Hydrothermal carbonization (HTC) technology is addressed in the framework of sewage digestate management. HTC converts digestate into a stabilized and sterilized solid (the hydrochar) and a liquor (HTCL) rich in organic carbon. This study aims to optimize the HTC operating parameters, namely the treatment time, in terms of hydrochar production, HTC slurry dewaterability, HTCL bio-methane yields in anaerobic digestion (AD), and process energy consumption. Digestate slurry was processed through HTC at different treatment times (0.5, 1, 2 and 3 h) at 190 °C, and the dewaterability of the treated slurries was addressed through capillary suction time and centrifuge lab-testing. In addition, biochemical methane potential (BMP) tests were conducted for HTCL under mesophilic conditions. Results show that by increasing the HTC treatment time the dewaterability was further improved, ammonium concentration in HTCL increased, and methane potential of HTCL decreased. 0.5 h HTCL had the highest bio-methane potential of 142 ± 3 mL CH₄/g COD yet the treatment time was not sufficient for improving the slurry's dewaterability. HTC treatment time of 1 h at 190 °C was identified as the optimum trade-off for improved dewaterability and utilisation of HTCL for biogas production. 1 h HTCL bio-methane potential can cover around 25% of the HTC and AD thermal and electrical energy needs without considering the eventual use of the hydrochar as a biofuel.

在污水消化物管理的框架中解决了热液碳化（HTC）技术。HTC将消化物转化为稳定和灭菌的固体（水焦）和富含有机碳的液体（HTCL）。这项研究旨在优化HTC的运行参数，即就碳氢化合物产生，HTC浆料的脱水性，厌氧消化（AD）中的HTCL生物甲烷产率和过程能耗而言的处理时间。在190°C下通过HTC在不同的处理时间（0.5、1、2和3 h）处理Digestate浆液，并通过毛细管抽吸时间和离心机实验室测试解决了处理后浆液的脱水性。另外，在中温条件下对HTCL进行了生化甲烷潜力（BMP）测试。结果表明，通过增加HTC处理时间，脱水能力得到进一步改善，HTCL中的铵浓度增加，HTCL的甲烷电势降低。0.5 h HTCL的生物甲烷潜力最高，为142±3 mL CHCOD为₄ / g，但处理时间不足以改善浆液的脱水性。在190°C下进行1小时的HTC处理时间被确定为最佳的折衷方案，以改善脱水性和将HTCL用于沼气生产。1小时的HTCL生物甲烷潜能可以满足HTC和AD热能和电能的大约25％，而无需考虑最终使用碳氢化合物作为生物燃料。