I started my research career in the field of composite materials. My first investigations consisted of the modifying of nanoclays with colorants and surfactants for its subsequent use as reinforcement and coloring additives in polymers. Although I enjoyed doing research in this field, soon I had the opportunity to change my research path towards waste management, renewable energy and environmental issues, field in which I have been focused during the last years. I developed my PhD studies around the application of hydrothermal carbonizaton (HTC) to the management of a variety of wastes (i.e. agro-industrial wastes, paper mill sludge wastes) to convert them into upgraded solids, called hydrochars, for subsequent energy generation. Nevertheless, the interest on HTC goes beyond the final energy application of the solid product, since hydrochars exhibit great properties that make them useful for environmental remediation and interesting as advanced-material precursors, whereas the liquid product, which is very rich in organic matter, has a great protential to be exploited in biorefineries.