MTBE in gasoline

What are the pros and cons of using MTBE in gasoline ... 

Because drinking water was affected by leakage from USTs, a political effort is underway to ban the use of MTBE in gasoline. At the time of this writing, much debate is ongoing. The State of California and several other... 

The competitiveness of the oxidation of isobutene compared to the conventional acetone cyanohydrin route (Equation 33) is not only related to its performance and better environmental standards but has to contend with the demands of other users for isobutene, particularly for MTBE and ETBE production. In fact the predominant methacrylic acid process is still the hydrolysis of acetone cyanohydrin however, the change of mood on the use of MTBE in gasoline blends in the USA, could signal a future shift of isobutene availability making it a more attractive feedstock for methacrylic acid production. 

Keller, A. Froines, J. Koshland, C. Reuter, J. Suffet, I. Last, J. Health and Environmental Assessment of MTBE in Gasoline, Report to the Governor and Legislature of the State of California as Sponsored by SB521, Vol. 1 Summary and Recommendations, Nov 1998. 

California Energy Commission. Supply and Cost of Alternatives to MTBE in Gasoline, Staff Report, Oct 1998 P300-98-013. 

The occurrence of MTBE in gasoline has been associated with a number of acute human-health effects including headache, nausea, eye irritation, vomiting, and dizziness. However, these symptoms were mainly observed through anecdotal reports in areas of MTBE use in gasoline. Consequently, these symptoms may not be specific to MTBE exposure but could have resulted from a variety of environmental hazards. To date, no large-scale, carefully planned epidemiologic studies on the effects of human exposure to MTBE have been conducted. 

The use of these additives was shown to have a positive effect on emission quality in large urban areas [2]. Nevertheless, the use of MTBE in gasoline which is one of the most frequent pollutants of groundwater, led to its detection in gasoline-impacted aquifers [3]. MTBE accounted for 4% (vol/vol) of all gasoline in the U.S.A. in 2002 [4] and its use has now been banned in several US states. MTBE is used without major restrictions in Europe and producers expect its utilization to remain stable [4]. The concern regarding the use of these compounds is due to their environmental impact on water quality. They are more soluble in water than the monoaromatics present in gasoHne. After several years of use of these compounds, it appeared from several stud-... 

Three well-conducted, controlled exposure studies have investigated the effect of pure MTBE on symptoms and objective measures of irritation and performance amongst healthy subjects, hi addition, there has been one similar study of effects of MTBE in gasoline on subjects that have reported themselves as being particularly sensitive to MTBE. There has also been one study of ETBE. 

Fig. 18.6 The 42 MHz proton spectra of various blends of ethanol in 10% MTBE in gasoline. All spectra were acquired with 12 scans on samples flowing at 2.00 ml min. The concentration dependence of the hydroxyl proton chemical shift is apparent in the expanded plots. Reprinted with permission from [28].

Perform a web search to learn what restrictions (if any) on the use of MTBE in gasoline might exist in your local area. 

The first factor is one reason why most pesticides used in agriculture are accepted, even though the chemicals used have some degree of risk associated with their use. Without pesticides, the crop production we have enjoyed over the past decades would have been reduced due to losses from insects and weeds and food prices would increase. Because the benefits of pesticide use have been clearly identified, the risk associated with their use is usually tolerated. Risk associated with other chemicals for which benefits are not clearly defined, such as MTBE, are less accepted. If it can be clearly demonstrated that use of MTBE in gasoline reduces the levels of benzene, a known human carcinogen, in air, then its use might be more acceptable (see chapter 2 for more discussion of MTBE). 

D4815, Alcohols and MTBE in gasoline D4864, Methanol in propylene X X ... 

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