Making brown coal green

Issue 19 | Autumn/Winter 2007

Report: Tim Mitchell
Photo courtesy of Loy Yang Power

A boiler operator checks the main boiler at Loy Yang Power in Gippsland.

At a time of greater awareness of climate change, Monash University researchers are leading the way in development of clean coal technologies. In addition to driving improved methods of electricity generation, clean coal innovation could also be the key to developing other renewable energy sources.

When it comes to brown coal-fired power plants it's not easy to be green.

High moisture content of up to 60 per cent water means, despite ongoing improvements, traditional combustion of brown coal remains highly inefficient, contributing to global warming and climate change.

Victoria possesses a huge reserve of brown coal. It has long been the main energy source driving the social and economic development of the State, meeting the vast majority of the growing economy's electricity needs.

Victoria's brown coal reserves are the best in quality in the world, and at the current rate of utilisation will last for at least another 500 years. However, one Monash expert Professor Chun-Zhu Li, from the Department of Chemical Engineering, says greater environmental awareness is now challenging the future use of brown coal, particularly in terms of the need to reduce carbon dioxide emissions. Failing to meet this challenge may compromise the future of the brown coal industry.

"This in turn may have major implications for the social and economic development of Victoria," Professor Li says.

Monash researchers are part of the solution to drastically cut the emissions from brown coal based power generation. Their development will involve a partnership of industry, researchers like the CSIRO and Cooperative Research Centre for Greenhouse Gas Technologies (CRCCO2) and governments as well as collaboration with national and international partners in countries like China, Germany, Japan and USA.

One three-year project led by Professor Li will aim to develop an oxy-fuel combustion technology for retrofitting to the existing power plants in the La Trobe Valley.

"Oxy-fuel combustion refers to the combustion of coal particles in a mixture of oxygen and recycled flue gas with the production of carbon dioxide in a form directly suitable for sequestration or storage with minimal further treatment," Professor Li says.

"Coupled with carbon sequestration, the implementation of oxy-fuel combustion technology in the existing power generation plants has the potential of drastically reducing their carbon dioxide emissions, even to near zero."

Professor Li's team will also explore an advanced gasification technology for Victorian brown coal.

"The unique thermochemical properties of Victorian brown coal makes it particularly suitable for power generation using gasification-based technologies," he says.

"Using gas turbines and fuel cells, gasification-based technologies offer very high power generation efficiencies. Power generation using the cheap Victorian brown coal does not have to be more carbon-intensive than that using the more expensive black coal or natural gas."

Expertise in clean coal research runs deep at Monash University. Monash has had a long tradition of research excellence in the area of brown coal science and technology, which has been a priority research area since its inception.

Prior research in Monash covers almost every aspect of brown coal science and technology, including its structure and properties, its drying, carbonisation, liquefaction, pyrolysis, combustion and gasification, its non-fuel use as well as the environmental aspects of brown coal utilisation.

Today Monash continues to enjoy an excellent international reputation in brown coal science and technology. When the Victorian Premier, Mr Steve Bracks, recently announced almost $10 million in research grants in this field, the University was involved in nine of the ten projects.

Vice-Chancellor, Professor Richard Larkins, welcomed the funding announcement, "Monash University has been at the forefront of clean coal technology since the 1970s and today remains committed to a role in climate change solutions and the effective utilisation of Victoria's valuable brown coal resource," he said.

"Monash's Gippsland campus, located close to Victoria's massive brown coal deposits, combined with a strong Clayton engineering base, means the University is ideally placed to provide ongoing leadership."

It was, he said, also an important step towards establishing the Gippsland campus as an important node of engineering research into clean coal technology.

Professor Li says the long term sustainable development of Victoria dictates that the emissions from power generation using the brown coal be minimised and that the use of brown coal be prolonged for as long as possible.

This he says will provide an economic bridge to true sustainable development and commercialisation of other economically competitive renewable energy technologies such as solar and biomass.

So, if Monash researchers have their way, brown coal will be green after all.