A study conducted at the University of Pisa introduces a novel circular economy strategy that tackles two of the most pressing global issues of the present day: the pressing necessity for a transition to renewable energy sources and the increasing issue of food waste. The research, published in the Journal of Environmental Chemical Engineering, aims to convert bread trash, one of the world's most common food wastes (almost one million tons per year), into a sustainable biofuel. The study investigates, for the first time, the sustainable synthesis of ethyl levulinate from bread waste. Ethyl levulinate is a bio-based compound with significant added value, already used in the chemical sector and as an oxygenated gasoline additive. The researchers devised a straightforward, cost-effective process that can be effortlessly scaled up to industrial scale. This process involves the use of a low-cost catalyst, dilute sulfuric acid, and high initial biomass concentrations. This method enables more concentrated product flows, lowering separation costs and improving overall process efficiency. By optimizing parameters such as temperature, reaction duration, and catalyst quantity, a maximum ethyl levulinate yield of 57% was achieved, which is especially remarkable given the raw material's waste origin. This study opens up new possibilities: for the first time, the compound was tested in gasoline engines, combined with commercial fuel at high concentrations. Experimental tests have shown that using ethyl levulinate reduces pollutant emissions and the percentage of fossil fuels in commercial fuels. This finding greatly increases the market potential of ethyl levulinate, which has been proven to be acceptable for use in both diesel and gasoline engines.