Tech #29 “Turning CO2 into Cement”
TURNING CO2 INTO CEMENT
Global climate change is a growing global problem every decade. Climate change is caused by increased greenhouse gases (namely Carbon Dioxide) being released into the atmosphere. Carbon Dioxide mainly comes from burning fossil fuels—coal, natural gas, and oil from power plants and oil refineries. However, a new type of technology developed from a California company named Calera is being introduced to climate-friendly energy production by reducing the amount of Carbon Dioxide output by replacing it with something more useful: cement.
Turning CO2 into Cement
Cement is the second most ...view middle of the document...
Figure 2 shows the process of converting Carbon Dioxide into self-cement and other chemicals. Notice that the smoke stack is releasing clean air, which is being replaced by the greenhouse gas CO2 emissions. Water and pollution are mixed together and dried by the spray dryers that use the heat in the flue gas. The Calera results of the dry compound is a white, chalky cement that can be substituted for the Portland cement that is typically blended with rock and other materials to make the concrete that is used to build anything between roads and buildings. Calera’s process of making calcium carbonate cement would not eliminate all CO2 emissions but in theory would reverse that equation. Brent Constantz, founder of Calera and crystallographer said, “For every ton of cement we make, we are sequestering half a ton of CO2. We probably have the best carbon capture and storage technique there is by a long shot.”
CO2 Reduction and Climate Change
Carbon Dioxide is the main contributor to greenhouse gases in the global climate change. CO2 is released from power plants and vehicles all over the world. Approximately 62 million cars are registered in the US alone, according to the U.S. Department of Transportation. There are also 2,775 power plants in the US alone. 30,000 parts per million of Carbon Dioxide are released from the 700-degree Fahrenheit fumes into the atmosphere from the turbines at Moss Landing power plant along the California coast is an example of the amount of CO2 released from one single power plant. This new idea of technology would reduce the amount of the greenhouse gas CO2 being released into the atmosphere and would capture and store it in cement. During the life of the concrete structure, the concrete carbonates and absorbs the CO2 released by the calcination during the cement manufacturing process. Full carbonation occurs once the concrete has returned to fine particles, and all the CO2 released by calcination is reabsorbed. Another benefit is that concrete is a locally produced material and is shipped only short distances, minimizing the amount of carbon dioxide released from vehicles. Its primary components are sand and gravel or crushed stone—which are materials that are universally available. Concrete is a material that can last a lifetime or even longer, with low...