NEW DELHI (PTI): Lead free petrol would be made available in all the four metropolitan Delhi. Madras Bombay and   Calcutta by December 1997 under a joint action plan of the environment and petroleum ministered to drastically reduce automobile exhaust pollution.

State-owned refineries will be investing a whopping Rs 9.05 billion immediately specifically to Update technology to make lead free petrol available at all the retail outlets in a three-year the span oil industry sources said.

During the period a phased reduction of lead content in petrol will also begin simultaneously the Sources said.

Lead content in petrol now being supplied by the refineries in the country to different regions ranges from 0.25 to 0.50 grams per liter on an average.

Environment ministry has directed the oil companies to bring down the lead limit in petrol from the existing level of 0.56 grams per liter to 0.15 grams per liter

The crackdown on the petroleum companies followed the initiative taken by environment and forest minister Kamal Nath who laid down the deadline by which lead free petrol was to be made available to car owners

There has been growing awareness among the public of the hazards of exhaust pollution known to have triggered off a variety of chest ailments including Asthma.

Automobile pollution is a major public health hazard in all the metropolitan cities particularly New Delhi where the vehicle population is the highest in the country.

Vehicles on Delhi roads alone emit about half a million tons of pollutants every year which contain about 100 tons of lead in the form of suspended particulate matter

Other pollutants are Sulphur dioxide carbon monoxide oxides of nitrogen and unburnt hydro carbon.

There is no natural lead content in petrol. It is blended in petrol as an additive at the end stage of its production in the refineries in the form of tetra ethyle lead (TEL) which is a toxic substance

The purpose of adding TEL to petrol is to improve its combustion quality. The burning/combustion quality of petrol in an engine is measured in terms of octane. The higher octane gives better performance of the engine due to its improved combustion quality oil industry sources said

Besides the compression ratio of an engine is directly related to fuel at the endian been to increase the Compression Ratio (CR) of car engines or deriving better fuel economy. An engine of CR-five can be at is factorial operated on petrol of 0 to 75 octanes whereas high performance engines of GR-10 will squire a fuel of labour 100 octanes. As a thumb rule an Increase of ne CR unit calls for increase of live octane of the fuel. In India on  octane) specification was revised i 1983 from 53 to 87 on with introduction of Maruti cars Similarly 93 on petrol is also available in some petrol pumps for use in imported cars.

Petrol is currently produced lending tel with Straight Run Naphtha (SRN) for meeting octane specifications of Barauni Dighot   Mathur are fine resin the country.

Reduction in the lead therefore necessitates installation of reformats to increase the octane number of Naptha to produce inspect Ms (petrol) the sources said.

Government has approved setting up of Catalytic Reforming Units (CRUs) at these three refineries at a total cost of Rs 9.05 billion

Out of the 12 operating refineries in the country the average led content in just three refineries is as high as 0.50 grams per liter and the remaining nine refineries it is low at 0.20 grams per liter but still way above the specifications insisted upon by pollution experts.

The only refinery in the country which now produces lead free petrol is Bengaing a on refineries based in Assam. But its petrol is mostly supplied in the north eastern region where pollution is not such a problem. Only Calcutta in the cast has a major exhaust pollution problem.

Introduction of lead free petrol however brings a host of other problems to car owners though it helps to clean up the environment to a certain extent

The major problem is redesigning of the engine in the car to handle lead free petrol. New cars rolling out of factories from 1997 would have to have modified engines. But there is no indication is yet as to how many car manufacturers have moved in this direction.

But the biggest problem is how to handle vehicles used to giving optimum performance only with lead in petrol. Who will redesign these engines the car manufacturers of the road side mechanics?

It is likely to be boom time for both if they undertake the job.

Article extracted from this publication >> May 27, 1994