降流式两步厌氧发酵制取氢烷气生物膜反应器内传递与转化特性及调控方法研究

Hythane is considered as a clean and efficient fuel. It has great potential for use in the future. Fermentative hythane production via anaerobic route using waste biomass can control the environment pollution whilst providing a sustainable energy source. This project will focus on the mass transfer and material conversion during the biofilm-based integrating hythane fermentation process. The main research will be conducted in the areas of kinetic study of biochemical reaction in mixed microorganisms, characteristics of biofilm and reactor control. Firstly, the impacts of fermentation parameters on the mixed hythane microorganism growth, fermentation and substrate degradation will be investigated. The kinetic characteristics of mixed microorganism growth and fermentation will be obtained. Subsequently, the growth and biofilm formation characteristics of mixed microorganisms will be investigated. The competition and synergy effects of mixed microorganisms will be illuminated. The models for biofilm growth and mass transfer will be obtained. Finally, an innovative two-step down-flow anaerobic biofilm reactor will be proposed for the integrating hythane fermentation. Comprehensive study on the flow, mass transfer and biochemical reaction in the reactor will be conducted. The mathematical model of mass transfer and material conversion in the reactor will be developed. The synergistic control strategies using flow and concentration fields for integrating hythane fermentation will be obtained. This project will be beneficial for the development and application of microbial energy conversion technology.

氢烷气是一种高效、洁净的新型燃料，具有广阔的应用潜力。通过发酵的途径将废弃生物质转化生成氢烷气可以在控制环境污染的同时有效缓解能源供给的压力。本项目将重点研究基于生物膜反应器的氢烷一体化发酵过程中的物质传递与转化特性，分别在混合微生物生化反应动力学、生物膜特性、反应器调控三个不同层次开展逐层递进的研究工作。揭示发酵参数对氢烷混菌生长、代谢及底物降解的影响规律，获得混菌生长和代谢的动力学特性。研究氢烷混菌在固体基质表面生长及成膜规律，明晰各个菌种之间的竞争和协同关系，建立生物膜生长模型及膜内传质模型。在此基础上提出构建新型的降流式两步厌氧发酵生物膜反应器，对反应器内流动、传质及生化反应特性开展系统的研究，建立反应器内流动及物质传递与转化的理论模型，获得流场和浓度场协同调控氢烷一体化发酵的方法。推动微生物能源转化技术的发展和应用。

我国生物质资源分布广泛、储量巨大，通过微生物厌氧发酵降解生物质废弃物制取清洁氢烷燃气具有显著的能源和环境效益，是生物质能领域的重要发展方向。本项目在生物质水热水解及氢烷混菌厌氧发酵特性、氢烷混菌在固体基质表面成膜规律及膜内传质特性、厌氧生物膜反应器传递与转化特性及调控方面开展创新的研究工作。首先，通过研究生物质水热水解过程细胞形态、组分及官能团的演变规律，揭示了生物质有机质析出规律、解聚特性及相互作用机制，探明了水解液副产物的微生物转化及脱毒机理，获得了水解液多组分均相厌氧发酵氢烷混菌的代谢动力学特性；探索了运行参数对混菌生物膜在固体基质表面成膜特性的影响规律，获得了生物膜生长过程中微观孔隙结构、生物膜厚度分布、细胞密度、胞外大分子成分等特征参数；基于混菌生物膜非均匀结构建立了膜内传质反应模型，获得了生物膜内混菌生长、底物消耗及代谢产物生成的相互耦合关系；提出了电场力驱动下抑制性副产物移除强化厌氧发酵新方法，获得了电渗析生物膜反应器内铵、挥发性有机酸等副产物移除与底物降解及燃气转化规律及特性，建立了描述反应器内物质传递的理论模型；构建了氢烷一体化发酵的降流式多层填充床生物膜反应器，获得了运行参数对底物降解及氢烷生成的影响规律，提出了氢烷组分调控方法，建立了生物质水热水解及氢烷厌氧发酵耦合系统的全生命周期评价体系，为微生物厌氧发酵制取氢烷燃气技术的发展和应用奠定基础。