2 weeks ago
Gas should be the go: Davey
By PHILIP HOPKINS
A LATROBE Valley expert has urged the gasification of the region’s brown coal to produce Australia’s fuel and fertiliser supplies, which are in crisis due to the Iran war, to help ensure Australia’s energy independence and create more Gippsland jobs.
“Here we go again! Mass panic and economic disruption that could have been avoided if we had just a little foresight and political courage – an oxymoron I know,” said Brian Davey, who has 40 years’ experience as a brown coal technology expert with the SEC and in university research.
Apart from electricity, “our coal can produce diesel, jet fuel, hydrogen, ammonia and urea just to name a few products – all with zero emissions”.
In Australia, the Iran war has produced fuel shortages on farms and in regional areas, and has led to surging fertiliser costs, prompting warnings from food industry leaders that a lack of food availability could threaten social cohesion.
Mr Davey said the brown coal could be gasified with modern technology gasifiers such as the one proposed by JPower from Japan and then using the Fischer-Tropsch (FT) process.
This is a proven technology developed in Germany in the early 20th century and refined since then to convert the syngas produced to liquid fuels.
“FT has been commercially used in South Africa, China, Malaysia, Qatar and a number of other countries,” he said.
Mr Davey said current brown coal stations use subcritical technology, with a power production efficiency rating of about 29 per cent; the next level is supercritical with about 35 per cent and then ultra-super critical, at about 42-45 per cent.
The other cycle, the Brayton cycle, involves gas, normally natural gas, but can also utilise the syngas from the gasification process to produce electricity.
The gas turbine can be combined with a steam generator that captures the waste heat from the gas turbine and heats water to feed a steam generator.
“This is called a combined cycle – they can get efficiencies up to 60 pc,” he said.
This process was the best for baseload power.
“Gasification of brown coal takes advantage of the chemical energy in the coal; convert that to gas and then you can burn that in a Brayton cycle, in a gas turbine or you can use it as a chemical base for other products,” Mr Davey said.
“Primary products produced from FT are diesel, jet fuel and petrol. Other hydrocarbons can also be produced. In addition hydrogen, ammonia and urea are products available from gasification.”
Mr Davey said the FT process produces a lot of heat, which can be harvested to provide power or be used in industries such as greenhouses along with some of the CO2 created.
“Heat and carbon dioxide (CO2) are two of the three largest cost inputs to greenhouses so effectively free heat and CO2 would make this industry extremely cost competitive,” he said.
“There is a huge opportunity to have an extensive greenhouse food-growing energy based in the Latrobe Valley. You get heat free and CO2 free from the gasification plant. CO2 is a great growth stimulant for plants.
“Secondary upgrading of the FT products will be required, but this is similar to what occurs in a traditional refinery.”
Mr Davey said the FT process does produce high quantities of CO2.
“However, this can be captured and stored, through proven technologies, in Bass Strait where some in the industry estimate there are billions of tonnes of storage capacity,” he said.
“It’s easy technology, the cost is as cheap as you will ever do it in the world. One reason it’s cheap – the short distance – about 66 kilometres. Also, Bass Strait is the best geology to store CO2 in the world, the subsea storage locations are fantastically porous and permeable; you put it in there, it goes in easily and stays there.
“As an offshoot benefit, CO2 storage can repressurise the sub-sea aquifers and slow onshore drainage of freshwater aquifers.”
The chief executive of Melbourne’s Global CCS Institute, Jarad Daniels, told a recent carbon capture and storage conference in Melbourne that CCS was growing rapidly around the world.
“CCS is recognised globally as a critical tool to address climate change,” he said.
CarbonNet, which is financed by the federal and state governments, aims to build a pipeline from the Latrobe Valley through South Gippsland to sequester CO2 from the Valley in the empty Bass Strait aquifers.
Mr Davey emphasised that Victoria has huge coal reserves – about 430 billion tonnes in total and 33 billion tonnes in the Latrobe Valley alone that are currently economically winnable.
“It is estimated that each tonne of coal will produce about 200 litres of very low sulphur diesel, so even if only half the coal was used for diesel production this would mean 3.3 trillion litres of diesel production capacity. Of course this would not happen in one year!” he said.
Currently Australia used about 450,000 barrels of diesel a day.
“For context, Loy Yang currently mines about 28 million tonnes of coal per annum. If this coal production was converted into diesel production, then this would cover about 25 per cent of Australia’s diesel usage and Australia would be a long way down the road to diesel fuel independence. It just shows what is possible,” he said.
“If we were even a little bit cleverer, we would pair this with hydrogen, ammonia and urea production to have truly home-grown industrial capability not subject to the whims of an erratic world.”
Mr Davey said having an advanced chemical plant would create high value wage jobs, even for the operators of the plant.
“But if you have a greenhouse industry – that is far more labour intensive than that plant will ever be. And it has a broad spectrum of jobs from unskilled to quite skilled,” he said.
Apart from this spectrum of jobs in the Valley because of this industry, Mr Davey said the gasifier plant could provide back-up to the power industry.
“It allows diversification of the power industry – it doesn’t have to be all renewables,” he said.
The mining of brown coal could be done with a much smaller profile. Rather than the current deep mines, Mr Davey said the mining methodology could be changed to create a quite wide and shallow mine, which could then be progressively rehabilitated.
This approach was used in brown coal areas in Germany and North Dakota.
“If you don’t do it on a progressive basis, you end up where we are today, with massive holes.”
In an interview with the Express last year, Dr Chris Hamilton, a leading Australian hydrocarbon specialist with 50 years’ international experience in industry, backed gasification, warning that Victoria is blessed with an enormous yet “stranded energy asset”.
“The state can significantly benefit through broader utilisation of this energy resource,” he told the Express.
“Gasification of brown coal offers the solution. Drying technology has been technically proven. New gasification technologies are available which better suit Victorian brown coal. Already sufficient test work trials have been carried out in Germany to support the commercial application of such technologies.”
Apart from electricity production, gasification also opens up broader international markets for products like Fischer-Tropsch diesel, methane, methanol, DME (the organic compound Dimethyl ether), ammonia and urea. Dr Hamilton said for gasification to succeed, it was very important that both the state and federal governments provide the right support and encouragement behind industry to initiate a concerted development program.
Coal gasification was first commercialised in Germany in the late 1920s, and has been further developed and applied all over the world. In 1956, the Morwell Lurgi gasification plant, using German gasification technology, was brought on stream to supply Melbourne with medium heating towns gas.
Using briquetted brown coal from the nearby Morwell briquette factory, the Lurgi gasification plant had five gasifiers and employed 200-300 people. The advent of Bass Strait natural gas, with its higher calorific value, led to the closure of the Morwell plant in 1969.
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