Full text loading...
-
Characterization of Sulfide Scales Deposited At Soultz-Sous-Forêts (France) in a Prototype Small Heat Exchanger
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 1st Geoscience & Engineering in Energy Transition Conference, Nov 2020, Volume 2020, p.1 - 5
Abstract
The Soultz-sous-Forêts (Soultz in the following) geothermal power plant currently reinjects brine at 70°C. In the framework of the H2020 MEET project, a prototype small heat exchanger (SHEX) has been tested at Soultz during three months in order to enhance energy production. Six metallurgies were tested during the lowering of brine temperature from 70°C to 40°C. The scales deposited in the SHEX have been characterized using ICP-MS and SEM-EDS. This test shows that the composition of scales is rather independent of the metallurgy and of the temperature. In the presence of corrosion and scaling inhibitors, scales are mainly composed of As- and Sb-bearing galena with sometimes minor Cu. This scale composition is identical to that currently encountered at Soultz when reinjecting the brine around 70°C. No new type of deposition was triggered by decreasing down to 40°C, but lowering of temperature tends to induce an increase of scale thickness. This characterization of scales is a key feature for the optimization of the heat exchanger: the thinner the scales, the better the heat exchange and a good knowledge of scales allows a better formulation of scale inhibitors, and potentially a better identification of the cleaning process to be implemented.