Hydrothermal carbonization (HTC) has emerged as a promising technology for sustainable use and waste valorization. One major challenge of HTC technology is the process water (PW) disposal or reuse, which is rich in dissolved organic carbon. This study evaluated the (i) potential of HTC to transform sugarcane industry by-products (sugarcane bagasse and vinasse) into useful materials for energy purposes, after, (ii) carry out the PW reuse in a novel HTC process with sugarcane bagasse. Relationships among composition, structure and morphology with fuel properties of hydrochars were evaluated. All hydrochars had lower volatile matter and higher fixed carbon content compared to the raw biomass. In addition, the decrease of H/C and O/C atomic ratios indicated an enhancement of the dehydration and deoxygenation reactions. Furthermore, the higher heating values (HHV) of hydrochars were in the range of 21.10–23.78 MJ kg^-1, compared to 15.43 MJ kg^-1 of the sugarcane bagasse. This result added to those from the van Krevelen diagram showed that the hydrochars presented fuel properties similar to conventional non-renewable energy sources, such as bituminous coal. Overall, the PW reuse did not promote great differences in the hydrochar properties and, consequently, no big changes on their fuel properties. Further, the hydrochar produced with sugarcane bagasse, vinasse, and sulfuric acid showed the highest heating value, and it was the most hydrophobic hydrochar among the others investigated. Therefore, the present study showed HTC and PW reuse as promising methods to treat the sugarcane industry by-products for solid fuel production.

水热碳化（HTC）已经成为一种可持续利用和废物增值的有前途的技术。HTC技术的一大挑战是工艺水（PW）的处理或再利用，它富含溶解的有机碳。这项研究评估了（i）宏达电将甘蔗工业副产品（甘蔗渣和酒糟）转化成用于能源用途的有用材料的潜力，（ii）用甘蔗渣在新型的宏达电工艺中进行了PW再利用。评价了碳氢化合物的组成，结构和形态与燃料性质之间的关系。与原始生物质相比，所有烃类均具有较低的挥发性物质和较高的固定碳含量。另外，H / C和O / C原子比的降低表明脱水和脱氧反应的增强。此外，^-1，相比之下，甘蔗渣为15.43 MJ kg ^-1。该结果加到van Krevelen图的结果中，表明碳氢化合物具有类似于常规不可再生能源（如烟煤）的燃料特性。总体而言，PW的再利用并没有促进水焦炭特性的巨大差异，因此，其燃料特性也没有太大变化。此外，由甘蔗渣，酒糟和硫酸制得的烃类具有最高的热值，并且是所研究的疏水性最强的烃类。因此，本研究表明HTC和PW的再利用是用于处理甘蔗工业副产品以生产固体燃料的有前途的方法。