Norway, a beautiful small country, has put a lot of focus on the research and technology development of good waste management systems. Institutions such as The Research Council of Norway and Innovation Norway have collaborated with universities and private organisations to work towards this cause.
The waste management action in Norway starts from its source — from each home. The waste is segregated primarily into food waste, paper, plastic, electrical, glass, metal, and others. A centralised waste collection at each residential area collects them weekly once or bi-weekly. It is then transported to a centralised waste dumping area where two technologies are used in the waste-to-energy plant: gasification and incineration technology.
With gasification technology, the waste dumped into the centralised dumping pit is transported to a gasifier where the waste is heated over 800 degrees Celsius in a controlled oxygen environment. The released hydrocarbon-rich syngas is cleaned and fired to produce steam. The steam is used to produce electric energy using steam turbine systems or routed to pipeline networks to heat up residences and for other industrial purposes.
In the incineration technology, the waste is directly fired inside an incinerator and produces steam from the heat energy. The exhaust gas is then cleaned and dispersed to the atmosphere.
To capture this released CO2, several interesting concepts and technologies have been developed in the country.
Kanfa AS based in Oslo offers standardised containers to capture CO2 from exhaust gas released to the atmosphere. The captured CO2 is liquefied and delivered at storage tanks, available for utilisation or permanent storage.
Recently, the company commissioned a pilot plant to capture the CO2 from a waste to energy plant located in Norway. “The pilot has been in operation at the Forum Oslo Varme Waste to Energy plant for almost a year, very successfully. It is based on Shell’s licensed technology,” says Knut Bredahl, Energy Transition Director of Kanfa AS.
Through a Heat Recovery Steam Generator, KANFA offers a solution to utilise heat energy that would otherwise be lost in the heat from the gas turbine generator exhaust, to generate steam for a secondary power generation stage.
“The full-scale plant at CCS Oslo will have a net-zero heat consumption – all the steam heating duty will be returned to the district heating system. This can of course vary from case to case, and can be optimised for each plant,” says Knut Bredahl.
Equinor, a major oil & gas producer in Norway, is also working to minimise its carbon footprint by extracting energy from wind using offshore installed floating wind turbines.
Another company, Poul Consult AS, has conceptualised a solution called “Sea Lotus” which can be integrated with offshore wind power.
In their proposed solution, the portion of the energy is produced from waste through gassification or incineration technology. The plant facilities are installed on an old ship hull or on a used drilling rig hull. The technology will use either a steam reforming process or an electrolysis method.
With the steam reforming process, the hydrocarbon is cracked with high temperature and pressure. Then produced hydrogen gas is stored in a subsea storage facility under pressure. The stored hydrogen will be supplied to offshore oil production facilities to run gas turbines or produce power using hydrogen fuel cells.
Electrolysis is another option under consideration for the production of hydrogen from water. Sea Lotus will be equipped with systems to convert seawater into freshwater for electrolysis. In the Electrolysis-based Sea Lotus, the waste will be incinerated to produce electricity, and exhaust gas will be routed to CO2 Capture and CO2 Compressor systems and further injected into an empty oil well for the production of oil and gas with a lower CO2 footprint.
The author is Managing director, Poul Consult AS, Norway