| Title | The Ph Dependent Thermal Stability of the Organic Tracers 1,5-NDS and 2-NSA |
|---|---|
| Authors | L. Sajkowski, B.W. Mountain, T.M. Seward |
| Year | 2016 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Tracer studies, naphthalene disulfonic acid, naphthalene sulfonic acid, NDS, NSA, experimental geochemistry. |
| Abstract | The pH dependence of the thermal stability of 1,5-naphthalene disulfonate and 2-naphthalene sulfonate have been investigated. The experiments were conducted using batch autoclave reactors. Two experimental temperatures were investigated (200℃, 300℃). The pH ranged from 3 to 9.85 and two ionic strengths were used (0.001 M, 0.05 M). The duration of each experiment was 40 hours. The results show that: 1) 1,5-NDS is not stable at 300°C, pH 3, 4, 9 and 9.85, I = 0.001M, 0.05M; 2) 1,5-NDS is stable at 200°C, pH 4, I=0.001 M; 3) the low thermal stability of 1,5-NDS can be explained by two mechanisms: steric hindrance and kinetics; 4) 2-NSA is stable at 200°C pH 3, 4, 9 and 9.85, I = 0.001M, 0.05M; 5) the stability of 2-NSA at 300°C is independent of ionic strength; 6) 2-NSA is thermally stable at 300°C and pH 9.85, I = 0.05 M; Further experiments are underway to confirm and expand our knowledge |