The pilot project “catch4climate”, for which four cement manufacturers have joined forces, is actively tackling the capturing of CO₂ and its subsequent industrial use. At the site of the cement plant at Mergelstetten in southern Germany, the consortium intends to build and operate its own demonstration plant on a semi-industrial scale, where the so-called oxyfuel process for CO₂ separation will be applied. In the future, the CO₂ captured at Mergelstetten will be used to produce so-called “reFuels” with the help of renewable electrical energy and turned into climate-neutral synthetic fuels such as kerosene for air traffic.

The cement industry is intensively researching solutions, to bring the CO₂ emissions, which are inevitably arising during the burning of limestone, into the product cycle or to use them for new products. For this, the CO₂ has to be captured during the cement production process. In order to demonstrate such processes in practice, the four European cement manufacturers Buzzi Unicem SpA - Dyckerhoff GmbH, HeidelbergCement AG, SCHWENK Zement KG and Vicat S.A. founded the joint venture company CI4C - Cement Innovation for Climate – at the end of 2019. The "catch4climate" project is intended to create the basis for a large-scale application of CO₂ capture technologies in cement plants, in order to enable the CO₂ to be used later as a raw material in other processes (CCU, CCS).

The Oxyfuel process (from Oxy = oxygen and fuel) is a clinker burning process in which pure oxygen is introduced into the cement kiln instead of air. Thanks to the pure oxygen, no other components like nitrogen gets into the burning process and with this, a highly concentrated CO₂ is created. The aim is to capture almost 100 percent of the CO₂ emissions from a cement plant in a cost-effective manner. By using this technology, the European cement industry could achieve a significant reduction in process-related CO₂ emissions and thus make an important contribution to climate protection. The realization of this project is still subject to the public research funding to be applied for.

The CI4C consortium has already entered the planning phase and is cooperating closely with the federal state of Baden-Württemberg in the “catch4climate” pilot project in Mergelstetten. A corresponding “Letter of Intent” was signed on November 18, 2020 in Stuttgart together with the Prime Minister and the Transport Minister of the federal state.