A low-carbon future is our best bet at mitigating climate change, but eliminating the use of fossil fuels is unlikely to happen overnight. According to the International Energy Agency, the burning of fossil fuels is likely to continue through 2040. Finding ways to reduce impacts in the interim is, therefore, essential. North Carolina startup NET Power has found a way to power the transition to a CO2-free future without parting ways with fossil fuels with its pioneering turbine technology.
Piloted at its natural gas plant in Houston, Texas, the technology is powered by carbon dioxide in lieu of the steam used in conventional plants, which is turned into mechanical energy and later electricity. The system draws on the Allam cycle, a process for converting fossil fuels using a single turbine into mechanical power while capturing the resulting water and CO2. This is made possible by using pure oxygen to burn the fuel. The CO2 is separated out in a heat exchanger, then compressed mechanically and a small amount is captured at high pressure, ready for pipeline transmission. The rest of the carbon is reheated and recycled into the combustion unit. The Allam cycle was developed by Rodney Allam in collaboration with 8 Rivers, an investment firm focused on innovative technology.
In addition to eliminating emissions such as CO2, particulate matter, mercury, SOx and NOx, the technology can also eliminate water consumption because it doesn’t require steam for power production.
Due to the high-efficiency design of the turbines, which are one-tenth the size of traditional turbines, NET Power says it will be able to deliver emission-free power at about $0.06 per kilowatt-hour — a major milestone for carbon capture. Carbon capture technologies have traditionally been energy intensive and those costs, using up to 30 percent of a power plant’s energy and as a result driving up the cost of electricity.
Once final testing is complete on its prototype, NET Power will begin operating its plant at full capacity in 2018. The plant is expected to produce enough electricity to power 40,000 homes. If successful, the startup intends to create a 300-megawatt power plant in 2021, which would power more than 200,000 homes. Additionally, the company plans to license the technology in an effort to drive an industry-wide shift.
“This is the biggest thing in carbon capture,” Howard Herzog, a chemical engineer and carbon capture expert at MIT, told Science. “It’s very sound paper. We’ll see if it works in reality. There are only a million things that can go wrong.”