PPE 12 Flashcards
(11 cards)
is defined as the percentage by volume of iso-
octane in a mixture of iso-octane and n-
heptane that knocks with some intensity as the
fuel is being tested.
research octane number (RON)
is the process of transforming C7–C10 hydrocarbons (heavy
naphtha) with low octane numbers to aromatics and iso-paraffins which have high
octane numbers.
Catalytic reforming
is the process in which light straight chain paraffins of low RON (C6,C5 and C4) are transformed with proper catalyst into branched chains with the same carbon number and high-octane numbers.
Isomerization
is the name given to breaking up large hydrocarbon molecules into smaller
and more useful bits. This is achieved by using high pressures and temperatures
without a catalyst, or lower temperatures and pressures in the presence of a
catalyst.
Cracking
There are two types of isomerization catalysts:
Pt/chlorinated alumina, Pt/zeolite
catalyst.
high temperatures (typically in the range of 450°C to 750°C)
and pressures (up to about 70 atmospheres) are used to break the large
hydrocarbons into smaller ones.
thermal cracking,
is a mild thermal cracking of vacuum or atmospheric residues to
produce light products and 75–85% cracked material of lower viscosity that can be
used as fuel oil.
Visbreaking
There are two types of visbreakers:
- coil visbreaking (furnace)
- soak visbreaking (soak drum)
is a solid byproduct of oil refining
that is rich in carbon.
Petroleum coke,
is a type of thermal cracking in which the heat required to complete
the coking reactions is supplied by a furnace, while coking itself takes place in drums
operating continuously on a 24 h filling and 24 h emptying cycles.
Delayed coking
unit is the heart of the refinery and is
where heavy low-value petroleum stream
such as vacuum gas oil (VGO) is
upgraded into higher value products,
mainly gasoline and C3/C4 olefins, which
can be used in the alkylation unit for
production of ultraclean gasoline (C7–C8
alkylates).
catalytic cracking
