From October 15, 2020October 14, 2022, I carried out experiments involving suberin recovery and characterization at the Bioeconomy Institute of Valladolid University, Valladolid, Spain under the supervision of Prof. Maria Jose Cocero, with a three-month secondment at the LAQV-REQUIMTE of the Universidade Nova de Lisboa, Caparica, Portugal. I have carried out the following works: (i) Isolation of suberin methyl esters by chemical conventional method; (ii) Recovery of intact suberin in a subero-lignin complex by supercritical hydrolysis in a continuous microreactor; (iii) Isolation of suberin from the subero-lignin complex by dioxane extraction; (iv) Subcritical hydrolysis of suberin in microwave, conventional batch and semicontinuous reactors (v) Extensive Characterization of suberin and its acid and methyl ester derivatives generated produced from the technologies mentioned in (i-iv) and (vi) Production of biolubricants from isolated suberin and suberinic acids.
perimental techniques, instrumental analyses and mathematical calculations. I spent the first three months understanding the conventional chemical pathway and the necessary methods for suberin characeterization. This way, I understood the clear advantage of ultrafast supercritical hydrolysis over the conventional chemical approach, which includes greater product yields and better product properties. I operated the ultrafast microrreactor and employed mathematical calculations to estimate the ion product values of water. I have recovered suberin intact in a subero-lignin complex and correlated the properties of the products with respect to the ion product values and reaction time. I have also developed the method to extract pristine suberin from the subero-lignin complex based on dioxane extraction. I also carried out subcritical hydrolysis in batch and semicontinuous reactors and compared the product composition in terms of cellulose, lignin and suberin yields to that of ultrafast hydrolysis products. I have characterized the subero-lignin complex (ultrafast supercritical hydrolysis product), the pristine suberin (isolated by dioxane extraction), suberin methyl esters (from alkaline methanolysis) and suberinic acids (from alkali hydrolysis) through a variety of techniques including surface micrography, thermal properties and structural functionalities. It was found that it is necessary to strike a balance between the combination of reaction time and ion product of water in order to avoid the formation of competing repolymerization reactions that would allow the liquefaction of cellulose and lignin to yield higher suberin amount. I have also developed a method to convert the suberinic acids into biolubricant base.
The results were discussed in detail in an academic article published in Green Chemistry (
https://doi.org/10.1039/D2GC02498E(opens in new window)). I have also partcipated in several activities to disseminate the results and raise attention to the project such as the Science Week, European researcher`s night, #ElFuturoDELaUVa and Day International Of Women And Girls In Science.
