NewGen Roundtable

Coal is Australia’s most important energy source. It supplies around three-quarters of Australia’s electricity, due to its easy accessibility and proximity to major centres of population. These features make Australian electricity one of the cheapest in the industrialised world. It constitutes around 40% of total energy used and its use for electricity has remained consistently high since the late 1960’s.

Coal types can be ranked into anthracite, bituminous, sub-bituminous coal (black coal) and lignite (brown coal), in descending order of energy content and geological age. Thermal coal is black coal used for combustion to heat steam for electricity generation (67% of world consumption). This is the common image of coal. The less well known but equally important face is metallurgical coal, used in the steel making process (16% of global consumption).

Coal is also the most geographically distributed fossil-fuel with 70 countries having proven reserves. Six percent of the world’s economically demonstrated black coal reserves lie in Australia, with the figure being 25% for brown coal, giving us the fourth largest reserves in the world. These reserves are tapped through over 100 operating mines with 35 new mines and expansions also proposed. Black coal reserves are distributed largely throughout Queensland and New South Wales. 

In the broader global context, coal is second only to oil in total primary energy supplied. It generates over 40% of the world’s electricity. However, this proportion is much higher in coal producing countries. Global coal use is strongly expected to grow to 2030, the amount determined by the nature and timing of CO₂ emissions policy measures. Possible reductions in coal usage in the OECD countries would be more than offset by the increase in usage from such countries as China and India, which both have large coal reserves.

In addition to being the leading producer, China is not surprisingly the leading consumer of coal by far, accounting for 41% of total consumption in 2008. China’s economic growth and infrastructure expansion largely explains the global surge in coal use in the last decade as well as the jump in Australia’s coal exports.

The importance of coal in Australia as an energy source is amplified by its status as our leading export. Australia leads the world in total coal exports and metallurgical coal exports (Indonesia exports the most thermal coal.) With strong demand from Japan, China, Taiwan, South Korea and India, this brings in over $50 billion in export revenue. Australia has eight coal exporting ports with five in central Queensland, one in Brisbane, Port Kembla (80 km south of Sydney) and the largest coal export facility in the world in Newcastle.

Looking into the future, Australian coal production is expected to increase by almost 1.8 percent per annum to 2030. This is due to an expected increase in exports of 2.4% per year combined with a 0.8% per annum decrease in coal for electricity generation as gas and renewables increase market share.

Coal systems in the future are expected to incorporate a suite of advanced technologies to improve efficiency and reduce emissions:

• Higher efficiency steam turbines
• Boiler efficiency improvements
• Auxiliary drive improvements
• Pre-drying brown coal
• Biomass co-firing
• Co-firing natural gas
• Solar heating
• Algal capture

Furthermore, carbon capture and storage technologies are required to ensure continued fossil-fuel use is possible in a low-emissions future. These are particularly important given the large forecast increase in demand in China and India.

Future use of coal is also expected to extend to coal-to-liquids production, as oil depletion raises fuel prices. Technological developments will also allow Underground Coal Gasification (UCG) to become more widespread for a variety of uses including chemical feedstocks and liquid fuels as well as electricity generation.

The Callide Oxyfuel Project is the world’s first oxyfuel retrofit to a pulverised coal-fired power plant. The plant is based on the modification of Unit No. 4 originally commissioned in 1969, located near the town of Biloela in central Queensland.

Oxyfuel technology involves the combustion of coal in a mixture of oxygen and recycled flue gas, as opposed to conventional coal combustion in air. The advantage of this technology is two-fold. Firstly, it builds on an established combustion process that is mature and reliable. Secondly, the process simplifies the CO₂ capture process to enable downstream geological storage and at the same time yields significant reductions in all other emissions associated with the combustion of fossil fuels.

The long-term goal of the project is to enable the commercial development and deployment of large-scale commercial oxyfuel CO₂ capture and storage technologies that can be used to generate electricity from coal and other fossil fuels in a cost effective, environmentally safe and sustainable manner. Worldwide, the demonstration of oxyfuel technology will mainly focus on retrofit to existing power stations, but in the longer term a new generation of purpose built plants could be developed in order to take full advantage of the technology.

A key component of oxyfuel technology is the Air Separation Units (ASU) used to provide the pure oxygen stream necessary for the process. At Callide A, work on the oxygen plant achieved a major milestone in May this year when two large ‘cold boxes’ and associated heat exchanger units supplied by Air Liquide were lifted into place after being shipped to Gladstone from South Korea. [PDF]

Significant progress has also been made on the modifications and additions required on the boiler for the oxyfuel combustion. These modifications include replacement of fans and burners, installation of additional heat exchangers and flue gas ducting, and modifications to the control logic of the unit.

Commissioning work on the oxyfuel demonstration is scheduled to begin in January 2011 and the plant should be fully operational by September 2011. For more information on the project, visit the project home page.

The CO2CRC made the announcement via media release on their website.

The CO2CRC/HRL Mulgrave Capture Project is researching pre-combustion carbon capture from a stream of syngas at HRL Developments Pty Ltd research gasifier.

The CO2CRC H3 Capture Project is investigating ways to improve post-combustion carbon capture from Hazelwood power station as part of the Latrobe Valley post-combustion capture (LVPCC) project.

The projects are trialling three technologies, solvents, membranes and adsorbents, in order to find the most effective and economic for application to Victorian brown coal.

“By reducing the cost of the capture part of CCS, which can be as much as eighty per cent of the total cost, we can make the technology much more viable for generators,” said Professor Dianne Wiley, CO2CRC Capture Program Manager.

In tackling the challenge of climate change, a question often asked, or rather, a statement often proposed, is “Why can’t we just get rid of coal?” Our second video animates the answers to this, our site goes into more detail about this, but the essential points summarised are:

• Coal provides three-quarters of Australian electricity
• Coal is inexpensive; Australian electricity prices are cheap on a global scale
• Coal is Australia’s biggest export – $55 billion in 2008-2009
• Coal directly employs over 30,000 people directly, and over 120,000 indirectly, and supports many regional communities

Now, these are all big numbers. Big numbers means big changes. And big changes take time, if they are not to be crippling.

There are proposals out there to move to 100 % renewables by 2020 such as Al Gore’s plan and a similar initiative in Australia by Beyond Zero Emissions. Stanford university professor Mark Jacobson’s plan has the year 2030 as the target.

These proposals, and others, are bold and inspirational, offering grand visions of an energy future that is clean and green. Each have their particular strategies of deploying primarily solar and wind technologies for electricity and transport. These efforts are admirable and to be applauded. However, these plans also gloss over or ignore aspects of energy transitions which will see them unfulfilled as they exist now.

Energy is not purely a technological consideration of which fuel source to harness through which devices. Sourcing, generating, distributing and using energy is a complex, iterative feedback network of technological, socio-economic, financial, legal and cultural systems, each of which are evolving and influencing each other.

The transition to an energy system substantially different from the incumbent is, therefore, a significant exercise well beyond the exclusive domain of technological availability or socio-economic acceptability. Historical trends, social inertia and cultural norms play equally important roles but these are neglected in our tunnel vision view of techno-economic solutions.

Here at NewGenCoal we will be looking at energy transitions more closely to provide a more comprehensive view of the forces and barriers at play in energy shifts. We’ll take a look at energy transitions in history, socio-technical transition theory, and expand the scope of consideration to include other factors which may be equally important as technological development.

Stay tuned for further commentary on what is involved in making this transition.

Algae, a.k.a green slime, a.k.a pond scum, is not what many people think of when it comes to green energy. Yet it is being increasingly investigated for its potential to both to sequester carbon as well as provide a source of bio-oil and power generation.

Algae are photosynthetic simple-celled organisms, using sunlight, water and other chemical inputs to grow and multiply. From an energy and climate change perspective, this process is potentially very useful. Feed inputs can include carbon dioxide and nitrogen oxide, major constituents of fossil-fuel powerplant flue gases. Being photosynthetic, the direct output is output is oxygen but once harvested the sequestered carbon in the lipids, proteins and cellulosic carbohydrate can be converted to bio-oils, biodiesel, ethanol and methane using conventional methods.

A common method to utilize algae is through a photo-bioreactor. The CSIRO’s ECOS magazine explains the process as follows: “The bioreactors contain specially selected species of micro-algae, suspended in water and nutrients for optimal growth. Fresh, salt, artesian or recycled water can be used and poor quality water works well. A stream of gas is drawn from the smokestack by a blower and passed through the bioreactor where the algae, bathed in sunlight, consume the CO2 component for photosynthesis. They can also break down nitrogen oxide pollutants. A portion of the media is drawn off and goes through a ‘dewatering’ process to concentrate the algae and finally yield a solid algal cake, suitable for oil extraction and other processing. Most of the water (98%) is returned to the bioreactor and the entire process has a low energy requirement.”




Algal farms beside fossil-fueled power stations are another option. A coal power plant produces about 1 tonne of CO₂ for every MWh of energy produced. It is estimated about 2 tonnes of CO₂ are required for producing one tonne of algae. Yield of algal biomass per hectare is about 0.3 to 1 tonne per day.

Microalgae have much faster growth-rates than terrestrial crops. Most strains of the green and green-blue algae can double their mass each 24-hour growing cycle. The per unit area yield of oil from algae is estimated to be from between 2,000 to 20,000 gallons per acre, per year. This is 7 to 30 times greater than the next ideal crop, Chinese tallow.

This paper published by the CSIRO shows that given the right conditions, algal biodiesel could be competitive with fossil diesel.

This dual-use feature of carbon sequestration and power generation is attracting increasing attention from researchers and energy companies.

Vattenfall, a Swedish energy company and a big player in carbon capture and storage, have launched a pilot plant using algae to scrub flue gases of carbon dioxide. The algae, cultivated in plastic tanks, can apparently scrub 10 times as much as land-based plants.

This post at PowerPlant CCS blog has a list of other commercial efforts to introduce large-scale algae carbon capture and processing projects, including MBD Energy in Australia. 

Like any emerging technology though, algae sequestration and biofuel production is not without its problems. The Harvard-MIT universities’ company Greenfuel Technologies was seen as a leader in this field before closing down  in 2009. While the global financial crisis was the primary factor, there were still technical and other cost challenges.

However, also like many emerging technologies, these challenges are not insurmountable. In a sign of the future role of algae, last month, European aerospace giant EADS unveiled what it called the world's first "hybrid" aircraft to run on algae fuel. The US Department of Energy has also crafted an Algal Biofuels Technology Roadmap http://www.energy.gov/news/9167.htm indicating this could be serious business.