小型规模厌氧消化设施应用进展和挑战

Applications and Challenges of High-efficient Small-Scale Anaerobic Digesters

传统户用沼气池建造成本低、运行简易,但产气量较低、产气不稳定、有机物稳定时间长;而大型工业化规模厌氧消化工程(≥50 t·d^(-1))不适合人均或单位面积产量低的易腐废物的就近就地处理。因此,在全球双碳目标约束的背景下,处理量0.5~30 t·d^(-1)的小型规模高效厌氧消化设施的应用需求日益增加。处理规模的缩减对厌氧消化主体反应器、易腐废物进料控制、预处理工艺、固液分离等后处理工艺、沼气净化和利用小型设备、沼液沼渣处理和利用方式、臭气等二次污染控制方式、自动化和远程控制等,从技术、设备、运维、技术模式等多方面都提出了新的挑战,需要合理控制处理成本,提高运行的稳定性。针对上述问题,系统梳理了小型规模厌氧消化设施的类型、技术特征、技术模式和应用案例,以期指导基于小型规模厌氧消化设施的循环系统的构建,从而实现易腐废物的负碳就近就地就农资源化。

Traditional biogas septic tanks have the advantages of low construction cost and easy operation requirements,but their biogas production is of low yield,unstable,and low efficiency.Whereas,large-scale anaerobic digesters(≥50 t/d)are expensive and sophisticated,therefore,not suitable for the decentralized treatment of easily biodegradable biowaste with low generation amount.Therefore,oriented by the global target of emission peak and carbon neutrality,the demand for the small-scale anaerobic digestion(0.5~30 t·d^(-1),SSAD)is increasing and gradually applied around the world.The reduction of treatment capacity of SSAD results in several challenges,from technology,equipment,operation,and maintenance,to technology modes,for example,including the digester type,mixing,inflow,pretreatment,post-treatment,dewatering,biogas purification and utilization,digestate treatment and utilization,odor control,automation,and remote control,etc.,owing to meeting the requirements on both appropriate cost and high efficiency.In response to the above questions,this paper systematically investigated the types,technical characteristics,technical modes,and application cases of SSAD facilities,to guide the construction of an ecologically sustainable system based on SSAD,to realize the carbon sink treatment of easily biodegradable biowaste.