Planeteers brings CO2 from the air into the sea

The Hamburg-based startup Planeteers captures CO2 where it is produced in large quantities and binds it in seawater for a long time. This contribution to climate protection was rewarded with a financing round in the millions and a prestigious startup prize in 2024.

His wife, whom he had met in New Zealand, was unable to obtain a visa for the country. Brinkmann began studying business administration at WHU - Otto Beisheim School of Management so that he could set up his own business and stay in his home city of Hamburg instead of traveling the world. He graduated in 2017 and was one of the founders of VIMATO in 2018. The startup, which focused on influencer marketing, was one of the first to receive funding from IFB Innovationsstarter GmbH's InnoFounder programme. Like two of Brinkmann's other startup projects, it did not succeed in the long term, but the experience gained during this time was still valuable to him.

The story of industrial engineer Frank Rattay has some parallels to the story of the other two. He also conducted business for large companies for many years, with a focus on mobility. He spent ten years working for the management consultancy Kearney for clients in the automotive industry and twelve for Airbus in management positions. He also aspired to be self-employed at some point and did not achieve the breakthrough he had hoped for with his first startup infresh and a machine for the automated preparation of meals. In retrospect, a parents' evening at which he met Florian Brinkmann was more groundbreaking.

The startup's contribution to combating climate change and reducing CO2 emissions is based on a natural process, the weathering of limestone. In this process, atmospheric CO2 reacts with rainwater (H2O) to form carbonic acid (H2CO3), which decomposes limestone (CaCO3) on the earth's surface. Bicarbonate (HCO3-) is formed. Rivers transport it into the oceans, which represent the largest carbon reservoir on our planet, where it is stored for well over 10,000 years. This reaction takes place in nature constantly, everywhere and on a large scale. The only catch: this process takes a very long time, stretching over a period of several thousand years.

To this end, the team built a plant in a backyard garage in the Eimsbüttel district with a capacity suitable for large quantities of bound CO2 that fits into a standard commercial container. The project began with detailed operational planning with appropriate design drawings, then the individual components required were defined. 80 % of these are available on the open market, 20 % were built in-house or developed further. There is a practical reason for opting for the container format: the systems should be easy to transport so that they can be set up directly at locations where large quantities of CO2 are produced, such as power plants and factories.

The year 2024 brought a breakthrough and a series of successes for Planeteers. The first prototype with a capacity of 60 tons of CO2 per year already proved its suitability for practical use at a biogas plant. Financial progress was also made. In the summer, a mid-seven-figure sum was raised in a seed financing round. Participants included BonVenture, the Smart Energy Innovationsfonds of Energy 360° AG and ClimaNow. The Hamburger Gründerpreis (Hamburg Founder's Award) in the startup category attracted a great deal of media attention in September. By the way, the team did not have to apply for the award. They received an invitation at short notice, pitched in the morning and were accepted in the evening.

So Planeteers alone cannot solve the CO2 problem, but it can at least make an important contribution. The team around the four founders would therefore like to see even more entrepreneurs seize the opportunity and combine climate protection with economic success.