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A three-way catalytic converter on a gasoline-powered 1996 Dodge Ram Simulation of flow inside a catalytic converter. A catalytic converter is an exhaust emission control device which converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction.
x with the aid of a catalyst into diatomic nitrogen (N 2), and water (H 2 O). A reductant, typically anhydrous ammonia (NH 3), aqueous ammonia (NH 4 OH), or a urea (CO(NH 2) 2) solution, is added to a stream of flue or exhaust gas and is reacted onto a catalyst. As the reaction drives toward completion, nitrogen (N 2), and carbon dioxide (CO
The total surface area of a solid has an important effect on the reaction rate. The smaller the catalyst particle size, the larger the surface area for a given mass of particles. A heterogeneous catalyst has active sites, which are the atoms or crystal faces where the substrate actually binds. Active sites are atoms but are often described as a ...
High surface area facilitates catalytic reaction or filtration. The open spaces in the cross-sectional area are 72 to 87% of the frontal area, so resistance to the flow of gases through the holes is low, which minimizes energy consumed forcing gases through the structure. The monolith is a substrate that supports a catalyst.
Other variables to consider are reactor dimensions, surface area, catalyst type, catalyst support, as well as reactor operating conditions such as temperature, pressure, and reactant concentrations. Schematic representation of a heterogeneous catalytic system from the subnanometer to industrial scale.
A fluidized bed reactor (FBR) is a type of reactor device that can be used to carry out a variety of multiphase chemical reactions. In this type of reactor, a fluid (gas or liquid) is passed through a solid granular material (usually a catalyst) at high enough speeds to suspend the solid and cause it to behave as though it were a fluid.
It is already demonstrated that this system works for alkene epoxidation without stirring or the addition of a co-solvent to drive liquid–liquid phase transfer. [1] [2] [3] The active site located on the external surface of the zeolite particle were dominantly effective for the observed phase boundary catalytic system. [4] [6]
[3] The shapes which the catalysts are packed onto must be able to form a consistent geometric arrangement to provide equal spacing in the catalyst bed (an area in the distillation column where the reactant and catalyst come into contact to form the products). This spacing is meant to ensure the catalysts are spread evenly within the column.