Effect analysis on hydraulic pulping coupled with anaerobic digestion of food wastes
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摘要:
根据餐厨垃圾高含水的特点,从水力模拟、浆化物料特性、设备运行关键指标及项目运行效果等方面对餐厨垃圾水力浆化预处理技术进行综合评价。计算流体力学 (CFD)的水力模拟结果表明,浆化过程中流体质点螺旋式汇聚至转叶,形成三股内旋状涡流,在流体内部产生明显的流速差和正负压分区现象,水力作用下可快速实现餐厨垃圾的浆化。浆料和杂质特征分析表明,浆化产物颗粒细小,有机质损失率低,杂质去除率高,可与后端不同资源化技术(如厌氧消化、好氧堆肥等)高度融合。以水力浆化与厌氧消化技术相结合的餐厨垃圾资源化项目为例,餐厨垃圾经水力浆化预处理后,有机质损失率约为8.5%;不可生物降解杂质分选率约94%;粗油脂提取率约91%,吨餐厨垃圾平均产油率为3.76%,产气率为85.57 m3(以标态计)。该处理方式较机械式预处理具有更高的资源化利用率,可大幅提升项目的经济效益。
Abstract:Considering the characteristics of the high water content of food wastes, the hydraulic pulping pretreatment technology was comprehensively evaluated from the aspects of hydraulic simulation, characteristics of pulp, key equipment operation indicators and project operation effect. The CFD (computational fluid dynamics) hydraulic simulation results showed that during the pulping process, the fluid particles spirally converged to the rotor blades to form three internal swirling eddies, which produced obvious velocity and pressure differences in the fluid interior. Under the hydraulic action, the pulping of food wastes could be performed quickly. The analysis of pulp and impurity characteristics showed that the pulping product was of fine particles, with low organic matter loss and high impurity removal, which could be highly integrated with different back-end resource utilization technologies (anaerobic digestion, aerobic fermentation, etc.). Taking the resource utilization project of food waste as an example, which adopted hydraulic pulping and anaerobic fermentation technologies, the relevant operation data showed that after the pretreatment of food wastes by hydraulic pulping, the loss rate of organic matter was about 8.5%, the separation rate of non-biodegradable impurities was about 94%, and the extraction rate of crude oil was about 91%. Moreover, the average oil production rate per ton of food waste was 3.76%, and the gas production rate per ton of food waste was 85.57 m3. The treatment method had a higher resource utilization rate compared to mechanical pre-treatment, which could greatly improve the economic benefits of the project.
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Key words:
- food waste /
- hydraulic pulping /
- pretreatment /
- resource utilization /
- anaerobic digestion
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表 1 某市餐厨垃圾成分(干基)
Table 1. Food waste composition (dry basis) in a city
% 易腐类 塑料 纸类 木竹类 玻璃类 陶石类 骨头 贝壳 金属类 86.98 3.76 0.08 0.24 0.62 0.45 5.06 2.41 0.40 表 2 水力制浆技术与机械式技术的对比优势
Table 2. Advantages of hydraulic pulping technology compared to mechanical technology
项目 工艺流程 垃圾适用性 处理能力 杂质分离效果 减量化率与
资源回收率浆液特征 传统机械
技术必须配置筛分,破碎,甚至细分选等环节;
设备多、流程长对餐厨和厨余垃圾
分类要求高单线产能<20 t/h 筛分过程的筛上和
筛下物仍然是垃圾,
需要再处理筛上物带走有机质和油脂,资源回收率低,废渣多 浆液粒径≤8 mm 水力制浆
技术一台设备即可完成
破碎、浆化、杂质清洗、杂质分离;工艺流程显著缩短对餐厨和厨余垃圾
分类要求不高单线产能10~60 t/h 轻、重杂质渣和有机质可独立分离,
便于进一步利用全物料制浆、提油;有机质和油脂回收率高;减量化率提高 浆液粒径≤1 mm 水力制浆
技术优势占地面积小,节约土建投资;运行稳定性高;运行耗能低 减少垃圾分类成本;有机垃圾可混合处理,可减少生产线数量,节约维护成本,
节约设备投资根据城市发展规划,一条合理的生产线
通过延长运行时间
即可满足未来垃圾
增量需求有利于垃圾组分的
全资源化利用;浆液
纯度高,有利于厌氧
系统效率和稳定油脂和沼气产量增加,收入增加;更符合垃圾资源化
利用的方向浆液粒径小,易于厌氧消化,产气量高 -
[1] 刘有胜, 杨朝晖, 曾光明, 等. PCR-DGGE技术对城市餐厨垃圾堆肥中细菌种群结构分析[J]. 环境科学学报,2007,27(7):1151-1156.LIU Y S, YANG C H, ZENG G M, et al. Application of PCR-DGGE to analyzing bacterial communities in culinary waste compost[J]. Journal of Environmental Sciences,2007,27(7):1151-1156. [2] 邓俊. 餐厨垃圾无害化处理与资源化利用现状及发展趋势[J]. 环境工程技术学报,2019,9(6):637-642. doi: doi:10.12153/j.issn.1674-991X.2019.05.300DENG J. Harmless treatment and resource utilization of kitchen waste: development status and trend[J]. Journal of Environmental Engineering Technology,2019,9(6):637-642. doi: doi:10.12153/j.issn.1674-991X.2019.05.300 [3] 王凯军, 王婧瑶, 左剑恶, 等. 我国餐厨垃圾厌氧处理技术现状分析及建议[J]. 环境工程学报,2020,14(7):1735-1742.WANG K J, WANG J Y, ZUO J E, et al. Analysis and suggestion of current food waste anaerobic digestion technology in China[J]. Chinese Journal of Environmental Engineering,2020,14(7):1735-1742. [4] 邴君妍, 罗恩华, 金宜英, 等. 中国餐厨垃圾资源化利用系统建设现状研究[J]. 环境科学与管理,2018,43(4):39-43.BING J Y, LUO E H, JIN Y Y, et al. Current situation of food waste recycling in China[J]. Environmental Science and Management,2018,43(4):39-43. [5] 徐振, 王国城, 罗小荣, 等. 协同模式下餐厨垃圾的资源化处理探究[J]. 再生资源与循环经济,2022,15(9):32-35.XU Z, WANG G C, LUO X R, et al. Research on the resource treatment of food waste under collaborative mode[J]. Recycling Research,2022,15(9):32-35. [6] 谭业琴, 俞钟陆, 魏孔忠. “双碳” 背景下中国餐厨垃圾处理现状及趋势[J]. 能源与节能,2022(4):63-65.TAN Y Q, YU Z L, WEI K Z. Current situation and trend of kitchen waste treatment in China under "dual carbon" background[J]. Energy and Conservation,2022(4):63-65. [7] 郝晓地, 周鹏, 曹达啓. 餐厨垃圾处置方式及其碳排放分析[J]. 环境工程学报,2017,11(2):673-682.HAO X D, ZHOU P, CAO D Q. Analyses of disposal methods and carbon emissions of food wastes[J]. Chinese Journal of Environmental Engineering,2017,11(2):673-682. [8] LI Y Y, JIN Y Y, BORRION A, et al. Current status of food waste generation and management in China[J]. Bioresource Technology,2019,273:654-665. doi: 10.1016/j.biortech.2018.10.083 [9] 呼佳宁, 林子吟, 费波. 餐厨垃圾生化处理机工艺恶臭污染特征研究[J]. 环境工程技术学报,2023,13(1):340-347.HU J N, LIN Z Y, FEI B. Study of odor pollution characteristics of bio-chemical processor treatment of kitchen waste[J]. Journal of Environmental Engineering Technology,2023,13(1):340-347. [10] 童胜宝, 刘文刚, 王智. 餐厨垃圾预处理工艺研究及现场应用[J]. 四川环境,2021,40(1):233-238.TONG S B, LIU W G, WANG Z. Study and field application of kitchen waste pretreatment technology[J]. Sichuan Environment,2021,40(1):233-238. [11] 卢璐, 郭婷, 韩璐, 等. 餐厨垃圾预处理+厌氧消化工艺技术实践[C]//2019年科学技术年会: 环境工程技术创新与应用分论坛论文集(三). 北京: 中国环境科学学会, 2019: 541-543. [12] 李梦雅, 张春环, 岳凤明, 等. 餐厨垃圾高温湿解提油系统工艺应用研究[C]//2022年科学技术年会: 环境工程技术创新与应用分会场论文集(一). 北京: 中国环境科学学会, 2022: 313-317. [13] 邢巨元, 祝金星, 张晨光, 等. 挤压预处理对餐厨垃圾厌氧消化的影响[J]. 中国沼气,2014,32(4):8-11.XING J Y, ZHU J X, ZHANG C G, et al. Extrusion pretreatment of kitchen waste for anaerobic digestion[J]. China Biogas,2014,32(4):8-11. [14] 史东晓, 汤晓艳, 陆祥昕, 等. 餐厨垃圾有机残渣资源化利用方式比较研究: 以常州市餐厨废弃物综合处置项目(一期)为例[J]. 环境卫生工程,2022,30(5):55-59.SHI D X, TANG X Y, LU X X, et al. Comparative study on resource utilization of organic residues from kitchen waste: a case study of kitchen waste comprehensive disposal project (phaseⅠ) in Changzhou[J]. Environmental Sanitation Engineering,2022,30(5):55-59. [15] 王瑞金, 张凯, 王刚. Fluent技术基础与应用实例[M]. 北京: 清华大学出版社, 2007: 33-40. [16] 王建龙, 秦美娜, 黄涛, 等. 基于CFD的雨水调蓄池颗粒物沉淀特性研究[J]. 环境工程,2021,39(12):44-50.WANG J L, QIN M N, HUANG T, et al. Sedimentation characteristics of particulate matters in runoff detention tank via CFD method[J]. Environmental Engineering,2021,39(12):44-50. [17] 刘伟. 基于 k- ε湍流模型的方锥管布浆器的流动特性[J]. 中华纸业,2013,34(8):30-33. doi: 10.3969/j.issn.1007-9211.2013.08.009LIU W. Flow characteristics of rectangularly tapered distributor based on k- ε turbulence model[J]. China Pulp & Paper Industry,2013,34(8):30-33. doi: 10.3969/j.issn.1007-9211.2013.08.009 [18] 熊荣军. 塑料轻质砂的颗粒分析方法[J]. 水运工程,2019(1):25-28.XIONG R J. Particle size analysis method of plastic light model sediment[J]. Port & Waterway Engineering,2019(1):25-28. [19] 李胜利, 崔鹏, 罗海斌. 激光衍射法和机械筛分法测定PVC树脂粒径分布的对比[J]. 聚氯乙烯,2020,48(9):28-30.LI S L, CUI P, LUO H B. Comparison between laser diffraction and mechanical screening for determination of particle size distribution of PVC resin[J]. Polyvinyl Chloride,2020,48(9):28-30. [20] 曹猛. 餐厨垃圾处理厂预处理工艺应用分析[J]. 中国资源综合利用,2022,40(9):29-32.CAO M. Application analysis of pretreatment process in kitchen waste treatment plant[J]. China Resources Comprehensive Utilization,2022,40(9):29-32. [21] 靖丹枫, 耿震, 程文, 等. 餐厨垃圾预处理工艺设计[J]. 市政技术,2020,38(5):254-257.JING D F, GENG Z, CHENG W, et al. Pretreatment process design of kitchen waste[J]. Municipal Engineering Technology,2020,38(5):254-257. [22] WEN Z G, WANG Y J, de CLERCQ D. What is the true value of food waste: a case study of technology integration in urban food waste treatment in Suzhou City, China[J]. Journal of Cleaner Production,2016,118:88-96. ⊗ doi: 10.1016/j.jclepro.2015.12.087