In recent years, sewage sludge management has been considered one of the biggest concerns in the wastewater industry for the environmental impacts linked to its high content of pollutants. Hydrothermal Treatments are a good option for converting wet biomass such as sewage sludge into high-value products. The digestate following anaerobic treatment of sewage sludge has high organic matter content despite initial conversion into biogas and is normally spread on land or composted; however, this does not fully harness its full potential. In fact, the digestate is a potential feedstock for hydrothermal processing and this route may produce higher value products. In this study, the potential of hydrothermal processing as a novel alternative to treat the digestate has been be evaluated. The effect of temperatures is evaluated with respect to product yields, biomethane potential and solubilisation of organic carbon. Three different temperatures were evaluated: 160, 220 and 250 °C at 30 min reaction time. The hydrochar yields obtained were 73.42% at 220 °C, 68.79% at 250 °C and 56.75% at 160 °C treatment. The solubilisation of carbon was increased from 4.62% in the raw feedstock to 31.68%, 32.56% and 30.48% after thermal treatments at 160, 220 and 250 °C, respectively. The thermal treatment enhanced the potential methane production in all products up to 58% for both, the whole fraction (hydrochar + processed water) and processed waters. The Boyle’s and Buswell’s equation were used to calculate theoretical methane yields for all hydrothermal products. Theoretical methane yields were compare with experimental data from biomethane potential (BMP) tests and it was found that the Boyle’s equation had closer agreement to BMP values.

近年来，污水污泥的管理已被认为是废水工业中最大的问题之一，因为其污染物含量高对环境造成了影响。水热处理是将湿生物质（如污水污泥）转化为高价值产品的好选择。污水污泥经厌氧处理后的消化物尽管最初已转化为沼气，但有机物含量仍然很高，通常会散布在土地上或堆肥；但是，这并没有充分利用其全部潜力。实际上，消化液是进行水热处理的潜在原料，该路线可能会产生更高价值的产品。在这项研究中，已经评估了水热处理作为处理消化液的新方法的潜力。就产品产量，生物甲烷势和有机碳增溶性来评估温度的影响。在30分钟的反应时间下评估了三种不同的温度：160、220和250°C。在220°C下获得的碳氢化合物产率为73.42％，在250°C下为68.79％，在160°C处理下为56.75％。在160、220和250°C的温度下进行热处理后，碳的溶解度分别从原料中的4.62％增加到31.68％，32.56％和30.48％。热处理将全部馏分（烃类+加工水）和加工水的所有产品中潜在的甲烷产量提高了58％。博伊尔方程和布斯韦尔方程用于计算所有水热产品的理论甲烷产率。