M. E. Zeynali [email protected] Petrochemical Synthesis Group, Petrochemical Faculty, Iran Polymer and Petrochemical Institute (IPPI), P. O. Box: 14965/115, Tehran, Iran, Abstract In this study the diffusion coefficients for reaction components were determined for unimodal and bimodal pore size distribution and assuming transitional diffusion regime using a more realistic, Stewart-Johnson, m...

A theoretical study of radial flow chromatography was carried out based on a general nonlinear multicomponent rate model which considers radial dispersion. external mass transfer, intraparticle diffusion. and nonlinear multicomponent isotherms. Radial dispersion and mass transfer coefficients were treated as variables which are dependent on the radial coordinate of the radial flow column. The m...

A new methodology for implementing radioactive particle tracking (RPT) in bubble columns with intense vertical rod internals was developed and implemented to investigate the effect of dense on hydrodynamics. The utilizes a hybrid Monte Carlo N-Particle (MCNP) simulation an automated RPT calibration device generate large number points accurate reconstruction instantaneous positions particles usi...

The application of collocation methods using spline basis functions to solve differential model equations has been in use for a few decades. However, the application of spline collocation to the solution of the nonlinear, coupled, partial differential equations (in primitive variables) that define the motion of fluids has only recently received much attention. The issues that affect the effecti...

We propose, theoretically investigate, and numerically validate an algorithm for the Monte Carlo solution of least-squares polynomial approximation problems in a collocation framework. Our investigation is motivated by applications in the collocation approximation of parametric functions, which frequently entails construction of surrogates via orthogonal polynomials. A standard Monte Carlo appr...

The structure-activity relations in the alumina-supported cobalt catalysts are studied at the realistic conditions of Fischer-Tropsch synthesis using in situ time-resolved XRD and catalytic measurements. Cobalt sintering during the first 3-5 h of the reaction and cobalt carbidisation at a longer time on stream (>8 h) coincide with catalyst deactivation.