MEtRICs, Mechanical Engineering and Resource Sustainability Center, Department of Science and Technology of Biomass, FCT- NOVA University of Lisbon, 2829-516 Caparica, Portugal.
MEtRICs, Mechanical Engineering and Resource Sustainability Center, Department of Science and Technology of Biomass, FCT- NOVA University of Lisbon, 2829-516 Caparica, Portugal; VALORIZA, Research Centre for Endogenous Resource Valorization, Polytechnic Institute of Portalegre, 7300-555 Portalegre, Portugal.
Waste Manag. 2021 Feb 1;120:303-313. doi: 10.1016/j.wasman.2020.11.040. Epub 2020 Dec 14.
In this study, hydrothermal carbonization (HTC) was used as a thermochemical conversion process to upgrade Refuse Derived Fuel (RDF). The effect of process temperature (250 °C, 275 °C and 300 °C), residence time (30 min and 120 min), and RDF-to-water ratio (1:15 and 1:5) on the main characteristics of the produced hydrochars and process waters was assessed. The HTC process yielded hydrochars with enhanced fuel properties when compared to the original feedstock, namely higher carbon content and heating value. The hydrochars also presented reduced oxygen and ash contents. The hydrochar produced at 300 °C for 120 min presented the lowest ash content (3.3 wt%, db) whereas the highest heating value was found for the hydrochar obtained at 275 °C for 120 min (28.1 MJ/kg, db). The HTC process was also responsible for a significant reduction in chlorine concentration, showing dechlorination efficiencies between 69.2 and 77.9%. However, the HTC process generated acidic process waters with high COD values (maximum 27.2 gO/L), which need to be further managed or valorized. Energy calculations were also performed, revealing that lower water amounts, lower temperatures, and longer residence times, represent optimal conditions for higher hydrochar yields and consequently good process efficiencies.
在这项研究中，水热碳化（HTC）被用作一种热化学转化工艺来升级垃圾衍生燃料（RDF）。研究了工艺温度（250°C、275°C 和 300°C）、停留时间（30 分钟和 120 分钟）以及 RDF 与水的比例（1:15 和 1:5）对所产生的水热炭和工艺水的主要特性的影响。与原始原料相比，HTC 工艺生产的水热炭具有增强的燃料特性，即更高的碳含量和热值。水热炭的含氧量和灰分也有所降低。在 300°C 下停留 120 分钟生产的水热炭的灰分含量最低（3.3wt%，干基），而在 275°C 下停留 120 分钟生产的水热炭的热值最高（28.1MJ/kg，干基）。HTC 工艺还导致氯浓度显著降低，脱氯效率在 69.2%至 77.9%之间。然而，HTC 工艺产生的工艺水呈酸性，COD 值很高（最高为 27.2gO/L），需要进一步处理或利用。还进行了能量计算，结果表明，使用较少的水量、较低的温度和较长的停留时间，代表着获得更高水热炭产率和良好工艺效率的最佳条件。
