SHAHAB is a PC- based simulator developed by Olefin Research Group (ORG), with the simultaneous simulation of the reactor, the firebox, the convection section and the transfer line exchanger in steam Cracking units. The reaction mechanism of thermal cracking of hydrocarbons is generally accepted as free-radical chain reactions. Using a rigorous kinetic model, a complete reaction network for rep...

Understanding the gas phase decomposition kinetics of the chemical precursors involved in the nucleation and thin-film growth processes is crucial for controlling the surface kinetics and the growth process. The growth of emerging materials such as InN and related alloys requires deposition methods operating at elevated vapor densities due to the high thermal decomposition pressure of these mat...

An endocytic vesicle is formed from a flat plasma membrane patch by a sequential process of invagination, bud formation and fission. The scission step requires the formation of a tubular membrane neck (the fission pore) that connects the endocytic vesicle with the plasma membrane. Progress in vesicle fission can be measured by the formation and closure of the fission pore. Live-cell imaging and...

Many industrial processes are based on radical gas phase chemistry. Detailed kinetic models are the most versatile way to model the chemistry for this processes, which is necessary for an optimal chemical reactor optimization and design. Due to the highly reactive nature of radicals however, the reaction networks easily contain up to hundreds of species and thousands of reactions. Providing the...

The kinetics of cellulose hydrolysis under extremely low acid (ELA) conditions (0.07 wt%) and at temperatures >200°C was investigated using batch reactors and bed-shrinking flow-through (BSFT) reactors. The maximum yield of glucose obtained from batch reactor experiments was about 60% for α-cellulose, which occurred at 205 and 220°C. The maximum glucose yields from yellow poplar feedstocks were...

At present work, under initial inventory with Th and U, the evolution of nuclides in subcritical devices under given thermal, fast, hardening fast and fission neutron field are studied without the detail structure of sub-critical device and the burn-up being considered. It is supposed that the subcritical reactor consists of uniform in which the flux of neutron is homogeneous. The fissile nucli...

This work presents a general mathematical model of a fixed bed gasifier, where both the transport resistances and the chemical kinetics are important at the reactor and the particle scale. Pyrolysis and gasification of the solid fuel (coal, plastics, biomasses or wastes) is only the first step of the whole process. Successive gas phase reactions of the released species are described with a deta...

An empirical rate equation was obtained for the methanation kinetics catalyzed by MCR-2X, a commercial catalyst prepared by Haldor-Topsoe. The studies were carried out in a fixed-bed reactor under differential conditions, and in a gradientless recycle reactor (Berry) over a range of total pressures, reactant concentractions (H2/CO ratios), and temperatures. The kinetics of methanation were foun...

The urea reactor is one of the most important units in the urea synthesis process. Rigorous simulation of the urea reactor is necessary and significant. Ho,wever, the complicated thermodynamic system and chemical reactions result in difficulties of modeling and simulation. In this work, the urea reactor is considered as a critical gas-liquid concurrent fluid reactor, in which some perforated pl...