Circular economy of native Euphorbiaceae: From second-generation biodiesel production to animal food. Taking advantage of marginal lands

Abstract

Biodiesel emerges as the renewable fuel that best suits the requirements of diesel vehicles. However, the dichotomy "food versus energy," that is, the allocation of resources to increase the energy matrix to the detriment of food generation and the advance of the agricultural frontier on native flora generating deforestation, are the current challenges of the science. This work aimed to evaluate the replacement of conventional oils to biodiesel production with inedible oils obtained from the seeds of four native species of Euphorbiaceae in Argentina. This type of plant grows in arid or semi-arid soils with a low rainfall regime, and therefore their cultivation areas do not coincide, nor compete, with those of the crop destined for traditional agri-foods, resulting in this a significant advantage. To produce second-generation biodiesel with unconventional oils, a heterogeneous enzymatic catalyst based on the biosilicification of the enzyme lipase from Pseudomonas fluorescens, was used. This strategy facilitates the stages of purification and subsequent reuse, employing oils with high free fatty acid (FFA) content and the potentiality of being used in batch or continuous systems. Additionally, the nutritional value of the expeller (cake) of each species obtained from the oil extraction was evaluated in mice. In this way, a sustainable model is proposed where the ?food vs. energy? dichotomy is satisfied.