MPa Of CO2 Research Articles

A Kinetic Analysis of Coal Char Gasification Reactions at High Pressures

A Langmuir−Hinshelwood (LH) rate equation is often used for the incorporation of gasification reaction kinetics data into gasification models, as it is applicable over a wider range of conditions than the nth-order rate equation. The use of a LH rate equation at high reactant partial pressures has been questioned, however, with some authors recommending extra terms based on additional reaction steps. Unfortunately, the lack of agreement on the details of these additional steps makes the incorporation of high-pressure gasification reactivity data into gasification models potentially a difficult task. This paper presents further analysis of previously published reactivity data for the reaction of reference chars with 0.1−3.0 MPa of CO2 and, separately, H2O. This analysis is done using LH-style rate equations well-established for use with up to 0.1 MPa of the reactant. It is shown that, in the absence of product gases, these established LH rate formulations can describe the measured high-pressure char−gas re...

Effect of Supercritical Fluids on C11β-Hydroxylation Activity of Absidia coerulea

The viability and C11beta-hydroxylation activity of Absidia coerulea were measured after treatment with compressed or supercritical CO2 and C2H4 under various initial pH and temperature conditions. The specific activity of A. coerulea on C11beta-hydroxylation can reach 23% and 75%, respectively, after treatment with 7.5 MPa of CO2 and C2H4, leading to the feasibility of enhancing both the solubility of the reactants and the beta-hydrocortisone yield for the hydroxylation of Reichsterin's substance acetate by using supercritical C2H4 as an alternative to the organic solvent.