The technology is expected to find a niche for power generation both in Norway, which imposes heavy taxes on producers of CO2, and in other countries seeking to reduce greenhouse gas emissions.
Aker says conventional power generation technologies are either incapable of removing all the CO2 and NOx emissions or produce other objectionable waste gases.
The engineering contractor claims that, while details of the new technology remain to be settled, independent research centers consider the method technically better and simpler than existing systems.
Aker's concept combines a number of existing technologies in a new way and incorporates special new membrane technology under development but not expected to be ready for another 3-5 years.
The process comprises three stages: air separation, combustion, and exhaust gas handling (see illustration). In the first stage, air is forced through the membrane to separate out oxygen, leaving a mixture that can be vented to the atmosphere or processed further to collect nitrogen for industrial use. The almost-pure oxygen from the first stage is combined with natural gas and pumped into a combustion chamber to drive a turbine and steam boiler for the generation of electric power and steam.
Aker said the exhaust materials from the combustion stage are virtually pure water and CO2. The CO2 then would either be compressed for industrial use or piped offshore for injection into an oil-producing reservoir.
The biggest difference between Aker's method, for which a patent is being sought, and existing solutions is that the natural gas is burned in pure oxygen rather than air, thus avoiding the creation of NOx by burning nitrogen.
An Aker official told OGJ that the Norwegian government is evaluating five plans for gas-fired power stations, but that these would be approved under the country's CO2 emissions laws only if CO2 output were cut drastically.
The official said Aker's power generation process is the only method so far that can feasibly meet the stringent CO2 targets, but that commercial viability would depend on government tax policies.
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