剩余污泥气化、液化劣势所在及其能量平衡  

Disadvantages of gasification and liquefaction on excess sludge and associated energy balances

作　　者：郝晓地[1] 朱昊睿 朱洋墨 吴远远 HAO Xiaodi;ZHU Haorui;ZHU Yangmo;WU Yuanyuan(Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies,Key Laboratory of Urban Stormwater System and Water Environment(Ministry of Education),Beijing University of Civil Engineering and Architecture,Beijing 100044)

机构地区：[1]北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室,中-荷污水处理技术研发中心,北京100044

出　　处：《环境科学学报》2024年第3期1-12,共12页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.52170018)。

摘　　要：剩余污泥处理、处置向能源化方向转变在“双碳”形势下已形成共识.除厌氧消化(生物气)及焚烧(热电联产)途径外,近年来对污泥进行热化学气化(非生物气)、液化的研究乃至应用亦开始被业界所关注.污泥气化、液化产生的混合能量气体(H_(2)+CO)与生物油理论上可以用作燃料,但实际制取过程并不顺利,除产物成分复杂外,产物所含能量甚至低于维持反应所需能量.因此,需要分别对各种气化、液化方式及产物劣势进行描述,特别要对能量投入产出平衡进行系统分析.基于热化学法中热解与水热这两种常见的气化、液化方式,基于技术原理首先分析2种方式、4种方法的劣势所在(产物含焦油、杂原子、重金属、多环芳烃等),继而详细计算4种方法在能量平衡方面的细节,以评价各种方法的工程实用性.能量平衡结果显示,热解气化和水热液化似乎存在能量盈余,但热解气化能量只有在达到一定产物低位热值后方能实现净能量输出;水热液化净能量盈余较多,但后续产物提纯、精炼亦需能耗,仍需要进一步能量评估.A consensus has been reached on treating excess sludge towards energy under the framework of the Carbon Peak and Carbon Neutrality.Besides anaerobic digestion(biogas)and incineration(combined heat and power),research and development on thermochemical gasification(nonbiogas)and liquefaction on excess sludge have also attracted attention from water industry.The mixed energy gas(H_(2)+CO)and bio-oil produced by sludge gasification and liquefaction can theoretically be used as fuel,but the actual production process is not smooth;besides the complexity of the product composition,the produced bio-oil contains even less energy than that required to maintain the process.Thus,it is necessary to describe various methods on gasification and liquefaction and their disadvantages,respectively,and moreover,a systematic analysis of input-output balances on energy must be conducted as well.Based on two common methods on gasification and liquefaction by thermochemistry,pyrolysis and hydrothermal,the disadvantages(tar,heteroatoms,heavy metals,PAHs contained in the products)of the two methods and four approaches are firstly analyzed on the basis of technical principles;then the energy balances of the four approaches are in detail calculated to assess their potential practicality.The results from the energy balances reveal that is seems to be net-surplus on energy from pyrolysis gasification and hydrothermal liquefaction,but pyrolysis gasification energy could be applicable only at reaching to a certain low calorific value,and furthermore hydrothermal liquefaction(despite largely netsurplus on energy)needs to be further evaluated on the energy balance as a process of purification and refining on the bio-oil has to be followed.

关 键 词：剩余污泥 热化学法 污泥热解 污泥水解 混合能量气体 生物油 

分 类 号：X705[环境科学与工程—环境工程]