An innovative production method relies on electrolysis to eliminate carbon emissions during cement production.
Manufacturing common Portland cement involves grinding limestone and heating it with coal, which releases carbon dioxide from both the burning coal and gases from the heated limestone. To help reduce these emissions, the team from MIT developed a manufacturing process that replaces the coal with an electrolyzer. As the electrolyzer splits water molecules, it produces an acid at one electrode that dissolves the pulverized limestone and causes solid calcium hydroxide (lime) to precipitate at the other. That lime is then used to create cement, while the pure CO2 steam can be captured and used in other applications.