Methane is currently an emerging alternative feedstock for biological processes. In this paper, we study a particular methane to lactate bioconversion process based on the bacterium Methylomicrobium buryatense 5GB1, with the aim of designing suitable state estimators and controllers for the process. First, a nonlinear unsegregated, unstructured model, consisting of six dynamic mass flow balance equations and six state variables, is constructed and implemented as a dynamic simulator in MATLAB and Simulink. Simulation results match qualitatively with experimental data from literature. Second, an observability analysis is performed with the aim of finding suitable sensor configurations for state estimation. For each of the resulting observable configurations a linear Kalman filter is constructed, of which the performance is evaluated. This performance is not satisfactory and, therefore, extended and unscented Kalman filters are designed to overcome the nonlinear nature of the system. Third, a controllability analysis is executed to establish controllability with respect to the process inputs. Both the observability and controllability give an assessment of practical observability and controllability by using empirical Gramians. A linear quadratic regulator (LQR) with integral feedback is constructed to control the biomass and lactate concentrations. The results for a combined observer and controller scheme are promising and give reliable simulation results.

甲烷目前是一种新兴的生物过程替代原料。在本文中，我们研究了一种基于伯氏甲烷甲基细菌的甲烷到乳酸生物转化的过程。5GB1，旨在为该过程设计合适的状态估计器和控制器。首先，构建一个非线性的非隔离，非结构化模型，该模型由六个动态质量流量平衡方程和六个状态变量组成，并在MATLAB和Simulink中作为动态模拟器实现。仿真结果与文献中的实验数据定性匹配。其次，进行可观察性分析，目的是找到用于状态估计的合适传感器配置。对于每个所得的可观察配置，将构建一个线性卡尔曼滤波器，并对其性能进行评估。这种性能不能令人满意，因此，设计了扩展的，无味的卡尔曼滤波器来克服系统的非线性特性。第三，执行可控性分析以建立相对于过程输入的可控性。可观察性和可控制性都通过经验格拉姆斯方法对实际可观察​​性和可控制性进行了评估。构建具有积分反馈的线性二次调节器（LQR），以控制生物量和乳酸浓度。观察者和控制器组合方案的结果是有希望的，并提供可靠的仿真结果。