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Coal must be mined sensibly

The use of clean coal mining and processing methods can ensure that a greater share of our coal reserves is put to use, and in a sustainable manner.

Coal is the predominant source of energy in India and constitutes the largest share in India's total energy production and consumption. Some 55 per cent of the country's energy needs is met by coal, and according to most projections, this coal-centric energy structure will continue for at least the next two or three decades.

As coal-based power generation is the predominant source of greenhouse gases in India, national climate change planning cannot ignore this issue. Hence, India has launched the ninth mission on Clean Coal Technologies (CCT) under the National Action Plan on Climate Change (NAPCC).

However, the quantity of coal to be used in future as indicated by some projections is also questionable, as it may be difficult to get that much of coal either domestically or through imports. Hence, planning based on such projections raises serious concerns about India's energy security.

Coal Availability

India's inventory of coal resources has been estimated at 267.21 billion tonnes (as on April 01, 2009). Of this, 39.6 per cent has been categorised as proved, 46.2 per cent as indicated and 14.2 per cent as inferred.

The estimated coal inventory includes coal lying at a depth of 1200 m which is not feasible for use either now or in the near future. It also includes inaccessible coal lying in protected areas or beneath forests, villages, towns or water bodies. Thus, the coal that can be extracted-taking into account geological, technical, and economic aspects is only a small proportion of total estimated coal inventory in the country, which might not last more than 45 years.

Hence, if India has to maintain a coal-centric power sector, it will have to import a huge quantity of coal. This is likely give rise to a host of new coal security concerns, including the trends in world coal prices, changing trade patterns, potential geo-political concerns and so on. In addition, in recent years, several countries (such as Germany, UK, Poland) have downgraded their reserve base, with overall world reserves reducing from 10, 000 billion tones to 4, 200 billion tones over 25 years (till 2007).

This further restricts the ability to import large quantities of coal. In fact, some projections peg the import demand for coal in India by 2030 at a level that is as high as total coal traded in the global market now. Hence, a sharp rise in Indian import of coal can cause a steep rise in international coal prices, and securing that kind of supply will be extremely difficult.

Three-Pronged Approach

Thus, it becomes imperative to augment domestic supply by using better technologies. This can happen at two levels. Firstly, by getting more coal extracted from the same reserves and, secondly, by getting more energy from the same amount of coal.
Of equal importance is to address local and global environmental challenges created by coal mining and coal-based thermal power generation.

The triple objective can be achieved by employing better technologies, which reduce efficiency loss and environmental externalities. Installation of clean coal technologies should start from coal mining itself. A balance between coal production from open cast mines and that from underground mines using efficient mechanised method coupled with international good practices minimising land degradation, pollution of water and air, and displacement of people would be the first step.

In recent years, the government has adopted various initiatives to introduce clean coal technologies in India through various R&D programmes, demonstration plants, pilot studies, among other steps.

IGCC Technology

The National Thermal Power Corporation (NTPC) and Bharat Heavy Electricals Limited (BHEL), for instance, have collaborated to design 100 MW demonstration plant for integrated gasification combined cycle (IGCC). In addition, various regulations have been introduced to accelerate the pace of movement towards clean coal technologies. For instance, a clean energy cess of Rs 50/tonne will now be levied to create a National Clean Energy Fund (NCEF) for financing research and innovative projects in clean technologies.

The government has also initiated collaborations with foreign countries for the acquisition of clean coal technologies. The use of super critical and ultra super critical plants and IGCC at the stage of combustion results in lower emissions as well as increased efficiency. Hence, such technologies should be explored.

But excessive reliance on combustion technologies or post-combustion remedial measures may not take us too far. Now, there are also talks about carbon capture and storage (CCS) technologies. However, adopting such technologies has serious challenges due to huge investment and land requirements. More importantly, maintaining a CCS system itself requires significant energy, delivering less energy per unit of coal.

Given such a scenario, making clean fuel out of coal through liquefaction and gasification can be a useful option. Direction of research and experiences shows that there is good potential for such technologies. In India, such technologies were tried in the 1980s by Indian Oil and ONGC, and while liquefaction was found to be too expensive, gasification raised some environmental concerns as well.

However, things have changed now. Environmental concerns might be addressed through refinement of technologies. In fact, CCS technology that has already been used to extract natural gas with better environmental outcomes can be useful to make coal gasification also more environment-friendly.

Currently, India is extracting coal through open cast and underground mining and has been able to access coal only up to a depth of about 600 metres, though about 90 per cent coal in India is mined through open cast method and the depth is normally not beyond 150 meters.

Through gasification technology, it has been possible to access coal up to a depth of 1.5 kilometres and in future even this might increase. Surely, we need technologies that will not only be clean, but will also convert large part of our coal from non-usable to usable, which is also in line with the spirit of NAPCC.

Tags: coal and handling, coal and mechanisation, coal and mining, energy needs, energy production

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