An Anaerobic Digestion System Inspired by Intestinal Peristalsis - Development of a Peristaltic Bioreactor with Mixing Via Rotational Flow and Negative Pressure Inflow

To enhance the energy-intensive mixing of highly viscous biomass in solid-state anaerobic digestion (SS-AD), a novel peristaltic bioreactor inspired by intestinal peristalsis was developed. The reactor uses rotational flow and negative pressure inflow to enhance the mixing efficiency. A prototype's performance was evaluated using a simulated biomass (total solids = 40%), and the mixing progress was quantified using a mixing index. The experimental results showed that the proposed rotational flow achieved complete mixing, unlike conventional axial flow. Furthermore, the application of negative pressure accelerated the mixing time from 5.2 min to 3.1 min. These findings validate our intestine-inspired approach, demonstrating its potential for developing compact and energy- efficient SS-AD systems.