green team

Greentown Labs announces newest startups to join Houston climatetech incubator

Five companies have joined Greentown Labs Houston, specializing in various "green" applications, from converting plastic waste into sustainable materials to developing energy-storage solutions. Photo courtesy Greentown Labs.

Greentown Labs announced that it added five startups to its Houston community in Q1 of 2025.

The companies are among a group of 19 that joined the climatetech incubator, which is co-located in Houston and Boston, in the same time period. The companies that joined the Houston-based lab specialize in a number of "green" applications, from converting plastic waste into sustainable materials to developing energy-storage solutions.

The new Houston members include:

  • Concept Loop, a project of Pakistan-based Innova8e Inc., aims to repurpose post-industrial and post-consumer plastic waste into sustainable building materials.
  • GeoFuels, a Sugar Land-based company that produces hydrogen by using baseload geothermal power and methane pyrolysis.
  • PLASENE, a Houston-based company with an innovative platform that converts plastic waste into liquid fuel and low-carbon hydrogen through its proprietary catalysts and modular, scalable, pre-engineered units platform. The company was named to Greentown's ACCEL Year 3 cohort earlier this year.
  • RepAir Carbon, an Israeli company with a fully electric, zero-heat carbon-removal technology that consumes minimal energy, operates without liquids or solvents, and produces no hazardous materials or waste.
  • RotorVault from Pasadena, California, is commercializing energy-storage and load-following solutions that are containerized, modular, and field-deployable systems built on flywheel technology.

Fourteen other companies will join Greentown Boston's incubator. See the full list here.

PLASENE and five other new members—Thola, Respire Energy, Andros Innovations, FAST Metals and Tato Labs—join Greentown Labs through its most recent Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, cohort. ACCEL, which works to advance BIPOC-led startups in the climatetech space, announced its third cohort last month.

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A View From HETI

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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