Gas-liquid multiphase computational fluid dynamics (CFD) of amine absorption column with structured-packing for CO2 capture
Abstract The gas−liquid multiphase Eulerian computational fluid dynamics (CFD) model was used to investigate hydrodynamics and CO2 removal efficiency of a pilot-scale amine absorber with structured-packing. The structured-packing was represented by a porous media zone having porous resistance, gas−liquid interfacial drag force, and liquid dispersion force. This study aimed to find a reasonable way to identify four modification factors of the Ergun coefficient that determine the hydrodynamic characteristics of structured-packing. The two modification factors (a and b) for porous resistance were mainly related to the liquid holdup (hL) with respect to the liquid load. The other two factors (c and d) for gas−liquid interfacial drag force depended on the specific wet pressure drop (ΔPwet/L) versus the gas load factor. The hL and ΔPwet/L increased in parallel with the increase of a and c, respectively, while the slopes of hL and ΔPwet/L increased with b and d, respectively.
Porous media Eulerian computational fluid dynamics (CFD) model of amine absorber with structured-packing for CO2 removal
Abstract A gas–liquid Eulerian porous media computational fluid dynamics (CFD) model was developed for an absorber to remove CO 2 from natural gas by mono-ethanol-amine (MEA). The three dimensional geometry of the amine absorber packed with nine elements of Mellapak 500.X (M500X) was constructed for the CFD domain. The momentum conservation equation included the porous resistance, gas–liquid momentum exchange and liquid dispersion to replace the structured-packing by the porous media model. The mass conservation equation involved the mass transfer of CO 2 gas into the MEA solution and one chemical reaction. The mesh independent test was performed on coarse, medium and fine meshes and the medium mesh (37,400 cells) was selected for further investigation. Parameters of the CFD model were adjusted to fit experimental data (wet pressure drop, liquid holdup, and CO 2 mole fraction along the column height) measured in a CO 2 -MEA system on M500X. This study demonstrated that the porous media CFD model can treat both hydrodynamics and CO 2 removal in the amine absorber with structured-packing.
Target of inhibition by the anti-lipogenic antibiotic cerulenin of sterol synthesis in yeast.
Abstract The antibiotic cerulenin inhibited the incorporation of 14 C-acetyl-CoA by 67% at a concentration of 9 × 10 −6 M but not that of 14 C-HMG-CoA into the non-saponifiable fraction in a cell-free extract of Saccharomyces cerevisiae . Cerulenin markedly inhibited the activity of partially purified HMG-CoA synthase. No inhibition of acetoacetyl-CoA thiolase activity was observed in the same preparation of HMG-CoA synthase. Therefore, cerulenin inhibition of overall sterol synthesis may be accounted for by the specific inhibition of HMG-CoA synthase activity.