This work presents a critical review of literature relative to hydrothermal and supercritical water technology applied to the upgrading of heavy oil fractions. It gives the reader insight into the role of water in the upgrading reactions,  kinetics and reactor configurations. This article is a landmark achievement as it gave the knowledge foundations to develop the process succesfully and later extend it into the upgrading of renewable resources like biomass and organic waste.

This work is a great importance as it is an initial approach into the use of heterogeneous catalysts to further upgrade and remove in-situ oxygen functionalities from the products. This article studied reaction pathways and effect of dopants in the catalyst, which has enabled the use of selected catalysts in further studies done for either oil or biomass upgrading.

This work is a great importance as it is the follow up of the knowledge generated for catalytic hydrothermal and supercritical water processing of polycyclic aromatic compounds. The work is extremely important as it was part of an international research consortium that included companies like BP and Hexxcell.. The contributions were important as highly active catalysts were synthetised and open the possibility of high profile collaborations. 

This work studies the effect of process conditions in the supercritical water oxidative cracking of polycyclic aromatic structures. The investigation showed that partial oxidation weakens the ariomatic structure and promotes further upgrading. These results are of great importance as they show the applicability of the process in oil upgrading applications and enabled Dr. Arcelus to extend it to other resources with high oxygen content like biomass and organic waste.

This work is landmark achievement for Dr. Arcelus first due to its originality, impact and also complexity. It is the product of a collaboration established between Universidad Iberoamericana, IER-UNAM and CIO Aguascalientes that succeeded in the design, commisioning and operation of a solar heated hydrothermal batch reactor. Good yields to bio-oil with similar characteristics to the ones obtained through conventional heating were obtained. This research gives proof that engineering processes can be fully operated by renewable energy and gives a step forward towards sustainable fuels.