Many oxidation reactions, including H-2 combustion with O-2, have been shown to admit the phenomenon of parametric sensitivity. Given its inertness to oxidation and non-flammable nature, supercritical CO2 (scCO(2)) is a desirable solvent for performing oxidations. Further, for oxidations that employ H2O2 as an oxidant, the use of scCO(2) as a solvent has been suggested for producing H2O2 in situ by reacting H-2 and O-2. Another significant, and as yet not fully understood, advantage of using scCO(2) is the ability to exploit its liquid-like heat capacity, which exhibits a maximum in the near-critical region (1.01-1.2T(c) and 0.9-2.0P(c)). It is shown in this modeling study that by performing an oxidation reaction in scCO(2), the temperature rise accompanying the highly exothermic reaction can be effectively controlled. To demonstrate this concept, we simulated the maximum temperature rise (DeltaT(ad)) for H-2 combustion with O-2 in CO2 in a constant-pressure adiabatic reactor, at feed temperatures ranging from 300 to 400 K and reactor pressures from 1 to 150 bar. At a feed temperature of 308.2 K, a five-fold reduction in DeltaT(ad) value (from 209 to 42 K) is predicted by tuning the operating pressure from 1 to 90 bar. In contrast, the DeltaT(ad) in N-2 medium is relatively insensitive in the 1-90 bar pressure range and is six times greater (roughly 270 K) compared to the value predicted with CO2 medium at 90 bar. Further, the values of beta (the dimensionless temperature rise parameter) may also be sensitively tuned with pressure in the near-critical region such that parametric sensitivity is minimized. These results indicate that the liquid-like heat capacities of scCO(2) may be exploited to control the adiabatic temperature rise and to ameliorate parametric sensitivity during exothermic reactions, a problem of fundamental and practical significance. (C) 2003 Elsevier Science Ltd. All rights reserved.