Coal-fired technologies attract major investment

Paul Boughton
New processes to combust coal more effectively and collect carbon dioxide economically have attracted investments worth billions of Euros.

Since 2009 RWE, Linde and BASF have been testing a new technology for separating carbon dioxide (CO2) from flue gas in a pilot plant at RWE's Niederaussem power station near Cologne. The results of the practical test are now available. In a statement, the three say that compared to processes commonly run today, the innovative technology that captures CO2 by means of new chemical solvents can reduce energy input by about 20 per cent. The new solvents also feature superior oxygen stability which reduces solvent consumption significantly.

The three companies started up the pilot plant in August 2009 at the RWE's coal innovation centre. BASF is testing the newly developed carbon capture process based on improved solvents in the course of this cooperation announced in 2007. Linde was responsible for pilot plant engineering and construction.

For over a year the companies have been trialling all aspects of CO2 scrubbing under real power plant conditions. This has focused mainly on CO2 scrubbing liquids from BASF and optimised process technology. One of the principal aims of the pilot work was to minimise the energy outlays for capturing the gas from the scrubbing liquid. The pilot plant is capable of capturing up to 300kg/h of the gas, which RWE says is equivalent to a separation efficiency of 90per cent for the flue gas amount processed.

"We are pleased with this breakthrough, which we have achieved by cooperating closely with BASF and Linde. By enhancing efficiency and accordingly reducing costs, we have created a critical success factor for carbon capture technology, which in our view is key to climate-compatible power generation from coal," said Johannes Heithoff, vice president R&D, RWE Power.

"The practical tests met all of the expectations we had after lab-testing the new solvent. This paves the way for scaling up the process to large power plants," added Andreas Northemann, business manager, global gas treatment, BASF Intermediates division.

Aldo Belloni, member of Linde's executive board, is also enthused: "We are very satisfied with the results of the practical tests, too. Further development of CO2 capture technology for treating power plant waste gases is among the focal points of our activities aimed at clean energy generation."

Sub-surface storage

Now the partners are working on solutions for demonstration and large-scale power plants (Fig. 1). First demonstration plants are scheduled to come on stream in 2015, and CO2 capture is expected to be used commercially in coal-fired power stations by 2020. This technology should allow more than 90 per cent of the carbon dioxide contained in the waste gas of a power plant to be captured for subsequent sub-surface storage or for chemical transformation, for example to give fertilisers.

RWE Power will spend about EUR9m on the development project, while the German Federal Ministry of Economics and Technology contributed about EUR4m to the cost of the pilot plant.

Meanwhile, Foster Wheeler has announced that a consortium, including its global engineering and construction group, has received an order from E.ON UK to support the front-end engineering design (FEED) for a post-combustion CO2 capture and compression plant proposed as part of E.ON's planned supercritical coal-fired power station in Kent, England.

Foster Wheeler's consortium partner for the carbon dioxide capture element of the project is Mitsubishi Heavy Industries, (MHI) of Japan.

E.ON is planning to replace its existing coal-fired units at Kingsnorth Power Station with two new high-efficiency 800 MW coal-fired units using the latest supercritical technology, which E.ON has said will produce power from coal more efficiently than ever before in the UK.

The planned CO2 capture plant will be designed to separate and capture CO2 from flue gas generated by the new coal-fired units, enabling the CO2 to be transported and stored permanently within a depleted gas reservoir under the North Sea.

The Foster Wheeler contract value for this project was not disclosed and will be included in the company's third-quarter 2010 bookings.

E.ON UK is one of two groups competing in the UK Government's carbon capture and storage (CCS) competition to build one of the world's first industrial-scale CCS demonstration plants. The UK Government's Department of Energy and Climate Change has recently confirmed E.ON's progression to the next stage comprising a FEED study.

The overall FEED activities will further develop the proposed CO2 capture and compression project at Kingsnorth and will involve engineering and design studies following which the competition winner will be selected by the UK Government. Foster Wheeler and MHI have already completed the pre-FEED.

"We are delighted to continue to play a key role in this landmark project, planned to include one of the world's first industrial-scale plants capturing CO2 from flue gases and the UK's first supercritical units," said Umberto della Sala, president and chief operating officer, Foster Wheeler. "We believe that the combination of our expertise in delivering innovative, technically optimised engineered solutions and MHI's leading CO2 recovery technology will continue to add significant value for E.ON."

In the US, Xcel Energy is now operating a first of its kind demonstration of a hybrid solar-coal approach, using parabolic-trough solar technology integrated with a coal-fired power plant. The project, located at Xcel Energy's Cameo generating station near Grand Junction, Colorado, is designed to increase the plant's efficiency, decrease the use of coal, test the commercial viability of concentrating solar power thermal integration, and lower carbon dioxide emissions.

Abengoa Solar developed the parabolic-trough technology, which concentrates solar energy to provide heat for producing supplemental steam for electric power production. The project is the first under Xcel Energy's new innovative clean technology (ICT) programme, an initiative to test promising new technologies with potential to lower greenhouse gas emissions and result in other environmental improvements. Through the ICT programme, the company can pursue the development, commercialisation and deployment of new power generation, energy storage and other technologies that support its clean energy strategy. It provides the opportunity to test these technologies and evaluate their cost, reliability and environmental performance at a demonstration scale before determining whether they should be deployed more widely.

Oxycombination technology

In other US news, energy secretary Steven Chu has announced the award of US$1 billion in American Recovery and Reinvestment Act funding to the FutureGen Alliance - Ameren Energy Resources, Babcock & Wilcox, and Air Liquide Process & Construction - to build FutureGen 2.0. The new project will repower Ameren's 200MW Meredosia unit four, located near Meredosia, in western Illinois, with advanced oxycombustion technology, which combusts coal in oxygen rather than air.

Finally, Siemens Energy has won a front-end engineering design contract from Summit Texas Clean Energy to provide coal gasification and power block technology for the Texas Clean Energy Project. The new 400MW poly-generation integrated gasification combined cycle (IGCC) project planned near Odessa, Texas, will use coal as its feedstock. The plant will capture 90 per cent of its CO2 emissions for enhanced oil recovery in the West Texas area.

Siemens will deliver the gasification technology, which includes two SFG-500 gasifiers


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