Unlike its post-combustion counterpart, pre-combustion capture takes a preventative approach. Rather than dealing with CO2 after it’s formed, pre-combustion capture transforms fossil fuels into a mix of hydrogen and carbon dioxide before they're combusted.
This technology is primarily used in Integrated Gasification Combined Cycle (IGCC) power plants. These power plants convert coal or other hydrocarbons into synthetic gas or 'syngas', allowing CO2 to be captured before the combustion stage.
How does Pre-Combustion Capture work?
The mechanics of pre-combustion capture may seem like the stuff of sci-fi, but the process is straightforward:
Firstly, fossil fuels, such as coal, are treated with oxygen and steam under high pressure and temperature conditions to produce syngas, primarily composed of carbon monoxide (CO) and hydrogen (H2).
This syngas then enters a 'shift reactor', where carbon monoxide reacts with steam to produce CO2 and more H2.
After this, the gas mixture undergoes a process called 'gas separation', where the CO2 is captured, leaving hydrogen-rich gas that can be burned for power without releasing CO2 into the atmosphere. Pretty cool, right?
Who’s pushing the Pre-Combustion Capture frontier?
Numerous companies are stepping up and steering pre-combustion technology towards a sustainable future. Here are a few of the pioneers:
GE Power: GE's IGCC technology is designed to increase efficiency and reduce the environmental impact of coal-fired power stations. They’re leveraging pre-combustion capture in their design to enable cleaner power production.
Siemens Energy: Siemens has developed SFG-850, an IGCC plant that facilitates pre-combustion capture. This technology allows the plant to produce clean power while significantly reducing emissions.
Shell: Shell’s gasification technology is used around the world in gasification plants, many of which utilise pre-combustion capture. They're also involved in several carbon capture and storage projects globally.
Final Thoughts
This technology presents a proactive approach to carbon capture, offering a way to curtail CO2 emissions right at the source. It’s not just about treating the symptoms; it’s about striking at the root of the problem.
