Abstract
The IDDP-1 well in the Krafla geothermal field in Iceland is the first well in the Icelandic deep drilling project. The superheated steam from the well is extremely hot (450°C) and the pressure is high (120 bar). The steam contains HCl and HF and is highly corrosive when it condenses. Different pilot studies were set up to investigate the usability of the superheated steam for power production. This included wet scrubbing equipment which, after the experiment, was inspected for corrosion and scaling. This involved visual inspection of the equipment and microstructural and chemical composition analysis of corrosion scale and scaling materials. A lump of scaling material was found in a narrow section of the scrubbing equipment, almost blocking the exit of the equipment. The water injection nozzles in the spraying chamber of the wet scrubbing equipment were free of scaling. Other parts had negligible scaling. The nickel alloy in the spraying chamber had small corrosion pits and cracks; this could possibly cause problems for a scale up that demands longer lifetime. The austenitic stainless steel used in the mixing pipe performed very well with negligible corrosion. The carbon steel pipes used in the system were corroded quite extensively.
