Fast food waste and lithium trash could make big biofuel

Your fast-food habit and smartphone could one day power a plane.


What if grease from your favorite chicken place could be transformed into sustainable, green fuel using only waste from your laptop's batteries? It sounds surreal, but it's based in science.

Scientists have discovered a new way to create biofuel using these traditional waste products that would reduce fuel emissions while simultaneously promoting recycling of these potentially harmful materials.

What's the news -- In a new study published Tuesday in the Journal of Renewable and Sustainable Energy, a team of scientists proposed a new approach to creating biofuel that would up-cycle waste from lithium batteries at the same time.

These batteries, while synonymous with technology like smartphones and even electric cars, also have a fairly limited shelf-life and begin to internally degrade after a few years of charging cycles. While good for smartphone companies trying to sell more products, this means that there's also a lot of lithium waste that can be harmful to the environment if not disposed of properly.

The authors write that a process like this could not only improve the practicality of biofuel as a fossil fuel alternative but could also offer a sustainable solution to the growing mounds of electronic, lithium waste.

How does it work -- Before the researchers could start experimenting with their biofuel formula, they had to first round-up discarded vegetable oil from local fast-food restaurants and homes. After straining the oil to remove any leftover food particles, they added a solution of methanol to improve the oils' performance.

Using a chemistry process called transesterification (a kind of chemical musical chairs that exchanges an acid-based chemical group for an alcohol-based one,) the researchers experimented with transforming the collected grease into biofuel using lithium waste to catalyze, or jump-start, the game of musical chairs.

Biofuel could be used as an eco-friendly way to fuel planes that are too big to be battery powered.Shutterstock

Gilberto Maia de Brito, the study's first author and an environmental engineering researcher at the Federal University of Espírito Santo in Brazil, said in a statement that this was the first time lithium had been used this way.

"The results achieved in this work will make it possible to expand the use of new types of metallic catalysts to a higher level, such as lithium, applied to the production of biodiesel," said Maia de Brito. "Before, in practice, these were just restricted to sodium hydroxide and potassium hydroxide.

The chemical reaction looked like this: when introduced to a lithium catalyst, a solution of used oil and methanol transformed into a solution of biodiesel and glycerol.

What were the results -- When looking at the composition of their biofuel, the team found that the reaction created a 90 percent yield on average and exhibited characteristics of a standard biofuel.

"We were surprised that what came out was not only some results, but actually very good results related to the yield production," Maia de Brito said. "The fast phase separation and the main chemistry and physics properties of that biodiesel produced from lithium were also surprising."

What's next -- The authors write that the success of this experiment demonstrates the feasibility of such an approach is producing reliable, large scale amounts of biofuel. In the future, this approach could potentially open doors for a partnership between transportation methods that use biofuel, like ships or airplanes, and smaller electric crafts like cars and bikes. This might not create a totally closed carbon loop, but at least a much more tightly connected one.

Abstract: Eco-green biodiesel is an alternative fuel produced by a sustainable methodology and using renewable sources as feedstock due to its green nature and lower emission of pollutants in comparison with conventional fuels. In this work, biodiesels were produced using an innovative source of catalysts, a mixture of metal hydroxides: lithium-sodium (LiOH+NaOH) or lithium-potassium (LiOH+KOH); due to the considerable increase in the consumption and disposal of Li-ion battery wastes (electronic residues) in recent years. Waste cooking oil samples from fast food chains and households were used as an oily raw feedstock without any prior treatment to produce eco-green biodiesel by transesterification reaction at room temperature. The recycling process not only removes Li-ion battery wastes and oily-contaminant from the environment, but also enables the generation of a green power source. The presence of lithium as a catalyst, for producing eco-green biodiesel, was investigated in order to verify previously, the possibility of using lithium recovered from waste Li-ion batteries present in electronic devices in general. As a result, nicely followed by hydrogen nuclear magnetic resonance, the biodiesel mean yield of 90% using 5 wt% LiOH with 95 wt% NaOH or KOH catalysts, was obtained and considered to be relatively high considering the high-resolution of this technique. Gas chromatography, thin-layer chromatography, hydrogen nuclear magnetic resonance, infrared spectroscopy, density and viscosity were the techniques performed to analyze the chemical structure and physical property of the biodiesel (methyl esters) produced samples in the presence of lithium catalyst.