Opinion

Producing clean coal is no easy task

ROHIT CHANDRA | Updated on January 22, 2018 Published on November 30, 2015

Up in the air The fate of clean coal REUTERS

Removing ash or moving to supercritical plants will result in more expensive coal and power. How do we manage that?

What is India doing to clean up its coal industry, given the proven negative, long-term consequences (local and global) of coal combustion? What ideas and initiatives can India project as good faith commitments to improving its coal sector and limiting coal use-related emissions?

Some misconceptions need to be addressed. First, India is not part of some small minority of countries that have experienced consistent coal consumption growth.

Most large, developing countries, and even some developed countries, have seen resurgences in coal usage from the early 2000s onwards. Second, carbon capture and sequestration (CCS) technologies are far from proven and decades away from financial viability.

Finally, India’s energy mix is not capable of dynamically reorienting towards non-coal alternatives in a 15 to 20-year timescale. In the long run, India must transition to renewables and non-fossil fuels but the golden age of renewables is still some decades away.

Looking at aggregate trends in India’s primary energy mix, perhaps the most salient feature is the increased consumption of natural gas over the last 10-15 years. But even now, natural gas is less than 10 per cent of India’s total primary energy consumption. Thus, coal will remain the dominant source of energy in India in the medium term, even as it makes investments to transition to other sources.

Coal washing

Fortunately, there are some attractive options. The first is coal washing. Coal washing, beneficiation, or preparation is the process of reducing the ash content of coal through physical separation. Indian coals on average contain 40 per cent ash, which is much higher than the 25-30 per cent ideally needed for the efficient burning of coal in thermal power stations. Burning ash leads to incomplete combustion, which releases many more airborne effluents than necessary. In addition, since most of India’s coal is not washed, India is needlessly transporting massive amounts of ash.

While coal washing is necessary for the steel industry, it has not really taken off as an intermediate activity for India’s power plants. This is because of a mix of legal and pricing obstacles. Since coal washing was not a notified end-use in the Coal Mines Nationalisation Act, prior to 1993 only Coal India Limited (CIL) was allowed to wash coal. The pricing differential between different grades of coal was less than the economic cost of washing, so the profit-maximising part of CIL never willingly wanted to enter the coal washing business.

Poor quality

Despite this reluctance, CIL has been washing 10-15 per cent of the coal it produces due to the poor quality of Indian coal, and because ministry of environment and forests (MoEF) guidelines have mandated that coal transported more than 1,000 km must be washed to below 34 per cent ash content. More recently, CIL has been bidding out washeries to private contractors. Unfortunately, private coal washing has, so far, not had the best reputation.

End-users of coal are aware that many private coal washing companies simply manage connections to get the best coal from mines (hence, not actually engaging in coal washing), and some companies also have a reputation for diverting coal for their own purposes.

The second idea deserving a closer look is domestic supercritical boiler design. Under the National Clean Coal Mission, collaborations were planned between Indian and foreign firms to create capacity for manufacturing boilers that could function at supercritical conditions. Supercritical boilers are superior to conventional boilers because they function at higher temperatures and pressures, which results in more efficient combustion and less waste heat. Supercritical boilers also result in fewer emissions and lower operating costs over the lifetime of a plant. However, buying them internationally is not cheap.

India’s first commissioned supercritical plant was built by the Adanis in Mundhra; they bought their supercritical boilers from Chinese suppliers. While BHEL has recently constructed supercritical boilers for NTPC’s upcoming plant in Bihar, many currently planned power plants still do not incorporate supercritical technologies. Part of the problem is that it is difficult to maintain the high heat rates required for supercritical operation with lower quality Indian coal.

Coal washing could help with this problem, but there is also a need to adapt boiler designs to be more compatible with Indian coal. BHEL and other manufacturers need to be more involved in making this a reality.

Transportation issues

Finally, the perennial problem of coal transportation and power plant siting persists. The initial logic of siting power plants close to coal deposits to minimise transportation costs did not succeed for a variety of reasons: coal-bearing States did not provide great investment environments, they had relatively ineffective State electricity boards (which were unable to build up State level generation assets), and did lose from the implementation of freight equalisation policies. Most of the surviving public sector plants in Bihar, Jharkhand and West Bengal are run by central PSUs, resulting in lesser allocation of power to the home States according to the Gadgil formula.

The resulting geography of power plants at the national level has led to extremely ineffective methods of coal transportation. Over 20 per cent of India’s coal still moves by road to power plants, which is less efficient than railways-based movement. The idealised vision of a stream of unimpeded coal wagons circulating between coalfield and power plant with bottom-opening technologies — so that they do not have to stop moving when dumping coal — has not been realised because of the parallel congestion of passenger and freight traffic on Indian Railways. For a truly effective power infrastructure, India needs to move less coal and more power. The development of interregional transmission networks and the rise of power markets has made this easier. But this requires a degree of coordination between Railways and power infrastructure planning. With the recent dedicated freight corridor projects and investments in rail infrastructure by Coal India, this may be changing.

These three ideas may be more energy efficient and reduce emissions, but they will be more expensive than the status quo. This means coal will be more expensive and power prices will have to increase. Without the downstream price signals to incentivise such investments, demand for coal washing, supercritical boilers, or more efficient plant siting and coal transportation will never materialise.

The current financial state of the distribution companies makes many of these ideas seem much closer to fiction than truth. By tipping the balance the other way, the benefits in both domestic and international spheres are considerable.

The writer is a doctoral candidate studying energy policy at the Kennedy School of Government, Harvard University. This article is by special arrangement with the Center for the Advanced Study of India, University of Pennsylvania

Published on November 30, 2015
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