کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
231205 1427422 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phase transitions in hydrothermal K2HPO4 solutions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Phase transitions in hydrothermal K2HPO4 solutions
چکیده انگلیسی

A 0.1 M potassium phosphate (K2HPO4) solution was reacted in a flow-through cell pressurized to 22 MPa. Reduced light transmission through the cell windows was observed at a setpoint temperature ≥400 °C, along with a decrease in effluent conductivity, but with no effect on flow. These observations suggest solution separation at ∼360 °C, with accumulation of a salt-concentrated liquid in the cell body and transition of a dilute liquid to a supercritical fluid at temperature >374 °C. High-pressure differential scanning calorimetry experiments confirm an onset temperature of 354 °C with an endothermic transition at 377 °C and 22 MPa. For apparent density, ρ = 150–500 kg/m3, the average transition temperature for 0.1 M solutions, 375 ± 5 °C, is slightly elevated relative to that of water at 371 ± 4 °C. Highest deviation for 1.0 M solutions, 365 ± 15 °C, is attributed to increased K2HPO4 hydrolysis and polymerization reactions.

Figure optionsDownload as PowerPoint slideHighlights
► K2HPO4 solutions are reacted at high temperature and pressure.
► Formation of salt-concentrated liquid and supercritical fluid occurs at T ≥ 400 °C.
► Transition temperature varies with K2HPO4 concentration and apparent density.
► Hydrolysis and polymerization reactions increase with T and salt concentration.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Supercritical Fluids - Volume 57, Issue 3, July 2011, Pages 207–212
نویسندگان
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