Slides in this set
Fractional Distillation of Crude Oil
1. The crude oil is first vaporised
2. It passes into the fractionating column which has
a NEGATIVE TEMP GRADIENT.
3. This separates the hydrocarbons based on boiling
points* - the shorter chains rise to the top as
gases and the larger chains condense out and fall
to the bottom as liquids
(less branching more van der waals packed closer
together higher bp. Branching van der waals
spread out lower bp.)…read more
Longer chains can be modified into smaller more
valuable and more in demand products e.g.
alkenes to make polymers. To do this the
following conditions are needed:
· High temperatures to break the strong
covalent bonds (500-10000C)
· High pressures (7000 kPa)
· Free radical reaction…read more
· Temperatures of 4500C and relatively low
· ZEOLITES = catalysts
· More efficient that thermal because less
energy is needed (reduces costs) and happens
a lot quicker because of the catalyst
Produces more unbranched chains which is
more useful in the production of fuels…read more
Combustion in Cars
1. Combustion in an internal combustion engine uses air and
nitrous oxides are produced.
2. These can then form acid rain in the atmosphere.
3. To remove these catalytic converters (platinum, rhodium
etc) are used by reducing the oxides into nitrogen gas.
N 2 + O2 2NO
2NO + O2 2NO2
2NO N 2 + O2
2NO2 2O2 + N2…read more