The global automobile industry is searching for a replacement for current combustion engines, powered by fossil fuels and which generate a consumption chain that is highly aggressive to the environment. Many countries have opted for policies to encourage the use of electric motors. A solution that, however, comes up against the processes for generating electrical energy, which are not always environmentally sustainable, and the serious problem of disposing of batteries.
An alternative fuel that has been studied to power the engines of the future is hydrogen. To date, the focus of research has been the use of hydrogen in a gaseous state, stored under pressure in tanks in vehicles. But this solution requires the implementation of a wide supply network for this gas, something that has not yet proven commercially viable, especially in countries with large territorial dimensions.
In this race to use sustainable fuels with the aim of achieving zero net carbon emissions (net zero), researchers from the Laboratory of Optimization, Design and Advanced Control (Lopca) at the Faculty of Chemical Engineering (FEQ) at Unicamp have developed a compact chemical reactor, a microreactor, capable of producing hydrogen from ethanol. It can be embedded in vehicles and coupled to fuel cells to power electric motors.
The technology makes it possible to use ethanol from the vehicle's tank to generate hydrogen that will power the electric motor. In this way, the invention can allow the manufacture of electric vehicles fueled by ethanol – an extremely timely solution adapted to the conditions of Brazil, a country rich in renewable sources, a scenario very different from countries that do not have this supply.
The technology, patented by the University with the support of the Inova Unicamp Innovation Agency, is a possible bet to reduce carbon dioxide emissions generated by motor vehicles. The energetic use of hydrogen results in energy and water, that is, waste that returns to the environment in the form of vapor. Professor Rubens Maciel Filho, from FEQ, explains the potential of this technology:
“We are talking about the possibility of producing hydrogen in vehicles from ethanol. This hydrogen can power fuel cells, enabling electrification and reducing CO2 emissions into the atmosphere. All of this in an easier and cheaper way, using technology developed in the country”.
A 3D printed microreactor
The microreactor, designed and built at Unicamp, is a reformer with reduced dimensions. It is approximately the size of a smartphone and its core, the heart of the system, is just 5 centimeters long. Inside the device, chemical reactions take place in a confined space. The device feeds with ethanol on one side and eliminates hydrogen on the other.
The technology developed provides several benefits, such as the intensification of processes, the maximization of heat and mass transfers and the possibility of carrying out high conversions in a short time. Maciel adds that “due to these characteristics, the efficiency and control of reactions are improved, when compared to conventional reactors”.
It is also worth highlighting the way the microreactor is produced. Its plates feature a mesh of microchannels made by 3D printing in metal-specific devices. 3D printing finds a wide range of uses in different areas of the industrial sector, with emphasis on the production of microsystems. The design of the internal parts requires a different architecture, something that conventional manufacturing processes, such as machining, casting, forming, among others, could hardly reproduce. This is a point that favors the application of technology by the industry.
Vesta Greentech is born, a spin off from Unicamp
The potential application of this technology has attracted the attention of automakers located in the country, as stated by engineer Aulus Roberto Romão Bineli, one of the founding partners of Vesta Greentech, a spin off from Unicamp, founded exactly one year ago. The company was created by the inventors of the microreactor to enable the commercial production of reformers (name of the set of hydrogen microreactors).
When it was released last year by Inova Unicamp, the University's technology achieved wide repercussion in the media and attracted the attention of the industry. “But these contacts are still confidential. For now we cannot announce any further details”, comments Bineli.
In addition to Bineli, Vesta Greentech also has as founding partners Maciel, André Luiz Jardini, researcher at FEQ, and Luis Fernando Cassineli, engineer and CEO of the company. The inventors of the technology licensed the patent developed at Unicamp, with support from Inova Unicamp, and are currently working on the additional development of the technology, improving it in accordance with customer expectations. Bineli explains the procedures for this adaptation phase as follows:
“We had an initial stage of more academic development, but the industry sees the technology with a different approach, it requires several technical factors that need to be adjusted. We are finalizing a new, more advanced prototype, which will soon be able to carry out operational tests”, he comments.
Bineli also explains that one of the factors that motivated the creation of Vesta Greentech was the leap in energy efficiency that the new technology can provide, something very attractive for automakers. “Conventional combustion engines have lower energy efficiency, around 15% to 20%. The use of new technology could allow the development of vehicles with efficiency between 40% and 45%, with the potential to be even greater. We see a great opportunity there”, details Bineli.
Another detail of the technology, according to the founding partner, is the increase in the efficiency of the ethanol used to feed the microreactor. According to him, the tests are not being carried out with anhydrous ethanol, common in fuel pumps, but rather with a type of ethanol diluted by up to 50%. “This increases the efficiency of the system and reduces CO2 emissions per kilometer driven”, he adds. All of this reinforces the commercial potential of this technology patented by Unicamp and which could soon be tested with vehicles from automakers installed in Brazil.
