Puiman Lars, Almeida Benalcázar Eduardo, Picioreanu Cristian, Noorman Henk J, Haringa Cees
Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 Delft, The Netherlands.
Biological and Environmental Science and Engineering, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
Bioengineering (Basel). 2023 Apr 25;10(5):518. doi: 10.3390/bioengineering10050518.
In large-scale syngas fermentation, strong gradients in dissolved gas (CO, H) concentrations are very likely to occur due to locally varying mass transfer and convection rates. Using Euler-Lagrangian CFD simulations, we analyzed these gradients in an industrial-scale external-loop gas-lift reactor (EL-GLR) for a wide range of biomass concentrations, considering CO inhibition for both CO and H uptake. Lifeline analyses showed that micro-organisms are likely to experience frequent (5 to 30 s) oscillations in dissolved gas concentrations with one order of magnitude. From the lifeline analyses, we developed a conceptual scale-down simulator (stirred-tank reactor with varying stirrer speed) to replicate industrial-scale environmental fluctuations at bench scale. The configuration of the scale-down simulator can be adjusted to match a broad range of environmental fluctuations. Our results suggest a preference for industrial operation at high biomass concentrations, as this would strongly reduce inhibitory effects, provide operational flexibility and enhance the product yield. The peaks in dissolved gas concentration were hypothesized to increase the syngas-to-ethanol yield due to the fast uptake mechanisms in . The proposed scale-down simulator can be used to validate such results and to obtain data for parametrizing lumped kinetic metabolic models that describe such short-term responses.
在大规模合成气发酵过程中，由于局部传质和对流速率的变化，溶解气体（CO、H）浓度很可能出现强烈梯度。我们使用欧拉-拉格朗日计算流体动力学（CFD）模拟，在工业规模的外环气升式反应器（EL-GLR）中针对广泛的生物质浓度范围分析了这些梯度，同时考虑了CO对CO和H吸收的抑制作用。生命线分析表明，微生物很可能经历频繁（5至30秒）的溶解气体浓度振荡，振荡幅度达一个数量级。基于生命线分析，我们开发了一个概念性的缩尺模拟器（搅拌速度可变的搅拌釜式反应器），以在实验室规模上重现工业规模的环境波动。缩尺模拟器的配置可进行调整，以匹配广泛的环境波动。我们的结果表明，工业运行倾向于采用高生物质浓度，因为这将大大降低抑制作用，提供操作灵活性并提高产物产率。据推测，溶解气体浓度的峰值由于[具体内容缺失]中的快速吸收机制而提高了合成气到乙醇的产率。所提出的缩尺模拟器可用于验证此类结果，并获取用于参数化描述此类短期响应的集总动力学代谢模型的数据。
