Blanket ban on petcoke not a wise move

Not really a waste: Petcoke-fuelled cement kilns use low-grade limestone

If used effectively, like in a cement kiln, this high-calorific value petroleum residue will help conserve natural resources

On November 17, the Centre informed the Supreme Court that it had banned the use of petcoke in Uttar Pradesh, Haryana and Rajasthan as a part of the efforts to curb the suffocating level of air pollution in the NCR region. That did not raise too many eyebrows.

After all, when it comes to sulphur content, petcoke with 75,000 ppm (parts per million) is clearly one of the dirtiest fuels on earth. Even coal, the biggest contributor to greenhouse gas emissions, has just 4,000 ppm of sulphur.

But what the apex court observed during the course of the hearing did surprise many – users and environmentalists alike.

“We may note that pollution caused by petcoke... is not a problem confined only to the NCR region but appears to be a problem faced by almost all states and Union Territories (UTs). For the present, we do not propose to give any direction to any other States and UTs but we request all the State governments and UTs to consider taking similar measures as have been taken by Government of India (in NCR),” the apex court has said, in effect suggesting a nation-wide ban on the use of petcoke.

A recent phenomenon

Emergence of petcoke, the bottom-of-the-barrel residue while refining crude oil, as a sought-after fuel is a recent phenomenon in India. Even as late as 2010-11 only 4.98 million tonnes of petcoke was consumed.

The demand for it shot up when global prices fell sharply after many developed countries chose to export the fuel rather than consume it.

Data from the Indian Petroleum & Natural Gas Statistics 2016-17 show that India’s consumption of petcoke in 2016-17 stood at 23.25 million tonnes with imports accounting for a significant share of it.

But is a blanket ban on petcoke usage across the country the right solution? Ironically, it is not, for multiple reasons, and if such a ban is indeed implemented, it will negate the very objective of making India environmentally more sustainable.

Too much at stake

India is the second largest refiner of crude in Asia after China with a refining capacity of about 234 million metric tonne per annum (MMTPA) and a throughput of over 245 MMTPA in 2016-17 that inevitably generated 13.94 million tonne of petcoke.

Indian petcoke typically has high sulphur content as the refineries are tuned to refine the cheaper crude which is typically heavier and dirtier.

Also, the refineries have been improving the quality of petrol and diesel to meet the automotive emission norms over the years (Bharat Stage VI fuel will have just 10 ppm of sulphur as against 10,000 ppm in mid-1990s). Better quality petrol and diesel means higher sulphur content in residues such as petcoke.

At the same time, refiners cannot stop producing petcoke. Making alternate products such as bitumin (this too has high sulphur content and is a challenge to store/transport it) or value-adding petcoke by installing hydrogenation systems will involve large investments.

That will be a bit too much to ask as many public sector companies have just created petcoke capacity at significant cost on seeing rising demand for the fuel. Also, refiners are investing lot of money to upgrade their processes to produce the cleaner BS-VI fuel.

Given that production of petcoke will continue in India for the foreseeable future, there is a clear need to find a way to dispose it in an environmentally friendly manner (even if imports of the fuel is banned/restricted) and cement kilns offer the best option.

Myriad uses

In cement kilns limestone is burnt at over 1500 degrees to produce clinker which is then crushed to produce cement.

When petcoke is used as a fuel, the lime in the clinker absorbs the sulphur (both lime and sulphur have a natural affinity for each other) and the sulphur that is eventually let out of the stack is way below the permissible norms.

Globally, 28 per cent of petcoke is used in the cement industry and 18 per cent in power plants with a de-sulphurisation unit that use limestone to scrub the sulphur from the exhaust. Cement kilns are already used in the country to dispose high-calorific hazardous waste such as paint sludge, tyre chips and even municipal waste.

There is another advantage in using petcoke in cement kilns. As petcoke has zero ash content, cement firms can use low grade limestone. This is a big advantage as almost 60 per cent of India’s limestone reserves is low grade in nature and cannot be used if coal (which has significant ash content) is used as fuel.

And a ban will force cement manufacturers to shift back to coal further exacerbating the delicate demand-supply situation there. In short, use of petcoke in cement kilns helps us to use our natural resources more judiciously.

Director general of Centre for Science and Environment Sunita Narain in a recent article on the subject of ‘petcoke conundrum’ while bemoaning the large scale import of the fuel advocated its use in cement kilns as a safe way to dispose it.

The National Green Tribunal has also been looking into the use of petcoke and in its order dated May 16, 2017, it chose not to ban the fuel. It instead asked the States to take a decision as to whether petcoke is an ‘approved fuel or not’ and ensure that users install necessary air pollution control systems to reduce sulphur emission. States such as Andhra Pradesh, Telangana, Gujarat and Karnataka have since notified petcoke as an ‘approved’ fuel.

The need of the hour is thus a clear cut policy which stipulates as to who can use/import petcoke and what stringent emission norms they have to adhere to. A nation-wide ban on its usage is a simplistic solution that will prove to be counter-productive.

Published on November 29, 2017
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