L7 : Destructive distillation of Coal - Coal & Petroleum, Science, Class 8 Video Lecture

hello friends this video on coal and
petroleum part 7 is brought to you by
example calm
no more fear from exam so now the
question is how do we get these useful
products out of coal how do we obtain
them from coal so for that purpose we
have this process called destructive
distillation of coal now this is a type
of distillation where the coal is
completely distracted to give all these
useful products like coal tar coal gas
coke and we can see now how exactly this
process happens now what what do we
basically do here we just heat the coal
to a temperature of almost more than
1,000 degrees Celsius and that too in
absence of air so without air without
oxygen we heat the whole new a very high
temperature of thousand degree Celsius
now what happens when we start heating
coal to such a high temperature in
absence of air so let's see exactly
what's going to happen then so we look
at the entire arrangement the entire
apparatus how we will set it up so that
we can get the various products out of
coal so for this purpose we would need a
horizontal glass tube as you can see
here this is the horizontal glass tube
we would need another vertical glass
tube we would need some coal pieces as
you can see here these are the whole
pieces so basically we are going to heat
these pieces of coal we also need a
vertical tube so here you can see the
vertical tube now they the two tubes are
arranged in such a way that they are
connected to each other so you see this
this glass pipe connects the horizontal
tube with the vertical tube we take some
water in the vertical tube as you can
see some water is present in the
vertical tube and we need a burner to
heat the pool so here you have the
burner so that's all we need to carry to
carry out destructive distillation of
coal now what is going to happen when we
heat this coal so let's see
and what we observe is as we heat the
coal some colorless vapors are formed
and these pollutants vapors rule through
these tube and reach the vertical tube
and these Canadians vapors condense to
form a black viscous snare at the bottom
of the vertical tube and this layer is
called coal tar so you see it is a dark
viscous layers whole tire is a dark
almost black in color it is a viscous
liquid so it seems to be very thick in
nature so basically how it you can
actually see it for yourself that over a
period of time from here you can see
some vapors those vapors travel down the
vertical tube and then in the vertical
tube after some time they form this dark
viscous layer at the bottom and this is
called coal tar so that's how coal tar
is formed now when you observe little
more closely you will see that there are
some other vapors which form a colorless
layer so as you can see here the color
is lit I mean it doesn't have any
specific color this layer so this
colorless layer which is present just
above the coal tar so that is called the
liquid ammonia because it has been found
that this layer contains a lot of
dissolved ammonia so this layer is the
liquid ammonia so that's how we get
liquid ammonia from coal now yet again
what do we see that there there are
certain vapors which do not react in any
way they do not get condensed they do
not form any layer in the vertical tube
but what do they do they just go out of
this vertical tube so we can actually
see some vapors coming out of this tube
so these vapors are nothing but cold gas
so that's how again we got another
product out of coal and finally what do
we see that when all the coal is already
heated and all these vapors have been
formed so whatever
do is left over in the horizontal tube
that is coke so the cork which is left
out here is you can see it is almost the
purest form of carbon because it
contains more than 60 percentage of
carbon in it
so that's how we derived for different
components from coal now why is it
called destructive distillation because
we have destructed the coal the goal is
no more there but instead of coal we
have so many different useful products
coke coal gas liquid ammonia coal tar so
we got four different products from coal
now you might say that I have been
telling since that time that these are
useful products useful products so how
are they useful in what we can we use
them so we will discuss about uses of
each of these components which we get as
a result of destructive distillation of
coal but before that let us have a quick
review of the various components which
we received here so coltan which was
gold that it was the black viscous layer
at the bottom so this layer was cold
that liquid ammonia was the colorless
layer above coal tar so this gray layer
which is not actually gray it is
actually colorless there is no color for
this layer so that is liquid ammonia the
unreacted vapor which is released which
gets released out that is nothing but
the coal gas and finally the porous
black residue left in the horizontal
tube that is coke so this is coke so
these were the four different components
or the four different products received
as a result of destructive distillation
so let's talk about coal tar so as I
said it is a black viscous liquid so you
if you actually put it in a vessel you
can actually feel how whiskers and how
thick it is and it is completely black
in color it has an unpleasant smell
enjoy the smell is so bad that you can
actually feel its presence nearby
however it can be useful in
manufacturing a lot of products like
perfumes plastics
pains medicines laughing balls so these
are some of the things where ever during
manufacturing these things old tire
turns out to be a useful thing so it
helps introducing so many different
substances so that means it is a useful
thing next is liquid ammonia liquid
ammonia is that colorless layer where we
find a lot of dissolved ammonia it acts
as an excellent fertilizer for better
plant growth now I hope all of you know
what is a fertilizer so these are
nothing but substances which when added
to the soil increases or enhances the
productivity of the plants because for
better growth and development water
plants need they need several nutrients
they need several minerals so they need
a lot of things which can help in their
growth and all these things are present
in the fertilizers now ammonia what is
ammonia ammonia is nh3 so ammonia
contains nitrogen and nitrogen is an
excellent thing for plant growth so
nitrogen is a macronutrient a nutrient
which is needed in large quantities by
plants so that means liquid ammonia acts
as an excellent fertilizer in that does
it can help in the in agricultural
aspects so here in this picture you can
actually see that in a corn field
nitrogen fertilizer is being applied
using this tractor next is coal gas coal
gas it is a mixture of several gases
like methane carbon dioxide and monoxide
hydrogen and small amounts of many other
gases so like a lot of gases together
form the coal gas it this Coyle gas is
mostly used as a source of heat rather
than source of light because the coal
gas can be oceans
source of light also in earlier days it
used to be used as a source of light but
these days it is mostly used as a source
of heat
it is a flammable gases fuel and it can
be supplied to the user via pipeline so
pipeline distribution system with the
help of pipes it can be transported from
one place to another now before this
natural gas supplies came up coal - was
also used as a fuel and it was term
called a lightening gas because you see
because it could be could have been used
as source of light that was one
advantage the second advantage was that
it could be transported very easily with
the help of pipelines so that was cold
as it is still now it is used as a fuel
and excellent fuel in industries and the
last one is coke
so coke is the porous black substance
which is left out when it is left as I
receive you after all the coal is burnt
so it is almost a pure form of carbon
because it contains almost sixty percent
carbon which is a very big percentage it
is used in the manufacturing of steel
because during the process of steel
manufacturing it is used as a reducing
agent now the other in fact you would be
surprised to know that there are certain
advantages which are associated with
coke when compared to coal a coil is
used for what kind of purposes like you
burn coal and you generate a lot of
energy so that that's how we make use of
coal now if you use coke instead of coal
you would see that the advantages with
coke are more why that's because in case
of coal and you use coke as a fuel the
smoke producing constituents are driven
off during coke formation so when coke
is formed from coal during that time
whatever components produce a lot of
smoke and cause air pollution all those
components are removed
so therefore coke is basically more
clean
they're too cold so any burn cook so the
air pollution is less so that means coke
is a cleaner fuel when compared to coal
so coke is also a desirable fuel for
stoves and furnaces so it is also used
as substitute of coal in domestic
heating purposes now I hope you
understood while it is used as a
substitute because it is a cleaner fuel
when compared to coal and it is also a
more efficient fuel when compared to
coal so these are the various useful
products which are obtained from coal
now not only this coke can also be used
to produce a lot of different gases for
example when the hot steam is passed
over coke so what is coke chemically
coke is like carbon it is as I said it
contains more than 50% of it is made up
of carbon so when hot steam is passed
overhead then the water vapor the hot
water vapor reacts with the carbon to
form carbon monoxide and hydrogen so
this mixture of carbon monoxide and
hydrogen forms water gas so basically we
can say that this water gas interm helps
and propelling coal gas so that's how we
can say that coke acts as the starting
material for preparing coal gas and
water gas so that is also we can say
that that is also another advantage of
having coke thank you
please visit www.payoor.com to watch
more educational videos with a better
experience please do not forget to Like
and subscribe to our YouTube channel for
latest updates thank you once again