3430 Tulln, Austria; Institute for Environment and Food Security, Montfortstraße 4, 6900 Bregenz, Austria.
BIOENERGY 2020+ GmbH, Inffeldgasse 21b, A-8010 Graz, Austria; University of Natural Resources and Life Sciences, Department for Agrobiotechnology, Institute of Environmental Biotechnology, Konrad Lorenz Str. 20, A-3430 Tulln, Austria; NNFCC Ltd, Biocentre, York Science Park, Innovation Way, York, YO10 5DG, United Kingdom.
J Biotechnol. 2019 Apr 10;295:80-89. doi: 10.1016/j.jbiotec.2019.02.004. Epub 2019 Mar 7.
The microalga Acutodesmus obliquus was investigated as a feedstock in semi-continuously fed anaerobic digestion trials, where A. obliquus was co-digested with pig slurry and maize silage. Maize silage was substituted by both 10% and 20% untreated, and 20% ultrasonicated microalgae biomass on a VS (volatile solids) basis. The substitution of maize silage with 20% of either ultrasonicated and untreated microalgae led to significantly lower biogas yields, i.e., 560 dm³ kg VS in the reference compared to 516 and 509 dm³ kgVS for untreated and ultrasonicated microalgae substitution. Further, the viscosities in the different reactors were measured at an OLR of 3.5 g VS dm d. However, all treatments with microalgae resulted in significantly lower viscosities. While the mean viscosity reached 0.503 Pa s in the reference reactor, mean viscosities were 53% lower in reactors where maize was substituted by 20% microalgae, i.e. 0.239 Pa s, at a constant rotation speed of 30 rpm. Reactors where maize was substituted by 20% ultrasonicated microalgae had a 32% lower viscosity, for 10% microalgae substitution a decrease of 8% was measured. Decreased viscosities have beneficial effect on the bioprocess and the economy in biogas plants. Nonetheless, with regard to other parameters, no positive effect on biogas yields by partial substitution with microalgae biomass was found. The application of microalgae may be an interesting option in anaerobic digestion when fibrous or lignocellulosic substances lead to high viscosities of the digested slurries. High production costs remain the bottleneck for making microalgae an interesting feedstock.
斜生栅藻被用作半连续厌氧消化试验的原料，与猪粪和玉米青贮料一起共消化。以挥发性固体（VS）为基础，玉米青贮料分别被 10%和 20%未经处理的和 20%超声处理的微藻生物质替代。用 20%未经处理和超声处理的微藻中的任何一种替代玉米青贮料，都会导致沼气产量显著降低，即参考组为 560 dm³ kg VS，而未经处理和超声处理的微藻替代组分别为 516 和 509 dm³ kgVS。此外，在 OLR 为 3.5 g VS dm d 时，在不同的反应器中测量了粘度。然而，所有用微藻处理的方法都导致了明显较低的粘度。当参考反应器中的平均粘度达到 0.503 Pa s 时，在以 20%微藻替代玉米的反应器中，平均粘度降低了 53%，即 0.239 Pa s，在恒定的 30 rpm 转速下。以 20%超声处理的微藻替代玉米的反应器的粘度降低了 32%，而以 10%微藻替代时，粘度降低了 8%。降低的粘度对沼气工厂中的生物过程和经济性有有益的影响。尽管如此，就其他参数而言，用微藻生物质部分替代并没有发现对沼气产量有积极影响。在消化纤维或木质纤维素物质导致消化泥浆高粘度的情况下，微藻的应用可能是厌氧消化的一个有趣选择。高生产成本仍然是使微藻成为一种有吸引力的原料的瓶颈。
