The high substrate variability and complexity of fermentation media derived from lignocellulosic feedstock affects the concentration profiles and the length of the fermentation. Failing to account for such variability raises operational and scheduling issues and affects the overall performance of these processes. In this work, a hybrid soft sensor was developed to monitor and forecast the evolution of cellulose-to-ethanol fermentation. The soft sensor consisted of two modules (a data-driven model and a kinetic model) connected sequentially. The data-driven module used a partial-least-squares model to estimate the current state of glucose from spectroscopic data. The kinetic model was recursively fitted to known concentrations of glucose to update the long-horizon predictions of glucose, xylose, and ethanol. This combination of real-time data update from an actual fermentation process to a high-fidelity kinetic model constitutes the basis of the digital twin concept and allows for a better real-time understanding of complex inhibition phenomena caused by different inhibitors commonly found in lignocellulosic feedstocks. The soft sensor was experimentally validated with three different cellulose-to-ethanol fermentations and the results suggested that this method is suitable for monitoring and forecasting fermentation when the measurements provide reasonably good estimates of the real state of the system. These results would allow the flexibility of the operation of cellulosic processes to be increased, and would permit the scheduling to be adapted to the inherent variability of such substrates. (Less)

中文翻译：

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迈向数字孪生：预测木质纤维素发酵演变的混合数据驱动和机械数字阴影

源自木质纤维素原料的发酵培养基的高底物可变性和复杂性影响浓度分布和发酵时间。不考虑这种可变性会引发操作和调度问题，并影响这些过程的整体性能。在这项工作中，开发了一种混合软传感器来监测和预测纤维素到乙醇发酵的演变。软传感器由顺序连接的两个模块（数据驱动模型和动力学模型）组成。数据驱动模块使用偏最小二乘模型从光谱数据估计葡萄糖的当前状态。动力学模型递归地拟合已知浓度的葡萄糖，以更新葡萄糖、木糖和乙醇的长期预测。这种从实际发酵过程到高保真动力学模型的实时数据更新的组合构成了数字孪生概念的基础，并允许更好地实时了解由木质纤维素原料中常见的不同抑制剂引起的复杂抑制现象. 软传感器通过三种不同的纤维素到乙醇发酵进行了实验验证，结果表明，当测量提供对系统真实状态的合理良好估计时，该方法适用于监测和预测发酵。这些结果将允许增加纤维素过程操作的灵活性，并允许调度适应此类底物的固有可变性。（较少的）软传感器通过三种不同的纤维素到乙醇发酵进行了实验验证，结果表明，当测量提供对系统真实状态的合理良好估计时，该方法适用于监测和预测发酵。这些结果将允许增加纤维素过程操作的灵活性，并允许调度适应此类底物的固有可变性。（较少的）软传感器通过三种不同的纤维素到乙醇发酵进行了实验验证，结果表明，当测量提供对系统真实状态的合理良好估计时，该方法适用于监测和预测发酵。这些结果将允许增加纤维素过程操作的灵活性，并允许调度适应此类底物的固有可变性。（较少的）这些结果将允许增加纤维素过程操作的灵活性，并允许调度适应此类底物的固有可变性。（较少的）这些结果将允许增加纤维素过程操作的灵活性，并允许调度适应此类底物的固有可变性。（较少的）