Coal & Coal as Chemicals Feed Stock Video Lecture | Chemical Technology - Chemical Engineering

We are discussing organic chemical technology
course, in module 1 we discussed about the
introduction to chemical process industry.
In lecture 1 and in lecture 2, we discussed
about the raw material for chemical process
industry and in the 3 rd, various unit process
and unit operation, which are being used in
the chemical process industry. Now, we will
be discussing module 2, in the module 2 contains
3 lectures, lecture 1 that will deal with
the Coal and Coal as Chemical Feed Stock for
the chemical process industry.
As you know, the coal is the major source
of energy; it provides 25 percent of the total
world energy consumption and generates 40
percent of the world’s electricity. There
has been continuous development in utilisation
of coal, as source of oil as substitute of
petroleum based fuel and chemical feed stock,
since beginning of the 19 th century and again,
gaining importance due to rising coast of
crude oil and limited oil resources.
Most of the chemicals derived from the coal
was by destructive distillation of coal, furnishing
mostly aromatic and acetyne route using coal
and lime stone. However, with the advancement
of technology, many other chemicals are being
made from the coal. Now, coal being considered
future raw material for fuel and chemicals
through synthesis gas along with it is major
use, as primary source of the energy.
One question come to mind, why coal as a chemical
feed stock because you see the coal from very
beginning of the 19 th century before coming
of the petroleum and the petrol chemical energy.
Coal was the root, from which we are producing
many of the chemicals especially, the aromatic
if in some of the inorganic chemicals, we
are also produced from the coke oven plant.
So, this was the route and this is the reason,
why the again the people are having the interest,
even the coal to liquid technology during
the 1930 German, they worked on the production
of the gasoline from the coal. But, only because
of the economical reason and with the ability
of the crude and petroleum, the process was
not actually commercialized.
As I discussed earlier, the Coal is the largest
source of energy all over the world and the
power production. But, the other routes where,
we are using the coal, that is the synthetic
fuel that may be in the form of the gaseous
liquid. Coke production that in the coke oven
plant, where we are producing the coke from
the coal and during the production of the
coke, we are generating coke oven gas.
Chemicals which are now being derived for
petroleum, natural gas route that can be produced
from the coal through this synthesis gas route
or through the calcium carbide route. Recent
development in utilization of the coal, coal
gasification that is being used as a fuel
from the synthesis gas to the FT synthesis
and the fertilizer feed stock. Already, we
are we are having the two fertilizer plant
based on the coal during the initial stage
of the development of the fertilizer industry
in India.
That was the one in the Ramagundam, another
was in the Talci, but because of the economic
reason, these two units because they were
the low capacity.
Coal to synthesis gas, that is the ammonia
and the other chemicals, that we are making
from the synthesis gas. Synthesis gas means,
when we are taking the hydrogen nitrogen from
the synthesis gas then it is going through
the fertilizer plant for the making of the
ammonia. And as you know, the ammonia that
is one of the major feed stock not only for
the chemical fertilizer industry, also for
the chemical industry. Coal to oil through
the FT synthesis, as I told you earlier also
that the coal to coal to oil through FT synthesis,
lot of the work done was done during the initial
stage.
But, only because of the economic reason,
the process could not be commercialized but
again there has been recent interest on this.
Coal to methanol and olefin technology, that
is coming in a big way from the coal gasification
to synthesis gas, synthesis gas to methanol
and methanol to olefin, that is the mto technology
methanol to olefin. Coal to dimethyl ether
through the methanol route, that is also getting
important because dimethyl ether that can
be directly blend with the gasoline.
Coal to plastic through the methanol to olefin
technology, because the during the process,
we will produce the propylene and propylene
to plastic are even the ethylene is also produced
in the process. And so the coal to plastic
technology, already in china, they are going
to have a plant based on the coal to plastic
technology.
Coal and coal as chemical feed stock, these
future technology are likely to play important
role in providing the alternate feed stock
for chemical industry. Let us discuss now,
about the, in very brief about the coal origin
and the composition.
Coal is the carbonaceous solid black or the
brownish black sedimentary rock, matter vegetation,
biological changes originated from the accumulation
of the partially decomposed vegetation. Formation
of the coal is started 250 to 300 millions
years ago and that had taken long time, in
the coal which you are seeing now and this
formed, that took around 250 to 300 million
years. Biological changes and subsequent effects
of the temperature and pressure alter these
deposits to coal.
Coal is composed of chiefly the carbon and
other elements like hydrogen, sulphur, oxygen,
nitrogen, moisture and non combustible inorganic
matter containing silica, iron, calcium, magnesium
and mercury. Mercury now again a rear the
problem of mercury machine that was not there
form the thermal power plant. But in many
of the coals, the amount of the mercury that
is very high and the mercury machine that
has been reported in the thermal power plant
so, the mercury again is a problem in case
of the especially, thermal power plant.
So, for the coal composition as you are seeing
here, the we are having the carbon and hydrogen,
apart from this, some of the undesirable part
is also there, that is the sulphur, which
is creating lot of problem. Because, the coal
is the sulphur content in the coal is varying
widely from one place to another place, just
the take the case of the Assam coal, that
it contain very high sulphur and the other
material, which are creating problem.
That is, the silica, iron, calcium, magnesium
compound, they are coming as as after the
burning of the coal or the gasification. So,
that is a big problem in case of the where,
the ash content is high. As in our country,
the ash content is very high that is, varying
from 30 to 40 percent in major coal reserve.
Coal is highly complex and heterogeneous substance,
coal has a wide range of composition, the
composition is sulphur content, mercury content,
calorific value of the coal vary widely from
one coal reserve to another coal reserve.
Coal may he hard or slightly softer depending
upon the source, Assam coal is much softer
than the other coal. And so, that was the
problem in utilization of the Assam coal in
the initial stage, when we try to use the
Assam coal in the boiler.
Coal resources, category of the coal resources
are based on the degree of assurance that
is, the coal reserve, proved reserve, indicated
inferred or the depth range. So, these are
two basis for the categorization of the coal
resources, let us discuss the definition of
the proved reserve or indicated reserve.
So, proved reserve the coal resource, which
has been reliably estimated and can be recovered
economically so, that we called, that is coming
in the category of the proved reserve. Indicted
reserve means, coal resource based on the
combination of direct measurement and reasonable
geological assumption. Then the inferred reserve,
coal based on the assumed continuity of the
coal bed’s depth range determines the economy
of the extraction and the scope of the exploration.
Composition of the Indian coal and coal in
other countries if you compare, the ash content
that is very high in Indian coal.
That is, around 30 to 40 percent in other
country, the ash content is less, sulphur
content is, here also although it is less
in compare to ash content in other country.
Carbon 25 to 30 percent and other country,
the carbon content that is high, hydrogen
less than 3, calorific value is also less
that the in the coal Indian coal, especially.
Coal reserve, worlds proven coal reserves
are estimated at about 860 million billion
tones, which is expected to last for about
120 years at the current level of production
and utilization. The global coal reserves
consists of 53 percent anthracite and bituminous
coal, 30 percent sub-bituminous coal, 17 percent
of lignite. Largest coal reserves of coal
are in China, USA, Russia, Australia and India,
India has the 5 th largest coal reserve in
the world of the total coal reserve. Delhi
88 percent of non-coking coal reserves, while
tertiary coals reserves account for measure
0.5 percent and the balance is the coking
coal.
Coal deposits are chiefly located in Jharkhand,
Orissa, Chhattisgarh, West Bengal, Madhya
Pradesh, Andhra Pradesh and Maharashtra. In
India, coal reserves from India upto the depth
of 1200 meters have been, that is not 1200,
120 meters have been estimated to be 276.81
billion tones as on April 1, 2010.
The global coal production in 2011 was 7 billion
tonnes, of which china accounted for approximately
half of the production and consumption. And
this is the reason, how the now the coal in
china that is been also used for the production
became. Total coal production in India during
2009 and 10 was 532.2 million tonnes, lignite
production in 2009 and 10 was 23.95 million
tonnes.
Lignite reserves in the country have been
estimated around 39.9 billion tonnes as on
March 31 st, 2010 and major deposits are in
Tamil Nadu. In Tamil Nadu, some of the plants
are there, which are using the lignite as
a source of power and as the source of chemical.
This is the status of the coal reserve in
India coking coal, non coking coal, tertiary
coal and the total coal that is the proved,
indicated, inferred.
Coal demand projection in the 11 th, 12 th,
13 th, 14 th, 15 th plan, these are the some
of the figures that is available. And so,
you can get an idea about the, what is the
coal demand during the next few years.
This is
the distribution of the coal reserves in various
states Andhra Pardesh, Arunachal Pradesh,
Assam, Bihar, Chhattisgarh, Jharkhand and
then the Madhya Pradesh. And these are the
proved, indicated, inferred and the total,
and the amount of the coal that is given here.
So, this is the coal reserve we are having
in India, if we guess there are some variation,
that may be there depending up on the source.
And coal reserves in the sedimentary rocks,
that the gondwana coals and the tertiary coals,
this is the figure that we are getting the.
This include the 450 segments and the established
through mapping in the northern eastern region.
Coal letters of assurance that has been given
to the power, iron and steel sector, small
and isolated plant, cement plant, ultra mega
power projects and this is the total blocks
that has been given and the letter of assurance.
Coal bed methane, coal bed methane there has
been an interest in the coal bed methane.
Because, coal bed methane is an environmentally
friendly clean fuel similar to natural gas,
preliminary activities related to exploration
of the CBM in India is started in early 1990.
And till 1997, the ministry of coal had allotted
some coal bearing areas of the CBM exploration.
As of the now, about 25 CBM reserves have
been established in 5 CBM blocks, CBM gas
production is about 2 lakh cubic meter per
day.
This is the block awarded under the program,
under round 1 exploration, round 2, round
3, total blocks 26. Area awarded, total CBM
resources, CBM wells drilled these are the
some of the features that is available from
the ministry of coal. Types of the coal because
we are having the different types of the coal
and the coal is classified into various grades
based on the composition calorific value and
degree of the qualification that has occurred
during it is formation.
Coal may be also classified as hard or soft
coal, low sulphur high sulphur coal, coal
may be also classified in rock types based
on the petrological components known as maceral.
Based on the maceral content, coal may be
classified clarain, durain, fusain and the
vitrain.
One general classification of the coal that
is, that is given in the form of the peat,
lignite, sub-bituminous, anthracite coal like
that. So, it will be discussing about the
classification, general classification that
is given. I will find the, peat is the precursor
of the coal formed, in the initial stage it
is in the form of the peat and from conversion
is taking from the peat to lignite and lignite
to sub-bituminous to bituminous and then the
anthracite.
So, peat is the precursor of the coal formed,
lignite with the further increase in the temperature
during the coal formation, peat is converted
to lignite. Lignite is considered as immature
coal, lignite are brownish coloured, soft,
low calorific value, it is compact in texture.
Sub-bituminous coal are black colour and are
more homogenous in appearance and their properties
range from lignite to those bituminous coal.
Bituminous coal is the usually black with
the high carbon content and calorific value,
anthracite coal is highest rank coal is a
harder glassy black coal and highest content
of the carbon and calorific value. Anthracite
coal is the best suited for making metallurgical
coke, for gasification to produce synthesis
gas and for combustion, as fuel for power
generation. The ash content is also low, graphite
is the highest rank and is the is difficult
to lignite ignite sorry. This is the typical
coal characteristics in selected Indian power
plants compared to selected Chinese and the
US.
Coal composition of the carbon, hydrogen,
nitrogen you see the carbon content, that
may be the around 25 to 62 in China. So, this
is the one of the advantage in case of the
China because the carbon content that is very
high.
Selection of the coal for various application
depends on it is composition and carbon content,
calorific value, moisture content, ash content,
composition of the ash, fusion temperature
of ash, coking quality, sulphur content.
Assessment of the coal quality, coal quality
plays an important role in the efficient utilization
as fuel and for gasification. It should have
high calorific value, high carbon content,
it is low ash content, it is always desirable
otherwise, the whole economy of the process
that will be affected. Low sulphur content,
low moisture, low cost, the quality of the
coal, coal depends upon it is rank. The coal
rank is arrange in the ascending order as
the lignite, sub-bituminous, bituminous coal
and the anthracite. Coal quality can be assessed
by proximate because these are the two methods,
that we are using for the assessment of the
coal quality, proximate and the ultimate analysis,
and the calorific value.
Proximate analysis involve the determination
of the moisture, volatile matter, ash and
the fixed carbon, ultimate analysis involves
determination of the carbon and hydrogen nitrogen,
sulphur, oxygen. Calorific value, the lower
calorific value, high calorific value these
are the or gross calorific value, these are
the some of the measurement of the calorific
value and then the useful heating value. Coal
as the fuel because the as I told you earlier
also, major portion of the coal we are using
as a fuel and the for the power generation.
But, fuel coal, other routes are also available,
that coal can be used as a liquid fuel also.
Coal accounts for the 53 percent of the commercial
energy sources in India, which is high compared
to the world average of 30 percent. The 11
th plan projected India’s coal demand to
grow at 97 percent per annum against 5.7 percent
during the 10 th plan, almost two fold increase.
The commercial coal in India is mainly consumed
by the power sector, steel sector and cement
so, you can say, the major share is the power
plants, steel plant and the cement.
Allocation of the coal blocks to the private
companies for the power sector, 20 blocks
iron and steel, small and isolated cement
plants and ultra mega power projects. Now,
we will be discussing about the coal, as a
chemical feed stock, why the importance of
the coal as the chemical feed stock. Because,
you see the all the coal originally was utilized
as a fuel for the production of the gasses,
you must be knowing about the producer gas,
town gas, blue gas these were the some of
the, through the gasification route that was
been used.
Many of the petro chemicals now, derived from
the petroleum and natural gas was earlier
derived from the coal and especially. from
the coke oven plants, because the aromatics
earlier benzene, toluene, xylene, the aromatics
and a large number of the organic chemicals
are present in in the coke oven gases. Today,
we are getting either through the coal tar
distillation or the separation of the benzyl
so, these are the that of the importance source
of the aromatics. During this, only thing
that in case of the coke oven plant, the yield
of the aromatics that is compatibly low.
With the starting of the coke oven plants,
it becomes source of organic and some inorganic
chemicals because during the the coke oven
plants or the coke oven gases, they also contain
the ammonia and that ammonia that is being
utilized by steel plant for making of the
either ammonium sulphate or the ammonium nitrate.
coal tar from the coke oven plants continues
to be the source of aromatics, naphthalene
and other valuable aromatics like pyridine,
picoline, quinolene this is the one of the
selected list, the important actually the
aromatic. Apart from this, large number of
aromatics are present in the from the coal
tar, that we are getting in the from the coke
oven plant.
Before coming of the petro chemical production,
a large number of the organic chemicals were
produced from the acetylene, produced from
the calcium carbide route, in which coal was
a important feed stock. China is come in a
big way for production of the chemicals from
the coal, because of the huge coal reserves
and the better quality of the coal they are
having.
With the rising cost of the crude oil and
dwindling crude oil reserves, coal has again
received attention all over the world to utilize
coal as an alternative source of chemical
feed stock, not only in the developing country,
in the developed country. But also, in India,
we are working to utilize the coal for the
production of the chemicals through the gasification
route.
Various routes for the production of the organic
and inorganic chemicals, coal carbonization
and the coal tar distillation, coal gasification
and use of synthesis gas as feed stock for
ammonia production, coal liquefaction by hydrogenation,
acetylene from the calcium carbide.
These are the some of the technology, which
has come during the recent year and getting
importance in utilization of the coal that
is, the coal to methanol technology. Because,
that is the in in intermediate, this is the
also of course, the production of the synthesis
gas and from the synthesis gas to methanol.
Coal to olefin technology because the methanol
to olefin technology or coal to olefin technology
because again it is the from the coal to methanol
and methanol to olefin.
Coal to plastic, this is also the from the
coal to olefin, these olefin are being used
for the making of the plastic. Already, China
they are going to have a plant based on the
coal for the production of the plastic, acetylene
from the calcium carbide made from the lime
and the coal and the various chemicals from
the acetylene. We are getting a large number
of the chemicals from the acetylene, which
we are earlier manufactured from the petro
chemical. Now, you see the this is the, how
the various process involved and what are
the actually the products we are getting and
the various coal chemicals, a long list is
there.
Coal, coal carbonization, high temperature,
low temperature carbonization because two
types of the carbonization were taking and
we are getting the coke and the gases, and
the coal tar that we are using for the production
of the your various actually, the inorganic
and organic compound. Ammonium sulphate that
is one of the very important part of the any
steel making plant, because in many of the
steel plant, they are making the ammonium
sulphate or ammonium nitrate.
Pyridine base ammonium thiocyanate fuel gas
then the solvent naphtha, benzene, toluene,
xylene, indene, all this actually cyclopentadiene
from the light oil or from tar, pitch coke,
road tar, crude naphthalene because naphthalene
earlier it was the route for making of the
phthalic anhydride. Now, we are making the
phthalic anhydride through the orthoxylene
route and then the coal gasification of course,
the synthesis gas and through the synthesis
gas, ammonia, methanol, oxosynthesis, Fischer
Tropsch synthesis conversion, tar and oils
for the phenols and the cresols. Coal based
fertilizer plant because as I told you, the
coal that has been a very important source
for this manufacture of the synthesis gas.
And the coal gasification and use of the synthesis
gas, as feed stock for production of the ammonia
has again received attention. Because. two
units we were having earlier, when we stared
the manufacture of the ammonia and the urea
at the our Ramagundam and the Talci plant
of the FCI, which was later on closed, because
of the because large number of the fertilizer
plant they came based on the natural gas or
the naphtha, and they were more economical.
So, partial oxidation of the coal is used
for production of synthesis gas and ammonia
CO from the partial oxidation is converted
to CO 2, which is used for the urea manufacture.
That is the process, we are using in case
of the ammonia manufacture and the urea manufacture,
synthesis gas is used as chemical feed stock
for production of large number of the chemicals.
Coal gasification that has become one of the
important source for producing fuel and the
synthesis gas.
Coal gasification, production of the fuel
from Fischer Tropsch synthesis getting significant
attention during recent years. Coal gasification
and production of synthesis gas is now, considered
to be a major potential on purpose source
of commodity. Petro chemicals, which are now
being produced through the crude oil route
or from the petroleum base.
Coal gasification, the cost of the coal and
higher cost of the chemicals derived from
the coal has been major constrain in it is
utilization, as a substitute of the petroleum
and natural gas, because the synthesis gas,
which we are getting from the naphtha or the
natural gas is much cheaper. Even the product
cost of production if you compare, the fertilizer
plant which is based on the coal and the fertilizer
plant based on the natural gas that is, the
cost it is more in case of the coal than the
natural gas. It is just in the descending
order if you take the natural gas then naphtha
then the coal so, the much higher cost of
production is there in case of the coal. And
especially, in Indian condition because of
the high ash content, that is also one of
the reason for the high cost.
This is in brief about the actually the various
products, which we are getting from the synthesis
gas and so, the methane, natural gas and naphtha
you have seen. But, one source from the coal,
you see from the coal because this actually
the various product from the synthesis gas
that we will be discussing, while discussing
about the petro chemical processes in the
synthesis gas and the chemical. But, in brief
here, just you can see the from the coal gasification
route, you will be getting the synthesis gas
and from the synthesis gas, a large number
of the product chemicals that can be generated.
That is, the methanol, methanol to formaldehyde,
acetic acid, dimethyltryptamine, MTBE, solvent,
chloromethane, fuel because the methanol blend
that can be also there. Now, the methanol
is coming in a big big way in the as a fuel
shell, the production of the CO and H 2 that
is the raw material for the formaldehyde,
acetic acid, ethylene. Hydrogen and nitrogen,
again this is also called sometimes synthesis
gas and this is for the production of the
ammonia and the urea.
Hydrogen, that you can separate from the CO
2 after conversion of the CO 2 CO 2, and that
CO 2 that is being used in the fertilizer
plant and that will be, sometime it is creating
problem gasification or the when in case of
the stock. So, during the production of the
hydrogen, about 10 tonnes of the CO 2 is also
produced. If you are not having the use of
the CO 2 in the process then that will create
problem, CO based on the CO, these are the
some of the chemicals. Acetic acid, acetic
anhydride, propanoic acid, acrylic acid these
are the some of the major actually, the chemicals
which are producing from the CO or the synthesis
gas.
Coal conversion technology coal gasification,
coal liqufication, that may be direct liqufication
or the solvent extraction where the, we are
adding the solvent and hydrogen, indirect
liqufication. Fischer Tropsch synthesis, that
may be again high temperature and low temperature,
carbonisation pyrolysis of the for coke making.
As I told you earlier also, that the calcium
carbide and acetylene that was the major source
of making many of the chemicals or now, we
called the petro chemical.
Because, there was no petro chemical if you
see the, when we started the petro chemical
refinery it was in the beginning of the 19
th century, it was the 1920, that some of
the petro chemical we recovered from the refining.
So, earlier before coming of the petro chemical
complex, it was the calcium carbide and from
the calcium carbide to acetylene and acetylene
that was been used for the manufacture of
large number of the chemical.
So, this is the process, how the calcium carbide
and calcium carbine to acetylene production
is there from after adding of the water, you
are producing acetylene and the CO again we
are regenerating.
These are the some of the product we are getting
from the acetylene, vinyl chloride polyvinyl
chloride, acrylonitrile, acrylic fibre because
earlier when the cracker plant was not there,
because now we are making the vinyl chloride
from the ethylene, which we are getting from
the cracker plant. Earlier, it was the vinyl
chloride from the acetylene route that was
being used for the polyvinyl chloride. And
now, still one plant Sriram chemicals and
fertilizer at Kota in India, they are using
the acetylene route for production of the
vinyl chloride and polyvinyl chloride.
Acrylic fibre again, acrylic fibre was because
acrylonitrile that was made from the acrylic
route and so, the acrylonitrile produced from
the acrylic, that was been used earlier for
the acrylic fibre. But now, acrylonitrile
we are having with the coming of the propylene,
now we are making to the petro chemical. Vinyl
alcohol, vinyl fluoride, vinylidene chloride,
acrylic acid, methyl metha acrylate, acetaldehyde,
acetaldehyde again because normally, we are
making through the ethylene or the alcohol
route but earlier it was through the acetylene
route, technology available. Vinyl ethers,
1 4 butadiene or chloreprene, for the chloreprene
also the acetylene route is available, chlorinated
solvents.
Coal to methanol technology, the process involves
the production of synthesis gas from coal
via partial oxidation followed by conversion
of the synthesis gas to methanol, this is
the technology that is been used for the production
of the methanol. Again we will be discussing
in detail about the production of the methanol
from the synthesis gas, while discussing about
the petro chemicals in module 6, module 7
sorry.
Coal to olefin technology, methanol from synthesis
gas from coal gasification can be converted
to dimethyl ether using bifunction catalyst,
which can be used as a gasoline blend or methanol
can be converted to olefin by MTO process.
This this process produces ethylene and the
propylene, olefin synthesis from synthesis
gas via dimethyl ether to olefin process,
that is also SDTO that is that is also available.
Olefin produced from the coal route can be
used for the manufacture of poly olefins and
that is the poly olefin. Plastic propylene
can be manufactured from methanol to olefin
technology, propylene from MTO can be used
for polypropylene, coal to plastic technology
based on coal is getting importance. China
is already going to have one commercial plant
for making polyethylene and the polypropylene
from the coal route. Major constrain in coal
to chemical route, variation in the coal quality,
which affect the efficiencies and the economics
of the gasification, changes in the syngas
composition due to variation of the coal quality.
Because you see coal quality that is varying
very widely from one place to another from
one source to another source. And so quality
even the, just you take the case of Assam
coal, although it is having high carbon but
very high sulphur content is there, some of
the coal are having very high ash content.
So, changes in the syngas composition due
to variation in the coal quality is there,
high ash content of the coal as in case of
the India, high sulphur content. Impurities
present in the coal may be determined determined
till, as they may affect the catalyst and
the process because the catalyst poisoning
there, may be there because of the some of
the impurities which are present in the coal.
Environmental consideration such as sulphur
content and CO 2 emission, which is there
in case of the your coal gasification route.
Mercury emission that is one of the another
problem, that we are having in case of the
coal because some of the coal they are having
the high mercury and so, because of the mercury
emission. Now, that has been made mandatory
for all the thermal power plant to monitor
the mercury content of the coal.
So, this was about the coal and the coal as
the chemical feed stock in the lecture 2 of
the module 2. We will be discussing about
the coke oven plant because that was the starting
of the production of the chemicals, which
now we are seeing through the petro chemical route.