Environment

KEY POINTS

Petroleum coke

·         Petcoke is a by-product from the refining of crude oil.

·         It consists mostly of carbon, with variable amounts of sulphur and heavy metals.

·         Petcoke, with its sulphur content having 75,000 ppm (parts per million) is clearly one of the dirtiest fuels on earth.

Variants

·         High grade petcoke which is low in sulphur and heavy metals can be used to make electrodes for the steel and aluminium industry.

·         Lower grade petcoke containing higher levels of sulphur and heavy metals is used solely as fuel.

Inevitability of petcoke

·         India is the second largest refiner of crude in Asia after China, with a huge refining capacity.

·         Indian petcoke typically have high sulphur content as a result of improved refining quality of petrol and diesel to meet the automotive emission norms over the years. E.g. BS IV

·         (i.e.) Better quality petrol and diesel means higher sulphur content in residues such as petcoke.

·         At the same time, it is difficult for refiners to stop producing petcoke as a by-product.

·         Making alternate products such as bitumen (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.

Other viable options

·         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.

·         Also, 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.

NGT order

·         The National Green Tribunal has chosen 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.

·         E.g. Andhra Pradesh, Telangana, Gujarat and Karnataka have notified petcoke as an ‘approved’ fuel.

Way forward

·         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 and negate the very objective of making India environmentally more sustainable.