World’s first ethanol-to-hydrogen conversion plant completed at the University of São Paulo

By Elton Alisson  |  FAPESP Innovative R&D – In the coming weeks, the world’s first ethanol-based renewable hydrogen fueling station will begin operations on the main campus of the University of São Paulo (USP) in the city of São Paulo, Brazil.

The announcement was made by the institution's rector, Carlos Gilberto Carlotti Junior, at the opening of the Energy Transition Research and Innovation Conference (ETRI) 2024, hosted by the Research Center for Greenhouse Gas Innovation (RCGI) between November 5th and 7th.

“We’re now inaugurating our hydrogen reformer. Starting next week [Nov 11 to Nov 17], we’ll be producing hydrogen from ethanol here at our university,” said Carlotti Junior.

The fueling station is the result of a project by the RCGI, an Engineering Research Center (ERC) created by FAPESP and Shell at the Polytechnic School (POLI-USP). The RCGI is one of the ERCs funded by the Foundation in partnership with companies.

The station will initially produce 4.5 kilograms (kg) of hydrogen per hour – about 100 kg per day. The fuel will be used to supply three city buses that will circulate around the USP campus in São Paulo, and one road bus, with a range of 450 kilometers (km), enough to travel from USP’s main campus to Piracicaba, in the interior of São Paulo state, explained Julio Meneghini, director of the RCGI, during a visit to the pilot plant for invited guests. One of the buses was used to take visitors to the station on November 5th.

“Preliminary studies show that if 18 diesel-powered city buses currently operating around USP were replaced with hydrogen-powered versions, the university would eliminate nearly 3,000 tons of CO₂ [carbon dioxide] emissions per year,” said Meneghini.

Through projects carried out within the RCGI, the researchers intend to evaluate the efficiency of these hydrogen-powered city buses. “We’ll now be able to evaluate these vehicles in a real cycle. This is very important for application, because in the automotive industry, in order to get to series production of a vehicle, you need to have the numbers very well determined and defined in real operations,” added Meneghini.

Competitive cost

The technology used in the pilot plant for converting hydrogen from ethanol is based on the use of a reactor developed by the São Paulo startup Hytron with the support of FAPESP’s Innovative Research in Small Businesses Program (PIPE).

Inside the equipment, called a reformer, ethanol and water are heated to 750 °C to trigger chemical reactions that break down ethanol molecules – made up of carbon and hydrogen atoms – to produce hydrogen and biogenic, non-fossil carbon monoxide.

“At the beginning of the reaction, ethanol itself is used to reach this temperature of 750 °C. Then by-products such as methane and CO are used to maintain that temperature,” said Meneghini.

Using technology developed by Raízen, one of Brazil’s largest sugar, ethanol and bioenergy companies, it was possible to integrate the entire process and use 7 liters of ethanol to produce 1 kg of hydrogen.

It also uses 2.5 kilowatt hours (kWh) to maintain the pressure and electrical systems. “But if we evaluate all these numbers, we can see that the hydrogen produced at the station will be extremely competitive, even for use in these four buses here at USP,” Meneghini concluded.

The gases produced by the reactions are purified in cylinders that separate CO (carbon monoxide), CO₂, methane, and hydrogen, which must reach a purity of 99.999% to be used in both the buses and the Mirai car that Toyota is providing for the project – the world’s first mass-marketed hydrogen vehicle, whose batteries are charged by the chemical reaction between hydrogen and oxygen in the fuel cell electric vehicle.

After being produced and leaving the purifier, the hydrogen is compressed and stored in tanks at a pressure of about 400 atmospheres. “This is already enough to fuel the buses and the Mirai vehicle, which can travel 120 km on 1 kg of hydrogen [with a full tank, the car can travel 600 km on 5 kg of hydrogen],” said Meneghini.

With the plant in full operation, the researchers want to determine, among other things, how much CO₂ is emitted to produce 1 kg of hydrogen, the actual consumption of the vehicles, and how long the station can be operated on average.

“When you turn the plant on and off, there’s a huge drop in efficiency. It has to operate at somewhere between 50% and 100% of its capacity. If we can’t find a use for all the hydrogen that’s produced, we’ll end up having to turn the plant off for certain periods of time or do a flare [burn], which doesn’t contribute to greenhouse gas emissions because hydrogen combustion doesn’t emit CO₂,’ Meneghini noted.

Climate emergency

Now in its seventh year, ETRI 2024 aimed to discuss the challenges and innovative solutions for reducing carbon emissions, bringing together academia, industry, government and society to promote a sustainable and fair energy transition, highlighted Karen Mascarenhas, conference coordinator.

“More than 500 participants from academia, business and government have registered for the event with the aim of accelerating the energy transition and reducing greenhouse gas emissions. Inspired by the urgency to act in the face of recent extreme weather events, we’re bringing science and innovation to make a positive and tangible impact on society,” she added.

The president of FAPESP, Marco Antonio Zago, emphasized that the institution has a long history of commitment to this agenda, exemplified by its funding of the RCGI and three strategic programs created more than 20 years ago: the FAPESP Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA), the FAPESP Bioenergy Research Program (BIOEN), and the FAPESP Research Program on Global Climate Change (RPGCC). But more needs to be done, he said.

“Despite this diversity of current initiatives, projects and programs, they’re probably still not enough. We need to be more ambitious and bold. There’s an urgent need to increase interaction and communication between these multiple research centers and initiatives,” he stressed.