Process Control in Solid Substrate Fermentation

本研究旨在开发一种基于蒸发冷却和换水策略的温度和水分控制系统，以控制少孢根霉挤压膨化玉米固体基质发酵的生物量。该过程控制方案基于自适应控制算法。该控制系统将与生物质浓度和底物转化率的估计相结合，这些值来自在线测量的发热量、氧气消耗、二氧化碳产生和水平衡。测量值和估计值将通过数学模型进行关联。丝状真菌固体发酵(SSF)是一种可行的替代液体深层发酵的方法，前提是发酵过程能够规模化，并且关键的发酵参数可以在线测量以达到过程控制的目的。固体发酵中的主要问题是调节发酵罐内的温度和湿度，以优化生长条件。建议通过将蒸发冷却和加水相结合来实现这一点，这是由一个复杂的“智能”控制器指示的。工艺条件也要通过数学模型进行估算。

This research is aimed at developing a temperature and moisture control system based on evaporative cooling and water replacement strategy in order to regulate the biomass productivity in the solid substrate fermentation of Rhizospus oligosporus on extruded corn. The process control scheme is based on adaptive control algorithm. The control system will be coupled to the estimation of biomass concentration and substrate conversion from on-line measured values of heat generation, oxygen consumption, carbon dioxide production, and water balance. Measured and estimated values will be correlated through mathematical modelling. Solid substrate fermentation (SSF) with filamentous fungi is a viable alternative to submerged fermentation if the process could be scaled up to industrial size and if the critical fermentation parameters can be measured on-line for process control purposes. The main problem in solid substrate fermentation is to regulated the temperature and the humidity in the fermenter so that the growth condition is optimized. It is proposed to do this by combining evaporative cooling and water addition as directed by a sophisticated "smart" controller. Process conditions are also to be estimated by mathematical models.