The best material to keep carbon dioxide from natural gas wells from fouling the atmosphere may be a derivative of asphalt, according to Rice University scientists. The Rice laboratory of chemist James Tour followed up on last year’s discovery of a “green” carbon capture material for wellhead sequestration with the news that an even better compound could be made cheaply in a few steps from asphalt, the black, petroleum-based substance primarily used to build roads.
The research appears in the American Chemical Society journal Applied Materials and Interfaces.
The best version of several made by the Tour lab is a powder that holds 114 percent of its weight in carbon dioxide. Like last year’s material, these new porous carbon materials capture carbon dioxide molecules at room temperature while letting the desired methane natural gas flow through.
The basic compound known as asphalt-porous carbon (A-PC) captures carbon dioxide as it leaves a wellhead under pressure supplied by the rising gas itself (about 30 atmospheres, or 30 times atmospheric pressure at sea level). When the pressure is relieved, A-PC spontaneously releases the carbon dioxide, which can be piped off to storage, pumped back downhole or repurposed for such uses as enhanced oil recovery.