Alstom and Siemens have both been awarded Phase III contracts in connection with the full scale carbon capture and sequestration plant proposd for the Mongstad site in Norway. The refinery site is also the location of the Technology Centre Mongstad (TCM), the world’s largest facility for testing and improving CO2 capture technology.

Gassnova, the Norwegian state-owned enterprise for CCS, has awarded Alstom a concept study contract, the scope to include a cost estimate for the erection and operation of a full-scale CO2 capture plant based on Alstom’s proprietary chilled ammonia process (CAP).

This study is part of the third phase of the Technology Qualification Programme being undertaken for the project. During the first phase Alstom successfully executed a feasibility study; during the second phase, which is currently on-going, Alstom is demonstrating with its own test plant recently commissioned at TCM the application of the company’s CAP technology for flue-gases coming from a gas-fired power plant. This second phase established the basis for the study now awarded. The knowledge gained will prepare the ground for widespread CO2 capture deployment. Alstom’s CAP process is a chemical absorption process, in which flue gas is contacted with an ammonia based solution which then reacts with the CO2. Raising the temperatures reverses the reaction – releasing the CO2 and allowing the solvent to be recycled. It has been successfully demonstrated at pilot plants in Wisconsin, USA (5 MW), and the first full chain carbon capture and storage validation plant in West Virginia, USA (54 MW) – both of which operated for over two years.

Siemens participation
Following successful completion of Phase 1 and award of contract for phase 2, Siemens has been selected by Statoil to participate in the third phase of the Technology Qualification Programme for a full-scale CO2 capture plant at the combined-heat and power plant at the refinery at Mongstad. This third and last phase of the Technology Qualification Programme started in September and is due to finish in April 2013.

In Phase 1, Siemens demonstrated the applicability of its proprietary PostCap process by proving that it can be scaled up to full size, has the required operational regularity and that high capture ratios can be achieved with limited life-cycle costs.

Phase 2 is already partially completed: The sub-tasks of conducting stress tests on the solvent and documenting emission data on an automated laboratory test rig have been performed within the time frame agreed. The remaining task of a 3000-hour performance test at an approved verification pilot plant with flue gas from a gas-fired boiler is ongoing.

The third and final phase is the concept phase and successful results in the Technology Qualification Programme will allow for the selection of the PostCap technology in later project stages. Nicolas Vortmeyer, head of technology innovation of fossil power generation at Siemens Energy, added: “The phased approach for the CCM project is very smart because Statoil and Gassnova can get a deeper understanding of the carbon capture technologies and gain trust in the co-operation with the potential plant supplier. Thus it contributes to eliminating risks in the implementation of first-of-its-kind demonstration projects.”

Siemens’ proprietary CO2 capture technology uses an amino-acid salt solution as a solvent and has proven to have several advantages compared to other post-combustion carbon capture processes, namely low energy consumption and low investment costs as well as nearly zero emissions. Furthermore, the PostCapTM unit can be operated within the common safety standards of a power plant. It is suitable for retrofitting existing plants and new power plants.