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2008
S M T W T F S
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january
2008
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28-10-2013
Group Members:
Hafiz Luqman Khalil (032)
Aqeel Asif (072)
Omer Riaz (087)
Hassam Khan (019)
Waqar Ahsan (012)
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Energy Engineering
5th Semester, Chemical Engineering
Submitted to:
Dr. Mohammad Suleman Tahir
Assignment No: 01
Topic: Statistics of Fuel Reserves of
Pakistan
Fuels
A substance which produce heat either by combustion or by nuclear fission or
fusion process is called as fuel.
o Fuels can be classified as solid, liquid and gaseous fuels.
Solid fuels : wood, coal, charcoal and coke
Liquid fuels : petrol, kerosene, diesel, alcohol etc
Gaseous fuels: methane, propane, butane, hydrogen, coal gas, gobar gas etc
o Primary Fuels: ( Naturally occurring) e.g. coal, wood, natural gas
o Secondary Fuels: (Artificially Prepared) Which are derived from primary
fuels e.g. kerosene, coke etc
Energy Scenario
The significance of energy and more importantly the services it provides for human
survival and comfort simply cannot be over emphasized. Without exception all
sectors of our economies, be it in the west or east, depend on the services provided
by various energy sources and technologies for its basic function. The need for
increased trade for energy1 and energy technologies, and for co-operation
between economies worldwide has never been greater, as countries become more
interdependent on each other, energy resources become more scarce and costlier
and impacts of emissions from fossil energy sources are felt locally and globally.
The geo-politics of energy and associated tensions, also add another dimension of
risk in addition to the risks of scarcity, risks to human health and climate change.
Fuel Oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a
residue. Broadly speaking fuel oil is any liquid petroleum product that is burned in
a furnace or boiler for the generation of heat or used in an engine for the
generation of power, except oils having a flash point of approximately 40 °C (104 °F)
and oils burned in cotton or wool-wick burners.
Production and consumption of Fuel oil:
Pakistan is a net importer of crude oil and refined products. Oil production in
Pakistan has fluctuated between 55,000 to 70,000 barrels per day (bbl/d) since the
1990s.The country produced 62,000 bbl/d of oil in 2012. Oil consumption has
grown over time and averaged 440,000 bbl/d in 2012. Pakistan currently has six oil
refineries with a total crude oil distillation capacity of 186,000 bbl/d, which run
mostly on imported crude oil.
Coal
“A natural dark brown to black graphite like material used as a fuel, formed from fossilized plants and consisting of amorphous carbon with various organic and some inorganic compounds.”
Coal may also be defined as a compact stratified mass of plant debris which has been modified chemically and physically by natural agencies, interspersed with smaller amounts of inorganic matter. ‘In situ’ and ‘Drift’ are the two major theories about coal formation.
Coal has been formed by the partial decay of plant materials accumulated million
of years ago and further altered by the action of heat and pressure.
Theories about Coal Formation
The natural agencies causing the observed chemical and physical changes include the action of bacteria and fungi, oxidation, reduction, hydrolysis and condensation - the effect of heat and pressure in the presence of water.
Many factors determine the composition of coal.
o Mode of accumulation and burial of the plant debris forming the deposits. o Age of the deposits and the geographical distribution. o Structure of the coal forming plants, particularly details of structure that
affect chemical composition or resistance to decay. o Chemical composition of the coal forming debris and its resistance to decay. o Nature and intensity of the peat decaying agencies. o Subsequent geological history of the residual products of decay of the plant
debris forming the deposits.
The ‘In Situ Theory’ of Coal Formation
Major in situ coal fields generally appear to have been formed either in brackish or fresh water, from massive plant life growing in swamps, or in swampland interspersed with shallow lakes.
The major points of in situ theory are discussed below:
o The development of substantial in situ coal measures thus requires extensive accumulations of vegetable matter that is subjected to widespread submersion by sedimentary deposits.
o Accumulations of vegetable matter and associated mineral matter, generally clays and sands, are balanced by the subsidence, or motion of the Earth’s surface, in the area on which these materials are accumulating.
o Coal formed like this has bands of coal and inorganic sedimentary rocks arranged in a sequence.
The ‘Drift Theory’ of Coal formation
It was the difference in coal properties of Gondwana coals that led to the formation of the drift theory. The mode of deposition of coal forming can be explained as said below:
Coal is formed largely from terrestrial plant material growing on dry land and not in swamps or bogs.
o The original plant debris was transported by water and deposited under water in lakes or in the sea.
o There will not be a true soil found below the seam of coal. o The transported plant debris, by its relative low density even when water
logged, was sorted from inorganic sediment and drifted to a greater distance in open water. The sediments, inorganic and organic, settled down in regular succession.
o The process of sedimentation of the organic and inorganic materials continues until the currents can deposit the transported vegetation in the locations.
o These deposits are covered subsequently by mineral matters, sand, etc. and results in coal seams.
o The depositions can also stop for a particular period and again begin to happen depending upon the tidal and current conditions.
o The coal properties vary widely due to the varied types of vegetation deposited.
Rank of Coal
Coal is complex combination of material, and the combination has great difference
from one formation or deposit to another. These differences result from
o The varying types of vegetation from which the coal originated.
o The depth of burial and the temperature and pressure at those
depths.
o The length of time the coal has been forming in the deposit.
Production and Consumption of Coal
Dry Natural Gas
Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of
methane, but commonly includes varying amounts of other higher alkanes and
even a lesser percentage of carbon dioxide, nitrogen, and hydrogen sulfide.
Natural Gas Reserves:
The miraculous Pakistan is blessed with infinite natural resources by the God
and natural gas is the most precious one. The recoverable reserves of natural gas
have been estimated at 29.671 trillion cubic feet (January 1st 2009). During July-
March 2008-09 the production was 3986.5 million cubic feet per day as compared
to 3965.9 mmcfd during the corresponding period last year showing an increase of
0.52%. Presently 26 private and public sector companies are engaged in oil and gas
exploration and production activities.
Applications:
Natural gas is an energy source often used for heating, cooking, and electricity
generation. It is also used as fuel for vehicles and as a chemical feedstock in the
manufacture of plastics and other commercially important organic chemicals.
Production and Consumption in Pakistan
Rice production in Pakistan
In Pakistan, rice production holds an extremely important status in agriculture and
the national economy. Pakistan is the world's fourth largest producer of rice, after
China, India and Indonesia. It produces an average of 6 million tons annually and
together with the rest of the South Asia; the country is responsible for supplying
30% of the world's paddy rice output.
Most of these crops grow in the fertile Sindh and Punjab region with millions of
farmers relying on rice cultivation as their major source of employment. Among the
most famous varieties grown in Pakistan include the Basmati, known for its flavor
and quality.
Paddy (or unmilled rice) is usually harvested when the grains have a moisture
content of around 25%. In most Asian countries, harvesting is carried out manually,
although there is a growing interest in mechanical harvesting.
Harvesting is followed by threshing, either immediately or within a day or two.
Again, much threshing is still carried out by hand (manually) but there is an
increasing use of mechanical threshers. Subsequently, paddy needs to be dried to
bring down the moisture content to no more than 20% for milling.
Like most countries in Asia, Pakistan sees agriculture as an important industry not
only in providing food and fiber domestically, but also in providing livelihood and
employment to majority of county’s population. On the average, agriculture
contributes one-fourth (about 22% in 2005-06) of total GDP, and is also a major
source of foreign exchange earnings. Rice is one of several agricultural commodities
that Pakistan exports.
Top 20 Rice Producers by Country—2011 (million metric ton)
Around 50% textile sector units in Punjab are using rice husk for burning their
boilers to generate power for bleaching and drying purposes.
Market Year Production Unit of Measure Growth Rate
Pakistan Milled Rice production year by year
Introduction of Rice Husk:
Rice husk is one of the most widely available agricultural wastes in many rice
producing countries around the world. Globally, approximately 600 million tons of
rice paddies are produced each year.
The cultivation of rice husk results in two major types of residues having attractive
potential in terms of energy.
a. Straw
b. Husk
Although the technology of rice husk utilization is well-proven in industrialized
countries of Europe and North America, such technologies are yet to be introduced
in developing world on commercial scale. The importance of rice husk and rice
straw as an attractive source of energy can be gauges from following statistics:
Rice straw
1 ton of rice paddy gives 290 kg rice straw
290 kg rice straw can produce 100 kWh of power
Calorific value = 2400 kcal/kg
Rice husk
1 ton of rice paddy produces 220 kg rice husk
1 ton of rice husk is equivalent to 410-570 kWh electricity
Calorific value = 3000 kcal/kg
Moisture content = 5 – 12%
What is rice husk?
The rice husk is the outer most layer of the paddy grain that is separated from the
rice grain during the milling process. In addition to protecting rice during growing
season, it can also be used as building material, fertilizer, insulation material or
fuel.
Around 20% of paddy weight is husk and rice production in Asia produces about
770 million tons of husks annually.
Typical analysis of rice husk Property Range
Bulk density (kg/m3) 96-160
Hardness 5-6
Ash, % 22-29
Carbon, % About 35
Hydrogen, % 4-5
Oxygen, % 31-37
Sulphur, % 0.04-0.08
Moisture, % 8-9
Rice husk was largely considered a waste product that was often burned or dumped
on landfills, according to Martin Gummert, postharvest expert at the International
Rice Research Institute.
“In Vietnam, it used to be a waste some years ago and dumped in the rivers, causing
a big problem, but now it has a value” Mr. Gummert said.
“In fact, in most countries, rice husk is not waste anymore.”
Characteristics of rice husk:
o It is difficult to ignite and does not burn easily with open flame unless air is
blown through the husk. It is highly resistant to the moisture penetration and
fungal decomposition, thus forming a good insulation material.
o Rice husk has a high average calorific value of 3410 kcal/kg and therefore is
a good, renewable energy source.
Applications and consumption areas of rice husk:
Suitability of RH to be used for different applications depends upon the physical
and chemical properties of the husk such as ash content, silica content etc. Direct
use of rice husk as fuel has been seen in power plants. Apart from its use as fuel,
RH finds its use as source raw material for synthesis and development of new
phases and compounds.
Rice Husk as a Fuel:
o It is mostly used as fuel in boilers for processing paddy and generation of
process steam. Heat energy is produced through direct combustion and/or
by gasification.
o Small sector process industries use fixed low capacity boilers, which are
manually fired using rice husk as a fuel. Partial and uneven fuel combustion
leads to smoke emission and decrease the fuel efficiency. As husks are
available virtually for free, the boiler efficiency and the degree of combustion
were the issues of receiving the latest attention.
o The technical and economic factors decide the effective use of rice husk as
fuel for power generation. Also, rice husk has been used as a useful and
alternative fuel for household energy. RH is also used as fuel in brick kilns, in
furnaces etc.
Formation of Activated Carbon:
Due to presence of large amount of hydrocarbon such as cellulose and lignin
content, rice husk can be used as a raw material to prepare activated carbons which
are complex porous structures.
They are obtained by two different processes:
o Physical or Thermal activation
o Chemical‖ activation.
In the former carbonization is followed by char activation; in the second one,
carbonization and activation are performed in a single step, using a chemical agent.
Physical activation of rice husk produces activated carbon that exhibits very low
specific area. Activated carbons are effective adsorbents due to their micro porous
structure.
Applications of rice husk Ash (RHA):
Rice husk ash has been widely used in various industrial applications such as
processing of steel, cement, refractory industry etc. Suitability of RHA mainly
depends on the chemical composition of ash, predominantly silica content in it.
RHA is found to be superior to other supplementary materials like slag, silica fume
etc.
Calorific value
“It can be defined as the amount of heat liberated in KJ or Kcal by the complete combustion of 1 Kg of fuel”
There are two types of calorific values
o Higher calorific value (HCV) = It is the total heat liberated in KJ or Kcal by the complete combustion of 1 Kg of fuel.
o Lower calorific value (LCV) = It is the difference of Higher calorific value and heat absorbed by water vapors. LCV = (HCV – X588.76) Kcal/Kg Where ‘X’ is the fraction of water vapors
Formula for calculating Calorific value:
The calorific value Q of coal is the heat liberated by its complete combustion with oxygen. Q is a complex function of the elemental composition of the coal. Q can be determined experimentally using calorimeters. Dulong suggests the following approximate formula for Q when the oxygen content is less than 10%:
Q = 337C + 1442 (H - O/8) + 93S
Where C is the mass percent of carbon, H is the mass percent of hydrogen, O is the mass percent of oxygen, and S is the mass percent of sulfur in the coal. With these constants ,Q is given in kilojoules per kilogram.
Calorific values of solid, liquid and gaseous fuels
Solid and liquid fuels Gross calorific value/ MJ kg−1
Alcohols
Ethanol
30
Methanol 23
Coal and coal products
Anthracite (4% water)
36
Coal tar fuels 36–41
General purpose coal (5–10% water) 32–42
High-volatile coking coals (4% water) 35
Low temperature coke (15% water) 26
Medium-volatile coking coal (1% water) 37
Steam coal (1% water) 36
Peat
Peat (20% water) 16
Petroleum and petroleum products
Diesel fuel 46
Gas oil 46
Heavy fuel oil 43
Kerosine 47
Light distillate 48
Light fuel oil 44
Medium fuel oil 43
Petrol 44.8–46.9
Wood
Wood (15% water) 16
Gaseous fuels at 15 °C, 101.325 kPa, dry Gross calorific value/MJ m− 3
Coal gas coke oven (debenzolized) 20
Coal gas continuous vertical retort (steaming) 18
Coal gas low temperature 34
Commercial butane 118
Commercial propane 94
North Sea gas natural 39
Producer gas coal 6
Producer gas coke 5
Water gas carbureted 19
Bomb Calorimeter
How Bomb Calorimeter works:
In such an apparatus the fuel is completely burned and the heat generated by
such combustion is absorbed by water, the amount of heat being calculated from
the elevation in the temperature of the water. A calorimeter which has been
accepted as the best for such work is one in which the fuel is burned in a steel
bomb filled with compressed oxygen. The function of the oxygen, which is
ordinarily under a pressure of about 25 atmospheres, is to cause the rapid and
complete combustion of the fuel sample. The fuel is ignited by means of an
electric current, allowance being made for the heat produced by such current,
and by the burning of the fuse wire.
This or a similar calorimeter is used in the determination of the heat of combustion of solid or liquid fuels. Whatever the fuel to be tested, too much importance cannot be given to the securing of an average sample. Where coal is to be tested, tests should be made from a portion of the dried and pulverized laboratory sample, the methods of obtaining which have been described. In considering the methods of calorimeter determination, the remarks applied to coal are equally applicable to any solid fuel, and such changes in methods as are necessary for liquid fuels will be self-evident from the same description.
The bomb is then placed in the calorimeter, which has been filled with a definite amount of water. This weight is the “water equivalent” of the apparatus, i.e, the
weight of water, the temperature of which would be increased one degree for an equivalent increase in the temperature of the combined apparatus. Such a determination is liable to error, however, as the weight of the bomb lining can only be approximated, and a considerable portion of the apparatus is not submerged.
Another method of making such a determination is by the adding of definite weights of warm water to definite amounts of cooler water in the calorimeter and taking an average of a number of experiments. The best method for the making of such a determination is probably the burning of a definite amount of resublimed naphthaline whose heat of combustion is known.
The temperature of the water in the water jacket of the calorimeter should be approximately that of the surrounding atmosphere. The temperature of the weighed amount of water in the calorimeter is made by some experimenters slightly greater than that of the surrounding air in order that the initial correction for radiation will be in the same direction as the final correction. Other experimenters start from a temperature; the same or slightly lower than the temperature of the room, on the basis that the temperature after combustion will be slightly higher than the room temperature and the radiation correction be either a minimum or entirely eliminated.
While no experiments have been made to show conclusively which of these methods the better is, the latter is generally used.
After each test the pan in which the coal has been burned must be carefully examined to make sure that all of the sample has undergone complete combustion. The presence of black specks ordinarily indicates unburned coal, and often will be found where the coal contains bone or slate. Where such specks are found the tests should be repeated. In testing any fuel where it is found difficult to completely consume a sample, a weighed amount of naphthalene may be added, the total weight of fuel and naphthalene being approximately one gram. The naphthalene has a known heat of combustion, samples for this purpose being obtainable from the United States Bureau of Standards, and from the combined heat of combustion of the fuel and naphthalene that of the former may be readily computed.
So, in this way Bomb calorimeter is used for the calculation of calorific values of different fuels.