Utanför Svensk media har det denna vecka varit en annan nyhet som cirkulerat,
Brazilian study: Switch from gasoline to ethanol linked to higher ozone levels"Sao Paulo proved a unique laboratory for studying the effects of ethanol and gasoline usage on local air pollution because 40 percent of the nearly 6 million light-duty vehicles there can run on either fuel. When the percentage of those vehicles using gasoline rose from 14 percent to 76 percent, ambient ozone concentrations in the city fell by about 20 percent, researchers found."
Switch from gasoline to ethanol linked to higher smog levels"The study's authors cautioned against applying the findings from Sao Paulo to other major cities, because an area’s specific climate, vehicle fleet, local industry and traffic patterns all play a role. However, the use of meteorological, economic and air-quality data could serve as a template for studying ethanol’s effect on air pollution elsewhere, the authors said.
“Ozone and nitric oxide are both contributors to urban smog, so depending on how well a city is able to mitigate air pollution, ethanol may not be the ‘green fuel’ that it is often called,” said Franz Geiger, a professor of chemistry at Northwestern University who worked on the study."
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"However, gasoline caused other problems, the researchers found: When that fuel became more popular, emissions of carbon monoxide and nitrogen oxide rose. (The authors did not study other pollutants, such as fine particles, which are a focus of their next study.)"
Ozone Levels Drop 20 Percent With Switch From Ethanol To Gasoline - See more at: http://www.northwestern.edu/newscenter/ ... VYgCU.dpufBrazil tests suggest more ethanol means more local smogNotera rubriksättningen.
Ursprung denna studie i Nature Geoscience (betalvägg): Reduction in local ozone levels in urban São Paulo due to a shift from ethanol to gasoline useÄr man insatt i Brasiliens etanolmarknad kanske man förstår att "gasoline" och "ethanol" i detta fall innebär något annat än i andra marknader, men knappast gemene artikelskrivare. Några av artiklarna nämner åtminstone att etanol i Brasilien är nästan E100 (the Indipendent, LA Times) men jag har inte sett någon tidning nämna vad "Gasoline" innebär i detta fall.
Utanför Sverige har etanolindustrin några allierade, Renewable Fuels Association gav utlåtande som "counter-point" i ovanstående artiklar, i stil med att Ozon är svårtstuderat/man måste ta hänsyn till Sao Paulos unika klimat och bränslestandarder i Brasilien, dock inga detaljer.
Urban Air Initiative har nu gett ut ett lite mer ingående svar:" This study claims a 20% reduction in ozone when drivers in Brazil switched from ethanol to gasoline. However, it’s important to point out that the gasoline used during the time of this study is actually a blend of 25 percent ethanol. This helps prove that mid-level ethanol blends are a benefit for consumers and emissions.
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"Brazil also has two fuels, E25 (25 percent ethanol, 75 percent gasoline) and Ethanol (95 percent ethanol, 5 percent water). "
Så med andra ord, studien jämförde inte "Ethanol vs Gasoline" utan E25 mot E95. Fortfarande väldigt intressant att titta på hur de olika utsläppen påverkas vid olika etanolblandningar, klimat med mera men ja, vi vet ju alla vad media brukar gilla att fokusera på