Investigations of organic inhibitors for silica scale control from geothermal brines–II

In an effort to find alternatives to brine acidification for control of siliceous scale deposition in geothermal resource production facilities, a second series of laboratory screening tests with new organic inhibitors has been conducted. In the first series of tests, organic inhibitors, usually consisting of dispersants and phosphino-carboxylic acid mixtures, were examined for silica scale control activity [Gallup, D.L., 2002. Investigations of organic inhibitors for silica scale control in geothermal brines. Geothermics 31, 415–430]. The present study consisted of screening additional inhibitor formulations obtained from seven different manufacturers in a laboratory pressure reactor using a synthetic brine solution. Several of the organic inhibitors yielded promising scale deposition results. Similar to the initial series of tests, brine acidification always out-performed the organic inhibitors. Acid precursors also appear to be acceptable alternatives to strong acids as a means of limiting corrosion, transportation risks and safety/handling issues. © 2005 CNR. Published by Elsevier Ltd. All rights reserved