Steam and Catalytic cracking (1 Viewer)

[Haku]

could some one explain the two please and give me some examples.

 

[serge]

I think steam cracking is most used in Australia
(teacher was complaining that the textbooks
dont go into it enough, since if we actually work
in Australia we'll probably be doing Steam cracking)

You need about 900 degrees celsius, pump steam
and heavy fractions of petroluem in...
eventually they crack into smaller fractions
(i forget if you need a catalyst for it)

umm... catalytic cracking uses zeolites
(aluminosilicates with high surface areas)
as catalysts, the temperature for cat. cracking
is much lower than Steam Thermal Cracking
I think its near the 400 degree mark...

examples of cracking

octane --> ethene + hexane

C8H18 --> C2H4 + C6H14

 

[Dreamerish*~]

Catalytic cracking uses a catalyst - zeolites to break heavy molecular mass fractions of petroleum into lightweight molecules such as ethene and propene.

Steam cracking is passing a mixture of alkanes and steam into hot metal coils, completely decomposing everything into short-chain hydrocarbons.