The researcher at the University of La Laguna (ULL) Laura Díaz has invented a utility model on a catalyst to produce biodiesel, which has been accredited by the Patent and Trademark Office and in which pumice, a volcanic material, is used as a support abundant and inexpensive.
Laura Díaz, PhD assistant professor and the University of La Laguna, has applied for another patent of hers for an energy crop coal also for biodiesel production, which is in the process of being granted, as reported by the academic institution.
The invention, which he shares with Candela Díaz and Andrea Brito, refers specifically to the chemical modification of pumice (aluminosilicate) with an alkali metal (lithium), and its use as a heterogeneous catalyst to carry out the transesterification reaction: reaction already started by the mixture of reagents, but being so slow requires a catalyst for reasons of economy.
It is used for oils of various kinds (clean vegetable oils, used frying oils, as well as oils from energy crops -non-edible-), such as oils from the seeds of Jatropha curcas and Pongamia pinnata, among others, in order to to produce fatty acid methyl esters (biodiesel).
This new catalytic material allows biodiesel to be produced at low temperature and, as it is a solid catalyst, it avoids washing the final product once the reaction has finished, so in addition to producing biodiesel discontinuously using a stirred tank type reactor, it opens the possibility of a continuous biodiesel production process.
Another advantage of the catalyst is that it is not subjected to a pretreatment to eliminate the possible water absorbed on the surface of the pumice, since lithium nitrate is used as precursor, instead of the corresponding hydroxide, which means carrying out a calcination stage, with the consequent advantage of a greater fixation of the metal on the surface of the solid.
This allows it to be reused for the transesterification reaction without any type of treatment and without reducing the yield for obtaining biodiesel, guaranteeing the durability of the catalyst.
The choice of pumice as a support for the preparation of the catalyst (Li/Pumite) compared to other synthetic materials used as catalysts in the production of biodiesel is very advantageous, since it is a natural material, of volcanic origin and, therefore, , of great abundance and of low cost.
Likewise, it is in granular form, so it can be used in the continuous production of biodiesel.
Pumice is a volcanic rock that is mainly composed of silica, alumina and natural zeolites, and is characterized by its high porosity.
Due to its porous structure, it has low density, high thermal insulation and chemical resistance, in addition to being a low-cost material, which makes it a preferred material for industrial applications.
The use of pumice as a heterogeneous catalyst for the aforementioned reaction does not produce biodiesel, but the modification of its surface with an alkaline metal, such as lithium, makes it an ideal catalytic material, adds the ULL.
The Heterogeneous Catalysis research group at the University of La Laguna has applied its previous experience in the field of heterogeneous catalysis to the study of obtaining biodiesel from frying oils and biofuels from waste.
The research activity of the group is grouped into obtaining biodiesel and biofuels, recovery of waste from an energy point of view, catalytic co-processing of vegetable frying oil and gas oil and hydrotreatment of oil, as well as hydrogenation of vegetable and animal oils.
