"Green Car" is by definition an oxymoron. There is no such thing as a "Green Car," electric, hydrogen, compressed air powered, or even using the fuel I often suggest: DME.
All efforts to make "Green Cars" will fail, just as the efforts of ancient alchemists to make lead into gold will fail: It's physics, the nature of the beast, that yields slowly to wishing and desire.
Some efforts to pretend cars could be clean have been either funnier or more disasterous than others. Amory Lovins HYPErcar was something of a joke, especially because he's rather Hindenberg shaped if you look at him, but the effort to "control" automobile related air pollution via the use of oxygenated fuels was a disaster, played out the first time with MTBE, methyl-tert-butyl ether.
A disclaimer: I have used lots of MTBE in my life.
It's a cool solvent because of its non-chiral asymmetry, a reasonably polar molecule (having an uneven distribution of electric charge) that hangs on to an organic portion.
This makes it sort of like soap molecules, molecules that while it is greasy, has a part that is notably friendly to interacting with water.
Guess what. Most of the world's dangerous liquid fossil fuel are underground, and many of them leak.
This means that gasoline ends up in ground water, and if it contains molecules that sort of like water - MTBE - those molecules will end up in the water, dragging along some gasoline related molecules with it.
This is what happened with MTBE.
MTBE, people complained, may be carcinogenic and the fact that it was measurable in almost any ground water near a leaky fuel tank drove people nuts.
This is sort of silly, since carcinogenic stuff - notably benzene - has always been associated with gasoline, but no matter.
MTBE which was supposed to make our air "clean" where "clean" is defined as slightly less dirty than "extremely filthy" was banned.
So much for the idea of environmental handwaving and wishful thinking.
Happily there is a paper in Chemosphere that suggests that the radiolysis (UV) and ozonolysis of water can help remediate this bastard child of car "greening" efforts.
The paper is by Garoma et al out of San Diego State University and is titled "Degradation of tert-butyl formate and its intermediates by an ozone/UV process." Chemosphere 73 (2008) 1708–1715
Some remarks from the paper:
tert-Butyl formate (TBF) is a major intermediate produced during
the biodegradation of methyl tert-butyl ether (MTBE) (Mormile et al., 1994). It is also produced during the oxidation of MTBE by chemical oxidation (Damm et al., 2002) and advanced oxidation processes (Barreto et al., 1995; Chang and Young, 2000; Stefan et al., 2000; Acero et al., 2001; Burbano et al., 2002; Garoma and Gurol, 2006). TBF is also detected in exhaust emissions from cars using reformulated gasoline containing MTBE (Froines et al., 1998). Earlier studies on the biodegradability of MTBE indicated that it degrades very slowly under aerobic conditions (Mormile et al., 1994; Yeh and Novak, 1994). Recent studies reported higherrates for MTBE biodegradation under reducing conditions (Bradley
et al., 2001; Finneran and Lovley, 2001; Somsamak et al., 2001)
than in aerobic environment. It was also reported that the degradation
of MTBE was significantly reduced by the presence of TBF.
Yeah, yeah, yeah...
The widespread detection of MTBE in drinking water sources
(surface water and groundwater) and treated water has caused
great concern in the scientific communities and public health
agencies because MTBE is suspected as a possible human carcinogen
(Mehlman, 2002). Consequently, 25 states including California,
which accounts for over 30% of US’s MTBE consumption, have
passed legislation that would completely ban or partially restrict
the use of MTBE in gasoline (EPA, 2004). However, MTBE that has
already been released into the environment will likely continue
to degrade groundwater and soils for several years to come because
MTBE is known to degrade slowly by microorganisms (Mormile
et al., 1994; Yeh and Novak, 1994). In addition, the
biodegradation rate for TBF is about four times less than that of
MTBE (Francois et al., 2003), and therefore, it will likely to accumulate
in groundwater. Thus, TBF must be removed from groundwater
before it can be used for domestic applications.
So how to clean it up?
Irradiate the water and whack it with ozone:
The main objective of this study is to investigate the application
of an ozone/UV process for the removal of TBF from dilute aqueous
solution, identify the degradation products, and propose degradation
pathways for TBF. Ozone/UV process has shown to be a viable
option for the removal of organic pollutants from water. With the
development of large scale ozone generators, capable of generating
ozone directly from atmospheric air, and energy efficient UV systems,
the process has been getting increasing interest.
So on and so forth, finished by a conclusion:
This study investigated the removal of tert-butyl formate (TBF)
from dilute aqueous solution using an ozone/UV process and identified
intermediates formed during the oxidation of TBF. tert-butyl
alcohol (TBA), hydroxy-iso-butyraldehyde (HiBA), acetone, formaldehyde,
and formic acid were identified as primary intermediates,
whereas pyruvaldehyde, acetic acid, pyruvic acid, and oxalic acid
were generated in the system as a result of further oxidation processes.
About 90% organic carbon balance was obtained during the
oxidation of TBF indicating that most reaction intermediates have
been identified and quantified.
Making ozone, by the way, requires energy.
So does most UV radiation devices.
Higher energy radiation is available from so called "waste" materials and probably would be as or more effective and cheaper, but that is not being investigated.