Intrinsic kinetics and design simulation in a complex reaction network; steam-methane reforming

Mass transfer effects in fermentations using immobilized whole cells

Using whole cell invertase of Saccharomyces pastorianus, entrapped in spherical agar pellets, sucrose hydrolysis was carried out in a continuously fed fluidized bed reactor. The effective rate of reaction determined experimentally for the catalytic pellet was correlated with particle radius (R), intraparticle concentration of enzyme (Ep) and external concentration of substrate (SR).

The results were elucidated by theoretical analysis incorporating internal mass transfer resistance. At high degrees of diffusional resistance, the effectiveness factor was successfully estimted from Bischoff's equation. A dimensionless number, mA R(k2Ep/KmD)0.5(Km/(Km + SR)), was used conveniently to predict the effectiveness factor in those cases wher the intraparticle diffusional effect was less significant. This number was employed to determine critical pellet size for an optimal reaction.

The relationship between the properties of the pellet (size and intraparticle enzyme activity) and its apparent kinetic constants (k′2 and K′m), estimated according to Lineweaver-Burk, are discussed.

Sucrose inversion by immobilized yeast cells in a complete mixing reactor

The article contains sections titled: 

1.	Introduction	
2.	Historical Development	
3.	Thermodynamic Data	
4.	Ammonia Synthesis Reaction	
4.1.	General Aspects	
4.2.	Catalyst Surface and Reaction Mechanism	
4.3.	Kinetics	
5.	Catalysts	
5.1.	Classical Iron Catalysts	
5.1.1.	Composition	
5.1.2.	Particle Size and Shape	
5.1.3.	Catalyst-Precursor Manufacture	
5.1.4.	Catalyst Reduction	
5.1.5.	Catalyst Poisons	
5.2.	Other Catalysts	
5.2.1.	General Aspects	
5.2.2.	Metals with Catalytic Potential	
5.2.3.	Commercial Ruthenium Catalysts	
6.	Process Steps of Ammonia Production	
6.1.	Synthesis Gas Production	
6.1.1.	Feedstock Pretreatment and Raw Gas Production	
6.1.2.	Carbon Monoxide Shift Conversion	
6.1.3.	Gas Purification	
6.2.	Compression	
6.3.	Ammonia Synthesis	
6.3.1.	Synthesis Loop Configurations	
6.3.2.	Formation of Ammonia in the Converter	
6.3.3.	Waste-Heat Utilization and Cooling	
6.3.4.	Ammonia Recovery from the Ammonia Synthesis Loop	
6.3.5.	Inert-Gas and Purge-Gas Management	
6.3.6.	Influence of Pressure and Other Variables of the Synthesis Loop	
6.3.7.	Example of an Industrial Synthesis Loop

Ammonia, 2. Production Processes

The role of mass and heat transfer in the design of novel reactors for oxidative coupling of methane

The effect of intraparticle temperature distribution on the catalytic effectiveness factor is derived, and its magnitude is estimated using an approximate solution. These calculations show that for the several cases examined the term containing the effect of temperature is less than 10% of that due to the concentration effect.

The effect of intraparticle temperature distribution on the catalytic effectiveness factor of a porous catalyst

A graphical method for determining the process conditions which give the minimum volume of reactor at a given outlet conversion is described, and illustrated by application to a multistage fluidized bed reactor for the catalytic oxidation of sulphur dioxide.

M. Shindo

Papers

The effect of intraparticle temperature distribution on the catalytic effectiveness factor of a porous catalyst

Optimum process conditions for a completely mixed multistage reactor