Brisbane company Carbon Energy (www.carbonenergy.com.au) has announced it has started generating electricity at its 5MW Bloodwood Creek facility near Dalby, using underground coal gasification (UCG) technology. The company has a contract with Ergon Energy to start supplying electricity to the grid in October of this year.
Carbon Energy’s technology is very different from the better known coal seam gas (CSG) method of extracting energy from the gas deposits which accompany all coal deposits. CSG recovers gas held in fractures of underground coal seams by water and ground pressure, and involves drilling into the coal seam and pumping groundwater in to force the gas to the surface. It often involves the controversial process of “fracking” – fracture stimulation – which fractures underground coal seams in order to increase the flow of gas and water.
UCG, by contrast, transforms solid coal into gas on site. A small amount of natural gas is pumped down ta well to heat the coal and initialise the gasification process. Air, or a combination of oxygen and steam, is then pumped into the coal seam, which initiates a reaction that converts the coal into gas. The technology was used in Soviet Russia in the 1930s, but never achieved large scale production because of the difficulty in maintaining a consistent quality of gas throughout the extraction process.Carbon Energy was spun out from the CSIRO in 2007 to commercialise the process, which CSIRO had been working on for ten years. They key was to ensure a consistent flow of gas, necessary to bring the technology to commercial reality. That has been done. The technology creates “syngas”, a mixture of carbon monoxide and hydrogen, which can be used to generate electricity by conventional means. Carbon Energy has pilot projects in the USA, Turkey, Chile and India. The company is listed on the ASX (CNX), with Incitec Pivot as its biggest shareholder.
UCG shows promise. It cannot be used on all coal seams, but has few of the environmental problems of CSG. The commercialisation of the technology through Carbon Energy’s relationship with Ergon is extremely promising, and may lead to large scale production across Australia.
