| Abstract |
A total of eight (8) calcite antiscalant chemicals (Aquaquest 305, Betz Dearbom DG9349, NALCO 9354, NALCO 1340HP, NALCO 1340HP Plus, CHEMCO 6344, Millsperse 815, EC6458A) wem tested for thermal stability and % inhibition eficiency. Physical changes like chamng and precipitate formation were noted during the thermai stability tests at 250░C and 300░C. Percent calcite inhibition of the chemicais were determined using the NACE test. The abiiity of the heated inhibitor to keep calcium ions in soiution provides a simple measurement of its inhibition efficiency. Structural degradation is further confirmed through an FTlR spectmphotometric scan of the inhibitors. After heating at 3tW"C, all inhibitors except for Aquaquest 305 exhibited frothing. The heated inhibitors eventually formed some precipitates at the bottom of the container which indicate hydrolytic degradation. CHEMCO 6344, Millsperse 815 and EC6458A gave low percent inhibition relative to the other inhibitors. Although precipitation is positive at 300░C in the thermal stability test, some inhibitors still exhibit high percent inhibitbn. The similar spectra obtained fmm FTlR scans for one sample treated at two different temperatures suggest that only partial degradation has taken place and most of the functional groups am still intact |