Switching to unleaded gasoline<\/p>\n
By Kardono<\/p>\n
JAKARTA (JP): The use of leaded petroleum is gradually being
\nphased out worldwide, because of increasing recognition of health
\nrisks of lead exposure and the introduction of catalytic
\nconverters, which require unleaded petroleum. However, as each
\ncountry considers the issues of leaded petroleum, the same
\nquestions are revisited concerning health risks, technical
\nfeasibility and costs.<\/p>\n
Unleaded petroleum, that grand scheme to help us all breathe
\neasier, is getting more attention. Some countries have replaced
\nleaded petroleum with the unleaded type whereas others, including
\nIndonesia, have still kept lead in petroleum as a main octane
\nbooster.<\/p>\n
Indonesia planned to phase out lead in petroleum in 1993 but
\nthe plan was stalled due to the economic crisis. Reports say
\nunleaded petroleum may be implemented as soon as July 2001 in
\nJakarta, to be followed by other cities.<\/p>\n
In general, the transition to unleaded petroleum will require
\nrefinery improvements and perhaps the use of other additives,
\nsuch as methyl tertiary-butyl ether (MTBE).<\/p>\n
The basic refinery options to produce unleaded petroleum
\ninclude catalytic reforming, which results in higher octane
\naromatics (such as benzene, xylene, and toluene) and
\nisoparaffins; and isomerization, which transforms normal
\nparaffins into higher-octane isoparaffins.<\/p>\n
Whereas, MTBE, one of the petroleum additives, is a chemical
\ncompound manufactured by the chemical reaction of methanol and
\nisobutylene -- a liquefied petroleum gas. It is among a group of
\nchemicals commonly known as \"oxygenates\" because they raise the
\noxygen content of petroleum.<\/p>\n
Most refiners have chosen MTBE over other oxygenates as a lead
\nsubstitute primarily for its blending characteristics and for
\neconomic reasons.<\/p>\n
MTBE has been used in petroleum to replace lead as an octane
\nenhancing material, which helps prevent the engine from
\n\"knocking\". Oxygen helps petroleum burn more completely and
\ntherefore reduce harmful tailpipe emissions from motor vehicles.
\nIn one respect, the oxygen dilutes or displaces petroleum
\ncomponents such as aromatics (e.g., benzene) and sulfur. In
\nanother, oxygen optimizes the oxidation during combustion.<\/p>\n
The Balongan refinery of the state oil firm Pertamina has
\nchosen catalytic reforming in the production of its unleaded
\npetroleum. The government's choice of the next type of unleaded
\npetroleum is still unclear. Thailand for example, is making the
\ntransition from leaded petroleum with 0.45 gram per liter to
\nunleaded petroleum using both refinery improvements and MTBE.<\/p>\n
In Malaysia, the production of unleaded petroleum is similar
\nto that in Thailand. In the European Union, unleaded petroleum is
\nmostly carried out by blending oxygenate additive of MTBE into
\npetroleum.<\/p>\n
In the United States, the unleaded petroleum program has been
\nimplemented through the Clean Air Act Amendments of 1990 (CAAA).
\nThe Act contained two primary requirements for cleaner petroleum.
\nThe first, known as the oxygenated fuels program, began during
\nthe winter of 1992-1993 and required all petroleum sold in 39
\ncarbon monoxide (CO) nonattainment areas to contain 2.7 percent
\noxygen. Nonattainment areas in the United States are areas which
\nhave failed to comply with ambient air quality standards, due to
\ntheir very high levels of emissions.<\/p>\n
The higher oxygen content helps to reduce CO emissions,
\nespecially during the winter months when most CO violations
\noccur. The other fuel program, known as the reformulated gasoline
\n(RFG) program which requires cleaner-burning reformulated
\npetroleum, has been sold in the nine worst ozone nonattainment
\nareas since Jan. 1, 1995.<\/p>\n
About 40 other cities have voluntarily adopted the RFG
\nprogram. Among requirements of the program are that the
\nreformulated gasoline must have an oxygen content weight of 2
\npercent, a maximum benzene content of 1 percent, and no heavy
\nmetals.<\/p>\n
RFG is also subject to a performance standard; among others it
\nshould lead to a 15 percent reduction of volatile organic carbon
\nand toxic air emissions from baseline levels between 1995 and
\n2000.<\/p>\n
Ambient monitoring data from the first year of the RFG program
\nin 1995 showed strong signs that RFG was working. For example,
\ndetection of benzene (one of the air toxins controlled by RFG,
\nand a known human carcinogen) declined dramatically, with a
\nmedian reduction of 38 percent from the previous year.<\/p>\n
Actually, neither the Clean Air Act nor the Environmental
\nProtection Agency (EPA) requires the use of MTBE in reformulated
\ngasoline. The 1990 Clean Air Act Amendment did not specify which
\noxygenate to use. However, both MTBE and ethanol are, in fact,
\nused successfully in the current RFG program with the MTBE more
\ndominantly used by some 80 percent fuel providers.<\/p>\n
Despite air quality improvement aspects of oxygenates in RFG,
\nthere is growing concern about contamination of drinking water by
\nMTBE in some areas. EPA is also concerned about detected MTBE in
\ndrinking water, as well as ground and surface waters.<\/p>\n
As of June 1999, MTBE was detected in 3.7 percent of samples
\nof water from California's drinking water systems. It was
\nreported that about 3 percent of ground water wells in RFG
\nprogram areas were detected to contain MTBE at or above five
\nparts per billion. This was primarily a result of leaking
\nunderground fuel storage tanks, and possibly from spills from
\ndistribution facilities.<\/p>\n
Some users do not accept the RFG program based on complaints
\nof MTBE contributing to negative health effects, increased fuel
\nprices, and lower engine performance. Reported health effects
\ninclude headaches, dizziness, nausea, sore eyes and throats, and
\nrespiratory irritation.<\/p>\n
Research about MTBE health effects has been inconclusive,
\nhowever, most studies have failed to find acute health effects.
\nRFG is expected to benefit health by helping areas achieve
\ncleaner air. On average, RFG has decreased the use of fuel by two
\nmiles to three miles per gallon because oxygenates have lower
\nenergy content than petroleum. There are reports of much more
\nsavings of fuel for some vehicles. There are also reports that
\nsmall engines do not perform well using RFG.<\/p>\n
There is now a growing debate concerning environmental and
\nhealth effects of MTBE. No doubt unleaded petrol using MTBE
\nadditive has resulted in cleaner air quality. However some
\nresearchers have revealed indications of MTBE contaminating
\nwater, and community members have also reported on its suspected
\neffects on health.<\/p>\n
Thus, the change from leaded to MTBE-unleaded petrol may lead
\nto a shift from the issue of improving air quality to water
\nquality problems. The states of California and Maine have ordered
\nthe phasing out of MTBE in their respective RFG programs. Several
\ncongressional hearings have been held to seek a solution.<\/p>\n
The lesson for us here is how to find the best available
\ntechnology in producing unleaded petrol. The decision is urgent
\ngiven growing concern about air quality due to leaded gasoline.
\nThere is no such thing as a clean technology for eternity because
\nthe clean technology that we might choose today may be no longer
\nclean in the future.<\/p>\n
Thus decisions on such an important matter must include all
\nrelated parties -- the government and the people, based on
\ncomprehensive assessment.<\/p>\n
The writer, who holds a Phd. in air pollution, works for the
\nAgency for the Assessment and Application of Technology (BPPT).<\/p>",
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