The Hazelwood coal fired power station in the state of Victoria is the most greenhouse intensive plant in Australia. It generates around 17 million tonnes of carbon emissions every year. The plant was originally due for decommissioning in 2005, but controversially had its licence extended until 2031.
I was thinking surely Hazelwood is expected to improve its environmental performance if left operational. And sure enough Hazelwood has been successful in securing a grant for a Carbon Capture demonstration project.
One of eight plants at Hazelwood has been fitted with a Carbon Capture Module, which removes around 90% of carbon (C02) from the flue gases. Explaining the process is quite complex, but essentially half the C02 is sequestered into a mineral call calcium carbonate. This is done by taking the captured C02 solvent and injecting it into ash water, a by-product of coal fired plants, that has a high concentration of calcium hydroxide (not nice stuff!). This generates a reaction that results in the production of fine particles of calcium carbonate. This is a non-hazardous mineral that sequesters the C02 and can be used as an additive for production of varying man-made materials such as cements and plastics.
The remaining C02 is captured and stored, with stage 2 of the project aiming to dispose of the C02 via possible geosequestration (pumping the C02 underground) or transport to other sites for water treatment or other industrial applications. The project is the first retrofit to an existing coal fire station in Australia and while the results are promising it’s still a long way off cleaning up Hazelwood.