THAR COAL RESERVES
THERE IS A NEED OF NEW COAL CONVERSION TECHNOLOGIES
SAIMA IBRAHIM (Saima_virgo1@hotmail.com)
Oct 12 - 18, 2009
Coal is one of major energy sources and, is contributing in world's energy system share of 23.80% and 23.75% of production and consumption respectively. But, the utilization of coal as a fuel is a potential threat to the environment. Undesirable products generated during the combustion contaminate atmosphere, water, and soil. In order to obtain clean fuels, the liquefaction and gasification of the world's mot abundant fuel i.e., coal, have gained increasing attention. The energy sector requires efficient and clean energy supplies.
In case of coal, we would have to ensure higher efficiencies, environmental acceptance, prolonging its availability and proper replacement for oil and natural gas. This is only possible through sustainable development of new coal conversion technologies.
Historically, coal has been used as a major source of energy for hundred of years. The industrial revolution and enhanced use of electricity was also due to coal. Until sixties, coal was the single largest source of primary energy. Large discoveries of oil and gas resulted in massive switchover from coal to furnace oil and gas.
It is estimated that the share of coal in global electricity generation now exceeds 37 per cent.
Pakistan, having some of the largest and superior quality coal reserves of the world, has great potential in the shape of 185 billion tones coal reserves standing 18th in the world.
Coal- the black gold -occurs in all the four provinces of Pakistan. Country has huge coal resources, about 185 billion tons, out of which 3.3 billion tons are in proven/measured category and about 11 billions are indicated reserves, the bulk of it is found in Sindh province. The current total mine-able reserves of coal are estimated at 2 billion tones (60 % of the measured reserves).
These coal reserves are well developed in Punjab, Sindh, Balochistan, and NWFP. Surprisingly, the share of coal in energy supplies for Pakistan is 7.6% during 2004-05. Coal consumption during 2004-2005 was brick kilns (49.5%), cement industries (32.1%), power (2.3%), and coke use (16.1%).
SINDH COAL RESERVES
Pakistan has emerged as one of the leading country- seventh in the list of top 20 countries of the world -after the discovery of huge lignite coal resources in Sindh.
The province of Sindh possesses around 99 per cent of the total coal reserves of Pakistan. These are located at Lakhra, Sonda, Badin, Metting, and Thar.
- The Lakhra field in District Dadu covers an area of over 1,309 sq. kms. However, exploration activities are confined to an area around 500 sq. kms. The coal seams have been developed at the depth of 50 to 150 meters. Annual production from this field is estimated at about 2 million tonnes per annum.
- The Sonda field covers 1,822 sq. kms. and coal seams are at a depth of 16 to 240 meters. The field comprises of four blocks: 1) Sonda-Thatta Block, 2) Jherruck Block, 3) Ongar Block, and 4) Indus East Block.
- Badin field has been discovered recently. Geological features indicate that Badin coalfield may extend towards Indus East block of Sonda field.
- Metting is the smallest field covering only 90 sq. kms. in District Thatta.
- The Thar field, one of the largest coal field in the world, is spread over an area of about 10,000 sq. kms. in District Tharparkar.
Pakistan's Thar Desert contains the largest coal reserves discovered to date, covering an area of 10,000 square kilometers. The Thar Coal Field can yield over 200 billion tons of coal used to produce electricity. It can yield sufficient power to make Pakistan self-sufficient in electrical power. Pakistan has reserves of natural gas, but these will start to diminish by 2010.
THAR COAL COMPOSITION
The rank of Thar coal ranges form lignite-B to sub-bituminous-A with high moisture and low sulfur content. The average chemical analyses of the coal samples from the entire Thar coalfield are:
Moisture (AR) 46.77% Volatile Matter (AR) 23.42% Fixed Carbon (AR) 16.66% Ash (AR) 6.24% Sulfur (AR) 1.16% Heating Value (Dry) 10,898 Btu/lb
WORLD COAL CONSUMPTION
- World coal consumption is projected to increase to 7.6 billion tonnes by 2020
- Coal use in developing countries of Asia alone is projected to increase by 2.4 billion tones.
- The coal share as a percentage of total energy consumed worldwide for electricity generation is projected to decline from 36 per cent in 1997 to 34 per cent in 2020. (Source: International Energy Book 2000)
Coal preparation, commonly known as coal benefication, is the process of cleaning, gradation, and preparation of uniform coal suitable for commercial consumption. Effective preparation of coal, prior to use, improves homogeneity of coal, improves utilization efficiency, results in less ash production, and more importantly reduces emission of toxic gases.
There are various technologies globally used for preparation of coal. While Pulverized Fuel technology is in use in cement industry, other technologies, though having significant application in power plants and other industries are more expensive. The various technologies used for the preparation of coal are described below.
PULVERIZED FUEL (PF) TECHNOLOGY:
In this process, coal is reduced to fine powder form, stored and then transported by air to the burner as coal air mixture for combustion.
FLUIDIZED BED COMBUSTION (FBC) TECHNOLOGY:
In this method, coal is added to the bed of heated particles and continuous mixing encourages complete combustion at a lower temperature then pulverized fuel technology.
COAL GASIFICATION (CG) TECHNOLOGY:
In this process, coal is brought into contact with steam and oxygen and thermo-chemical reactions produce fuel gas. This process is mainly used in power generation and is a costlier method of fuel preparation.
COAL-LIQUID-MIXTURES (CLMS) TECHNOLOGY:
These include the coal-oil-mixture and coal-water-mixture. These are costly technologies. The disadvantage of coal-oil-mixture is that 60 per cent of the total energy is derived from oil.
COAL-BRIQUETTING (CB) TECHNOLOGY:
In this process, coal is compacted for use, transportation, or further processing. The main purpose of briquetting is to convert low-grade coal into compact mass having higher calorific value.
Pakistan is faced with serious energy crises. It is widely known that the present level of energy generation in the country is far short of that is necessary to sustain the rate of industrial growth and satisfy growing consumer requirements.
In the energy-hungry societies of today, every indigenous source of energy must therefore be tapped and put to optimum use. Pakistan has considerable oil, gas, coal reserves; tidal, solar and hydel potential. It is ironic that Pakistan has fourth largest coal reserves in the world but it is importing 2.5 million tons of coal per annum for cement industry. At the same time, due to high cost of energy resources, the government has also decided to enhance the share of coal in the overall energy mix from 5 % to 18% up to 2018.
COAL AS AN ALTERNATIVE SOURCE OF ENERGY
One of the possible ways for the utilization of Thar coal is its conversion into methane gas, which can be used as Thar Synthetic Natural Gas (TSNG). Bio-gasification of Thar coal is favored for several reasons. First, it has high moisture content, which makes it unsuitable and expensive for use in more conventional thermal processes. For bio-gasification process, the moisture content is an advantage, because aqueous systems are necessary for microorganisms. Proximate analysis of Thar coal shows that it has moisture content of 46.77%.
Second, it is being considered a young or immature coal, which has not undergone a great deal of polymerization and oxygen loss. It is much closer in structure to the original biological components than a higher rank coal.
Among the other alternative sources, coal is the main source for producing cheaper electricity and its availability is much higher. In view of anticipated shortfall of electricity and other energy resources during the next 10 years, demand for indigenous coal would grow in power generation considerably.
The Sindh government should also convince the federal government to allow establishment of at least two coal-based power plants of 500MW each at/around Karachi. This is the need of the hour because KESC has a dependable capacity of 1300MW only as against a peak demand of over 2000MW. This can be done by following a bidding process based on price per kwh and by following an amended Power Policy. Estimated lignite deposits in Sindh, suitable for electric power generation and other applications, are around 218 billion tons- about 98% of coal deposits of the country.
Exploration of Thar coal will supplement the existing energy outputs in the country and will give boost to the economy of Sindh province.
Government would develop infrastructure, including road network to access the Thar coal reserves.
There is a huge allocation by the Petroleum and Natural Resources Division, as the government allocated Rs 850 million for 19 development projects. Out of total allocation, Rs 500 million has been allocated for Thar coal project. The total cost of the project has been estimated at Rs 1 billion and government would generate money from its own resources. Government has also allocated Rs 22.696 million for the ongoing project of National Coal Policy. The total estimated cost of the project is Rs 23 million. Government has also allocated Rs 35 million for the ongoing project of Feasibility Study Gasification of Thar Coal. The total cost of the project has been estimated at Rs 126.649 million.
THAR COAL: INCENTIVES
To ensure greater use of coal by various industries, the GoP should follow 'carrot and stick policy'. Cost optimization is the carrot and obligatory use is the stick. In the past, cement industry had switched over from natural gas to furnace oil, only because the government refused to supply gas to cement plants. The same policy can now be followed to switchover from furnace oil to coal.
Since the GoP will be the largest beneficiary of this switchover, it should provide incentives to the coal miners as well as the cement industry. To avoid frontloading of the projects, the GoP should abolish import duty on coal mining and related handling (transport and storage) equipment and requisite plant and machinery to be installed at cement plants.
Because of Thar coal's extraordinary importance for power generation, industrial development, and the economy, Sindh government and GOP are making all out efforts to develop this huge deposit for power purpose. It is one of the world's largest lignite deposits discovered by GSP in 1992.
The GSP had successfully completed coal resources evaluation in the four specific tracts/ blocks of Thar coalfield. The evaluation study of the GSP consisted of drilling 167 bore holes with a cumulative depth of over 50, 000 meters and chemical analyses of more than 2, 000 coal samples. On the basis of these studies, the required coal potential of a minimum of 500 million tons in each block has been established by the GSP. The recent studies on coal bed methane (CBM) proposed to be carried out in Thar will enhance the value of this deposit.
If all the oil reserves of Saudi Arab & Iran put together these are approximately 375 billion barrels, but single Thar coal reserve of Sindh is about 850 trillion cubic feet, which is more than oil reserves of Saudi Arab & Iran.
These reserves estimated at 850 trillion cubic feet (TCF) of gas, about 30 times higher than Pakistan's proven gas reserves of 28 TCF.
These coal reserves of worth USD 25 trillion can not only cater to the electricity requirements of the country for next 100 years but also save almost four billion dollars in staggering oil import bill.
Just 2% usage of Thar Coal can produce 20,000 mega watts of electricity for next 40 years, without any single second of load shedding.
If the whole reserves are utilized, then it could easily be imagined how much energy could be generated.
The coal power generation would cost Pakistan PKR 5.67 per unit while power generated by Independent Power Projects cost PKR 9.27. It requires just initial 420 billion rupees investment, whereas Pakistan receives annually 1220 billion from tax only. Petroleum lobby is very strong in Pakistan and they are against any other means of power generation except for the imported oil. This lobby is major beneficiary of the increasing oil bill that is estimated above 15 billion dollar this year.
Thar Coal can possibly enable us to produce enough electricity to power the entire country.