کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
230994 1427406 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of pressure on decomposition of formic acid in sub- and super-critical water
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Effects of pressure on decomposition of formic acid in sub- and super-critical water
چکیده انگلیسی

The effects of pressure on formic acid decomposition in sub- and super-critical water from near the critical pressure to extremely high pressures (20–100 MPa) at temperatures of 380 and 400 °C were investigated. Near the critical pressure, the dehydration and decarboxylation rates decreased with increasing pressure. The apparent activation volumes near the critical pressure were high where the isothermal compressibility of water was large, implying that formic acid attracts water molecules better than the transition state does, and that the partial molar volume of the transition state is larger than those of the reactants. At higher pressures, dehydration rate increased with increasing pressure. Comparisons with experimental results for HCl addition at constant pressure suggest that dehydration proceeds via an ionic reaction at high pressures. The pressure may affect formic acid decomposition in supercritical water negatively through solvation effects near the critical pressure, and positively through ionic reactions above 30 MPa.

Figure optionsDownload as PowerPoint slideHighlights
► Pressure affects negatively formic acid decomposition near the critical pressure.
► Apparent activation volume is higher at higher isothermal compressibility of water.
► Solvation effect is important for pressure dependence near the critical pressure.
► Pressure affects positively dehydration reaction at high pressure (>30 MPa).
► Reaction order of H+ concentration for dehydration at high pressure was unity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Supercritical Fluids - Volume 71, November 2012, Pages 114–119
نویسندگان
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