“双碳”背景下低碳污泥处理处置技术路线优化探索

Exploration on Optimizing the Technical Route of Low-carbon Sludge Treatment and Disposal under the Background of“Carbon Peak and Carbon Neutralization”

通过对以厌氧消化(路线1)、好氧发酵(路线2)、干化焚烧(路线3)为核心的主流污泥处理处置技术路线及其优化提升方案的碳排放量进行核算,探究了污泥处理处置低碳发展路径。研究表明,路线1A“厌氧消化+脱水+土地利用”和路线1B“热水解+厌氧消化+脱水+土地利用”主要碳排放类型为加热热耗;路线2A“脱水+好氧发酵+土地利用”和路线2B“深度脱水+好氧发酵+土地利用”主要碳排放类型分别为CH_(4)逸散、药剂投加;路线3A“脱水+半干化+焚烧+建材利用”和路线3B“改性分离+脱水+半干化+焚烧+建材利用”主要碳排放类型为药剂、辅料消耗,针对主要碳排放类型制定优化对策可降低相应单元的碳排放量。此外,厌氧消化前置热水解单元、干化焚烧前置污泥改性分离单元后,均具备明显降低碳排放量的优势,减碳幅度分别约58%、63%;好氧发酵前置深度脱水单元的碳排放量受脱水药剂的影响较大,且减碳优势不明显。

In order to explore the low-carbon development path of sludge disposal,the article compared carbon emissions of the anaerobic digestion(route 1),aerobic fermentation(route 2),and dry incineration(route 3),the mainstream sludge treatment and disposal technology routes with their optimization and improvement schemes.The results show that the main carbon emission types of route 1A/1B(anaerobic digestion+dehydration+land use,thermal hydrolsis+anaerobic digestion+dehydration+land use)are heating heat consumption,route 2A/2B(dehydration+aerobic fermentation+land use,deep dehydration+aerobic fermentation+land use)are CH_(4) fugitive,pharmaceutical dosing,route 3A/3B(dehydration+semi-drying+incineration+building materials utilization,pre-sludge modified separation+dehydration+semi-drying+incineration+building materials utilization)are agent/excipient consumption.And targeted optimization countermeasures can reduce the carbon emissions of the corresponding units.In addition,by setting a thermal hydrolysis solution unit before anaerobic digestion and the pre-sludge modified separation unit before drying and incineration,the advantages of carbon emission reduction are obvious,reaching about 58%and 63%respectively.The carbon emission of the aerobic fermentation pre-deep dehydration unit is greatly influenced by the dehydration agent,and the carbon reduction advantage is not obvious.