Fuel additives: of claims and counter-claims

May 09, 2005 02:00 AM

Two Nigerian scientists, Dr Augustine Ani and Dr Titus Okereke, in this reaction to a report on the safety of a fuel additive, MMT, posit that the claim of toxicity of the chemical is false
The Nigerian chemical industry has lately been thrown into frenzy following the total ban placed on the supply and distribution of leaded fuel in the country by the Federal Government. Attention has since been turned to the most suitable additive(s) for use in blending petrol consumed in the country free of lead.

In the thick of this consideration, a report came out last month by the India's CPCB (Central Pollution Control Board) and EPCA (Environment Protection Control Authority), which warned that some oil companies might be using manganese-based octane enhancer known as MethylcyclopentAdienyl Manganese Tricarbonyl (MMT), which could be hazardous to both humans and the environment.
According to EPCA, MMT is a cheaper chemical used to improve octane value in petrol. The CPCB has asked states to ensure that such blended fuel was not supplied in Delhi.
"We have found that MMT can increase deadly emissions from a vehicles and therefore a warning has been issued."

The report has since elicited reactions from the Nigerian public, in view of Nigeria's dependence on fuel importation. However, reacting to the postulation, Dr Augustine Ani, a Lagos-based Consultant Surgeon and Dr Augustine Okereke, a retired lecturer of the University of Benin and Chairman/CEO of HoniKomb (Nigeria), faulted the claims of the Indian bodies on MMT. In a presentation by the duo, the eminent scientists posited that global research into MMT on the other hand, proved the additive to be safe.
"We are in possession of a document titled 'Status Report concerning the use of MMT in gasoline' issued by a coalition known as the International Council on Clean Transportation (September 2004," stated the report.

This body includes the Alliance of Automobile Manufacturers (AAM), the Association of International Automobile Manufacturers, and the Canadian Vehicle Manufacturers Association constituting the "MMT Task Force" that sponsored a series studies and comprehensive MMT test programme, referred to as AAM study.
These studies were done principally by the Health Effect institute of the USA. However, on the front page of the document, there is a bold Disclaimer notification stating as follows:
"This document does not necessarily represent the views of organisations or government agencies represented by ICCT reviewers or participants".

Furthermore, a concurrent independent statistical review by Environ, a USA based environmental research institution, draws among others the following conclusion:
-- The AAM study conclusions are based on flawed and inappropriate statistical analysis.
-- The AAM study analysis ignores confounding variables and incorrectly attributes all differences in emission performance to the presence of MMT.
-- Vehicle design and variability dwarf all other factors impacting vehicle emissions. The AAM study seems to ignore this simple fact. The coalition of automobile manufacturers that conducted these studies is indeed a partisan party that has had a serious vested interest in the fuel additive market, being the principal sponsors of the oxygenerates (MTBE and ETBE).

These were the principal additives of the USA fuel formulations as well as many other countries and looked quite set to completely take over the market with the increasing rejection and phasing out of TEL (Tetraethyl Lead). All along, the coalition had to contend with the threat of MMT breaking into the world market from its primary base in Canada and it did everything including massive lobbying of the US. Congress and relevant Government Agencies to discredit MMT.
Unfortunately, around the mid-nineties MTBE was banned world-wide for environmental contamination and almost at the same period MMT got its waiver from the US Environmental Protection Agency for use in the USA, and has since gained increasing world-wide acceptance including Britain, France, the European Union, Australasia, India, Indonesia, Argentina, South Africa, Ghana, most Middle-East and Central American countries etc. In all, there are over 100 refineries in more than 20 countries that use MMT for their fuel treatment. Not surprisingly, the aggressive challenge will continue for some while to come.

Participants of a World Oil Conference held in Johannesburg, South Africa in 2003 witnessed a forceful presentation by the Allied Automobile Manufacturers criticising South Africa for its use of MMT. The host country armed with its own "Environmental Health Risk Assessment" by INFOTOX of South Africa creditably defended its used of the fuel additive.
The harmful effect of manganese (neurotoxic), a progressive neurological syndrome known as "manganism" was described as early as 1837 by Couper and this was among miners who processed manganese in large mines and caves. Attention later shifted to workers engaged in steel mills, battery plant workers and dwellers in cities with elaborate railways. Over the past century, abundant evidence has been collected from these occupational and city settings and these have inspired a lot of experimental studies largely carried out on animals in laboratories.

It is true that exposure to MMT that is stored in an enclosed space can be harmful to health if inhaled over a significant period; but these harmful effects fall within the purview of occupational hazards, which are well addressed in the Product Handling Manual or Material Data Safety Sheet.
However, post combustion MMT (i.e. what comes out of the engine tail pipe) is immediately decomposed on exposure to light -- with a half life of fifteen seconds -- and the resultant manganese oxide falls into the soil. Comparison has been made by measurement of atmospheric manganese in cities which have extensive underground railway system and which were not using MMT-treated gasoline and cities where cars drive on MMT-treated gasoline and it was found that the former are10 times higher in manganese. In either case, the total amount of manganese inhaled every 24 hours even in cities with relatively higher atmospheric manganese is less than 2.0ug mm, and this is not up to 2 % of the body's daily requirement.

Post combustion manganese presents as manganese phosphate and silicate which are inert. This however undergoes rapid photolysis in sunlight or any light at all, resulting in manganses oxide which drops into the soil or sinks on water surface. This explains why there is no correlation between respirable manganese and MMT use in cities where it is predominantly used for fuel treatment (Health Canada 1994).
Manganses is an essential body trace element requirement. An adult requires an average daily intake of 120ug mm, and gets it largely from dietary sources such as vegetable, hazel nuts and tea. It is essential for the synthesis of various body co-enzymes that are necessary for its metabolic activities. It is completely false to contemplate or state that anything can enter the brain directly through the nasal passages of man without first circulating in the blood. The blood/brain barrier happens to be the exclusive entry point of any substance-gaseous exchange, nutrients, drugs, toxins, chemicals etc. into the brain and these must be carried in the circulatory system.

Care should be exercised in translating some findings in animal experiments to humans. No known study of clearance rate or absorption rate of manganese has been done in man. These is no individual on this earth who has suffered from post-combustion manganese related illness in almost 30 years that MMT has been in use.
Scientific studies have shown that in major Canadian cities, levels of ambient urban manganses concentration do not reflect major changes in MMT use. Furthermore, personal exposures of all groups studied was less than 50 % of the (air reference value of 0.11ug/cm. It was concluded that from all analysis, the combustion products of MMT in gasoline do not represent an added health risk to the population (Health Canada 1994). This has remained the benchmark against which any further contributions are assessed.

Manganese oxide on catalytic converters
(a) do not adversely affect performance,
(b) do not adversely affect surface area of the catalysts, and
(c) actually extend the life span and durability of catalysts surfaces by inhibiting the deposition of phosphorus and zinc compounds.
The use of MMT-treated fuel does not adversely affect the ability of On-Board Diagnostic/Catalyst monitoring systems to identify graded emission components. It is proof of these through scientific studies that compelled the US Environmental Protection Agency to grant waiver for the use of MMT in the USA in 1995. MMT is the most researched and tested fuel additive in history.

Aside from the waiver for the use of MMT in the USA as approved by the USEPA, in 1995, the additive is currently being used by all the refineries in Canada. The use of MMT is included in the European Union standards (CONCAWE). It is approved for use in Australia and New Zealand. In Africa, it is currently being used by all state-owned Refineries in South Africa, (SAOL) and in Ghana (Tema Oil Corporation).
The use of MMT in refinery operations significantly reduces refinery emissions into the atmosphere. In automobiles, it specifically reduces the level of NOx and CO emissions by up to 40 % as well as various hydrocarbon particles such as smoke from worn down engines, making it an anti-pollution additive. It also permits significant reduction in fuel aromatics (which are carcinogenic) in refinery operations.

Source: This Day
Alexander's Commentary

Change of face - change of phase

In the period of July 20 till August 3, 2015, Alexander will be out of the office and the site will not or only irreg

read more ...
« April 2020 »
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30

Register to announce Your Event

View All Events