Carbon capture key to emissions reduction

By John Nustad, Aker Clean Carbon

Climate change experts and researchers, as well as the International Energy Agency (IEA), have recommended the retrofitting of carbon capture plants to large utility point sources in order to limit the economical impact of global warming.

Emissions of CO2 from burning fossil fuels rank among the biggest contributors to man-made climate change. The main fraction of CO2 disposal is related to large volume of flue gases from different types of industrial plants, such as gas- and coal-fired power stations. Currently, some 4000 power stations account for 40 per cent of man-made CO2 emissions.

Reducing these emissions is imperative to reduce or reverse future global warming and its consequences.

The climate change experts and researchers have recommended applying carbon capture plants on large industrial point sources in order to limit the economical impact of global warming. IEA’s Energy Technology Perspective from June 2008 has estimated the need for 20 to 35 new coal-fired power stations (500 MW) with CCS annually in the period 2010 to 2050. As a result of political initiatives, several countries, including the UK, US, Netherlands and Norway, are now planning large-scale pilot plants to be in operation between 2014 and 2015. The target for these plants will be to demonstrate in full scale the capture technology, safe transport and permanent storage of CO2. Another objective is to reduce the overall cost by technical improvements.

As the largest exporter of coal in the world, Australia has a real opportunity to lead the way in actively exploring applications of carbon capture and storage technology with Australian power producers.

At Melbourne’s Carbon Capture and Storage World Conference in June, Aker Clean Carbon presented the merits of an advanced carbon capture process. The advanced process provides optimum flue gas pre-treatment, minimum energy requirements, minimum emissions to air, low solvent degradation and corrosion, and cost effective design and construction

Of the three main alternative carbon capture technologies, pre- and post combustion and oxy-fuel, post combustion technology would be the most appropriate approach in Australia. Post combustion systems can be retrofitted to existing fossil fuel power plants as well as on new builds. Furthermore, shutdown of the capture process will not interrupt power production.

Concerns regarding possible risks of carbon capture and CO2 storage have been addressed through six different Aker Clean Carbon pilot plants built and operated since 1996. CO2 has been captured from flue gas and successfully demonstrated safe storing of around one million tonnes of CO2 per year offshore since that time from a gas sweeting plant.

Aker Clean Carbon has been awarded the contract to providing the capture technology for the Technology Centre Mongstad (TCM) amine-based capture plant in Norway. The plant will be one of the most advanced capture plants in the world.

The TCM scale-up from the MTU is about 45 times and the capture capacity is
78, 000 tonnes CO2 per year. The plant will treat flue gases from two different sources; a gas power plant (CHP) ~3.5 vol per cent CO2 and a residual catalytic cracker (RCC) ~12.9 vol per cent CO2. The plant has incorporated high flexibilities such as: turn-downs (16-100 per cent), desorber operating pressures, packing heights, alternative reboilers and desorbers.

The plant includes a concrete absorber with a liner. The absorber is the largest equipment in the facility and the material selection will require minimum maintenance. The plant also includes a proprietary energy saver that will reduce the heat requirement in the desorber part of the plant by 10 to 25 per cent pending type of selected solvent. Our minimum emission technology (close to zero) will also be tested and verified at Mongstad. The plant will be ready for start-up in June 2011.
Having invested more than $70 million in carbon capture and storage technology, Aker Clean Carbon is now planning to invest a further $60 million by 2016. In Australia we hope to introduce a patented carbon capture technology as well as a mobile test facility. Everyone agrees that CO2 emissions need to be limited in order to stabilise global warming. Together with solar, nuclear, wind, energy efficiency and hydro technologies, carbon capture and storage is part of the solution.