new findings

Rice research team's study keeps CO2-to-fuel devices running 50 times longer

Ahmad Elgazzar, Haotian Wang and Shaoyun Hao were members of a Rice University team that recently published findings on how acid bubbling can improve CO2 reduction systems. Photo courtesy Rice.

In a new study published in the journal Science, a team of Rice University researchers shared findings on how acid bubbles can improve the stability of electrochemical devices that convert carbon dioxide into useful fuels and chemicals.

The team led by Rice associate professor Hoatian Wang addressed an issue in the performance and stability of CO2 reduction systems. The gas flow channels in the systems often clog due to salt buildup, reducing efficiency and causing the devices to fail prematurely after about 80 hours of operation.

“Salt precipitation blocks CO2 transport and floods the gas diffusion electrode, which leads to performance failure,” Wang said in a news release. “This typically happens within a few hundred hours, which is far from commercial viability.”

By using an acid-humidified CO2 technique, the team was able to extend the operational life of a CO2 reduction system more than 50-fold, demonstrating more than 4,500 hours of stable operation in a scaled-up reactor.

The Rice team made a simple swap with a significant impact. Instead of using water to humidify the CO2 gas input into the reactor, the team bubbled the gas through an acid solution such as hydrochloric, formic or acetic acid. This process made more soluble salt formations that did not crystallize or block the channels.

The process has major implications for an emerging green technology known as electrochemical CO2 reduction, or CO2RR, that transforms climate-warming CO2 into products like carbon monoxide, ethylene, or alcohols. The products can be further refined into fuels or feedstocks.

“Using the traditional method of water-humidified CO2 could lead to salt formation in the cathode gas flow channels,” Shaoyun Hao, postdoctoral research associate in chemical and biomolecular engineering at Rice and co-first author, explained in the news release. “We hypothesized — and confirmed — that acid vapor could dissolve the salt and convert the low solubility KHCO3 into salt with higher solubility, thus shifting the solubility balance just enough to avoid clogging without affecting catalyst performance.”

The Rice team believes the work can lead to more scalable CO2 electrolyzers, which is vital if the technology is to be deployed at industrial scales as part of carbon capture and utilization strategies. Since the approach itself is relatively simple, it could lead to a more cost-effective and efficient solution. It also worked well with multiple catalyst types, including zinc oxide, copper oxide and bismuth oxide, which are allo used to target different CO2RR products.

“Our method addresses a long-standing obstacle with a low-cost, easily implementable solution,” Ahmad Elgazzar, co-first author and graduate student in chemical and biomolecular engineering at Rice, added in the release. “It’s a step toward making carbon utilization technologies more commercially viable and more sustainable.”

A team led by Wang and in collaboration with researchers from the University of Houston also shared findings on salt precipitation buildup and CO2RR in a recent edition of the journal Nature Energy. Read more here.

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A View From HETI

Cemvita has named a new leader in Brazil. Photo via cemvita.com

Houston industrial biotech company Cemvita has announced two strategic moves to advance its operations in Brazil.

The company, which utilizes synthetic biology to transform carbon emissions into valuable bio-based chemicals, acquired a complementary technology that expands its IP and execution of scale-up capacity, according to a news release. The acquisition will bring additional synthetic biology toolsets that Cemvita believes will assist with compressing and commercializing timelines.

The company also appointed Luciano Zamberlan as vice president of operations based in Brazil.

Zamberlan will lead operational execution, site readiness and early commissioning activities in Brazil. He brings more than 20 years of experience in biotechnology to the role. He recently served as director of engineering at Raízen, Brazil’s largest ethanol producer and the world’s largest producer of sugarcane ethanol. At Raízen, he coordinated the implementation of four greenfield plants and oversaw operational teams and process optimization for second-generation ethanol (E2G) and biogas.

“I am very pleased to join Cemvita, a company at the forefront of transforming waste into valuable, sustainable resources,” Zamberlan said in the release. “My expertise in scaling-up innovation, coupled with my experience in structuring and commissioning greenfield industrial operations, is perfectly aligned with Cemvita's mission and I'm eager to bring my energy and drive to accelerate Cemvita's industrial performance and contribute for a circular future.”

Cemvita expanded to Brazil in January to help capitalize on the country’s progressive regulatory framework, including Brazil’s Fuel of the Future Law, enacted in 2024. The law mandates an increase in the biodiesel content of diesel fuel, starting from 15 percent in March and increasing to 20 percent by 2030. It also requires the adoption of Sustainable Aviation Fuel (SAF) and for domestic flights to reduce greenhouse gas emissions by 1 percent starting in 2027, growing to 10 percent reduction by 2037.

“These steps enable us to augment Brazil’s longstanding bioindustrial ecosystem with next-generation capabilities, reducing early commercialization risk and expanding optionality for future product platforms,” Marcio Silva, CTO of Cemvita, said in the news release. “Together, they strengthen our ability to move from proof-of-concept to industrial reality.”

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