What Does Catalytic Conversion Mean?
Catalytic conversion is a process for converting a heavy hydrocarbons, chemicals or fuels to light hydrocarbons, chemicals or fuels through the use of catalysts. The products obtained from catalytic conversion are less toxic, less corrosive, more usable and more environmentally friendly. Modern conversion uses zeolites as the catalyst. Catalytic conversion is used in oil refineries and hydrocarbon processing units.
A catalytic converter is used in vehicles for conversion of toxic pollutants in exhaust gas to less toxic pollutants by catalyzing. Catalytic converters are used with internal combustion engines fueled by either gasoline or diesel — including lean burn engines.
Corrosionpedia Explains Catalytic Conversion
Catalytic conversion vaporizes and breaks the long-chain molecules of the high-boiling hydrocarbon liquids into much shorter molecules by contacting the feedstock, at high temperature and moderate pressure, with a catalyst. This chemically converts pollutants to less harmful substances. This is achieved by using lower temperatures and pressures in the presence of a catalyst.
Fluid catalytic cracking (FCC) is one of the most important conversion processes used in petroleum refineries. It is widely used to convert the high-boiling, high-molecular-weight hydrocarbon fractions of petroleum crude oils to more valuable gasoline, olefinic gases and other products. Cracking of petroleum hydrocarbons was originally done by thermal cracking, which has been almost completely replaced by catalytic cracking because it produces more gasoline with a higher octane rating. It also produces byproduct gases that are more olefinic, and hence more valuable, than those produced by thermal cracking.
Catalyst poisoning occurs when the catalyst is exposed to exhaust containing substances that coat the working surfaces, encapsulating the catalyst so that it cannot contact and treat the exhaust. The most notable contaminant is lead; other common catalyst poisons include fuel sulfur, manganese, silicon and phosphorus. Since the cracking reactions produce some carbonaceous material (referred to as catalyst coke) that deposits on the catalyst and very quickly reduces the catalyst reactivity, the catalyst is regenerated by burning off the deposited coke with air blown into the regenerator.