ISOTHERMAL FLOW CALORIMETER FOR PRESSURES TO 600-BAR

An isothermal flow calorimeter is described which is suitable for measuring enthalpies of reaction and the composition dependence of enthalpies of mixing at high pressures. With the calorimeter, endothermic and exothermic processes can be studied from 5 to 70 degree C and from 1 to 600 bar. Experimental results are reported for the excess enthalpy H**E for n-hexane with cyclohexane and methanol with water at 298. 15 K and various pressures. The pressure dependence of H**E is discussed and compared with results available in the literature and those obtained indirectly from the temperature dependence of the excess volume V**E at various compositions.