In the battle against greenhouse gases, carbon capture has always been a hot topic, but has never materialized as a practical and widely used technology. Carbon capture is the process of removing carbon from smokestack emissions before it enters the atmosphere. For the most part, carbon capture and storage discussions have hinged on future developments that would hopefully make it a feasible option.
The inexpensive and practical solution may be plain old limestone. It turns out, according to research currently being done in Europe, that installing a limestone derived material in power plant smokestacks can actually absorb about twice as much carbon dioxide as the traditional complicated and expensive systems in use today. Currently, researchers in Europe are testing the material in two different power plants, both at the megawatt scale.
The secret to the limestone system is simple chemistry. When heated, limestone will react with carbon dioxide to produce calcium carbonate. This reaction releases heat, and, when heated further, the carbon dioxide can be extracted. What’s more, the heat produced by this activity (up to 900° C) generates steam that is used to drive turbines. This makes the limestone process twice as energy efficient as older carbon capture technology because the heat needed to spur the chemical reaction also contributes to driving the turbines that produce electricity.
The idea for this technology is not new, but the inefficiency and expense of current carbon capture technology has spurred further research into lime as a medium for trapping carbon. The research performed at the megawatt level is promising, but this carbon capture method is still untested at a large scale commercial power plant. According to scientists, a 50 megawatt scale test is needed before the technology is ready to progress to commercial use.
Energy Curtailment Specialists, Inc.