Oxy buys direct air capture firm Holocene

Occidental Petroleum (Oxy) has purchased the direct-air-capture (DAC) company Holocene for an undisclosed sum. This is the energy company’s second recent purchase of a carbon capture firm; in 2023, it bought Carbon Engineering for $1.1 billion.

Both DAC firms use forms of chemical looping to remove carbon dioxide from the ambient air as a pure, concentrated stream that can be injected into geological storage or sold.

Holocene collects the CO₂ through chemical combination with an amino acid dissolved in water. It then reacts that complex with a guanidine-based chemical that binds CO₂, and the product precipitates as a solid, regenerating the amino acid. Heating that solid releases pure CO₂ and regenerates the guanidine.

Carbon Engineering has two intersecting loops as well but instead grabs CO₂ from the air with potassium hydroxide and passes it to calcium carbonate before the heat-driven CO₂ -release step. In early April, Oxy said it would start operations later this year at a plant in Texas that uses the chemistry to capture 500,000 metric tons (t) of CO₂ annually.

In response to questions about plans for Holocene’s technology, Oxy spokesperson Will Fitzgerald referred C&EN to Holocene’s website. On April 18, that site went from a thorough description of the start-up’s technology and market differentiation to a single page with two paragraphs stating the acquisition had taken place and a link to Carbon Engineering’s website.

In the fall, Holocene scored one of the largest carbon removal deals so far for a DAC firm when Google agreed to purchase $10 million in carbon credits at a rate of $100 per metric ton of CO₂ removed from the atmosphere. Mara Harris, a public affairs manager at Google, says in an email that the acquisition does not change the contract the tech giant has with Holocene.