Quote:
Originally Posted by mithun I've heard that Naphtha is mainly used in adulteration. Is that true ? |
Please spare some time to read this 48 page
CSE (Centre for Science and Environment) Report on the independent inspection of fuel quality at fuel dispensing stations, oil depots and tank lorries. It is an eye-opener.
The samples were collected from December 20, 2001 to January 18, 2002 in the National Capital Territory (NCT) and National Capital Region (NCR) of Delhi.
This report was submitted to the Environmental Pollution (Prevention and Control) Authority on 5th February 2002.
The link is
http://www.cseindia.org/campaign/apc/pdf/Fnladul.pdf
An excellent synopsis of this report appeared in the Daily Excelsior, Business Section and is reproduced below:
Petrol, diesel at petrol pumps, oil depots adulterated: CSE
NEW DELHI, Mar 14: Motorists Beware ! The petrol or diesel available at your nearby petrol pump or oil depot could be adulterated.
Almost 26 per cent of the petrol or diesel sold at the various retail outlets in Delhi could be adulterated with elements like pentane, benzene, toluene or heptane, a study conducted by the Centre for Science and Environment (CSE) on the level of fuel adulteration in the national capital shows.
What is worse, current detection methods and prescribed standards for fuel quality are far too weak to detect the prevailing level of adulteration, the CSE said in a report.
"If adulteration is not caught, it is not because it is not happening. It goes undetected because detection methods and standards are too weak to catch it," Ms Anumita Roy Choudhry of the CSE said.
By the time the petrol or diesel makes its way from the refinery to the retail outlet, there is a considerable reduction in its sulphur level.
According to the CSE report, the fuels in oil terminals and retail outlets in the capital like petrol pumps is mysteriously lower compared to what mathura refinery produces.
In fact, comparison of fuel specifications different batches of fuels as recorded at the Mathura refinery, and Bijwasan depot, by the Indian Oil Corporation (IOC) over a period of more than a month, showed that while the sulphur level in diesel at the refinery varies from 400-480 ppm, it reduces to a uniform consistent level of 200 PPM at the depot.
In case of petrol, the sulphur level reduces to a ridiculous level of 110 PPM, as against a range of 350 ppm to 450 ppm tested at the Mathura refinery. Even at the retail outlet the levels are far below what the refineries are producing.
"In the absence of a plausible explanation for the difference in the fuel sulphur levels at the refinery and the depots, these low sulphur diesel and petrol samples could be adulterated ones," the CSE report says. CSE’s independent assessment of the fuel adulteration problem in the National Capital Territory of Delhi (NCT) and the National Capital Region (NCR) follows a direction from the Environment Pollution (prevention and control) Authority (EPCA) under the Supreme Court order dated November 22, 2001.
The EPCA was directed by the apex court to constitute an agency, which would independently carry out random inspection at petrol pumps, oil depots and tank lorries in Delhi and give report with regard to the quality of petrol and diesel available there.
Accordingly, the Society For Petroleum Laboratory (SFPL), Noida, was set up for the purpose.
Out of the 72 samples tested, 8.3 per cent were found to be adulterated, a sharp increase from the adulteration rate of one to two per cent reported earlier.
However, the failure rate of 8.3 per cent reported by the SFPL was an underestimate considering the fact that while interpreting the benzene data in petrol samples, it did not take into account the supreme court order that petrol must not have more than one per cent benzene.
Instead, while checking petrol for adulteration, SFPL is still using the older specification of three per cent maximum limit for benzene. After correction the total number of failed petrol samples increased to 15 (out of 72), that is 30 per cent of the petrol samples. The total sample failure rate, thus, increased to 26 per cent.
The inadequacy of current testing methods was proved by the fact that SFPL failed to detect adulterated samples that were deliberately sent to it by the CSE in the list of the 72 samples tested.
What weakens the testing system even further is the fact not only are the range of the parameters too broad, some of the key parameters of fuels like aromatics and olefins in petrol and polyaromic hydrocarbons in diesel are not even regulated and, hence, cannot be tested to check adulteration. Worse, even among the parameters that are currently tested, important tests like sulphur, benzene and cetane rating of diesel are not done on a routine basis.
The lax testing standards mean that an intelligent mix of common adulterants like kerosene and light diesel oil with diesel or naptha and other solvents with petrol may not show up in routine bis tests. Yet, a small mix of 10-15 per cent without violating the standards can help to reap lucrative profits - as much as Rs 25000 profit a day just by mixing 15 per cent naptha with petrol.
Experts point out that mixing kerosene and diesel oil in diesel over a prolonged period may impair engine performance and raise emissions.
Detecting adulterants in petrol is as difficult under the current bis specifications. For example, intelligent calculations are possible to work out the right proportion of adulteration - a mix of 20 per cent naptha in petrol with 92 octane can still meet the minimum requirement of 88 octane.
In view of the padding of some amount of adulteration within the permissible range of bis standards, it is important to be cautious about the samples that are at the margin, the CSE says. These samples would need confirmatory and precise tests for more accurate detection that are not done currently, it says.
To confirm this, the CSE conducted a limited set of tests on the samples, in its pollution control laboratory, that help to analyse individual hydrocarbon structure of the samples for more accurate fingerprinting. This enables comparison between fuel samples from retail outlets, depots and refineries and reveals any abberation that may occure due to adulteration.
The tests conducted by CSE showed an astonishingly high variation, in some aromatic compounds like hexane, pentene, xylene, between petrol and diesel samples from depots and refineries, which would have gone undetected under bis test methods employed in India.
According to the CSE, alternative fuel testing methods are available and applied in other countries for more accurate results, to deal with the problem of smuggling and mixing of cheaper and untaxed fuels. (UNI)