Multistep Bioelectrochemical Reaction Cascade in Continuously Operated Flow Reactors (BioElectroFlow)

连续操作流动反应器中的多步生物电化学反应级联 (BioElectroFlow)

• 批准号: 445947004
• 负责人: Professor Dr.-Ing. Bodo Fiedler
• 金额: --
• 依托单位: Organic & Bioorganic Chemistry
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/445947004?language=en
• 关键词: Multistep; Bioelectrochemical; Reaction; Cascade; Continuously

The main objective of this project is to elucidate the key scientific questions to enable multistep bioelectrochemical reaction cascades in continuously operated flow reactors. The transition from AiO electrode setup in a batch to a continuously operated bioelectrochemical process starts from the established one-step bioelectrochemical system in the first project phase. This will be extended to a three-step bioelectrochemical reaction cascade, the oxidative valorization of 5-hydroxymethylfurfural (HMF) to valuable 2,5-furandicarboxylic acid (FDCA) catalyzed by two different unspecific peroxygenases (UPO). This cascade setup will allow the detailed study of different steady-state conditions through different reactor configurations, operating points as well as systematic properties of enzyme/electrode interactions. The reactor cascade can be operated with immobilized UPOs on the electrode surface as a sequence of plug flow reactors (PFR) as well as circulation loop reactors in continuously operated stirred tank reactor mode (CSTR). Alternatively, homogeneously solubilized UPOs can be applied that are recycled via an additional ultrafiltration membrane unit in the recirculation stream. By these two fundamental different reactor cascade configurations, a deepened understanding on affecting key performance parameters will be generated. Furthermore, challenges pointed out in the previous project will be addressed by designing improved porous Globugraphite (GG) electrodes. Key objective is to improve H2O2 productivity and Faradaic efficiency (F.E.). Several approaches will be explored, such as varying the polyvinyl butyral (PVB) content to influence the porosity of the GG and implementing multiple segmented GG modules. The latter ones might be separated by isolation or connected as units of different porosity. This will allow for a gradient of the H2O2 generation rate needed in a PFR setup to minimize H2O2 accumulation and enzyme deactivation. The following key scientific questions will be addressed: • How do the flow reactor geometry and increased flow rate influence mass transfer across/through the electrode, possible diffusion limitation as well as enzyme stability? • How does the morphology of the GG need to be varied by polyvinyl butyral (PVB) content, ZnO particle size and wall thickness to affect pore size in a way to maximize / tailor H2O2 productivity and F.E.? • How can the durability of GG electrodes be increased by thermal treatment and/or wall thickness to withstand the internal gas pressure? • How is a segmented graphite electrode to be designed to enable a length gradient in H2O2 generation rate? • How do different reactor operation modes (e.g. batch, PFR, CSTR) and resulting different linear flow rates influence performance indicators such as total turnover number (TTN), turnover frequency (TOF), enzyme deactivation constants and productivity?

该项目的主要目标是阐明在连续操作的流动反应器中实现多步生物电化学反应级联的关键科学问题。从AiO电极批量设置到连续操作的生物电化学过程的过渡始于第一项目阶段中建立的一步生物电化学系统。这将扩展到三步生物电化学反应级联，即由两种不同的非特异性过氧合酶（UPO）催化的5-羟甲基糠醛（HMF）氧化还原为有价值的2，5-呋喃二甲酸（FDCA）。这种级联设置将允许通过不同的反应器配置、操作点以及酶/电极相互作用的系统特性来详细研究不同的稳态条件。反应器级联可以与电极表面上的固定化UPO一起操作，作为活塞流反应器（PFR）的序列以及连续操作的搅拌釜反应器模式（CSTR）中的循环回路反应器。或者，可以应用均匀溶解的UPO，其通过再循环流中的另外的超滤膜单元再循环。通过这两种基本不同的反应器级联结构，加深了对影响关键性能参数的理解。此外，在以前的项目中指出的挑战将通过设计改进的多孔石墨（GG）电极来解决。关键目标是提高H2 O2生产率和法拉第效率（F.E.）。将探索几种方法，例如改变聚乙烯醇缩丁醛（PVB）含量以影响GG的孔隙率和实施多个分段GG模块。后者可能通过隔离而分离，或作为不同孔隙度的单元而连接。这将允许PFR设置中所需的H2 O2产生速率的梯度，以使H2 O2积累和酶失活最小化。将解决以下关键科学问题：·流动反应器的几何形状和增加的流速如何影响跨/通过电极的传质，可能的扩散限制以及酶的稳定性？·GG的形态需要如何通过聚乙烯醇缩丁醛（PVB）含量、ZnO粒度和壁厚来改变以影响孔径，从而最大化/定制H2 O2产率和F.E.？·如何通过热处理和/或壁厚增加GG电极的耐用性以承受内部气体压力？·如何设计分段石墨电极以实现H2 O2生成速率的长度梯度？·不同的反应器操作模式（例如分批、PFR、CSTR）和由此产生的不同线性流速如何影响性能指标，例如总周转数（TTN）、周转频率（TOF）、酶失活常数和生产率？