Oxygen-blown gasifiers and oxy-fuel combustion systems offer cost advantages over their air-blown counterparts for CO2 capture and sequestration—but coal gasification and, oxy-combustion of coal require tremendous amounts of oxygen. Oxygen is also required for industrial processes such as the manufacture of steel, glass, chemicals, and pharmaceuticals.
And the cost of producing pure oxygen is high.
Working with researchers from Arizona State University and New Mexico State University and with financial support from the US Department of Energy and LP Amina, WRI is advancing a sorbent-based oxygen production process that may prove to be as much as 60 percent cheaper to operate than standard cryogenic air separation methods.
In this process, air is passed through a bed of advanced ceramic sorbent, which absorbs the oxygen. The bed material is then swept with a carrier gas, such as steam, and the oxygen is released into the sweep gas. When the steam is condensed, a pure stream of oxygen is produced. The process can also operate with CO2 as the sweep gas or with vacuum.
This oxygen separation technology, featuring a new sorbent material with an affinity for oxygen, operates at a temperature 200 ˚C lower than previous sorbent-based methods and has faster adsorption and release kinetics for greater efficiency and improved economics.
The CAR technology is based on sorption and storage of oxygen at high temperatures (~ 600-800 ºC) in a fixed bed containing mixed ionic and electronic conductor materials. The stored oxygen is released for use in the boiler by partial pressure reduction using a sweep gas such as hot recycled flue gas, steam or a combination.