New technology can collect CO2 from a truck's exhaust pipe

Every year, trucks shipping goods across Switzerland emit over a million tons of CO₂, according to figures from the Swiss Federal Statistical Office. The share of electric trucks is growing but the exact percentage has not been made public. In the EU, just 600 electric trucks weighing at least 16 metric tons were registered in the first quarter of 2023, compared to 86,455 combustion-engine ones. Qaptis aims to reduce the carbon footprint of these conventional freight trucks with its new decarbonization system, which traps the CO₂ coming out of the exhaust pipe and stores it in a liquid state. With a prototype now installed at a local freight carrier, with which Qaptis has entered into a strategic partnership, the startup is poised to run pilot tests under real-world conditions. “We plan to begin operating our first test vehicle in late 2024,” says Théodore Caby, Qaptis co-founder and COO.

Capturing CO₂ at the source

The system’s core technology was developed at the Industrial Process and Energy Systems Engineering Laboratory in EPFL's School of Engineering. It involves transitioning CO₂ from a gas to a liquid state while using as little outside energy as possible in order to create a virtuous circle. Qaptis’s system is intended to be installed on existing trucks. Once the CO₂ is collected from a truck’s exhaust pipe, it’s cooled and separated from other gases (nitrogen and oxygen) by passing the mixture over an adsorbent in powder form. “We eventually plan to use an organometallic powder that will further improve our process,” says Caby. “But the one we have in mind isn’t yet being produced on an industrial scale.” After the adsorbent becomes saturated, it’s heated using the heat from the combustion engine. This releases the CO₂, which high-speed turbochargers then compress into a liquid so that it takes up less volume. “We’ve finally completed the first step, which was transferring our core technology from the lab to industry,” says Caby. “Now we’ll focus on developing a device that can be installed directly in trucks.”

If our planet is to reach net zero by 2050 as recommended by the Intergovernmental Panel on Climate Change (IPCC), we’ll need to do more than cut our greenhouse gas emissions and transition to renewable energy – we’ll also need to remove billions of tons of CO₂ from the atmosphere. Companies in a number of industries are adopting carbon-capture technology, while others are developing systems for carbon storage and utilization. For instance, captured CO₂ has applications in the production of food, fertilizer, energy, building materials and synthetic fuels. This latter application is where Qaptis’s system comes in: the liquid CO₂ will be stored in a tank behind the cab and can be drained when the truck returns to its freight terminal. “We initially plan to target local freight carriers that want to reduce their environmental impact,” says Caby. Later on, the firm will develop a recovery system allowing drivers to empty their CO₂ tanks at gas stations, so that its technology can be employed more broadly.

A CHF 1.3 million initial funding round

Qaptis reached a major R&D milestone this past spring when its prototype produced the first drops of liquid CO₂. Although still somewhat cumbersome, the prototype can be hooked up with standard connections and can run under normal conditions. It was initially tested at a US firm with which Qaptis has long-standing ties, but was recently transferred to Tolochenaz for further optimization work. However, it’ll still be a few more months before the system is miniaturized enough to be installed on vehicles. Caby explains: “Our goal is to create a breakthrough device that’s modular and compatible with different kinds of trucks. So we’ll need to go through several iterations outside the lab in order to make it ready for everyday use.”

Thanks to a successful funding round last March, when Qaptis raised CHF 1.3 million from business angels and venture-capital funds, the firm is set to embark on this next phase of development. “We’re currently in talks with a large local freight carrier that would like to implement our technology soon,” says Caby. “We’ve also been contacted by businesses in Asia, but for now we’re focused on the Swiss, German and Austrian markets.” One day, Qaptis’s technology could be used for other types of vehicles too, such as ships.