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InläggPostat: tis 08-04-29 13:35 
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http://pubs.acs.org/cgi-bin/sample.cgi/ ... 62085v.pdf

Rapporten ger sken av att ha kommit på att det 2020 skulle kunna ge stora problem om större delen av bilparken i LA drevs av E85 jfrt med bensin.
Efter ett antal linjär regressions resonemang och fina färgglada bilder ser det inte alls bra ut för E85 (eller E80 som de menar E85 är i USA?).
Men om man läser tabell1 på sid 2 blir man lite mer fundersam:

Citat:
(4) percent
change
from
gasoline
to E85


Under den kolumnen minskar alla cancerogena ämnen utom
CO, formaldehyde, Acetaldehyde och TOG

Alla andra som bensen, NO2, paraffin bond group, toluene bond group, xylene bond group, isoprene bond group reduceras mkt kraftigt, oftast med omkring 80%.

Hur kommer de egentligen fram till att det blir fler cancerfall med E85 då?

De gör ett stort nummer av 2000% ökning av aldehyder samt ozon t.ex., men aldehyder bryts ju ned kort efter bildandet, finns det några uppgifter på hur snabbt egentligen, i kaliforniensol?
Ozon, hur är det med den?

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InläggPostat: tis 08-04-29 14:30 
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Blev medlem: mån 07-01-01 20:57
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OK, lite research...:
http://www.cleanfuelsdc.org/pubs/docume ... dStudy.pdf

Citat:
While the model used in this study by Mark Z. Jacobson is very extensive and
sophisticated, the quality of the results from any modeling study always dependant on the
quality of the inputs used for the model. In the present case, these inputs are
questionable, mainly due to the time projection out to 2020. The California Air
Resources Board (CARB) is currently struggling with an emissions inventory to be used
in air quality models that will attempt to predict 2010; yet Professor Jacobson is
attempting to predict 2020. Furthermore, the differences in air quality predicted for 2020
between ethanol and gasoline fuels are much smaller than the differences expected in
California for just gasoline vehicles in the four years between now and 2010. Thus, even
the base gasoline predictions are uncertain for a year so far in the future as 2020, let alone
the potential emissions using E85.
As a group of sensitivity simulations, future expected trends in various emissions
categories might be a useful addition to a study comparing gasoline with E85. However,
this reviewer believes a more convincing comparison would be based on a simulation of a
near term year (e.g. 2006 or 2010) using the latest current gasoline emissions and a
compilation of currently available E85 emissions data. To be sure, as discussed below,
this would still be a “fictional” exercise because so few vehicles now can use E85, but it
would be based on the best emissions estimates currently available. Even though a total
use of E85 might be assumed in one of these near-term scenarios, the results could be
used to provide an approximation to the impact of any level of E85 utilization. Trying to
project 14 years into the future for all emissions adds too many uncertainties due to
changes in gasoline and ethanol technology, let alone potential differences between them.
Currently only about 1 percent of vehicles are capable of using E85 nationwide. Thus,
any vehicles remaining on the road in 2020 would need to be retrofitted. All new
vehicles sold between now and then would have to be either flex-fuel capable between
gasoline and E85 (or perhaps even dedicated E85) or they too would have to be
retrofitted. There really is a paucity of data now on the emissions of existing E85-
capable vehicles. Also new emissions-technology improvements and catalyst
formulations are being developed every year. Rapid developing technologies are a major
source of uncertainty for the emissions for each fuel themselves, let alone the differences
between gasoline and E85 by 2020. Given such uncertainties and the fact that this study
by Professor Jacobson showed results that actually were very small (less than 2 ppb
ozone) impacts, it is reasonable to state that zero impact could be considered to be within
the range of uncertainty for this study.


Citat:
ACE Statement in Response to Stanford University Ethanol Report
Sioux Falls, SD (April 12, 2007) – In response to a paper released today by Mark Z.
Jacobson of Stanford University and published in the online edition of the journal
Environmental Science & Technology, the American Coalition for Ethanol (ACE) issued
the following statement:
“Air quality has improved in every city, county, and state that has switched from straight
gasoline use to ethanol blended fuel. Those are real world results, not predictions.
In a way, it is refreshing to see that the anti-ethanol naysayers continue to be relegated to
making dire predictions of what 'might happen if' - because it shows they have no
negative real-world experience to report. Ethanol’s record as a clean air fuel is
unmatched. The track record for the predictive models issued by ethanol opponents –
especially with respect to California predictions – has been less than stellar.

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