Biodiesel produced by residual feedstock, such as waste cooking oil, is, indeed one of the strategies to reduce production costs, valorize wastes and contribute for a faster decarbonization in transportation sector, plus, it does not compete with food security. However, the high sulfur content in these residual feedstocks is becoming an enormous concern, not only due to the decreasing of economic sustainability, but also envorimnetal sustainability.

Together with PRIO, which is the largest biodiesel producer in Portugal, I wrote an article on this subject, which was approved at the WASTES conference 2023 and will be published as a chapter in a book. Once published I will put the link in this section.

Prio provided the laboratory, labor, samples and technical-scientific assistance, in addition to a scholarship for a graduate student at the Polytechnic Institute of Setúbal, in order to assess the sulfur content in different residual raw materials, from different suppliers. and from different countries, and to evaluate the most appropriate type of treatment in terms of sustainability.