THE 24 74 3 $;ESM^IAAP THE WORLD BANK o .~~~~~~~~~~~~~~T w6 South Asia Urban Air Quality Management Briefing Note No. 7 Catching Gasoline and Diesel Adulteration Adulteration of gasoline and diesel with lower-priced materials is common in South Asia as elsewhere in the world. Some adulterants increase emissions of harmfulpollutants from vehicles, worsening urban air pollution. Others do not, although there is often an indirect adverse effect on society through the loss of tax revenue. This note describes the impact of different types of adulteration on air quality and various methods for detection. dulteration of automotive gasolines and diesel Impact on Emissions and Health r_ fuels is widesprea throughoutSouthAsia.T Not all forms of adulteration are harmful to public vcan result in sub-optimal performance of trn ratn fsuels and s-opte alperoo raay,e o health. Some adulterants increase emissions of transportatio fuls an ofe,btntalas'edt harmful pollutants significantly, whereas others have increased tailpipe emissions of harmful pollutants. The harmful pollutant sifictly, whereases heav Centr forSciece ad Enironent CSE)recetly Iittle or no effect on air quality. In some cases health Centre for Science and Environment (CSE) recently efctarinrct-'oexnpelrgsae prepared a report on gasoline and diesel adulteration in effects are indirect- for exarnple, large scale Delhi [I], providing a good overview of the scope of the diveron o tioned sene idizedso household use to the diesel sector does not increase problem and some technical and economic data on the subject. This note reviews typical forms of adulteration, emissns from del vehice but de r toor ' of kerosene which can otherwise be used for cooking. their impact on exhaust emissions, and how adulteration Lack of availability of subsidized kerosene forces the may be detected. poor to continue to use biomass and exposes them to Types of Adulteration high levels of indoor air pollution. In South Asia, indoor air pollution in turn claims far more lives than urban Financial incentives arising from differential taxes are (outdoor) air pollution (for more information see 1-41). generally the primary cause of fuel adulteration (see [2] for background). In South Asia, gasoline carries a much Whenever considering the impact of fuel adulteration on higher tax than diesel, which in turn is taxed more than air quality, itis importanttokeep the impactof adulteratioll kerosene (see [3] for a discussion on transport fuel in perspective: the effects on emissionis of basic engine taxation). Industrial solvents and recycled lubricants are design and maintenance usually far outiweigh those other materials with little or no tax. oj changes in fuel composition. When engines are out of tune with the specifications set by the manufacturers, Specific types of adulteration may be broadly classified or are poorly maintained, they will emit substantially more as follows: pollutants - even when operating on fuels that meet all * Blending relatively small amounts of distillate fuels like specification requirements - than properly maintained diesel or kerosene into automotive gasolines. vehicles. * Blending variable amounts (as much as 30 percent) of Fuel adulteration can increase the tailpipe emissions gasoline boiling range hydrocarbons such as industrial of hydrocarbons (HC), carbon monoxide (GO), oxides solvents into automotive gasolines, of nitrogen (NO) and particulate matter (PM). Air * Blending small amounts of -spent waste indnstrial toxin emissions - which fall into the category of solvents such as used lubricants -which would be unregulated emissions - of primary concern are costly to dispose of in an environmentally approved benzene and polyaromatic hydrocarbons (PAHs), both manner - into gasoline and diesel. well known carcinogens. Air toxin emissions such as * Blendingkeroseneintodiesel,oftenasmuchas2O-30 benzene depend mostly on fuel composition and percent. catalyst performance. PAHs in the exhaust arc duc * Blending small amounts ofheavierfuel oils intodiesel fuels. primarily to the presence of PAHs in the fuel itself and, in the case of gasoline, in part due to PAH formation by composition. Adulterants may contain halogens, silicon, fuel combustion in the engine. Aside from fuel quality, phosphorous or other metallic elements (found in recycled the amounts of pollutants emitted depend on such lubricants); these in turn are quite outside the normal parameters as the air-to-fuel ratio, engine speed, gasoline composition range. They will cause increased engine load, operating temperatures, whether the emissions and may even cause vehicle breakdown by vehicle is equipped with a catalytic converter, and corroding fuel injection systems and carburetters, and by the condition of the catalyst. causing deposits on valves, fuel injectors, spark plugs, oxygen sensors and exhaust catalysts. Even low levels Gasoline adulteration of adulterants can be very injurious and costly to the Kerosene is more difficult to burn than gasoline, so vehicle operator. that its addition results in higher levels of HC, CO and For gasoline, any adulterant that changes its volatility can PM emissions even from catalyst-equipped cars. The affect driveability. High volatility (resulting from the higher sulfur level of kerosene (for example, the addition of light hydrocarbons) in hot weather can cause permissible level in India is 0.25 percent by weight as vapor lock and stalling. Low volatility in cold weather against 0.10 percent for gasoline) can deactivate the can cause starting problems and poor wann-up. catalyst and lower conversion of engine-out pollutants. If too much kerosene is added, octane quality will fall Diesel adulteration below the octane requirement of the engines and engine The blending of kerosene into automotive diesel fuel is knocking can occur. Besides possibly damaging the widely and legitimately practiced by the oil industry engine mechanically, knock can increase PM, HC and worldwide as a means of adjusting the low temperature NOx emissions. The latter two are, amongst others, operability of the fuel. This practice is not harmful or ozone precursors. With gasoline vehicles not equipped detrimental to tailpipe emissions, provided the resulting with catalysts, the exhaust smell from kerosene is often fuel continues to meet engine manufacturers' rather acrid, creating unpleasant conditions in crowded specifications (especially for viscosity and cetane city streets. number). However, high-level adulteration of low sulfur When gasoline is adulterated with diesel fuels, the same (for example, 0.05 percent) diesel fuel with higher-level general effects occur but usually at lower levels of added sulfur kerosene can cause the fuel to exceed the sulfur diesel fuel. Both diesel and kerosene added to gasoline maximum. will increase engine deposit formation including in fuel PAHs and nitrogen-containing PAHs in diesel exhaust injectors, potentially leading to increased emissions of PM, arise primarily from a "flow-through" effect from the HC and CO. PAHs in the fuel composition. As a result, the addition of Gasoline may also be adulterated with gasoline boiling kerosene tends to reduce exhaust PAH emissions because range solvents such as toluene, xylenes and other kerosene generally does not contain significant amounts aromatics, or light materials such as pentanes and of PAHs. hexanes (rubber solvents) - available at low or zero As a simplified picture, black diesel smoke results from tax for their normal industrial use. The gasolines in inadequate air/fuel mixing in the cylinder with locally these cases may well continue to meet all over-richzones.Higherfuelinjectionrates,dirtyinjectors specifications. With "judicious" adulteration, the and injection nozzle tip wear through use can lead to gasoline would not exhibit driveability problems. Larger locally over-rich zones in the combustion chamber. Over- amounts of toluene and/or mixed xylenes could cause fueling to increase power output, a common phenomenon some increase in HC, CO and NO emissions, and worldwide, results in higher smokeemissions and lower significantly increase the level of air toxins - fuel economy. Dirty injectors are common because especially benzene - in the tailpipe exhaust. The injector maintenance is costly in terms of actual repair adulterated gasoline itself could also have increased costs and down-time consequential losses. The addition potential human toxicity if frequent skin contact is of heavier fuels increases in-cylinder deposits and fouls allowed. Extremely high levels of toluene (45 percent injectors. or higher) could cause premature failure of neoprene, The addition of heavier fuel oils to diesel is usually easy styrene butadiene rubber and butyl rubber components in the fuel systems. This has caused vehicle fires in to detect because the fuel will be darker than normal. other parts of the world, especially in older vehicles. Depending on the nature of these heavier fuel oils and the possible presence of additional PAHs, there Adulteration of gasoline by waste industrial solvents is could be some increase in both exhaust PM and especially problematic as the adulterants are so varied in PAH emissions. a Tests for Identifying Adulteration automotive gasolines, diesel luels and kerosene would be essential. Usually there are fairly well established ratios A number of analytical techniques are available to detect between key gasoline hydrocarbons such as benzene, toluene thadulerationI sampll descrnibuesand beowcs iortant and the three isomeric xylenes (unless there is a benzene- petroleum saling techniques a s od toluene-xylene extraction plant at the refinery) so that GC could yield very useful data in skilled hands. Some short results more quickly but cannot give results that are as time duration tests (15 minutes) have been developed for detailed or quantitatively accurate as laboratory tests. For detailed oqai a. F quick fingerprinting of gasolines suspected of being adulterated the majority of the tests, accurate data on uncontaminated with kerosene or diesel and these can be easily detected. fuels are also a pre-requisite. Density Ash content determination Where ash forming contaminants such as silicones and Some field tests can be used to identify some of the more phosphates from waste industrial solvents may be involved, gross adulteration taking place. The most rugged of these laborator tests such as ASTM D 482 to measure ash is density determination by portable hydrometers. The CSE content ory teld sul a 482 theasure ash repot sowstha, a 15C, utootiv gaolie sld n Dlhi conentcould yield useful data since neither gasoline nor reot shows that, at l 5°C, automotive gasoline sold in Delhi diesel fuels normally have measurable ash contents. Othe typically has a density of 0.74-0.75 kilograms per liter (kg/ options include atomic absorption (AA) or emission I) and kerosene around 0.79-0.80 kg/l. Diesel fuel has a spectrographY calibrated for trace metals. density in the neighborhood of 0.835-0.855 kg/l. Used properly, good-quality hydrometers could detect significant Markers adulteration if an accurate density on the base gasoline, for example attheshipping terminal, is available. Success with Various chemical markers can be used to identify this approach hinges on a good analytical testing regimen adulteration, such as of kerosene in gasoline. Covert methods with correlation between field hydrometers and laboratory include the use of visible dyes which has been successfully equipment. The use of digital densitometers as per ASTM applied in industrial countries. However, where visible dyes (American Society for Testing of Materials) D 4052 have been used in South Asia, they have not been effective. provides greater accuracy but these are relatively expensive More sophisticated methods include invisible dyes which units and need a closely controlled environment not likely are reacted in field tests with another chemical to produce to be found in the field at the point of sale. a color (used in the Philippines) and chemical markers. Chemical markers increase the cost of products: markers Evaporation must be purchased and added, and detection equipment needs to be bought, operated and maintained. Various evaporation techniques such as the ASTM D 381 unwashed gum test will detect very low concentrations (1-2 Steps to Minimize Adulteration percent) of diesel fuel in gasoline and fairly low (5 percent) It goes without saying that an important step in tackling levels of kerosene in gasoline. This is not a field technique, fuel adulteration is reducing incentives for engaging in Distillation this commercial malpractice to the extent possible. The incentive in turn depends on the relative benefit (from The ASTM D 86 type of distillation can be useful for adding low-priced materials) and cost (from the risk of detecting kerosene and diesel in gasoline and also being caught and fined or having onc's business license significant additions of toluene and mixed xylenes in revoked). The benefit arises from differential taxation, gasoline. Accurate and complete D 86 distillation data on tax evasion and different production costs, and can be the uncontaminated fuels would be essential for reduced but not elimninated. It is also important to bear in comparison and some kind of correlative data among the mind that fiscal policy has multiple objectives, and reducing laboratories involved to validate test precision. Judicious fuel adulteration is only one amongst many. As such, blending of, for example, pentanes, hexanes and toluene concerns about fuel adulteration, however serious, cannot into automotive gasoline could go undetected by this test and should not be the sole driver of fiscal policy. The cost since these are normal gasoline constituents. depends on the ability of the regulating authorities to detect adulteration, and to impose sufficiently punishing sanctions Gas chromatography (GC) to deter recurrence of fuel adulteration. GC is a powerful laboratory-based tool for detecting The manner in which retail fuels are distributed has an hydrocarbon-based adulterants but requires experienced important bearing on fuel adulteration. For example, having analysts as well as skilled interpretation of the results. Original large numbers of small, independent transport truck GC fingerprints on as many potential base fuels such as operators moving fuels from terminals to the point of sale U creates an environment conducive to adulteration. Conclusions Adulteration may also be occurring with the collusion of Identifying and checking fuel adulteration presents a the retail outlet operator. If government officials are difficult challenge in the face of enormous incentives involved in adulteration, establishing a good monitoring involved. Yet as vehicle emission standards are and enforcement mechanism becomes all the more progressively tightened in South Asia, fuel quality and difficult. One effective "market-based" approach is the vehicle technology are increasingly integrated, so that practice in many industrial countries whereby oil having fuels that meet the specifications becomes all the companies market at retail and assume responsibility more important for meeting the new emission standards. throughout the supply chain to guarantee fuel quality in This note shows that order to protect their public image and market share. * Adulteration by heavier materials -such as addition Even in the best of circumstances, taking and maintaining of waste industrial solvents and kerosene to gasoline samples for checking fuel quality is not easy. In South or heavier fuel oils to diesel - will at worst destroy Asia, finding proper sample containers and not being fuel injection systems and generally cause deposits on personally harassed at retail outlets while sampling are automotive parts, leading to serious increases in tailpipe just two of the very real operational problems to be emissions. resolved. The CSE report describes the problems of * Adulteration of automotive diesel fuels by kerosene auditing and sampling retail outlets. These problems are does not have an adverse effect on exhaust compounded by lack of experience in checking emissions, but adversely affect public health by specifically for adulteration. reducing the availability of kerosene for household The Indian Standards test methods being used today are use to the poor. derived mainly from the Institute of Petroleum (IP)/ASTM * Fuel adulteration has significant financial benefits for method equivalents from the early 1990s. Properly those engaged in it. Therefore, anyone investigating it executed, they should be able to give acceptable results, must have the direct protection of local law enforcement even though some results quoted in the CSE report agencies in taking field samples. There must also be indicates poor precision in some items such as testing for credible and independent laboratory testing available sulfur content. Precision and repeatability could be to achieve any measure of success. improved by setting up programs for cross-checking inter- laboratory variability. This requires action by the responsible References agencies within Government. The first step is recognition I. Centre for Science and Environment. 2002. A report on the of the existence and seriousness of the problem - both independent inspection offuel quality atfuel dispensing stations, from the consumer and environmental perspectives - oil tanks and tank lorries, March. Available at . historically high levels of tolerance for fuel adulteration, 2. Viewpoint Note No. 237. 2001. "Abuses in Fuel Markets", September. Available at . appropriate regulatory and enforcement steps can be taken. 3. Pollution Management in Focus Discussion Note No. 11. 2001. Although there have been calls for more restrictive density "Transport Fuel Taxes and Urban Air Quality", December. Available at . satisfactory vehicle operation and limit emissions. I2Fou20Ipd. s 4. ESMAP Indoor Air Pollution newsletter, available at . This briefing note was prepared in July 2002 as part of the South Asia program on urban air quality management, funded in part by-the joint UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP). The objective of the program is to support the region-wide process of developing and adopting cost-effective and viable policies and efficient enforcement mechanisms to reverse the deteriorating trend in urban air. A full set of briefs and other materials are available at . For further information, contact Sameer $Skbar (sakbar@worldbank org) or Masami Kojima (mkojima@worldbank org) about the program, and Ronald Tharby (Rdtharby@aol.com) about this note.