Dot point 1.2.1 (1 Viewer)

[kimmeh]

i know its a stupid dot point to ask, but i dont know how much detail i should answer this (im doing a check over of all my notes):

identify the industrial source of ethylene from the cracking of some of the fractions from the refining of petroleum

so far i have:
The major source of ethane is petroleum. It is a mixture of hydrocarbons. Each hydrocarbon can be separated by the process of fractional distillation. This is done in a large fractioning column. Different hydrocarbons will condense at different heights because they have different boiling points. The heavy hydrocarbons (kerosene, diesel) that have high boiling points condense at the bottom and are found at the bottom of the tower. The lower and lighter hydrocarbons (refinery gas, petrol and naptha) that require lower boiling points are usually found at the top of the fractioning column and are used commonly as fuels (LPG, bottled gas, petrol) or to manufacture petrochemicals.

should i be adding details of thermal and cracking processes ?

 

[Constip8edSkunk]

isnt there another dot point that covers the process?

 

[:: ck ::]

talk more about the process
the dotpoint is mainly about the processes of cracking :
- steam cracking and
- catalytic cracking

maybe talk about the naptha and LPG fractions of the tower and how the cracking occurs for these two fractions ...

 

[Ragerunner]

Your answer you said "The major source of ethane is petroleum"? Ethane?????

Since it only asks you to identify you won't need to say much, just know that ethene comes from the cracking of longer hydrocarbons.

You can explain the other methods such as steam cracking, which wouldn't be a bad idea

you can also put an example of a long hydrocarbon such as C10H22 and show how it converts into ethene and another by-product.

 

[Xayma]

You dont need to include most of what you posted in the first thing because it is talking about ethene (ethylene) (On a side not can we be marked down if we refer to ethylene as ethene?).

Something better would be:

Ethylene only constitues a small amount of petroleum deposits, since it is an important industrial resource alternative means of its production are needed. These can come from the dehyrdation of ethanol but this is not practical so catalytic cracking is used.

In this process long hydrocarbons are heated in the presence of a catalyst. This breaks the bonds in the hydrocarbons to form ethylene and another hydrocarbon, if this hydrocarbon is again longer then ethylene (or if it is ethane) it can be broken down further.

Catalytic cracking also solves problems with excess long chained hydrocarbons, since long chain hydrocarbons are present in greater quantities then needed, they must be processed or disposed off, if they were to be disposed large quantities of landfill would need to be produced etc.

NB: You will want to recheck that its just from memory. Also summarise to fit how many lines/marks are given for the question

 

[worlds greatest]

its an identify dot point, so really they wont ask more than 1 or 2 marks on it.
so basically just say that
u can get ethene from various fractions of crude oi, usually lpg gas or naptha, via catalytic cracking, or steam cracking. then u expand on that

oh and show equations

 

[xiao1985]

Originally posted by worlds greatest


oh and show equations

eqn is easy tho... just haf to balance the products and reactants... and make sure u haf ethene on the product side, and soem long chained carbon on reactant side...

catalyst for catalytic crackin was al3o4 to my vague memory... sigh~~~ gettin old now...