WORKSHOP
ON EFFECTIVE IMPLEMENTATION OF TRANSITION TO UNLEADED FUELS
Moderators:
Dr. C. B. Prakash, and Ms. M. Lovei: Panelists: Mr. P. N. Rangan,
Dr. M. Ahmed, Dr. Roy, Mr. B. Ramaiah, Mr. P.V.R. Ayyar, Mr. M.K.
Suri, Mr.
M.N. Muralikrishna
Occupational
health practices in IndianOil refineries with respect to TEL
Dr.
M. Ahmed
Indian Oil has seven
refineries out of a total of fourteen refineries distributed all over
India. It refines 40% of petroleum products. It’s market share in distribution
of petroleum products is 55%. TEL is blended with motor spirit to boost
the Octane number, for reduction/elimination of knocking of the engine.
It was first used in the year 1923. The Indian Oil is well aware of
its responsibility towards the health of their employees as well as
the general population, and hence, it was decided to discontinue blending
of Tetra Ethyl Lead in Gasoline. A process called catalytic reforming
now achieves higher Octane.
TEL is a toxic chemical
that has been in use for over 6 decades. This will probably go down
in the history of petroleum refining as one of the most toxic substances
used as an anti-knock agent. Severe toxicity including deaths had been
reported from all over the world during its use in the early 60’s. With
the identification and assessment of its occupational risk it was seen
that it was necessary to ensure that its manufacturing, distribution
and blending are properly regulated with prime concern towards worker’s
health. With due precaution and safety measures, TEL does not have any
effect on the personnel who are employed in blending operations. The
features identified during the clinical examination are of a general
nature and are not attributable to the toxicity of TEL.
About 70-75% of
lead is emitted from exhaust pipes of vehicles as inorganics salts of
lead in various particle sizes. The particle sizes ranging between 0.015
micron to 10 micron are aerodynamic with a life of 7-30 days. Particles
above 10 micron are subject to significant sedimentation. The inorganic
lead have deleterious effects on the human system especially intellect
deficit, mostly seen above 40 microgram/dL of blood. The use of TEL
in motor gasoline is being phased out and the anti-knock property is
being achieved by a process of Catalytic Reforming.
Progress
in Phasing-out Lead from gasoline in India
Mr.
T.K. Bandhyopadhyay
He gave an overview
of phasing out lead from gasoline in India. Unleaded petrol was made
available in Delhi and Agra in 1998, September. This change has brought
down lead level in the ambient air by 60%. The main aim was to make
it available to all cities in India by 2000, April. The other strategies
for this included lowering the cost of unleaded petrol, availability
of unleaded petrol in rural and urban areas, mass awareness campaigns
through various ministries about the use of leaded and unleaded petrol.
In India, as in
most developing countries, the main source of lead pollution is automobile
exhaust. Developed countries like the U.S., U.K., Germany and Japan,
only unleaded petrol is sold. In the U.S., the virtual elimination of
leaded gasoline resulted in a 77% decrease in the average blood lead
level of the population between 1976 and 1991. In U.K, a 50% drop in
gasoline lead levels corresponded with a 20% drop in blood lead levels.
The WHO estimates
that 15-18 million children in developing countries are suffering from
permanent brain damage due to lead poisoning and several millions of
children and pregnant women in practically all the developing countries
are exposed to elevated levels of lead.
Engines capable
of operating on lead free gasoline opens the markets for catalyst technology.
In Delhi, the Government has already initiated action for phase out
of taxis that are 15 years old or more. Financial incentive for replacement
of all post 1990 autos and taxis with new vehicles on clean fuels by
2001 is being provided. With phase out of lead from gasoline we hope
the particulate lead concentration in the air will come down substantially.
Transition
to Unleaded Fuels - The U.S. Experience
Dr.
B. Sonowane
Control of lead
exposure requires preventive measures at the local, national, and global
level. In certain developed and developing countries, identification
of the lead problem has, in most instances, brought effective measurable
results due to preventative interventions and regulatory actions. For
many populations around the world where human exposure to lead is excessive,
it results in disease especially in infants and children.
Leaded gasoline
remains a major source of exposure in most of the developing countries
and has been largely eliminated in the United States, Canada, Brazil
and Western European countries. Tetramethyl and tetraethyl lead had
been used as an additive in gasoline from the 1920s as an octane booster,
lubricant for engine intake and exhaust valves and as an anti-knocking
agent. Because of increasing knowledge about health concerns associated
with lead exposure, lead reduction program in the United States began
in 1970. Typical lead levels in the U.S. urban environment in the 1970's
were in the range of 0.5 to 10 ug/m3 and perhaps 90% of this was attributable
to lead in gasoline. The amount of lead in the air was related in large
part to the amount of lead in fuel. The health concern of children was
the principal driving force for regulating the lead content of fuels.
Under The Clean Air Act, U.S. EPA restricted lead use in gasoline. Automotive
manufacturers were required to design vehicles that could operate on
low-lead or unleaded fuels and a time schedule was set for phasing-out
leaded gasoline. The Clean Air Act provided the regulatory authority
to the U.S. EPA to control airborne lead attributable to motor vehicles
emissions. In 1980, National Research Council of the United States published
a document on lead in the environment outlining steps for regulatory
decision-making to reduce lead levels. The U.S. EPA promulgated a National
Ambient Air Quality Standard for Lead in 1978 based on the findings
that in children ages 1 to 5 years, a blood lead level above 30 ug/dl
was associated with an impairment of heme synthesis in cells as measured
by an elevation in erythrocyte protoporphyrin and was considered adverse
health outcome for children chronically exposed to lead.
The first steps
taken by automotive industry to reduce lead levels in gasoline in the
United States was by introducing a plantinum-based catalytic converter.
Substantial number of motorists continued to use leaded gasoline because
of its lower price. The EPA took further regulatory action to ensure
the phasedown of lead in gasoline in 1983 - 1985 by changing the basis
of calculating allowable levels of lead in gasoline from the total fuel
base to leaded gasoline only. This regulatory action resulted in a substantial
decrease in the amount of lead used in gasoline. In 1990, the U.S. Congress
mandated the eventual phase-out of lead in gasoline. The EPA estimated
a 34% reduction in lead use over the period of 1983 to 1990. By 1983,
unleaded fuel was just over 50% of the total gasoline market in the
United States, and by 1995 it represented almost the entire market.
When the phasedown really took effect, lead use was reduced to 7.1 thousand
metric tonnes in 1986 and 4.4 thousand in 1992. The Agency estimated
that the marginal cost of removing lead from gasoline was about one
cent for each gram of lead providing a cost - benefit.
A national survey
of blood lead levels conducted as a part of the National Health and
Nutrition Examination Survey II (NHANES II) in 1976 - 1980 revealed
that average blood lead levels in the United States adjusted for race,
sex, age, urbanization, etc. decreased approximately 37% between 1976
and 1980. This decline in blood lead levels correlated with a decline
in the use of leaded gasoline over the same period. Similar trend was
true for children, pregnant women and women of childbearing age. When
evidence indicated that lead concentrations of less than half the previous
CDC guidelines (30 ug/dl) can impair cognitive and physical development
in children and increase blood pressure in adults, in 1991 the Centers
for Disease Control and Prevention (CDC) recommended that intervention-level
for lead toxicity to 10 ug/dl. The CDC recommendation for universal
screening with blood lead assumes that many children have mild (10-24
ug/dl) to moderate (25-44 ug/dl) lead poisoning. That this condition
can be accurately and reliably detected by available screening tests
and that this condition is harmful to children and benefits out weigh
the risks associated with intervention. The EPA has established standards
designed to limit the amount of lead that the public is exposed to air.
Over a three-month period, the amount of lead that the public inhales
cannot contain more than 1.5 ug/m3. EPA limits the amount of lead in
unleaded gasoline to 0.05 grams of lead per gallon of gasoline. The
National Institute of Occupational Safety and Health (NIOSH) recommends
that workers not be exposed to lead levels more than 100 ug/m3 for up
to 10 hours. Lead emissions from automobile exhaust now contributes
only marginally to lead levels in the environment. Thus, the removal
of lead from gasoline in the United States is a public health victory,
however, low levels of lead exposure still remains a problem and a challenge
for public health agencies in the United States.
Oxygenated additives
have been used as octane enhancers in gasoline since the late 1970's,
due to the phase-out of lead. The 1990 Clean Air Act Amendments required
the use of oxygenated gasoline in several areas of U.S. that failed
to attain the National Ambient Air Quality Standard (NAAQS) for CO.
In addition, in 1995, a reformulated gasoline (RFG) program using oxygenates
was to be implemented to reduce ozone levels in certain regions. Methyl
tertiary-butyl ether (MTBE) has become the most widely used motor vehicle
oxygenate in the U.S. Other agents with oxy properties included fuel
oxygenates such as, ethyl tertiary-butyl ether (ETBE), tertiary-amyl
methyl ether (TAME), diisorpropyl ether (DIPE) and methanol. The Clean
Air Act Amendments requires at least 2.7% by weight oxygen content for
gasoline sold in CO non-attainment areas, (i.e., 15% by volume MTBE
or 7.5% ethanol and 2% for RFG (approximately 11% vol MTBE or 5.7% ethanol).
Some analyses of
ambient CO measurements in some cities with winter oxygenated gasoline
programs find a reduction in ambient CO concentrations of about 4 to
10%. Oxygenated fuels also reduce exhaust emissions of total hydrocarbons,
benzene and 1,3-butadiene, but increase the emissions of aldehydes (acetaldehyde
from the use of ethanol or ETBE and formaldehyde from use of MTBE).
Safety
Measures in refineries
Dr.
S.N. Roy
A brief account
of safety measures adopted during TEL blending in the oil refineries
were explained by him. Pre-implantation and annual medical check-up,
training in handling and disposal of wastes, and education on health
hazards through books were some of the safety measures followed.
Can
unleaded gasoline be used on older vehicles?
Mr.
M.N. Muralikrishna
In the capacity
as a Chairman of the two wheeler Technical Sub-Committee of Association
of Indian Automobile Manufacturers, I confirmed that unleaded gasoline
can be used on current and old two-wheelers without any detriment to
performance or reliability. With regard to automobiles, while the new
generation models are fully equipped to use unleaded gasoline, lots
of doubts were raised about usage of unleaded gasoline in older vehicles.
After referring to Association office in Delhi, we received confirmation
that even on old generation vehicles (like Fiat and Ambassador) unleaded
gasoline can be used without any difficulty. In fact, over the past
year or so, this is happening in Delhi and manufacturers have not received
any complaints on this issue.
Petroleum
Industry Comments
Mr.
C. Shankar and Mr. P.V.R. Ayyar
Gasoline is one
of the main transportation fuels used worldwide. Quality of gasoline
fuel (Petrol) is governed by development of new generation vehicles
and environmental concerns. Gasoline fuel quality in particular and
other petroleum fuels in general is undergoing real change in recent
years to meet the needs of the new generation vehicles and also emission
standards dictated by ambient air quality/human health concerns.
While most of the
developed countries have phased out lead, in India also the process
of phasing out lead has started since 1994 with the supply of low leaded
gasoline in metro cities. Incorporation of new refining processes with
huge investments is the order of the day for petroleum refineries so
as to meet the challenge of lead phase out. Indian Petroleum Industry
has drawn elaborate plans to supply unleaded gasoline in the entire
country by year 2000 in line with the directives of the Government.
Tetraethyl Lead has traditionally been used for meeting the octane requirement
of motor gasoline worldwide. Consequently vehicular emission has been
one of the major source of lead pollution particularly in cities. With
the rapid industrialization and economic prosperity, transportation
sector has witnessed rapid growth in developing countries like India.
To mitigate lead pollution caused by vehicular emission, Govt. of India
has drawn out a time bound schedule to phase out lead from motor gasoline
by year 2000. In the seven refineries across the country, Indian Oil
Corporation has taken prompt steps to gear up the production of unleaded
petrol. This is being achieved by a combination of appropriate technology
adoption, catalyst management, blend optimization and process parameter
adjustments. Indianoil’s initiatives to harmonize the operations with
the environment will continue.
Landmark
Events
Mr.
P.N. Rangan
He brought to the
attention certain recent historic " call to action" events:
- Dec.1994: Summit
of Heads of States pledged to develop national plans for phase out
of leaded gasoline.
- Oct.1995: Ministerial
conference on environment for Europe called for reduction and ultimate
phase out.
- May 1996: World
Bank called for a global phase out of leaded gasoline and offered
to help countries design feasible phase out schedules and incentive
frameworks.
- June 1996: Second
United Nations conference on human settlements (called Habitat 11)
included elimination of lead from gasoline as a goal in its agenda.
- May 1997: Environmental
ministers from G-7 plus Russia endorsed phase out of leaded gasoline.
Recommendations
of Workshop
Dr.
C. B. Prakash
From all the panel
members which included representatives from the government of India,
the automotive and petroleum industries in India, and the foreign experts,
there was a consensus that the use of lead should be completely phased
out from Indian gasoline as soon as possible. In fact the government
and industry in India are targeting a date of April 1, 2000, for completing
the lead phase out.
Based on the various
presentations and subsequent discussions during the panel, the final
conclusions and recommendations from this panel are as follows:
1.
In the modern times, it is criminal to allow the use of Lead in gasoline
2.
There are two major issues related to the use of leaded gasoline. First,
lead emissions resulting from the use of leaded gasoline are toxic,
and their severe adverse health effects on children, pregnant women,
and adults are well documented. Secondly, a most effective emission
control technology, "Catalytic Converters", which reduce the
motor vehicle emissions by about 90% cannot be used if lead is present
in gasoline. The lead poisons the catalyst and makes it totally ineffective.
3.
The manufacturer and promoters of tetra ethyl lead (TEL) advocate that
older cars would have difficulty in operating on unleaded gasoline.
Based on the general consensus and the clear statements by auto manufacturers,
it was concluded that most vehicles including cars, jeeps, and 2 and
3 wheelers currently representing the Indian fleet can operate very
satisfactorily on unleaded gasoline. Hence the statement of TEL supporters
is a myth and not a reality.
4. The amount of
TEL used in Indian gasoline increases the gasoline Octane number by
approximately 2 points. There are many options for replacing this octane,
hence TEL can be eliminated today. India should look at the following
available options and select the one or more options which are most
cost effective and least harmful.
- Changes in gasoline
composition: Gasoline is a mixture of hundreds of individual hydrocarbons
(HC) which have different octane. One can make changes at the refinery
and adjust the quantities of various HC in gasoline to obtain the
desired Octane. Generally, Aromatics, Isomeric Compounds, and Alkylates
have higher Octane. However, it should be remembered that changes
at the refinery are costly, and increasing the amount of Aromatics
in gasoline increases Benzene emissions, which is carcinogenic.
- Adding other
higher Octane components, such as ethers (MTBE) and alcohol (Ethanol).
These components are currently not available in India in sufficient
quantities and may need to be imported. Thus the economics and other
environmental implications of this option need further evaluation.
The use of other Octane enhancers such as MMT, which contains heavy
metal, should be avoided.
- Use of special
Additives. A new additive technology, which improves the fuel combustion
and reduces the combustion chamber deposits (CCD) in the engines,
has been demonstrated to reduce the octane demand or octane appetite
of the engines. Thus the use of such additive would reduce CCD, reduce
the octane demand of the engines, and allow the vehicles to perform
satisfactorily on a lower octane gasoline. The additive is used in
very small quantities (parts per million) and is highly cost effective.
Its cost is similar or lower than TEL. This option also avoids changes
at the refineries and major capital investments. Thus it warrants
a very careful consideration as a potential option for eliminating
the use of TEL.
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