Hydrothermal carbonisation of mechanically dewatered digested sewage sludge-Energy and nutrient recovery in centralised biogas plant.
Hydrothermal carbonisation of mechanically dewatered digested sewage sludge-Energy and nutrient recovery in centralised biogas plant.
复制标题
DOI：
10.1016/j.watres.2021.117284
复制
发表时间：
2021-05
期刊：
影响因子：
12.8
通讯作者：
Ann-Mari Hämäläinen;M. Kokko;V. Kinnunen;Tuomo Hilli;J. Rintala
中科院分区：
文献类型：
--
作者：
Ann-Mari Hämäläinen;M. Kokko;V. Kinnunen;Tuomo Hilli;J. Rintala
本研究旨在评估水热碳化（HTC）在中央沼气厂的厌氧处理中的作用，该沼气厂接收来自区域污水处理厂的脱水污泥并生产生物甲烷和肥料。在210 °C、230 °C或250 °C下，在30分钟或120分钟HTC处理中，原样（总固体（TS）25%）或以用废弃水稀释（15%TS）的形式使用化学调理和机械脱水的污泥，并将产生的浆料过滤以产生烃和水。不同的烃贡献了初始质量的20-55%、TS的72-88%、能量含量的74-87%、碳的71-92%、磷的86%以上和氮的38-64%，所述碳存在于初始的烃态中。氢焦的能量含量（较高的热值为11.3-12.2 MJ/kg-TS）与热解态的能量含量相似，而灰分含量增加（从43%增加到57%）。HTC处理产生了体积为脱水淀粉态的42-76%的淀粉，具有28-44 g/L的可溶性化学需氧量（SCOD），其中挥发性脂肪酸（VFA）贡献了10- 34%，以及182-206 mL-CH 4/g-SCOD的甲烷势，没有任何主要的抑制迹象。除了滤液中的布洛芬和苯并三唑外，在美国各州检测到的所有32种药物都低于氢焦和苯并三唑的检测限，而重金属集中在氢焦中，但低于国家肥料使用限制，除了汞。HTC与集中式沼气厂的整合外推可将年沼气产量提高5%，铵回收率提高25%，水热炭燃烧后估计可产生83 GJ，或每年将350吨磷直接用于农业。
This study aimed to assess the role of hydrothermal carbonisation (HTC) in digestate processing in centralised biogas plants receiving dewatered sludge from regional wastewater treatment plants and producing biomethane and fertilisers. Chemically conditioned and mechanically dewatered sludge was used as such (total solids (TS) 25%) or as diluted (15% TS) with reject water in 30 min or 120 min HTC treatments at 210 °C, 230 °C or 250 °C, and the produced slurry was filtered to produce hydrochars and filtrates. The different hydrochars contributed to 20–55% of the original mass, 72–88% of the TS, 74–87% of the energy content, 71–92% of the carbon, above 86% of phosphorous and 38–64% of the nitrogen present in the original digestates. The hydrochars’ energy content (higher heating values were 11.3–12.2 MJ/kg-TS) were similar to that of the digestates, while the ash contents increased (from 43% up to 57%). HTC treatments produced filtrates in volumes of 42–76% of the dewatered digestate, having a soluble chemical oxygen demand (SCOD) of 28–44 g/L, of which volatile fatty acids (VFAs) contributed 10–34%, and methane potentials of 182–206 mL-CH4/g-SCOD without any major indication of inhibition. All 32 pharmaceuticals detected in the digestates were below the detection limit in hydrochars and filtrates, save for ibuprofen and benzotriazole in filtrate, while heavy metals were concentrated in the hydrochars but below the national limits for fertiliser use, save for mercury. The integration of HTC to a centralised biogas plant was extrapolated to enhance the annual biogas production by 5% and ammonium recovery by 25%, and the hydrochar was estimated to produce 83 GJ upon combustion or to direct 350 t phosphorous to agriculture annually.